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

Abstract

A great deal of variability exists in coconut populations of the Lakshadweep group of islands in India, which is regarded as one of the likely centre's for coconut domestication. It is possible to gain insights into the evolution of coconut populations in these islands by undertaking detailed studies of these populations. In this study, the variability and phylogenetic relationships within populations of Laccadive Ordinary Tall (LCT) and Laccadive Micro Tall (LMT) from Amini and Kadmat Islands were studied using microsatellite markers. LCT collections from these two islands were earlier grouped, according to fruit shape, into three type's viz., elongated, round or oval shaped and pear shaped ones. Three accessions of LMT, one each from Amini and Kadmat, and a variant of LMT from Kadmat Island, characterized by the round shaped fruit and nut, were also used for the studies. Seedlings raised from these types were analysed using 20 highly polymorphic SSR markers. Elliptical type from Amini, which are described as 'Niu Kafa' type, emerged as distinct from other populations and was related to round or 'Niu Vai' type from Amini. Pear shaped type from both the islands, which was considered as the introgressed form, showed affinity and appear to have developed as a result of introgression between elliptical and round types. When the LMT palms were analyzed, the LMT palms from Amini and Kadmat clustered together, while the round variant of LMT from Kadmat Island was found to be distinct. A large extent of variations were also found among individual palms of these distinct types when analyzed using SSR markers, highlighting the importance of selection of LCT mother palms for hybrid seed production.

Genetic relationship and diversity among coconut (Cocos nucifera L.) accessions revealed through SCoT analysis

“…The results of the present study, using 23 coconut accessions and 15 SCoT primers, indicated that 87.2 % of the scored fragments were polymorphic, which was relatively high compared to earlier studies utilizing dominant marker systems like RAPD (Upadhyay et al 2004 ; Manimekalai and Nagarajan 2006b ) and ISSR (Manimekalai and Nagarajan 2006a ). Seven of the primers gave 100 % polymorphism in the 23 samples, making them comparable to polymorphism observed with SSR markers (Perera et al 1999 ; Rivera et al 1999 ; Merrow et al 2003 ; Rajesh et al 2008a , b , 2014 ). Pair wise similarity coefficient’s ranged from 0.37 to 0.91 indicating the capability of SCoT markers to detect high levels of genetic diversity among the coconut accessions analyzed.…”

Genetic Structure and Diversity of Attalea vitrivir Populations in Brazilian Cerrado

“…The AMOVA, performed with two hierarchical levels, showed that the highest percentage of variation (93.3%) was found within populations, while among population component contained 6.7% of the total variation (Table 3). Comparable results have been found for perennial palms with an outcrossing breeding system, such as Cocos nucifera (Lebrun et al, 2005;Rajesh et al, 2014), Geonomas hottiana (Silva et al, 2011), Astrocaryum (Oliveira et al, 2014), Elaeis oleifera (Ithnin et al, 2017). These results are also in accordance with those obtained by Büttow et al (2010), who observed higher variation (83.68%) within populations of Butia capitata.…”