Exploration and Collection of Coconut Germplasm in Kadmat and Amini Islands of Lakshadweep, India

Abstract

Coconut, Cocos nucifera L. is an important plantation crop of the tropics. Lakshadweep group of islands in the Arabian Sea are considered to be home to some important coconut cultivars. The present exploration was planned to sample the variability within the population of Laccadive ordinary tall (LCT), Laccadive micro tall (LMT) from two islands, Amini and Kadmat, of Lakshadweep. Sampling was done from 24 sites in Amini and 13 sites in Kadmat. On an average 10 palms were sampled from each site. During the trip, five accessions of LCT, three of LMT and one of Kaithathali were collected. Eight fruit component measurements were recorded to study the variability in the population. Intra-population variability was observed in both LCT and LMT. Three forms of LCT belonging to niu kafa, niu vai and introgressed types could be identified. Elongated angular fruits (elliptical) with 70% husk were niu kafa types, round or oval shaped ones with 55% husk were niu vai types and pear shaped ones with 58% husk were the introgressed forms. This exploration trip unearthed the missing link of niu vai type in the form of round fruit type which has not been reported earlier. Identification of different groups in LCT has far reaching implications in breeding. In the production of hybrids involving LCT, selection of mother palms of LCT is crucial. It is suggested that the elliptical fruit types may be avoided in the production of commercial hybrids, since it has high percentage of husk.

Genetic and phylogenetic relationships of coconut populations from Amini and Kadmat Islands, Lakshadweep (India)

“…Characterizing of coconut diversity, earlier undertaken through morphological traits, has now given way to the use of molecular markers, especially microsatellites, which are preferred because of their co-dominant and multi-allelic nature and their capacity to detect high polymorphism (Rivera et al, 1999;Perera et al, 2000;Rajesh et al, 2008a,b ' and 11°1 6' N latitude and 72°45' and 72°48' E longitude, having a land area of 3.20 sq km). The variability in fruit shapes among LCT and LMT (Figures 1, 2) was reported earlier by Samsudeen et al (2006). Nuts were transported and planted in the nursery at the International Coconut Gene Bank for South Asia (ICG-SA), Kidu, Karnataka State in the main land.…”

“…Coconut constitutes the only economically important crop in Lakshadweep Islands and diverse forms of coconut have been reported from these islands. Wide variability and diversity has been reported earlier from coconut populations in these islands using morphological and molecular analysis (Krishnamoorthy and Jacob, 1982;Jacob, 1993;Samsudeen et al, 2006;Devakumar et al, 2010). Gunn et al (2011) provided evidences suggesting that the region around the southern margins of the Indian subcontinent, comprising of Lakshadweep Islands, Sri Lanka and Maldives, represented a possible center of coconut domestication.…”

“…Coconut types in Lakshadweep islands have been described by earlier workers as mainly belonging to 'Niu kafa' type (Krishnamoorthy and Jacob, 1982). The occurrence of 'Niu vai' types and also introgressed forms, which developed as a result of crossing between 'Niu kafa' and 'Niu vai' types, have also been reported (Samsudeen et al, 2006 ). Laccadive Ordinary Tall (LCT) was considered as a form under 'typica' with medium sized nuts, good quality and quantity of copra and an annual yield of 100 nuts/ palm (Narayana and John, 1949).…”

“…In an expedition to Amini and Kadmat islands (Samsudeen et al, 2006), significant variations were observed in Laccadive tall collections when grouped according to fruit shape and husk percentage viz., elliptical (70% husk), round (55 % husk) and pearshaped (58% husk). This exploration indicted that LCT is a mixed population and the earlier described Laccadive Ordinary types belong to the different forms of LCT identified now.…”

Molecular cloning and characterisation of an acyl carrier protein thioesterase gene (CocoFatB1) expressed in the endosperm of coconut (Cocos nucifera) and its heterologous expression in Nicotiana tabacum to engineer the accumulation of different fatty acids

“…Coconut (Cocos nucifera L.), a member of the monocotyledonous family Aracaceae (Palmaceace), is an important oil-yielding plantation crop that is of considerable economic and social importance in the tropics (Rivera et al 1999;Samsudeen et al 2006). The endosperm tissue of coconut stores a substantial amount of oil, which has been used extensively for human consumption and other purposes all over the world.…”