Morphological characterization of tall coconut (Cocos nucifera L.) germplasm conserved in ex-situ field genebanks in Sri Lanka.

Abstract

Abstract Germplasm characterization is very important to identify novel traits which are essential for the breeding process to develop improved hybrids. Germplasm characterization can be achieved in * * ' three means as morphological, molecular and biochemical characterization. Through the characterization of different coconut varieties, diversity among them can be comprehended which is a pre-requisite for genetic improvement. A total of 157 coconut accessions were conserved in the four main ex- situ field genebanks in Sri Lanka namely; Raddegoda, Lenawa, Pallama and Pottukulama. Out of these 157 accessions 95 accessions are belonging to the tall variety. This contains unidentified duplicates and closely related accessions which are not necessary to rejuvenate in future, hence, can reduce the cost of * l rejuvenation. The study focuses on identifying morphologically, the most diverse accessions among 95 tall coconut accessions conserved ex-situ field genebanks in Sri Lanka. Previously collected morphological data i.e. stem, leaf and inflorescence characters, during the past two years was analyzed using statistical software (MINITAB 14) to select most diverse 42 tall accessions out of the above 95 accessions available in ex-situ field genebanks. These were selected by observing their grouping pattern at 66.67 similarity level of the dendrograms. Results revealed the diversity of morphological data among tall accessions indicating the potential of them to be utilized in breeding programmes. The study also unveiled the duplications among accessions with respect to stem, leaf, inflorescence, nut count and Suit components which will help in formulating future conservation strategies and conservation of true genetic diversity. Further, all these grouping patterns revealed that the variation is not explained by the geographical regions. Thus the observed variation is attributed to the specificity of each population. 54 Proceedings o f Wayamba University Research Congress 2017, Senate Research and Higher Degrees Committee Table 1: selected 42 accessions LENAWA RADDEGODA PALLAMA POTTUKULAMA Sitrakala Dadella Kalawewa Moorock Kivulakelle Galenbundunuwewa Galenbidunawewa Pitiyakanda Thammenna Medagama W anathawilluwa Clovis Yatawatta Mahakumbukkadawara Ihalakagama Namalwatta Mirishena Beliatta Blackstone St. Anne's Ambakelle tall Alutwatta Lanlib Margret Dickwella zoyzawatta Hangiliyagama Kasagala Namalwatta Heediwatta Diddenipotha Debarayaya Debarayaya Adikarigoda magama Kalagedihena Kirulapona Malsiripura Mangala eliya Keenakelle Maliboda Walahapitiya