Metroglyph Analysis for Estimation of Morphological Variation in Chickpea (Cicer arietinum L.) Germplasm

Abstract

Chickpea (Cicer arietinum L.) is an important pulse crop with considerable significance for food and nutritional security. The present study evaluated morphological variation among 21 chickpea genotypes, including 20 germplasm lines and the check variety Pusa-362, using Metroglyph and index score analysis. The experiment was conducted using a randomised block design with three replications, and data were collected for twelve quantitative traits associated with phenology, plant architecture, yield-contributing attributes and seed yield. Analysis of variance revealed highly significant differences among the genotypes for all the traits examined, indicating the presence of considerable genetic variability within the experimental material. For all traits, the phenotypic coefficient of variation exceeded the corresponding genotypic coefficient of variation, suggesting the influence of environmental factors on trait expression. High broad-sense heritability estimates were observed for biological yield (96.28%), days to maturity (96.02%), and number of pods per plant (95.96%), reflecting the predominance of genetic effects in the inheritance of these traits. Furthermore, high genetic advance expressed as a percentage of the mean was recorded for biological yield, number of pods per plant, number of secondary branches per plant, and seed yield per plant, indicating substantial scope for improvement through phenotypic selection and highlighting the effectiveness of these traits as selection criteria in breeding programmes. Based on Metroglyph analysis using number of pods per plant and number of seeds per plant as plotting characters, the 21 genotypes were grouped into four complexes containing 11, 7, 2 and 1 genotype(s), respectively. Total index scores ranged from 20 to 29. Genotypes CG 75, CG 287 and CG 101 recorded high index scores and were distributed across different complexes, indicating their potential utility as diverse parental lines. The study suggests that Metroglyph analysis can support the preliminary classification of chickpea germplasm and assist in identifying promising genotypes for breeding programmes.