Mechanisms of inheritance in durum wheat genotypes

Abstract

Creating high-yielding cultivars with improved grain quality is a major priority in durum wheat breeding. Variability, her-itability and genetic advance were studied for the following traits: grain yield, plant height, productive tillering, spike length, number of spikelets per spike, number of kernels per spike, kernels weight per spike, thousand kernel weight, protein content, wet gluten content, SDS-sedimentation value, yellow pigments content, vitreousness and test weight of 90 durum wheat genotypes of different origins. The phenotypic coefficient of variation (PCV) was established to be higher than the genotypic coefficient of variation (GCV) for all studied traits, which reflects the impact of the environmental conditions on the variation of these traits. The highest phenotypic (PCV-41.66%) and genotypic (GCV-41.39%) coefficients of variation were established for sedimentation value. High broad-sense heritability coefficients (h 2 BS) were established for almost all studied traits. The heritability for these traits ranged from 54.74% for number of kernels per spike to 98.72% for SDS-sedimentation value. The lowest coefficient of heritability was established for kernels weight per spike-5.5%. High genetic advance as a percentage of the mean was calculated for the following traits: SDS-sedimentation value (84.71%) and grain yield (20.95%). A high herita-bility coefficient combined with high genetic advance was found for the following traits: SDS-sedimentation value and grain yield. This shows the presence of additive gene effects in the exression of these traits and therefore direct selection by these traits is possible under our conditions.

Full text

1112
Bulgarian Journal of Agricultural Science, 29 (No 6) 2023, 1112–1119
Mechanisms of inheritance in durum wheat genotypes
Krasimira Taneva, Rangel Dragov*, Spasimira Nedyalkova, Violeta Bozhanova
Agricultural Academy, Field Crops Institute, Chirpan, 6200, Bulgaria
*Corresponding author: dragov1@abv.bg
Abstract
Taneva, K., Dragov, R., Nedyalkova, S. & Bozhanova, V. (2023). Mechanisms of inheritance in durum wheat gen-
otypes. Bulg., J. Agric. Sci., 29(6), 1112–1119
Creating high-yielding cultivars with improved grain quality is a major priority in durum wheat breeding. Variability, her-
itability and genetic advance were studied for the following traits: grain yield, plant height, productive tillering, spike length,
number of spikelets per spike, number of kernels per spike, kernels weight per spike, thousand kernel weight, protein content,
wet gluten content, SDS–sedimentation value, yellow pigments content, vitreousness and test weight of 90 durum wheat
genotypes of dierent origins. The phenotypic coecient of variation (PCV) was established to be higher than the genotypic
coecient of variation (GCV) for all studied traits, which reects the impact of the environmental conditions on the variation
of these traits. The highest phenotypic (PCV-41.66%) and genotypic (GCV-41.39%) coecients of variation were established
for sedimentation value. High broad-sense heritability coecients (h2
BS) were established for almost all studied traits. The
heritability for these traits ranged from 54.74% for number of kernels per spike to 98.72% for SDS-sedimentation value. The
lowest coecient of heritability was established for kernels weight per spike – 5.5%. High genetic advance as a percentage of
the mean was calculated for the following traits: SDS-sedimentation value (84.71%) and grain yield (20.95%). A high herita-
bility coecient combined with high genetic advance was found for the following traits: SDS-sedimentation value and grain
yield. This shows the presence of additive gene eects in the exression of these traits and therefore direct selection by these
traits is possible under our conditions.
Keywords: qualitative traits of grain; phenotypic coecient of variation; genotypic coecient of variation; herita-
bility; genetic advance
Introducton
Durum wheat (Triticum durum Desf.) is an important ce-
real crop used by man mostly for food. Due to its specic
characteristics such as hard and compact endosperm, high
vitreousness, high protein and carotenoid content, high-qual-
ity gluten with high extensibility and low elasticity, it is ex-
tremely suitable for processing into pasta products (Sissons,
2016).
The ultimate goal of any breeding program is the creation
of high-yielding varieties in dierent environments. Pheno-
typic diversity analysis is useful to determine the genetic
diversity of crop genetic resources, which is necessary for
successful crossing (Dagnaw et al., 2022). Hybridization is
an important source for creating diversity. The study of ge-
netic diversity is the basis for plant breeding improvement.
An eective plant breeding strategy uses genetic diversity
as a source of new alleles for crop improvement. Essential
to the success of recombination breeding is the appropriate
selection of genotypes as parents to produce highly heterosis
crosses and the presence of genetic diversity in the source
population (Bello et al., 2012). Modern breeding programs
for durum wheat are aimed at improving the agronomic and
qualitative traits of the grain.
Breeding based on phenotypic variation is not ecient,
and therefore selection based on the evaluation and use of

1113
Mechanisms of inheritance in durum wheat genotypes
genetic diversity in the desired direction is extremely import-
ant for the breed-improvement programs of durum wheat.
Accordingly, information on genetic variation, heritability,
genetic advance, and correlational relationships is neces-
sary for a successful parental selection in breeding programs
(Adhikari et al., 2018).
Genetic studies provide information on the extent of ge-
netic control, particularly trait expression and phenotypic
reliability in predicting breeding outcomes. Heritability is an
indicator for transmission of desired traits from parents to o-
spring that is widely used in breeding programs (Lipi et al.,
2020). The heritability assessment is a useful parameter for
breeders because it allows the prediction of possibilities for
successful breeding, as it reects the correlation between phe-
notypic variation that can be inherited, in other words the her-
itability coecient measures the reliability of the phenotypic
value as an indicator of the genotypic value. The heritability
assessment facilitates the selection of methods and traits used
in the initial and advanced phases of breed-improvement pro-
grams, allowing the study of the mechanisms, genetic values
and variation of each trait (Al-Naggar et al., 2022). Genetic
advance (GA) is another important parameter that serves to
determine the expected response of the breeding process. The
combination of high genetic advance with high heritability
predicts the most eective breeding conditions (Terfa, Gur-
mu, 2020) and indicates the presence of additive genes in the
inheritance of the trait. Phenotypic and genotypic coecients
of variation, heritability and genetic advance are widely used
to determine the amount of variation in breeding materials,
to determine appropriate selection procedures and to predict
breeding progress in the improvement of important traits
(Clarke et al., 2010). A high to moderate range of coecients
of variation provides greater opportunities for selection of de-
sired genotypes (Sravani et al., 2021).
The assessment of heritability and genetic advance is
used in breeding numerous crops. There are popular publica-
tions of genetic studies on rice (Demeke et al., 2023), maize
(Asare et al., 2022), sorghum (Sawadogo et al., 2023) and
others.
The aim of this study was to determine the degree of vari-
ation, heritability, genetic advance and environmental impact
in a sample of 90 durum wheat genotypes of diverse origins.
This research will enable the prediction of possible
breeding advance in improving grain yield and quality in the
breed-improvement program for durum wheat.
Material and Methods
The study included 90 modern durum wheat (Triticum
durum Desf.) genotypes - varieties from all over the world
and breeding lines. The Bulgarian durum wheat is present-
ed by 26 modern varieties and 36 breeding lines developed
in the Institute of Field Crops (IFC, former Cotton and Du-
rum Wheat Research Institute), Chirpan and Dobrudzha
Agricultural Institute, Northern Bulgaria. The foreign ger-
mplasm introduced in Bulgaria is presented by the varieties
from several European countries, including Italy, France,
Austria, Hungary, Germany, Russia and Ukraine, and the
USA. All the genotypes were grown under eld conditions
for three years 2020–2022. A randomised block method
was used in four replications with an experimental plot
size of 15 m2. The accepted technology for growing durum
wheat was used.
The following traits were monitored: grain yield (Y) – t/
ha, plant height (H) – cm, productive tillering (PT) – number,
spike length (SL) – cm, number of spikelets per spike (NSS)
– number, number of kernels per spike (NKS) – number,
kernels weigth per spike (KWS) – g, grain protein content
(GPC) – percentage, wet gluten content in grain (GWG) –
percentage, SDS-sedimentation value (SDS) – cm3, vitreous-
ness (VIT) – %, test weight (TW) – kg/hl, thousand kernel
weight (TKW) – g, Minolta yellow index b* (MK).
The grain protein content was determined by the Kjeldahl
method (N x 5.7) according to BNS EN ISO 20483: 2014,
and wet gluten – according to BNS EN ISO 21415-2: 2008.
The gluten strength was evaluated by measuring the sedi-
mentation value of wholemeal our in a lactic acid - sodi-
um dodecyl sulfate (SDS) solution at a standard sedimen-
tation time (ICC 151: 1990). Vitreousness was determined
according to BNS EN 15585: 2008. Thousand kernel weight
was determined according to BNS EN ISO 520: 2010. Test
weight was determined according to BNS EN ISO 7971-1:
2009. The values of yellow colour b* were measured accord-
ing to CIE L*a*b* cubic colour space, which is considered
the most operational and informative one. The measurement
was made per grain using a Minolta CR-410 chroma meter.
The higher the b* value, the greater the amount of carot-
enoids. The chroma meter was calibrated with a standard
calibration plate.
The total heritability (h BS2) for the studied traits was
calculated by the variance components method based on the
results from the three years of cultivation. Primary data were
processed with analysis of variance (ANOVA). The variance
components were calculated according to Snedecor and Co-
chran (1980). All the studied genetic parameters, formulas
for their calculation and designations are presented below
(Table 1).
The results were processed statistically with a two-way
analysis of variance (ANOVA) by means of Statistica, ver-
sion 13.0 (TIBCO Software).

1114 Krasimira Taneva, Rangel Dragov, Spasimira Nedyalkova, Violeta Bozhanova
Results and Discussion
Heritability is an indicator of phenotypic variance, which
is due to genetic reasons and has predictive function in plant
breeding (Eid, 2009). According to Khan et al. (2009), the
higher the heritability coecient, the simpler the selection
procedures. Broad-sense heritability only shows whether
there is sucient genetic variation in a population and how
the population will respond to the selection pressure (Mila-
tović et al., 2010).
Based on the collected data from the conducted 3-year
experiment with the set of 90 genotypes of diverse origin
the variation, broad-sense inheritance and genetic advance
were determined for the following traits: grain yield, plant
height, productive tillering, spike length, number of spikelets
per spike, number of kernels per spike, kernels weight per
spike, thousand kernel weight, protein content, wet gluten
content, SDS-sedimentation value, yellow pigments content,
vitreousness and test weight.
The performed analysis of variance shows that the mean
squares, the years of cultivation and the interaction between
them are signicant for all studied traits (Table 2).
The mean values, the range of variation and the pheno-
typic and genotypic coecients of variation of all investigat-
ed traits for the 90 durum wheat genotypes for the growing
years are shown in Table 3.
The PCV was higher than the GCV for all studied traits
and reects the impact of environmental conditions (year of
Table 1. Genetic parameters and formulas for their cal-
culation
σ2 g = (MSg – MSgy)/yr Genotypic variance
σ2
gy = (MSgy – MSe)/r Variance of interaction between
G and Y
σ2
e = MS eError variance
σ2
ph = σ2
g + σ2
gy/y + σ2
e/ry Phenotypic variance
h BS
2 = (σ2
g / σ2
ph) x 100 Broad-sense heritability
GA = k x (σ2
ph)0.5 x hBS
2/(100/ x
–)
Genetic advance
K – selection intensity – 2.06
PCV = √ σ2
ph/ x
 X 100 Phenotypic coecient of vari-
ation
GCV = √ σ2
g/ x
 X 100 Genotypic coecient of vari-
ation
MSg Mean squares of genotype (g)
MSgy Mean squares of interaction
(gxy)
MSeMean squares of error
y Number of years of cultivation
r Number of repetitions
x
Mean value
Table 2. Mean squares value from ANOVA for 14 quantitative traits of 90 durum wheat genotypes
Traits Genotype (G) Environment (E)
(year)
G × E Error
Grain yield 5.31*** 362.31*** 1.6*** 0.18
Plant height 450*** 20980.86*** 65*** 0.2
Productivity tillering 2.685*** 32.9*** 2.4*** 1.7
Spike length 2.74*** 117.5*** 0.8*** 0.02
Number of spikelets per spike 13.2*** 114.6*** 4.5*** 0.01
Number of kernels per spike 150*** 902*** 67.9*** 1.1
Kernels weight per spike 0.495*** 2.4*** 0.2*** 0.003
Thousand kernel weight 64*** 772*** 11.7*** 0.03
Grain protein content 3.4*** 362.6*** 1.0*** 0.01
Sedimentation value 1121.9*** 249*** 14.4*** 0.9
Grain wet gluten content 14.9*** 1593.5*** 4.6*** 0.02
Minolta kernel 2.1*** 53.3*** 0.5*** 0.04
Vitreousness 286*** 6350*** 69.6*** 0.02
Test weight 40*** 670*** 6.6*** 0.02
*** – signicant at p < 0.001

1115
Mechanisms of inheritance in durum wheat genotypes
cultivation) on the variation of these traits. The highest PCV
was established for sedimentation value (SDS – 41.66%)
and productive tillering (YPG – 16.0%). The highest GCV
was established for SDS-sedimentation value (41.39%). A
smaller dierence between the PCV and GCV was observed
for traits: yield, grain protein content, wet gluten content in
grain, yellow pigment content and test weight, indicating
less environmental impact on the phenotypic expression of
the respective trait.
The greatest dierence between the PCV and GCV was
established for the traits of productive tillering and kernels
weight per spike, which is an indicator of a greater impact
of the environmental than of genotype on the variation of
these traits. On the other hand, the coecient of variation
is used to determine the diversity that exists in each popula-
tion. A coecient of variation (CV) above 20% is considered
an indicator of high diversity, a CV value between 10 and
20% - moderate diversity, and less than 10% - low diversity
(Deshmukh et al., 1992). In our study, high diversity was
observed for trait SDS-sedimentation value (CV-41.66%).
Moderate diversity was established for traits: grain yield
(14.5%) and productive tillering (16.0%). The lowest PCV
was found for test weight (2.82%), yellow pigment content
(2.90%), wet gluten content in grain (4.12%), protein content
(4.15%), number of spikelets per spike (5.66%), thousand
kernel weight (6.20%), vitreousness (6.49%), spike length
(7.65%), plant height (7.84%) and number of kernels per
spike (9.34%).
The phenotypic variance of all studied traits and its two
main components: genotypic variance and environmental
variance, are presented in Table 4. The value of genotypic
variance was higher than the one of environmental variance
(years of cultivation) for traits: plant height, thousand kernel
weight, sedimentation value, yellow pigment content, vitre-
ousness, and test weight. It comes to show that the genotypic
component of variation is a major contributor to the overall
phenotypic variation of these traits. The environmental vari-
ance was higher than the genotypic variance for traits: grain
yield, productive tillering, spike length, number of spikelets
per spike, number of kernels per spike, kernels weight per
spike, protein content, wet gluten content in grain and there-
fore means that the environment is a major contributor to the
whole phenotypic variation of these traits.
In our study, very high heritability coecients (h2
BS)
were established for all the traits except for productive tiller-
ing and kernels weight per spike (Table 4). The heritability
for these traits ranged from 54.74% for number of kernels
per spike to 98.72% for SDS-sedimentation value. In support
of our results, Muhammad et al. (2017) reported high broad-
sense heritability coecient for the traits: spike length, thou-
sand kernel weight and grain yield. According to Kumar et
al. (2014) high heritability is an indication that the traits are
much less aected by environmental conditions. The lowest
coecient of heritability was found for productive tillering
– 11.0% and kernels weight per spike – 5.5%.
Genetic advance is an important breeding parameter
in addition to heritability by which the degree of improve-
ment of desired traits can be predicted. Genetic advance,
expressed as a percentage, is categorized as low (0-10%),
moderate (10-20%) and high (≥20%) (Johnson et al., 1955;
Falconer, Mackay, 1996).
High genetic advance as a percentage of the mean was
calculated for the following traits: SDS-sedimentation value
(84.71%) and grain yield (20.95%). Moderate genetic advance
Table 3. Variation coecient, means values and its ranges for 14 quantitative traits of 90 durum wheat genotypes
Traits Min Max Mean PCV% GCV%
Grain yield 3.3 6.8 5.3 14.5 12.1
Plant height 71.1 110.3 90.2 7.84 7.25
Productivity tillering 2.7 4.1 3.4 16.0 5.3
Spike length 5.8 8.7 7.3 7.65 6.43
Number of spikelets per spike 18.3 23.9 21.4 5.66 4.59
Number of kernels per spike 36.4 54.8 43.7 9.34 6.91
Kernels weight per spike 1.5 2.7 1.9 12.89 9.56
Thousand kernel weight 36.6 50.3 43.0 6.20 5.61
Grain protein content 12.9 16.3 14.8 4.15 3.48
Sedimentation value 16.8 57.9 26.8 41.66 41.39
Grain wet gluten content 27.1 34.2 31.2 4.12 3.43
Minolta kernel 15.6 17.8 16.6 2.90 2.53
Vitreousness 67.9 95.6 86.8 6.49 5.65
Test weight 68.8 78.0 74.7 2.82 2.58

1116 Krasimira Taneva, Rangel Dragov, Spasimira Nedyalkova, Violeta Bozhanova
was calculated for three of the studied traits: plant height
(13.90%), spike length (11.14%), number of kernels per spike
(10.53%), thousand kernel weight (10.44%) and vitreousness
(10.12%). Low genetic advance was found for the traits: ker-
nels weight per spike (1.46%), productive tillering (3.67%),
yellow pigment content (4.56%), test weight (4.85%), grain
wet gluten content (5.87%), grain protein content (6.03%) and
number of spikelets per spike (7.68%). High heritability com-
bined with high genetic advance is considered to indicate the
presence of additive gene eects, while high heritability com-
bined with low genetic advance is an indicator of non-additive
gene eects on the control of the respective trait. In the present
study, additive gene eects were found for the following traits:
SDS-sedimentation value and grain yield. This indicates the
possibility of conducting ecient selection of genotypes by
phenotype in early generations and achieving rapid selection
progress on these traits.
Broad-sense heritability for SDS-sedimentation value in
wheat was found to range from moderate to high in previous
studies, which was also conrmed by our results (Clarke et
al., 2010). High heritability and high genetic advance for this
trait were also reported by Choudhary et al. (2020). There
is information about low heritability of this trait in Turkish
breeding lines of winter durum wheat (Akcura, 2009).
Some authors reported low heritability of grain yield
(Alemu et al., 2020) and others – low heritability combined
with high genetic advance (Wolde et al., 2016; Dagnaw et
al., 2022), while still others found high heritability of this
trait in durum wheat under various environmental conditions
(Rapp et al., 2018). Kumar et al. (2014) reported high her-
itability and high genetic advance for biological plant yield
and the presence of additive gene eects. There is also con-
icting information regarding the heritability of vitreousness
in durum wheat (Branković et al., 2014; Branković et al.,
2018). Branković et al. (2014) reported moderately high the
broad sense heritability for grain vitreousness (71%). In our
study, high heritability combined with high genetic advance
were found for trait grain yield and high heritability com-
bined with moderate genetic advance for vitreousness.
High heritability combined with high genetic advance
for grain yield, thousand kernel weight, number of kernels
per spike, spike length and plant height were also reported
by other authors (Wolde, et al., 2016; Nishant et al., 2018;
Bendjama, Ramdani, 2022). Devesh et al. (2018) in their
study reported high heritability and high genetic advance for
thousand kernel weight. Thapa et al. (2019) reported high
heritability and high genetic advance for the following traits:
kernels weight per spike, thousand kernel weight, grain
yield, number of kernels per spike as well as low to moderate
high genetic advance for plant height. Additive gene eects
for number of kernels per spike and kernels weight per spike
under irrigated conditions were reported by Morteza et al.
(2018).
Regarding protein and gluten content, a high heritabili-
ty coecient was combined with low genetic advance. This
indicates the presence of non-additive gene eect and signif-
icant environmental impact on the expression of these traits.
Protein content is one of the most important quality parame-
ters of durum wheat. Breeding for increasing protein content
is known to be complicated due to the existing negative cor-
Table 4. Component of variance (σ2), broad-sense heritability (h2
BS %) and genetic advance (GA) for 90 durum wheat
genotypes
Traits Variance σ2h2
BS % GA as % of
mean
σ2
ph σ2
gσ2
yσ2
g/ σ
2
y
Grain yield 0.59 0.412 0.473 0.87 70 20.95
Plant height 50.02 42.8 21.6 1.98 86 13.90
Productivity tillering 0.302 0.032 0.233 0.14 11 3.67
Spike length 0.312 0.22 0.26 0.85 70.5 11.14
Number of spikelets per spike 1.466 0.966 1.0496 0.65 65.9 7.68
Number of kernels per spike 16.66 9.12 22.27 0.41 54.74 10.53
Kernels weight per spike 0.06 0.033 0.066 0.5 5.5 1.46
Thousand kernel weight 7.11 5.81 3.89 1.49 81.7 10.44
Grain protein content 0.377 0.266 0.33 0.81 70.56 6.03
Sedimentation value 124.66 123.06 4.5 27.35 98.72 84.71
Grain wet gluten content 1.655 1.144 1.526 0.75 69.12 5.87
Minolta kernel 0.232 0.177 0.153 1.157 76.29 4.56
Vitreousness 31.77 24.04 23.19 1.04 75.67 10.12
Test weight 4.444 3.711 2.193 1.69 83.51 4.85

1117
Mechanisms of inheritance in durum wheat genotypes
relation with grain yield and the signicant environmental
impact on the variation of this trait (Würschum et al. 2016).
There is conicting information regarding the heritability of
protein content in the dierent growing conditions and gen-
otype groups used. Akcura (2009) reported low to moder-
ate heritability coecient for these traits. Rapp et al. (2018)
used two dierent groups of durum wheat containing 159
and 189 genotypes tested at multiple locations across Europe
and determined a relatively high heritability value for protein
content of around 75% for both groups of genotypes used.
Our results with a signicantly smaller number but diverse
genotypes support the ndings of the latter authors. Under
our conditions, high heritability coecients were found for
both traits: 70.56% for protein content and 69.12% for wet
gluten content. Genetic advance was low for both indicators
- 6.03% and 5.87%, which shows the presence of non-addi-
tive gene eects. Consistent with our results, Bayisa et al.
(2020) reported a low genetic advance and high heritability
for test weight and correspondingly the presence of non-ad-
ditive gene eects in the expression of this trait. Other au-
thors reported high heritability moderately high genetic ad-
vance for this trait and correspondingly the presence of both
additive and non-additive gene eects (Rajput, 2018).
Numerous studies have been conducted related to estab-
lishing the heritability of yellow pigment content in durum
wheat under dierent conditions and genotypes and with
dierent methods (Clarke, 2005; Clarke et al., 2008; Ron-
callo et al., 2012; Gautam et al., 2023). Clarke (2005), an-
alysing the existing studies, concluded that the heritability
of pigment concentration is high and this allows selection
for this trait in early generations. Clarke et al. (2008) found
that yellow pigment content was controlled by several genes
with an additive eect, inuenced by environmental factors
and epistatic interactions (Roncallo et al., 2012). Our results
indicate the presence of non-additive gene eects, as the es-
timated genetic advance is low. Therefore, under our condi-
tions, an eective selection for this trait is impossible.
The lowest heritability coecient combined with the
lowest genetic advance in our study was established for ker-
nels weight per spike and productive tillering. This comes to
indicate that non-additive gene eects prevail in the inheri-
tance of this traits and ecient genotype selection by phe-
notype in early generations is not possible under our condi-
tions. Thapa et al. (2019) reported high heritability and high
genetic advance for productive tillering.
Conclusions
The analysis of variance performed shows that the mean
squares, the years of cultivation and the interaction between
them are signicant for all studied traits.
The phenotypic coecient of variation (PCV) was high-
er than the genotypic coecient of variation (GCV) for all
studied traits and reected the impact of environmental con-
ditions (year of cultivation) on the variation of these traits.
The highest PCV (41.66%) and GCV (41.39%) were estab-
lished for sedimentation value.
The greatest dierence between the PVC and GVC was
established for the traits of productive tillering and kernels
weight per spike, which is an indicator of a greater impact
of the environmental than of genotype on the variation of
these traits.
High diversity was observed for trait SDS-sedimentation
value (CV-41.66%). Moderate diversity was established for
traits: grain yield (14.5%) and productive tillering (16.0%).
The lowest PCV was found for test weight (2.82%), yel-
low pigment content (2.90%), wet gluten content in grain
(4.12%), protein content (4.15%), number of spikelets per
spike (5.66%), thousand kernel weight (6.20%), vitreousness
(6.49%), spike length (7.65%), plant height (7.84%) and
number of kernels per spike (9.34%).
Very high heritability coecients (h2
BS) were established
for all the traits except for productive tillering and kernels
weight per spike. A high heritability coecient combined
with high genetic advance was found in our study for the
following traits: SDS-sedimentation value and grain yield.
This indicates the presence of additive gene eects in the
expression of these traits and therefore direct selection for
these traits is possible under our conditions. High heritability
combined with moderately high genetic advance was found
for the following traits: plant height, spike length, number of
kernels per spike, thousand kernel weight and vitreousness.
This indicates the presence of additive and non-additive gene
eects and therefore selection for these traits under our con-
ditions would be dicult. A low heritability coecient and
low genetic advance was found for kernels weight per spike
and productive tillering in our study. Therefore, this trait is
controlled by non-additive genes and direct selection is im-
possible.
Acknowledgements
This work was supported by the Bulgarian Ministry of
Education and Science under the National Research Pro-
gramme „Healthy Foods for a Strong Bio-Economy and
Quality of Life” approved by DCM # 577 / 17.08.2018”.
References
Adhikari, B. N., Joshi, B. P., Shrestha, J. & Bhatta, N. R. (2018).
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Received: October, 20, 2023; Approved: November, 13, 2023; Published: December, 2023