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Information on genetic variability is a prerequisite for further improvement of the yield and quality of coffee. However, lack of information on genetic variability for specialty coffee accessions has been one of the major problems in coffee improvement program. Forty nine coffee (Coffea arabica L.) germplasm accessions, which were collected from Gomma Wereda, were evaluated at Agaro research station with the objective of estimating the genetic diversity. The experiment was conducted in simple lattice design with two replications during 2011/12 cropping season by superimposing on six years old coffee trees which were planted in July, 2006 and grown under uniform coffee shade tree (Sesbania sesban) conditions. Data on 26 quantitative characters were recorded. The analysis of variance showed significant (P<0.05) variation among the accessions for all morphological traits except percentage bearing primary branches, leaf area, bean thickness and rust incidence. This indicated the existence of variability among the tested materials. Cluster analysis of quantitative characters grouped the 49 coffee germplasm accessions into five clusters. This makes the germplasm accessions to be moderately divergent. The distances between most of these clusters were highly significant at (P<0.01), suggesting the possibility of getting suitable accessions for hybridization program among the tested materials. Principal component analysis showed the variation in the first two principal components, which explained the lion's share of the observed variation, (42%), was mainly due to inter node length of main stem and primary branches, leaf length, hundred bean weight, plant height, number of main stem nodes, number of primary branches, length of primary branches, number of secondary branches and canopy diameter. So, these traits were identified as a source variation among Gomma wereda coffee accessions and can be used for selecting diverse parents in future coffee hybridization program.
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Time Journals of Agriculture and Veterinary Sciences
Vol. 1 (4): 47-54 November, 2013
www.timejournals.org/tjavs
© 2013 Time Journals
ISSN:2360-736X
Genetic Diversity Analysis of Some Ethiopian Specialty
Coffee (Coffea arabica L.) Germplasm Accessions
Based on Morphological Traits
*Getachew WeldeMichael1, Sentayehu Alamerew2 , Taye Kufa1 and Tadesse Benti1
1 Jimma Agricultural Research Center, P.O. Box, 192, Jimma, Ethiopia
2 Jimma University, College of Agriculture and Veterinary Medicine, P.O. Box, 307, Jimma, Ethiopia
* Corresponding author
Email- getachewweldemichael@gmail.com
Accepted 20 November,2013
ABSTRACT
Information on genetic variability is a prerequisite for further improvement of the yield and quality of coffee.
However, lack of information on genetic variability for specialty coffee accessions has been one of the major
problems in coffee improvement program. Forty nine coffee (Coffea arabica L.) germplasm accessions, which
were collected from Gomma Wereda, were evaluated at Agaro research station with the objective of estimating
the genetic diversity. The experiment was conducted in simple lattice design with two replications during
2011/12 cropping season by superimposing on six years old coffee trees which were planted in July, 2006 and
grown under uniform coffee shade tree (Sesbania sesban) conditions. Data on 26 quantitative characters were
recorded. The analysis of variance showed significant (P<0.05) variation among the accessions for all
morphological traits except percentage bearing primary branches, leaf area, bean thickness and rust incidence.
This indicated the existence of variability among the tested materials. Cluster analysis of quantitative
characters grouped the 49 coffee germplasm accessions into five clusters. This makes the germplasm
accessions to be moderately divergent. The distances between most of these clusters were highly significant at
(P<0.01), suggesting the possibility of getting suitable accessions for hybridization program among the tested
materials. Principal component analysis showed the variation in the first two principal components, which
explained the lion’s share of the observed variation, (42%), was mainly due to inter node length of main stem
and primary branches, leaf length, hundred bean weight, plant height, number of main stem nodes, number of
primary branches, length of primary branches, number of secondary branches and canopy diameter. So, these
traits were identified as a source variation among Gomma wereda coffee accessions and can be used for
selecting diverse parents in future coffee hybridization program.
Keywords: Coffea arabica , cluster analysis, genetic diversity , principal component, specialty coffee
INTRODUCTION
The southwestern highlands of Ethiopia are the birth
place and home to Arabica coffee (Coffea arabica L.)
(Kassahun et al., 2008). Coffee is at the centre of
Ethiopian culture and economy and contributes to about
35% of the country’s foreign currency earnings (Gole and
Senebeta, 2008). It accounts for 10% of the gross
domestic product, and supports the livelihoods of around
25% of the population of Ethiopia (Gole and Senebeta,
2008). The estimated area of land covered by coffee is
about 600,000 hectares, whereas the estimated annual
national production of clean coffee is about 350,000 tons
(Alemayehu et al, 2008). Ethiopia is currently producing
an estimated 9.8 million bags that would rank the country
as the third largest coffee producer in the world after
Brazil and Vietnam, beating out Colombia (ICO, 2012).
Coffea arabica L. is originated in Ethiopia and there is a
Time J.Agr.Vet.Sci. 48
great genetic diversity in the country and the existence of
such genetic diversity provides immense opportunity for
coffee improvement (Fikadu et al., 2008). However,
despite the vast area of cultivation, wealth of tremendous
genetic diversity and importance to the national economy,
the productivity of coffee is very low (about 0.71 t/ha)
(Alemayehu et al., 2008).
Although many factors hampered production and yield
per unit area, the major factors contributing to such low
coffee yield include predominant use of unimproved local
coffee landraces, as well as conventional husbandry and
processing practices, which in turn seriously hampers the
overall national coffee production and productivity of the
smallholder coffee farmers in the country (Kufa, 2010).
Furthermore, coffee genetic resources are under serious
threats of extinction, mainly due to deforestation,
replacement of traditionally grown landrace by improved
varieties, environmental degradation and change in land
use (Gole and Teketay, 2001). Thus, it is pertinent to
collect and conserve coffee accessions from different
coffee growing regions of the country to reduce the loss
of coffee genetic resources and improve the productivity
of the crop by developing high productive coffee varieties.
Having mandated to coordinate coffee research in
Ethiopia, Jimma Agricultural Research Center (JARC)
has been collecting coffee germplasm from different
coffee growing region of the country and so far about
5960 accessions have been conserved at JARC and its
sub-centers (Kufa, 2010). However, coffee genetic
diversity study did not get the attention that it deserves
and only few researchers have conducted genetic
diversity analysis on coffee in Ethiopia. Ermias (2005)
reported genetic variability among 81 west Wellega
coffee germplasm accessions for most of the characters
considered. In another work, Yigzaw (2005) reported high
genetic variability among 16 coffee germplasm
accessions of Northwest and Southwest Ethiopia for
morphological characters. Similarly, Mesfin (2008) also
reported the presence of wide genetic diversity among
141 coffee germplasm accessions collected from South
and Southeast Ethiopia. Olika et al. (2011) also
characterized 49 coffee germplam accessions collected
from Limu Kossa wereda for morphological characters
and reported the presence of wide genetic variability.
Information about genetic diversity within and among
genotypes of any crop is fundamental to estimate the
potential of genetic gain in a breeding program and for
effective conservation of available genetic resources
(Sakiyama, 2000). It may also be important for selecting
promising parental lines in hybrid variety development
(Barbosa et al., 2003). Such information could also serve
as a bench mark for future assessment of genetic erosion
(Hammer et al. 1996).
Gomma is one of the major coffee producing weredas
of Jimma Zone and coffee from this area is well known by
the name of ‘Limu Coffee’ and fetches very high price on
the world market for its peculiar winy flavor (Desse,
2008). However, systematic diversity analysis was not
conducted for specialty coffee accessions collected from
this wereda. The limited success in variety development
program for specialty coffee could partly be attributed to
lack of well characterized and distinctly variable breeding
materials that are readily available for use. Thus, the
present study was carried out to estimate the genetic
diversity of Gomma wereda specialty coffee germplasm
accessions using morphological traits.
MATERIALS AND METHODS
Description of the Study Site
The experiment was conducted at Agaro station of the
Jimma Agricultural Research Center. The center was
established in 1973 on land area of 27 ha near Agaro
town, 45 km far from Jimma and 397 km from Addis
Ababa. Agaro is located at 7’’50’35- 7’’ 51’ 00’’ N latitude
and 36’’35’30’’E longitude and at an altitude of 1650
meters above sea level. The mean annual rainfall of the
area is 1616 mm with an average maximum and
minimum air temperatures of 28.4 0C and 12.40C,
respectively. The major soil type is Mollic Nitisols with
pH of 6.2, organic matter 7.07%, nitrogen 0.42%,
phosphorus 11.9 ppm,CEC (cation exchange capacity)
39.40 cmol (+)/kg (Zebene and Wondwosen, 2008).
Experimental Materials
Forty seven C. arabica L. germplasm accessions which
have been collected in the year 2005 from the Gomma
wereda of Jimma Zone and two standard checks that are
maintained in the ex- situ field gene bank of Agaro station
were used for this study (Table 1). The experiment was
superimposed during the 2011/12 cropping seasons on
six years old coffee trees of the 49 accessions which
were planted in July, 2006 and grown under uniform
coffee shade tree (Sesbania sesban) conditions.
Methods of Data Collection
During the course of this study, data on 26 quantitative
characteristics, namely : Height up to first primary branch
(cm) , total plant height (cm) , number of main stem
nodes (no) , average inter node length of main stem (cm)
, main stem diameter (cm) , angle of primary branches(
deg) , number of primary branches (no), average length
of primary branches (cm) , number of nodes of primary
branches (no) , average Inter node length of primary
branches (cm), percentage of bearing primary branches
(%), number of secondary branches (no) , canopy
diameter (cm) , leaf length (cm) , leaf width (cm), leaf
area (cm2), fruit length (mm) , fruit width (mm), fruit
thickness (mm), bean length (mm), bean width (mm),
bean thickness (mm), hundred bean weight (gm), yield
per tree (kg), coffee berry disease (%) and rust incidence
WeldeMichael et al 49
Table 1. Geographical origin of the studied coffee ( Coffea ararbca L.) germplasm accessions at Agaro research station
*=Standard check variety
No.
Accession
No.
Farmers’ association
Specific
location
Altitude
No.
Farmers’ association
Specific location
Altitude
1
L01/05
Chadero Suse
Chedaro
1540
26
Bako Kuju
Arfeti
1750
2
L02/05
Chadero Suse
Chedaro
1540
27
Bako Kuju
Jida
1750
3
L03/05
Chadero Suse
Chesech
1540
28
Bako Kuju
Jida
1750
4
L04/05
Chadero Suse
Chesech
1540
29
Bako Kuju
Jida
1750
5
L05/05
Gabena Abo
Kefemo
1540
30
Bako Kuju
Jida
1750
6
L06/05
Gabena Abo
Kochele
1540
31
Debi Kechamo
Eno
1660
7
L07/05
Gabena Abo
Kochele
1540
32
Debi Kechamo
Eno
1660
8
L08/05
Gabena Abo
Kochele
1540
33
Debi Kechamo
Eno
1660
9
L09/05
Gabena Abo
Kochele
1530
34
Debi Kechamo
Eno
1670
10
L10/05
Gabena Abo
Kochele
1530
35
Debi Kechamo
Edio
1630
11
L11/05
Gabena Abo
Kochele
1530
36
Limu Sapa
Baole Kilfadi
1680
12
L12/05
Gabena Abo
Gabeni
1600
37
Limu Sapa
Baole Kilfadi
1680
13
L13/05
Omo-Boko
Chore
1740
38
Limu Sapa
Baole Kilfadi
1680
14
L14/05
Omo-Boko
Chore
1750
39
Limu Sapa
Baole Kilfadi
1680
15
L15/05
Omo-Boko
Chemaro
1770
40
Limu Sapa
Kiefa Adi
1700
16
L16/05
Omo-Boko
Chemaro
1770
41
Omo Gobo
Malgobu
1720
17
L17/05
Omo-Boko
Chemaro
1770
42
Omo Gobo
Malgobu
1720
18
L18/05
Omo-Boko
Chemaro
1700
43
Omo Gobo
Malgobu
1720
19
L19/05
Omo-Boko
Chemaro
1710
44
Omo Gobo
Dargoba
1740
20
L20/05
Goja Kemisse
Balcho
1660
45
Omo Gobo
Dargoba
1740
21
L21/05
Goja Kemisse
Balcho
1660
46
Omo Gobo
Siliko
1690
22
L23/05
Goja Kemisse
Kemisse
1640
47
Omo Gobo
Siliko
1690
23
L24/05
Goja Kemisse
Kemisse
1640
48
-
-
-
24
L25/05
Goja Kemisse
Kemisse
1620
49
-
-
-
25
L26/05
Bako Kuju
Arfeti
1750
Time J.Agr.Vet.Sci. 50
(%) , were collected from each accession using the
standard procedures of IPGRI (1996).
Statistical Analysis
Data were subjected to analysis of variance (ANOVA)
using SAS version 9.2 (SAS, 2008) to examine the
presence of statistically significant differences among
accessions for the characters studied. The relative
efficiency of simple lattice design over RCBD
(randomized complete block design) was estimated and
simple lattice design was found to be efficient. Hence, the
data were analyzed using simple lattice design. Least
Significant Difference (LSD at P = 0.05 and 0.01) was
employed to identify accessions that are significantly
different from each other.
In this study, 22 morphological characters that showed
statistically significant variations among the accessions
were used for clustering and principal component
analysis. The data were subjected to cluster analysis so
as to determine the variability among the accessions.
Hierarchical clustering was employed using the similarity
coefficients among the 49 coffee accessions. Clustering
was performed using the proc cluster procedure of SAS
version 9.2 (SAS, 2008) by employing the method of
average linkage clustering strategy of the observation.
The numbers of clusters were determined by following
the approach suggested by Copper and Miligan (1988) by
looking into three stastics namely Pseudo F, Pseudo t2
and cubic clustering criteria.
Genetic divergence between clusters was determined
using the generalized Mahalanobis's D2 statistics
(Mahalanobis, 1936) using the equation: D²p =
(Xi XjS1(Xi Xj).
Where: D2p= the distance between any two groups i
and j;
Xi and Xj = the p mean vectors of accessions i
and j, respectively.
S-1 = the inverse of the pooled covariance
matrix.
The D2 values obtained for pairs of clusters were tested
for significance at 5% and 1 % level of significance
against the tabulated values of p degrees of freedom,
where p is the number of variables considered (Singh
and Chaudhary, 1987). Principal component analysis was
also performed by employing SAS version 9.2 (SAS,
2008 ).
RESULTS AND DISCUSSION
Mean squares for the 26 quantitative traits from analysis
of variance (ANOVA) are presented in Table 2.
Significant (P<0.05) differences among the coffee
germplasm accessions were observed for all traits
except for percent of bearing primary branches, leaf area,
bean thickness and rust incidence.
The significant variations observed for most of
morphological traits in a population is the result of
combination of the genotypic and environmental effects
(Welsh, 1990).The variability present for important traits
in the present study clearly proved the possibility to bring
considerable improvement mainly in coffee yield and
coffee berry disease resistance through selection and
hybridization. Bayetta (1997) reported high genetic
variability within the Arabica coffee population for yield,
CBD (coffee berry disease ) resistance and growth
characters. The existence of variability among Arabica
coffee accessions was further confirmed by many authors
who reported significant differences among coffee
germplasm accessions collected from major coffee
growing regions of the country (Ermias , 2005; Yigzaw,
2005 ; Olika et al., 2011). The D2 value based on the
mean of coffee germplasm accessions resulted in
classifying the 49 accessions into five groups (Table 3).
This indicates the tested coffee germplasm accessions
were moderately divergent. Cluster I and II were the
largest with nineteen germplasm accessions (39% each)
followed by cluster III and IV with 5 germplasm
accessions (10% of the total population, each ) and one
accession (2% ) into cluster V.
In the present study, accessions collected from
different kebeles /sub- districts/ clustered together, for
instance, accessions collected from the seven kebeles
clustered together in cluster I and II. In support of this,
Bayetta (2001) reported that morphological variation is
more important than variation in geographic origin as
indicator of genetic diversity in coffee. Seyoum (2003)
has also reported that accessions collected from
Gambella, Kullo, Keffa, Illubabor, Wello, Wellega, Maji,
Harar, and Sidamo were clustered together, despite the
fact that they were collected from different geographic
origins. In addition, in the present study, accessions
collected from same kebeles were clustered into different
clusters, suggesting the existence of high genetic
diversity within each collection sites. So, this diversity
could be exploited further in order to increase the genetic
base of specialty coffee varieties. Genetic divergence as
measured by Mahalanobis (1936) generalized distance
(D2) has been one of the important statistical tools to
provide a rational basis for selection of parents in
breeding programs. Mahalanobis distance (D2) of the five
clusters of 49 coffee germplasm accessions based on 22
quantitative traits is presented in Table 4. The chi-square
test for the five clusters indicates that there were highly
significant differences between clusters except cluster I
&II, I &III and II&IV. The maximum inter cluster distance
was between cluster III and IV (183.94) followed by IV
and V (165.72), I and IV (108.95), I and V (103.24). The
minimum being between II and IV (29.53) followed by I
and II (30.07) (Table 4). In general, this study revealed
that the germplasm accessions included in this study
were moderately divergent.
The importance of genetic diversity to maximum
heterosis has been reported by many investigators.
WeldeMichael et al 51
Table 2. Analysis of variance (Mean squares) for 26 quantitative characters of 49 coffee germplam accessions grown at Agaro
(2011/12).
* *=highly significant (p<0.01), *= significant (p<0.05), ns= non significant
HUP= height up to first primary branch. TPH= total plant height, NMSN= number of main stem nodes, AILMS= average inter node length of
main stem, SD= stem diameter, APB= angle of primary branches, NPB= number of primary branches, ALPB= average length of primary
branches, NNPB= number of nodes of primary branches, AILPB= average inter node length of primary branches, NSB=number of secondary
branches, CD= canopy diameter, LL= leaf length, LW= leaf width, FL= fruit length, FW= fruit width, FT= fruit thickness, BL= bean length, BW=
bean width, HBW= hundred bean weight, CBD =coffee berry disease, Yd/tr= yield per tree, RCBD= randomized complete block design, LSD=
least significant difference , CV= coefficient of variation.
Character
Mean square of treatment
(48)
Mean square of error
LSD
Efficiency
relative to
RCBD (%)
CV (%)
Unadjusted
Adjusted
Intra block
(36)
RCBD
(48)
0.05
0.01
HUP
41.46
38.86**
7.79
9.71
6.00
8.05
110.83
8.84
TPH
802.79
757.11**
272.62
318.85
35.14
47.12
106.22
7.03
NMSN
20.40
19.51*
9.32
13.31
6.66
8.93
123.39
8.93
AILMS
0.48
0.41*
0.17
0.24
0.89
1.20
126.26
7.44
SD
0.59
0.56**
0.11
0.21
0.72
0.97
167.38
8.44
APB
44.11
42.89**
13.06
16.12
7.76
10.41
110.13
5.70
NPB
124.47
121.37**
52.76
57.99
14.60
19.48
102.62
12.06
ALPB
61.56
49.48*
22.80
33.94
10.45
14.02
127.72
6.18
NNPB
7.5
7.79**
1.49
2.39
2.63
3.60
136.65
6.69
AILPB
0.21
0.19**
0.05
0.07
0.47
0.63
131.06
5.96
PBPB
30.54
28.24ns
27.55
28.10
10.55
14.08
100.15
6.91
NSB
2541.41
1933.00*
905.65
1147.9
64.86
86.97
112.25
24.79
CD
486.17
375.06**
118.6
184.27
23.91
32.06
132.54
5.70
LL
2.19
1.54*
0.64
0.97
1.75
2.35
130.11
14.50
LW
0.32
0.26**
0.08
0.12
0.64
0.85
123.61
5.70
LA
101.71
73.28 ns
32.53
50.75
12.53
16.80
133.02
11.94
FL
0.75
0.77**
0.27
0.34
1.12
1.50
111.73
3.24
FW
0.50
0.48*
0.23
0.32
1.05
1.41
118.24
3.94
FT
0.50
0.56*
0.27
0.36
1.12
1.51
117.32
5.29
BL
0.74
0.7**
0.16
0.17
0.8
1.06
100.94
4.35
BW
0.19
0.18**
0.043
0.037
0.42
0.56
86.10
2.89
BT
0.06
0.054 ns
0.033
0.035
0.36
0.49
101.92
4.30
HBW
8.1
7.83**
0.86
1.01
1.98
2.65
106.74
5.46
CBD
462.52
452.11**
162.37
279.75
28.14
37.73
145.37
70.2
Rust
159.50
134.65ns
90.43
115.69
20.51
27.51
113.02
15.29
Yd/tr
0.098
0.08*
0.045
0.05
0.43
0.57
101.03
35.20
Time J.Agr.Vet.Sci. 52
Table 3. The distribution of germplasm accessions into five clusters based on D2 analysis for 49 coffee germplasm accessions tested at
Agaro (2011/12).
Table 4. Average inter-cluster divergence (D2) values obtained based on 22 quantitative characters of 49 coffee germplasm
accessions tested at Agaro (2011/12).
**=Highly significant P<0.01(χ 2) =40.29
Bayetta et al. (2008) reported the requirement of genetic
divergence among parents with respect to geographic
origin and/or morphological traits for maximum heterosis
to occur in certain hybrid characters like yield and stem
diameter. Wassu et al.(2008) also reported maximum
heterosis in crosses involving diverse parents with
respect to geographic origin compared to crosses having
parent’s from similar geographic origin.
Principal component analysis revealed the first six
principal components with eigenvalues greater than one
accounted for 70 % of the total variation among the
accessions for 22 quantitative traits (Table 5).
The first principal component which accounted for 25 %
of the variability among coffee germplasm accessions
were attributed to discriminatory traits such as inter node
length of main stem and primary branches, leaf length
and hundred bean weight. Likewise, 17% of the total
variability among the tested coffee accessions accounted
for the second principal component originated from
variation in plant height, number of main stem nodes,
number of primary and secondary branches, average
length of primary branches and canopy diameter. So,
these traits played major role in classifying coffee
accessions into different clusters and should be
considered in selecting diverse parents in crossing
program. This finding is partly in agreement with the
finding of Olika et al. (2011) who have reported bean
length, hundred bean weight, leaf length and leaf width
contributed to the variation among Limmu coffee
accessions.
CONCLUSION
The analysis of variance revealed the presence of
significant differences for most of the traits, indicating the
presence of variability which can be exploited through
selection and hybridization. The cluster analysis for 22
quantitative characters classified 49 coffee germplasm
accessions into five clusters and most of inter-cluster
distances were significantly different. So, crossing coffee
accession from these divergent clusters will result in
heterosis and recombinant in segregating generation.
Besides, the traits with the largest values in the first two
principal components played major role in clustering the
accessions and should be considered for selection
program.
AKNOWLEDGEMENTS
The authors would like to acknowledge Jimma
Agricultural Research Center for allocating the required
budget for the research.
Cluster
No.
No. acc.
Percent
(%)
Accessions
1
19
39
L23/05 L08/05, L11/05, L40/05, L19/05, L15/05, L32/05, L31/05 L25/05, L36/05, L48
/05, L17/05, L35/05 , L20 /05, L12/05 ,L37/05, L39/05, L42/05 and F-59
2
19
39
L07/05, L33/05, L43/05 , L44/05 , L26/05, L45/05, L18/05, L47/05, L41/05, L05/05,
L03/05, L13/05, L28/05, L34/05, L14/05, L09/05, L16/05, and L27/05 and 744
3
5
10
L10/05, L06/05, L01/05, , L21/05 and L46/05
4
5
10
L24/05, L04/05, L30/ 05 L38/05 and L29/05
5
1
2
L02/05
Cluster
I
II
III
IV
V
I
30.07
32.36
108.95**.
103.24**
II
83.87**
29.53
96.33**
III
183.94**
70.14**
IV
165.72**
WeldeMichael et al 53
Table 5. Eigenvectors and eigenvalues of the first six principal components for 22 morphological characters of 49 Arabica coffee
germplasm accessions
HUP= height up to first primary branch. TPH= total plant height, NMSN= number of main stem nodes, AILMS= average inter node length of main stem,
SD= stem diameter, APB= angle of primary branches, NPB= number of primary branches, ALPB= average length of primary branches, NNPB= number of
nodes of primary branches, AILPB= average inter node length of primary branches, NSB=number of secondary branches, CD= canopy diameter, LL= leaf
length, LW= leaf width, FL= fruit length, FW= fruit width, FT= fruit thickness, BL= bean length, BW= bean width, HBW= hundred bean weight, CBD
=coffee berry disease, Yd/tr= yield per tree, PC= principal component.
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Characters
Eigen vectors
PC1
PC2
PC3
PC4
PC5
PC6
HUP
0.14
0.09
-0.28
-0.10
0.28
-0.5
TPH
0.15
0.42
-0.1
-0.01
0.17
0.06
NMSN
-0.18
0.36
-0.16
0.13
0.19
0.03
AILMS
0.35
0.05
0.13
-0.14
-0.08
0.16
SD
0.14
0.29
-0.12
0.01
0.23
-0.35
APB
0.13
0.14
-0.34
-0.22
0.19
0.35
NPB
-0.17
0.39
-0.01
0.15
-0.05
0.10
ALPB
0.12
0.30
0.44
-0.12
-0.06
0.12
NNPB
-0.19
0.21
0.41
0.1
0.1
0.01
AILPB
0.32
-0.01
-0.11
-0.22
-0.15
0.1
NSB
-0.01
0.32
-0.15
0.23
-0.38
-0.001
CD
0.03
0.32
-0.38
-0.18
0.1
-0.13
LL
0.30
0.02
0.05
-0.27
0.04
0.04
LW
0.29
0.07
0.06
-0.23
-0.02
-0.05
FL
0.29
0.01
-0.05
0.24
0.02
0.19
FW
0.27
-0.11
0.17
0.1
0.06
-0.19
FT
0.10
-0.14
0.13
0.03
0.49
0.40
BL
0.09
0.01
0.11
0.42
0.05
0.26
BW
0.25
-0.11
0.1
0.41
0.1
-0.22
HBW
0.32
-0.04
0.1
0.37
0.1
-0.16
CBD
-0.2
-0.06
-0.02
-0.01
0.57
0.04
Yd/tr
0.17
0.15
-0.33
0.20
-0.1
0.24
Eigen values
5.59
3.67
2.12
1.64
1.38
1.14
Percent variation
0.25
0.17
0.10
0.07
0.06
0.05
Cumulative variation
0.25
0.42
0.52
0.59
0.65
0.70
Time J.Agr.Vet.Sci. 54
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... Morphological characters have been used to classify coffee germplasm collected from major coffee growing areas in Ethiopia. The findings [17][18][19][20][21][22][23] proved the possibility of measuring genetic diversity using morphological markers. When it comes specifically to the Limmu coffee collections, Olika et al. [19] conducted diversity analysis on 49 coffee accessions collected from Limmu-kossa woreda using morphological markers and reported that there was sufficient diversity among the accessions for quantitative traits. ...
... The authors also reported that cluster analysis grouped 49 accessions into four divergent groups (Table 1). In a similar other experiment conducted on another batch of Limmu coffee collection (SET IV), Getachew et al. [18] reported that there was considerable variation among the 49 coffee accessions for quantitative traits and the coffee accessions were grouped into five clusters with significant genetic distance, suggesting the possibility of getting suitable accessions for hybridization program among the tested materials ( Table 2). According to the authors, PCA analysis showed the variation in the first two principal components, which explained the lion's share of the observed variation, (42%), was mainly due to internode length of the main stem and primary branches, leaf length, hundred bean weight, plant height, number of main stem nodes, number of primary branches, length of primary branches, number of secondary branches and canopy diameter. ...
... In-line with this result, Yirga et al. (2021), stated positive direct effects of inter-node length of primarybranches, bean thickness, and average inter-nodelength of the main-stem, number of primary-branches, stem diameter, and bean weight on yield per tree. Similarly, Getachew et al. (2013), also reported a positive direct effect of average inter-node-length of primary-branches, number of primary-branches, number of nodes on primary branches, fruit length and thickness, and stem diameter on yield per plant. ...
Article
Full-text available
The investigation was conducted to assess the extent of genetic diversity of South Ethiopian Arabica coffee genotypes for agro-morphological characters. Seventeen Arabica coffee genotypes were evaluated at Awada, Shebedino, and Wonago in south Ethiopia. Analysis of variance revealed significant variation among genotypes, environments, and genotype by environment interaction(GEI) for most of the characters investigated. Mean performance analysis confirmed the presence of genotypes superior for yield. Moderately high-to-high broad-sense heritability along with moderate-to-high genetic advance values were found for 15 traits, thereby indicating the possibilities of improvement through selection. Most agro-morphological traits were positively associated among themselves and with yield. Path coefficient analysis showed a positive direct effect of 11 characters on yield, indicating the significance of those traits for direct selection to increase coffee yield. Cluster analysis grouped genotypes into two main clusters and four sub-clusters. The first five principal components explained 74.05% of the total variation. The highest yield was recorded for genotypes AW7705 and AW105 which could be promoted as promising candidates for the release of a new cultivar for Arabica coffee growing regions in South Ethiopia and other similar agro-ecologies. Genotype, environment, and GEI have a significant effect on yield performance. Hence, the coffee yield improvement program should pay careful attention to a multi-location and season testing strategy to develop high-yielding cultivars. Investigation of management options after the high-yielding season is also advised to minimize high-seasonal yield oscillation.
... Morphological markers in coffee are vital to distinguish variation based on phenotypic observation differences, like: -leaf size and shape, young and old leaf color, fruit character, branching habit, plant height and the length of internodes [15]. Moreover, a number of scholars reported the existence of coffee arabica genetic variation in Ethiopia through conducting a research using a different coffee geremplasm population: -on Amaro Kele coffee [16][17][18] on 26 Wollega coffee; [19] on 49 Limmu coffee accessions while the other scholar [20] on 81 Wollega coffee accessions. However, till now achievements of the general characterization using morphological marker is a base to design future coffee breeding program and improvement for desirable traits. ...
... These enormous proportions of coffee diversity existing in Ethiopia is being exploited as germplasm by gathering or picking, in more or less managed forests, or grown in highly diversified cropping systems spread over different types of environments. These collections have been used to assess the diversity of the Ethiopian coffee genepool by the analysis of phenotypic characters (Getachew et al., 2016) and using DNA-genetic markers (Silvestrini et al., 2007), to search for traits of agronomic interest, and to improve yield and quality by hybridization with different cultivars. Also, Merga et al. (2020) reported the availability of genetic diversity among twenty-six genotypes of wollega coffee landrace in western Ethiopia using organoleptic traits. ...
... The name 'coffee' is believed to originate from the name of the province Kaffa in the southwestern part of the country, where according to legend; a goat herder discovered coffee beans during the sixth century A.D. (Gomez-Ruiz et al., 2007). Coffee is under-story plant of the ever-green afromontan rain-forest of the southern western part of the country and it originated in the southwestern part of Ethiopian highland where it was first discovered (Getachew et al., 2013). It is from this part of the country that coffee spread to the rest of the world and constituted the ancestor of the present day coffee plantations across the globe (Kassahun et al., 2008). ...
Thesis
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Background: Arabica coffee (Coffea arabica L.) is the fine flavored, aromatic type makes up 60-65% of total production and usually fetches the highest prices. Arabica Coffee is the most important and backbone of Ethiopian economy, which accounts for an average 60% of export earnings. Coffee is a perennial crop which can be harvested multiple times of years, and it is known to be affected with a characteristic biennial, which is more pronounced in the species Arabica coffee. The immediate objective of this study was to analyze Arabica coffee bean yield longitudinally by using Linear Mixed Model (LMM), and to assess its Genotype by Environment interaction (GEI). Coffee Bean Yield (CBY), Coffee Yield, and Yield are used interchangeably in this document. Methods: The data for this study came from coffee variety field trials conducted by Jimma Agricultural Research Center (JARC) over several years. The trial was conducted in south west Ethiopia across coffee growing areas (Jimma, Agaro, and Metu). The experimental design of the trial was RCBD with 4 replications and 17 Arabica coffee genotypes. A complete CBY data set of these coffee growing areas which had been collected during 2005-2011 was considered in this study. Exploratory Data Analysis (EDA) and LMM were employed for longitudinal analysis, whereas combined ANOVA and AMMI model were used for GEI analysis. All analyses were done with the help of R statistical package. Results: The LMM results revealed that the heterogeneous variance function (varIdent(t)) and autoregressive order three (AR3) were, respectively, found to give better fit to the variance and correlation structure among measurements of CBY. Biennial interacts significantly with location and genotype. The estimated variance of random effect of block associated with intercept and biennial were (b0j) = (221.81)2 and (b3j) = 145.242, respectively. The result also showed significant location by linear and quadratic time effect interactions. Estimates of quadratic time effects for Jimma, Agaro, and Mutu were, respectively, -151.51, -66.05, and -4, whereas estimates of linear time effects for these locations were 158.92, 158.92, and 31.08, respectively. The combined analysis of variance revealed that the genotype, environment, and GEI effects are highly significant (P-values<0.001). GEI accounted for 16.2% of the total sum of squares and was about 2 times larger than that of genotypes. The AMMI procedure revealed that AMMI-5 was the best truncated AMMI model that can sufficiently explain the information contained in GEI. The first three interaction principal components (IPC1, IPC2, and IPC3) retained by Gollob’s F-test for graphical display accounted for 64.2% of GEI. Conclusion: The measurements of CBY that are obtained from Arabica coffee tree over time induce an autocorrelation which is known as serial correlation. There is initially an increasing and gradually a decreasing trend in Arabica CBY over time years with linear rate of growth. There is also a differential response of genotypes and environments in the presence and absence of biennially. The major factor that influences the yield performance of Arabica coffee in Ethiopia is the environment, and among 17 Arabica coffee genotypes, G1, G2, G3, G7, G8, G9, and G12 have the best performance with G1, G2, G3, G8, and G12 being relatively stable across the test environments. It was recommended to use information from longitudinal and GEI analysis to investigate the effect of time and biennial and the association between genotype and environment in Arabica CBY.
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Despite Ethiopia is endowed with diverse genetic base for the Arabica coffee and is the center of origin, there length of the longest primary branch, number of main stem nodes, stem girth, internode length on the main stem, canopy The study result revealed that total yield per hectare was higher for promising hybrid 75227x1681 (3491 Kg/ha) followed kg/ha through direct selection indicating the need to look heterotic hybrids to maximize yield as high as 2500-3000 kg/ha. is still a limited availability of yield competitive improved variety; hence, the national average productivity is far below diameter and yield for three consecutive years (2019 to 2021) per hectare basis. The results revealed the existence of the world’s average. Due to this reason, the national average productivity is very low. From the various sets of pure lines by 75227xAngafa (3023 Kg/ha) grown at Awada and for 75227X1681(1437 Kg/ha) at Leku. As the promising hybrid this study aimed to evaluate coffee hybrid genotypes for yield and yield components. The experiment was conducted at 3.45cm), canopy diameter (199221.77cm), number of main stem nodes (27.96 30.66), number of primary branches from 2016 to 2021. Data were collected for plant height, number of primary branches, number of secondary branches, (52.08 –58.83), number of secondary branches (148.23 –179.25), average length of primary branches (107.00–116.84cm). productivity, it is essential to develop hybrid coffee varieties that are high yielding, stable and disease resistant. Therefore, variety development program in Ethiopia, it had been observed that it is rarely possible to improve yield above 18002000 experiment was conducted by using a randomized complete block design (RCBD) with three replications during the years statistically significant variations among the growth characters. Total plant height (1.99-2.45m), stem diameter (2.82– genotypes out performed than the existing improved varieties at Awada and Leku, there will be a better chance of getting at full bearing stage to identify high yielding hybrids for commercial use. Therefore, to bridge this gap and improve coffee Awada and Leku to depict the growth and yield characteristics of four Arabica coffee promising hybrid genotypes). The improved Arabica coffee hybrid varieties within south Ethiopian growing environment. Therefore, the experiment should Thus, it could be useful to further evaluate the performance of the best performing hybrids foryield and growth characters be repeated in different representative trial site to recommend suitable and stable hybrid variety for south coffee growers.
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A key step in characterization of germplasm is the identification of phenotypic variation present in a given population. A study was carried out to determine the effect of different dosages of gamma rays (50 and 100Gy) on phenotypic variation using 21 standardized morphological descriptors of the UPOV Tea Test Guidelines. The trial comprised of open-pollinated seed stocks from six commercial tea cultivars namely TRFCA SFS150, TRFK 303/1199, EPK C12, GW Ejulu-L, TRFK 301/1 and TRFK 301/4 along with untreated controls. Data was collected for three seasons (dry, warm wet and cold wet) using five randomly selected plants from each treatment. Principle Component Analysis using 17 informative descriptors showed the first eight principal components accounted for 78% of the total variance, with 15 being highly informative. Cluster analysis further identified characters such as young shoot anthocyanin colouration at base of the petiole, leaf blade shape/color/length, shoot color/length, density of pubescence, plant vigour and density of branches as most discriminating descriptors resulting in four phenotypically well-defined groups. Most traits showed significant correlation, an indication that the traits could be used for indirect selection. The study provides a basis for rapid and early screening of base populations for identification of elite cultivars.
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Coffee (Coffea arabica L.) plays a major role in the economy of Peru and the world. The present study aims to elucidate the agro‐morphological variability of coffee genotypes maintained in the National Institute of Agrarian Innovation (INIA) germplasm collection. Therefore, 20 vegetative, reproductive, and phytosanitary traits of 162 coffee accessions of INIA's germplasm collection were evaluated and analyzed. Correlation results indicate that a simultaneous selection of characters, such as number of branches per plant, number of nodes per branch, leaf area, and weight of a hundred fruits, can contribute to increase coffee yields. Additionally, coffee yield was negatively correlated with the incidence and severity of coffee leaf rust, and interestingly the occurrence of small and compact coffee plants with high resistance to the disease was also found. The analysis of Tocher and Mahalanobis D² determined the formation of 10 groups of divergent coffee accessions; where clusters 1 (accession codes 20, 29, 38, 54, 67, 71, 117, 24, 26, and 27), 5 (accession codes 46 and 53), 9 (accession code 159), and 10 (accession code 203) group promising accessions that can be used in breeding programs. Principal component analysis showed that at least five of its principal components managed to explain 70.01% of the total variation in the collection. Finally, the high coefficients obtained for the phenotypic, genotypic, and heritability variation confirm the existence of additive genes in the evaluated population, that would ensure the success of coffee breeding programs based on the selection of traits of agronomic importance.
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Background: Natural forest degradation for coffee management and intensification in natural forest has been playing a great role in affecting forest carbon (C) stock potential in western and southwestern Ethiopia which is not studied well. By considering this issue, the current study was conducted with the aim to assess the soil C stock changes as a result of conversion of natural forest to coffee-based forest at Anfilo District, western Ethiopia. The District is 642 km west of Finfinne (The country’s capital city). For the present study, two adjacent land uses, protected natural forest (PNF) (1,576 ha) and forest with coffee (FWC) (2,364 ha) were considered. In light of this, soil samples were collected for the analysis of C content and bulk density (BD). Soil samples were taken by using ‘‘X’’ design from land size of 1mx1m (four at corners for C content and one in the center for BD analysis) at two levels of soil depths (0–20 and 20–40 cm) separately. Accordingly, a total of 120 soil samples (60 for C content and 60 for bulk density) were collected and taken to laboratory for the determination of C content and BD. Walkley-Black method was used to estimate soil C stock. Independent t –test was used to test for differences in soil C stocks at significant level of 0.05. Results: The findings of the present study revealed that significantly higher soil C stock was recorded for PNF (136.2 + 8.42 t C ha⁻¹) than FWC (90.76 + 4.97 t C ha⁻¹) (p<0.05). Conclusion: The study concluded that conversion of natural forest to coffee-based forest leads to a reduction of SOC by 33.4%, which is equivalent to the emission of about 166.613 t CO2 ha⁻¹ to the atmosphere. Thus, maintaining and enhancing the soil carbon sequestration potential of this forest soil should be required through implementation of different conservation mechanisms.
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Fifty eight Amaro coffee (Coffea arabica L.) accessions and six standard check were evaluated for genetic variability and character association at Awada Agricultural Research Sub-Center, Southern Ethiopia using morphological traits. The experiment was laid out in an 8x8 simple lattice design with eight coffee accessions per each incomplete block. The mean square for 19 quantitative characters revealed significant difference (P<0.05) among the accessions in coffee bean yield, plant height, height up to first primary branch, main stem diameter, canopy diameter, number of bearing primary branches, fruit width, fruit length, bean thickness, bean width, leaf width, 100-coffee beans weight, coffee berry disease and coffee leaf, average inter nodes length of main stem, length of first longest primary branch, number of primary branches, bean length, leaf size. High phenotypic and genotypic coefficient of variation was recorded for coffee bean yield, coffee berry disease and coffee leaf rust disease severity. Genotypic coefficients of variation were very close to their corresponding estimates of phenotypic coefficient of variation suggesting greater role of the genotype in the expression of these traits. High estimates of heritability and genetic advance as percent of mean observed for coffee berry disease, coffee leaf rust and bean yield. Coefficient of variation, heritability estimates, confirmed presence of variation among tested accessions. However, additional traits of interest should be studied over year and locations including physiological, quality and biochemical analysis with the support of advanced molecular techniques. Keywords: Coefficient of variation, Heritability, genetic advance
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The aim of this study was to estimate the extent of genetic variation and association among yield and yield-related traits. Forty nine Coffea arabica accessions from Limu (Jimma, Ethiopia) were tested at Agaro Agricultural Research Sub Center, Ethiopia from 2004 to 2009 in simple lattice design with two replications. Variances component method was used to estimate genetic variation, broad sense heritability and genetic advance. Association of traits was also estimated using standard method. The germplasm accessions differ significantly for most of the traits. Relatively high phenotypic (45.11 and 30.18%) and genotypic coefficient of variation (25 and 24.90%) were observed for yield and number of secondary branches in the order of magnitude. Hundred bean weight (81.13%) showed the highest heritability. Yield per plant showed significant positive phenotypic correlation with percentage of bearing primary branches (r = 0.53) while it revealed significant positive genotypic correlation with bean width (r = 0.47), fruit length (r = 0.61), hundred bean weight (r = 0.59), plant height (r = 0.28), canopy diameter (r = 0.29), leaf length (r = 0.30) and percent of bearing primary branches (r = 0.62). Over all, the study confirmed the presence of trait diversity in Limu coffee accessions and this could be exploited in the genetic improvement of the crop through hybridization and selection.
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Africa is known as the centre of origin and genetic diversity for all coffee species produced worldwide. It is also one of the most vulnerable regions to global climate change. In most African countries, natural forest ecosystems with high levels of biodiversity are under serious threat, largely due to increasing population pressures and subsequent deforestation and land degradation. The destruction of natural coffee habitats coupled with changes in weather patterns can adversely affect coffee genetic resources and the livelihoods of millions of people in Africa and elsewhere. This paper deals with environmental preservation and coffee diversity in Africa, and takes into account opportunities and challenges in the face of global climate change and financial crisis. Sustainability includes environmental, social, and economical components, which are linked with importance and risks to the use of natural resources for development and human well-being. Special attention is given to the sustainable use and conservation of native coffee habitats and genetic resources for the future development and competitiveness of the coffee sector in Africa and globally. The diversity in coffee genes, species and ecosystems, traditional farming practices and technological innovations such as mitigation and adaptation strategies to climate change need to be exploited in the African continent to produce superior quality coffee types and remain competitive in the world market. The wild or cultivated coffee species/cultivars have specific ecological and input requirements to adapt and thrive in their places of origin and thus preserve diversity in Africa or in other coffee producing countries. This presentation provides a brief insight into the huge opportunities and challenges facing the environment and conservation of coffee generic resources in Africa, and includes an overview of coffee research and conservation experiences in Ethiopia, the birthplace for Arabica coffee. It draws conclusions about the need for urgent implementation of sound conservation measures to warrant the sustainability of healthy ecosystem services, development of the coffee sector and improving the living standards of people worldwide and in the African continent in particular. Introduction Coffee belongs to the genus Coffea, in the Rubiaceae family. There are about 103 species of genus Coffea, all exclusively restricted to the tropical forests of Africa, Madagascar and islands of the Indian Ocean (Mascarene Islands). Of all the species, only two (Coffea arabica L.) and Coffea canephora Pierre ex Froehn) have commercial value in the world coffee industry. Coffea arabica is the only species occurring in Ethiopia and is geographically isolated from the rest of the Coffea species. It is naturally restricted to two isolated mountain forests on the western and eastern sides of the Great Rift Valley in southern Ethiopia. It is the most popular and widely cultivated coffee species in the world, dominating 70% of total coffee production and over 90% of the market. The remaining proportions come from Robusta coffee, which originates from the equatorial lowland forest of west and central Africa. Arabica and Robusta coffees have been adapted and thrive best in the tropical highland and lowland areas of coffee producing countries, respectively. There may also be several other coffee species in the natural forests of Africa that may be used by indigenous and local communities for different purposes but these remain for future studies.
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Two sets of tropical maize inbred lines, one derived from the BR-105 population and another derived from the BR-106 population, were assayed for Amplified Fragment Length Polymorphism's (AFLP) and for Simple Sequence Repeat (SSR), in order to investigate genetic distances among lines and their relationship to heterotic group assignment and single cross yield performance. Genetic distances were on average greater for interpopulation than intrapopulation crosses for both AFLP and SSR. Cluster analysis was in agreement with the original assignment for heterotic groups. Inbred line 16, derived from BR-106, was assigned to the BR-105 set, in agreement with single cross yield performance from intra- and interpopulation crosses. However, the same pattern was not observed for SSR where another two lines from BR-106 were also assigned to the BR-105 set. Correlation coefficients of genetic distances (GD) with F1 grain yield and heterosis were high for BR-106 ×BR-106 crosses (0.91** and 0.82** for AFLP and SSR, respectively), moderate for BR-105 × BR-105 crosses (0.52* for AFLP and SSR) and low for BR-105 × BR-106 crosses (0.29 and 0.16 for AFLP and SSR, respectively). The lower correlation at interpopulation level was due to the smaller range of GD caused probably by a previous selection for combining ability. General results showed that the AFLP molecular marker is efficient in assigning maize lines to heterotic groups and that AFLP-based GD is suitable for predicting the maize single cross performance for intrapopulation crosses of broad-based populations. The efficiency of SSR in assigning lines to heterotic groups and for predicting single cross performance was smaller than AFLP.
Chapter
Coffee cultivation in the world has benefited greatly from the successful breeding programmes, which have given the farmers productive cultivars adapted to specific cropping conditions. For example, presently in Brazil the improved arabica coffee cultivars (Coffea arabica L.) produces three to four times more than the cultivars used in the past. However, yield in this species seems to have reached a plateau, which is hard to overcome. Examples are the yield of improved Mundo Novo, Catuaí Vermelho and Catuaí Amarelo lines, which are still the most productive today. Therefore, one of the great challenges for the breeders is to increase the yield of the present cultivars. Another great challenge for the breeder is to transfer genes to improve coffee resistance/tolerance to disease and pests, since the arabica species is very susceptible to them. Although C. arabica has twice the number of chromosomes than the other species in the genus, some inter-specific hybridization has been successfully exploited. The world wide occurrence of coffee tree rust (Hemileia vastatrix Berk.et Br.) for example, and the damage it causes, have aroused the interest of the breeder in finding resistant arabica coffee cultivars by natural or artificial hybridization with Coffea canephora Pierre. Breeding by hybridization in coffee, as in other plants, requires identification of genetic variability for the characteristics to be improved, the choice of the most promising hybridization, and the application of methods, which favour selection of superior hybrids, lines or populations. In this context, DNA marker technologies have been proposed as useful tools for research programs. This technologies may be of great potential to help breeding, especially in coffee, because it is a perennial crop with a long juvenile period.
Article
The results of collecting missions in Albania in 1941 and 1993 and in South Italy in 1950 and in the eighties allowed a comparison to be made of the material cultivated. The number of landraces still cultivated recently, as compared to their former number, was the basis for the estimation of genetic erosion. Genetic erosion (GE) was calculated as GE=100%-GI (Genetic integrity). Genetic erosion was found to be 72.4% in Albania and 72.8% in South Italy, respectively. These results prove the high degree of genetic erosion in landraces from different parts of the Mediterranean area. Apart from the economic conditions, several other factors are responsible for genetic erosion, among them breeding system, crop type (i.e., garden or field crop) and crop group (e.g., cereals, vegetables and pulses).The results show that in the areas investigated there are still landraces for in situ conservation. Ex situ conservation in genebanks proved to be a possibility. An integration process is necessary to prevent losses in crops which are difficult to propagate under ex situ conditions. The complementarity of both conservation methods is stressed.
Statistical analysis system (version 9.2) DNA markers for coffee tree breeding Coffee biotechnology and quality
  • Sas Institute
  • Nc Cary
  • Ns Sakiyama
SAS (2008). Statistical analysis system (version 9.2), SAS Institute, Cary, NC.USA Sakiyama NS(2000). DNA markers for coffee tree breeding. In: T. Sera, C.R. Soccol, A. pandy and S. Roussos (Eds.), Coffee biotechnology and quality. Kluwer Academic Publishers, Dordrecht. pp. 179-185.