attached
: Coconut (Cocos nucifera L.) is classified into three
main varieties in Sri Lanka as tall, dwarf and intermediate with
each variety including several forms of coconut. Sri Lanka
Yellow Dwarf (SLYD) is a coconut form included under the
variety dwarf and it is a parent of the improved coconut hybrid
CRIC65. Morphological differentiation of SLYD from Sri
Lanka Yellow Semi Tall (SLYST) and a mixed morphological
group (ML) of SLYD and SLYST is impossible at the seedling
stage. The objective of the present study was to derive DNA
fingerprints for SLYD and SLYST for distinct identification at
any stage during its life cycle.
A total of 30 palms were genotyped with sixteen
polymorphic SSR primer pairs and data were analysed with
the PowerMarker V3.25 software. The results revealed SLYD
specific DNA fingerprints at SSR loci CAC65, CAC4, CNZ10,
CnCirD8 and CNZ6. These markers scored specific homozygous
alleles for SLYD with very high allelic frequency, and scored
very low frequencies in SLYST and ML phenotypes. SLYD
formed a clear separate cluster in the UPGMA dendrogram
while SLYST and ML formed separate mixed clusters. Thus
the present study was successful in generating specific DNA
fingerprints for SLYD and this information will be of practical
use in differentiating SLYD at the seedling stage, especially in
the establishment of isolated coconut seed gardens for mass
production of improved coconut cultivars having SLYD as a
parent.
