Use of Molecular Markers for Breeding of the Coconut Palm 'Cocos nucifera'

Abstract

Coconut palm, 'Cocos nucifera', is the most widely grown plantation crop in Sri Lanka and plays a major role as a perennial oil crop and as an important constituent of the Sri Lankan diet. Breeding of the coconut palm for characters such as high yield of copra, drought tolerance and pest and disease resistance is a high priority. Coconut breeding has progressed a long way over a period of about 75 years through mass selection and inter and intra-varietal hybridisations. However, the optimum utilisation of the natural variability by classical breeding is constrained by lack of vegetative propagation methods, long breeding cycle and the high cost and land requirement for breeding experiments. Development of molecular markers to assist the coconut breeding programme was regarded as a timely move in planning future breeding strategies. Thus, this work represents the most probably the first attempt to study the genetic variation in the coconut palm population in Sri Lanka by RAPD and RFLP assay procedures. ... The potential of the RAPD technique for assessment of genetic diversity in the coconut palm is well evident. Development of RAPD markers to tag genes of interest is achievable provided that well defined segregating families are available. Bulk segregation analysis is suggested as a suitable method for tagging useful traits in coconut with RAPD markers. RAPDs can be immediately applied for evaluation of germplasm collections. The relative merits of RFLP and RAPD are discussed with a suggestion to use a methylation sensitive enzyme (eg. PstI) to clone coconut DNA inserts as potential RFLP probes instead of using high copy sequences.