Varietal Classification of New Coconut (Cocos nucifera L.) Forms Identified from Southern Sri Lanka

Abstract

Coconut in Sri Lanka is currently classified into 15 different coconut forms grouped under three varieties, namely Typica, Nana and Aurantiaca. Several new coconut morphotypes that were not represented in the previous classifications were identified during a recent coconut germplasm exploration mission in the Southern Province of Sri Lanka. The visual morphological features of several new coconut morphotypes (Ran pol, Bothal thembili, Juwan, Murusi, Dothalu and Thatin) were characterized with the objective of including them in the taxonomic classification of coconut in Sri Lanka. Stature and breeding behaviour were the main features observed while stem morphology, root bole formation, crown size, nut morphology and bearing patterns, and other specific morphological features were recorded. The data provided morphological evidence to classify Ran pol, Juwan and Rath gon thembili as new forms of variety Typica; Green dwarf 'Murusi', Yellow dwarf 'Murusi' and Brown dwarf 'Murusi' as forms of variety Nana; and Bothal thembili as a new form of variety Aurantiaca. The morphotypes, Thatin and Dothalu were identified as forms of variety Typica but the sample size was too small for confirmation.

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Varietal Classication of New Coconut (Cocos nucifera L.) Forms Identied
from Southern Sri Lanka
G K Ekanayake1,3, S A C N Perera1, P N Dassanayake2, J M D T Everard1
1Coconut Research Institute of Sri Lanka
2University of Sri Jayawardenepura, Sri Lanka
3Current Address: Dhammissara National College, Nattandiya, Sri Lanka
Author for correspondence: S A C N Perera E mail: chandrikaperera2003@yahoo.com
ABSTRACT
Coconut in Sri Lanka is currently classied into 15 different coconut forms grouped under three varieties,
namely Typica, Nana and Aurantiaca. Several new coconut morphotypes that were not represented in the
previous classications were identied during a recent coconut germplasm exploration mission in the Southern
Province of Sri Lanka. The visual morphological features of several new coconut morphotypes (Ran pol,
Bothal thembili, Juwan, Murusi, Dothalu and Thatin) were characterized with the objective of including them
in the taxonomic classication of coconut in Sri Lanka. Stature and breeding behaviour were the main features
observed while stem morphology, root bole formation, crown size, nut morphology and bearing patterns, and
other specic morphological features were recorded. The data provided morphological evidence to classify
Ran pol, Juwan and Rath gon thembili as new forms of variety Typica; Green dwarf ‘Murusi’, Yellow dwarf
‘Murusi’ and Brown dwarf ‘Murusi’ as forms of variety Nana; and Bothal thembili as a new form of variety
Aurantiaca. The morphotypes, Thatin and Dothalu were identied as forms of variety Typica but the sample
size was too small for conrmation.
Key words: coconut, varietal classication, Sri Lanka.
INTRODUCTION
The classication of coconut has not been
adequately standardized, and different authors
in different countries use different terminology.
Generally, coconut is classied, based on
its stature and breeding behaviour, into two
broad groups or types: tall (also termed typica)
and dwarf (also termed nana). In addition, a
few intermediate groups, sometimes referred
to as semi-talls or semi-dwarfs have also
been recognized. King coconut in Sri Lanka
(Liyanage, 1958), Gangabondom in India
(Menon and Pandalai, 1958) and Niu Leka Dwarf
in Fiji (Powell, 1868; Bourdeix et al. 2005) are
examples of such intermediate groups.
The rst systematic classication of coconut
germplasm in Sri Lanka was reported in 1958
COCOS, 2010, 19: 41 - 50
Printed in Sri Lanka
RESEARCH ARTICLE

42
(Liyanage, 1958). This classication, based
largely on stature and reproductive behaviour
of the palm, recognizes three varieties, namely
Typica (tall), Nana (dwarf) and Aurantiaca
(intermediate). There are several morphotypes
in each variety and these were termed as ‘forms
within varieties’. Liyanage’s classication
recognizes 13 forms within the three varieties.
With the subsequent additions made by
Wickremaratne (1984) and Perera et al. (1997)
15 coconut forms have been recognized within
the three varieties in Sri Lanka (Table 1).
Variety Typica Nar. (tall) is the most abundant
coconut variety in Sri Lanka and most coconut
growing countries. It is tall in stature and naturally
outbreeding. Typica forms usually take 5-6 years
to ower and they produce owers continuously.
They are hardy palms that tolerate a wide range
of environmental conditions. Typica, Navasi,
Gon-thembili, Ran-thembili, Pora-pol, Bodiri,
Kamandala and Dikiri are the different forms of
the variety Typica (Table 1). The form Typica
(Sri Lanka Tall), is grown on a commercial scale
for production of endosperm, shell and bre
products. The other forms are found scattered in
small numbers, mainly in home gardens. They
are of little economic signicance other than as
candidates for breeding improved varieties.
Variety Nana (Griff) Nar. (dwarf) is short
in stature and naturally inbreeding. It owers
early in about 3-4 years from planting and is
a seasonal bearer. Nana forms suffer adversely
from drought, pests and diseases. Dwarf
coconuts are not grown on a plantation scale
but are extensively used in the production of
coconut hybrids because of their short stature,
precocity and profuse bearing ability. Green
dwarf (pumila), yellow dwarf (eburnea,), red
dwarf (regia) and brown dwarf braune (Perera
et al. 1997) are the forms of the variety Nana
(Table 1).
Variety Aurantiaca Liy., which includes
king coconut and similar forms, is intermediate
in stature, predominantly inbreeding and
late owering. Flower production, which
commences about 5 to 6 years after planting,
is seasonal. The low tolerance to drought, pests
and diseases restricts the areas in which king
coconuts thrive. Tender king coconut, with its
bright orange epicarp, and high sucrose, sweet
nut water, is a very popular beverage coconut.
Variety Aurantiaca has three forms, namely king
coconut (thembili), rathran thembili and navasi-
thembili (Table 1).
Genetic variation in the germplasm pool
provides material for crop improvement. Much of
the diversity of coconut forms hitherto identied
in Sri Lanka has already been extensively
tested in breeding programmes. However, there
is a need for more germplasm with diverse
characteristics to meet the requirements of the
coconut breeding programme. A survey, in the
Southern Province of Sri Lanka, to explore new
germplasm to enrich the Coconut Research
Institute germplasm collection (Everard et al.
2004), identied several new coconut phenotypes
that merit detailed morphological assessment
(Ekanayake et al. 2007). The aim of the current
study was to morphologically differentiate the
new forms identied in the Southern Province,
and accordingly classify them under varieties.
Ekanayake et. al.

43
MATERIALS AND METHODS
A survey was conducted in Galle area
(Coordinates 603’0”N 80013’0”E) (Figure 01)
in the Southern Province of Sri Lanka. The
surveyed lands were home gardens and small
holdings where the traditional coconut varieties
are planted, rather than the plantations where the
Table 1: Varieties and forms of coconut found in Sri Lanka
commercial cultivars are grown. Much of the
information regarding the different phenotypes
and their locations were received from the
coconut pickers in the area.
Six new morphotypes of coconut, identied
in the survey, by their vernacular names, Ran
pol, Bothal thembili, Juwan, Murusi, Dothalu
Varietal Classication of New Coconut (Cocos nucifera L.) Forms Identied From Southern Sri Lanka

44
and Thatin were assessed by studying the
morphological parameters of the stem, crown and
fruit, their reproductive and bearing behaviour
as well as other specic morphological features.
All these morphotypes were found in a few
villages clustered around Unawatuna in Galle
District of the Southern Province of Sri Lanka.
Samples of 7-10 palms each of Ran pol, Bothal
thembili, Juwan and Murusi were assessed
but only two palms of Thatin and one palm
of Dothalu were available for this study. The
morphological traits were scored over a period
of 3 years to observe the temporal variation
of the traits in each phenotype. Apart from the
morphological traits specied in Table 2, other
visually observable specic features of the new
morphotypes were also recorded.
Table 2: Morphological characters and the traits scored for
characterizing coconut morphotypes
RESULTS AND DISCUSSION
Grouping the new phenotypes under coconut
varieties
The main morphological features used to
group coconuts are the stature and breeding
behaviour. In addition, the presence or absence
of a bole, shape of the crown and regularity of
bearing were taken into consideration. These
features of the varieties Typica, Nana and
Aurantiaca, and of the newly identied coconut
morphotypes are presented in Table 3. Some
features of the new morphotypes are illustrated
in Figures 1-9.
Ekanayake et. al.

45
Varietal Classication of New Coconut (Cocos nucifera L.) Forms Identied From Southern Sri Lanka
Figure 1: Ran pol crowns and nuts
Figure 3: Juwan coconuts
Figure 5: Thatin coconut Figure 6: Dothalu coconut
Figure 4: Murusi (Green)
Figure 2: Bothal thembili

46
Figure 7: Rath gon thembili Figure 8: Yellow Murusi
Figure 9: Brown murusi
Ekanayake et. al.

47
Table 3: Basic morphological descriptors utilized in coconut varietal
classication in Sri Lanka and the corresponding features of the seven
newly identied coconut morphotypes
The variety Typica essentially comprises tall
and predominantly cross pollinating coconut
palms. The data presented in Table 3 suggest that
Ran pol, Juwan, Thatin, Dothalu and Rath Gon
thembili can be grouped under variety Typica.
Presence of a root bole is yet another prominent
morphological feature dening tall coconuts and all
the above mentioned phenotypes display prominent
root boles. Furthermore, these phenotypes exhibit
well spread crowns and a year-round bearing
pattern, which are also features characteristic of
Typica. In regard to Thatin and Dothalu, as the
sample size in the current study was inadequate,
their grouping needs to be conrmed by studying
more palms or by studying the selfed progeny of
the 2 morphotypes.
Varietal Classication of New Coconut (Cocos nucifera L.) Forms Identied From Southern Sri Lanka

48
Bothal thembili, with its intermediate stature,
self pollinating breeding behaviour and the
orange coloured fruit epicarp can be included in
the variety Aurantiaca, which includes all king
coconut types in Sri Lanka. The medium sized
crown and intermittent nut production provide
further evidence for this classication.
The dwarf stature, predominantly self
breeding nature, absence of a root bole, relatively
small crown and the seasonal nut production
provide evidence for considering Murusi as a
Nana (dwarf) variety.
Classication of the new coconut phenotypes
as forms within varieties
Distinct morphological features are used to
classify different forms within a variety. The
different forms within a variety possess the
basic requirements to be included under that
particular variety. In addition, each form has
unique morphological features to distinguish it
from all the other forms. Fruit colour, fruit size,
fruit shape, petiole colour, mesocarp or endocarp
softness and thickness, and the prolicacy of
nut production are examples of traits used to
distinguish forms within varieties. Table 4
presents the specic morphological features of
the new coconut phenotypes, identied from
Southern Sri Lanka, which enable them to be
regarded as forms within the three main varieties
of coconut in Sri Lanka. Consequently, the new
forms listed in Table 4 are not only different from
each other, but also different from the forms
identied by Liyanage (1958), Wickremaratne
(1984) and Perera et al. (1997).
Table 4: Specic morphological features of the new coconut types identied
in Southern Sri Lanka and their classication as forms within
varieties
* Sample size was inadequate to classify precisely
Ekanayake et. al.

49
The green, yellow and brown phenotypes
of ‘Murusi’ are classied within the relevant
colour form of variety Nana (Table 4). This
differentiation between Murusi and the relevant
colour form of dwarf is mainly based on the
differences in nut size and kernel weights of the
dwarf and Murusi forms (Table 5). As shown
in Table 5, Green and Brown Murusi produces
larger and heavier nuts than the relevant dwarf
forms while Yellow Murusi produces smaller
and lighter nuts than Yellow dwarf.
Many of the forms of coconut identied
earlier (Kamandala, Bodiri, Pora pol, Dikiri
etc.) were also naturally distributed in the
Southern Province of Sri Lanka and testies to
the rich morphological diversity of coconuts in
the area. The local community identies the new
coconut phenotypes by their vernacular names
indicating that they have been grown or found
naturally in the area over a long period of time
and are not freaks or recent mutants. However,
these traditional coconuts are endangered due
to ongoing urbanization and coconut replanting
programmes. Recognizing these coconut
Table 5: Comparison of the nut size and kernel weight of the dwarf and
Murusi forms
phenotypes as forms and their inclusion in
the classication will draw attention to the
possible existence of more traditional coconut
phenotypes in Sri Lanka and the need for their
conservation as germplasm accessions. These
diverse materials are likely to carry valuable
genes for exploitation in future coconut
hybridization programmes for diverse uses in
addition to being used directly for commercial
purposes such as beverage coconuts and daily
culinary requirements.
ACKNOWLEDGEMENTS
The authors thank Dr. L. Perera, Head of
the Genetics & Plant Breeding Division of the
Coconut Research Institute of Sri Lanka for
his constructive comments on the research and
the manuscript. We gratefully acknowledge the
nancial assistance received from the Coconut
Genetic Resources Network for the initial
survey to identify farmers’ varieties and from
the Sri Lanka Coconut CESS Fund for the
characterization and conservation of Southern
Coconut germplasm.
Varietal Classication of New Coconut (Cocos nucifera L.) Forms Identied From Southern Sri Lanka

50
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