Morphological characterization of selected Capsicum accessions and development of species identification key for Chili

Abstract

Capsicum is widely grown as an essential spice crop in Sri Lanka. The existing germplasms of Capsicum conserved at Plant Genetic Resource Centre (PGRC), Gannoruwa were initially identified as two species, Capsicum annuum, and Capsicum frutescens, instead, it is hypothesized that there may be additional genotypes within the existing germplasm collections. Hence, the present study was focused on evaluating twelve Capsicum accessions and to characterize morphologically including 24 qualitative and seven quantitative traits to assess the genetic diversity among plants. The experiments were carried out at the open field and protected house of PGRC, Gannoruwa by randomized complete block design with four replicates. Morphological characters were analyzed using analysis of variance (ANOVA) and multivariate methods. Significant variance among genotypes was obtained for most of the quantitative characteristics (p<0.05). Early flowering (41d) and fruiting (69d) was observed in accessions C-2018-12-232, NM-9-3-R1, NM-6- 2-R2-B, and ACC# 1249B, while the remainder accessions exhibited late flowering (>47d) and harvest (>75d) nature respectively. Principal component (PC) analysis explained more than 73.12 % of total variability for the first three components. PC1 was highly positively correlated with seed beak prominence, corolla color, and seed shape, while PC2 was highly correlated positively with fruit color, shape at the blossom end, and fruit positions. Hence this study attempted to develop a species identification key for chili species by employing morphological traits, though seed shape can be considered as a power tool. Moreover, the dendrogram confirmed that the germplasms resemble into three chili species as C. annuum, C. chinense, and C. frutescens.