CHARACTERIZATION, CHARACTER ASSOCIATION AND DIVERSITY ANALYSIS IN CAPSICUM

Abstract

An investigation was carried out to study characterization, character association and genetic diversity of capsicum at the Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during 2012-2015. Evaluation and morphological characterization of 24 Capsicum accessions were performed using different qualitative and quantitative characters. Wide range of variations among the accessions in respect of plant, leaf, flower, fruit and seed characters were observed. From the field performance it was evident that, the accessions CA-16, CA-20, CA-18 and CA­ 05 were the higher yielder where as the accession CA-19 produced very shy yields. Correlation studies between yield and yield components indicated that fruit diameter, fruit length, plant height and seeds per fruit were significantly and positively correlated with yield. Genotypie correlation coefficient was higher than phenotypic ones in most of the cases, indicating strong inherent relation among the characters. From path coefficient analysis, it was observed that number of fruits/plant, diameter of fruits and fruit weight were the important components of yield of Capsicum. Based on multivariate analysis, 24 capsicum accessions were grouped into five clusters. The highest number of accessions (8) was in cluster Ill followed by cluster II (6) and the lowest (2) was in cluster IV. Principal component analysis revealed that the first four axes were accounted for 79.49% of total variation. Inter-genotypic distance was the highest (4.184) between CA-19 and CA-20 and lowest (0.420) was between CA-05 and CA-17. From the principal co-ordinate analysis, the highest inter-cluster distance (39.99) was estimated between cluster I and cluster IV, and the lowest (11.5) was between cluster II and cluster V. The inter-cluster distance was higher than the intra-cluster distance. Accessions CA-16, CA-18, CA-20 and CA-05 were selected as promising genotypes. RAPD analysis of 24 Capsicum accessions was done to detect genetic diversity at the DNA level. Selected five primers (0PB­ 08, OPC-05, OPJ-13 and OPW-08) amplified 29 bands of which 25 were polymorphic. Similarity indices ranged from 51.71 to 98.18%. Dendrogram based on Nei's (1972) genetic distance using UPGMA indicated that, different level of genetic identity and distance was present among the studied 24 Capsicum accessions.