Abdul Vahab, MSuresh, SKAU2019-06-042019-06-042004172308http://krishikosh.egranth.ac.in/handle/1/5810106698PGThe experiment entitled “Molecular characterization of ivygourd [Coccinia grandis (L.) Voigt]” was conducted at the Departments of Olericulture and Plant Biotechnology, College of Agriculture, Vellayani. The objectives were to assess the genetic divergence of the germplasm both at morphological and molecular level using RAPD markers in 25 ivygourd genotypes. Analysis of variance of the observations showed significant difference among the accessions for all the characters. The yield obtained in the range of 1.3 kg (CG 2) to 18.41 kg (CG 19) per plant. High PCV and GCV were observed for primary branch length, fruit per plant, total number of harvest and yield per plant. High heritability along with high genetic gain was observed in all the characters. The range of heritability was 98.83 to 63.02. All characters except days to first flowering are positively correlated with yield both at phenotypic and genotypic level. Primary branch length, average fruit weight, seeds per fruit and fruits per plant had positive direct effect on yield. In D2 analysis all the accessions are grouped into six clusters. The cluster III had maximum number of genotypes. The character yield per plant had maximum contribution to cluster formation. In molecular characterization the yield of DNA ranged from 1.44 ng/l to 9.24 ng/l. The purity was 1.29 to 2.28. A total of 41 RAPDs were generated when PCR amplification was carried out using 28 decamer primers (Operon Inc., CA, USA) of Kit A and Kit B. Of these 39 bands were polymorphic. Four primers, OPA 18, OPB 11, OPB 10 and OPB 6 produced reproducible banding pattern on atleast two runs. These primers yielded 48 scorable bands with an average of 12 bands per primer. The similarity coefficient values ranged from 0.421 to 0.918. From the dendrogram the 25 ivygourd genotypes were clustered into 10 groups. The largest group consisted the genotypes CG 11, CG 10, CG 18, CG 17, CG 2, CG 13, CG 9, CG 22, CG 21 and CG 6. The genotypes CG 16, CG 19, CG 12, CG 7, CG 4 and CG 1 formed individual separate clusters. The result of both morphological and molecular level characterization revealed similarity in the case of genotype CG 19, the highest yield. Though the genotype CG 13 was second in yield with other special attributes, it fell into a cluster along with other moderate to poor yielders. This shows the impact of environment on the expression of the characters and necessity of molecular markers in the characterization of landraces in ivygourd.ennullThesis