DUS descriptors based morphometric characterization to analyze genetic variability in gladiolus
Present investigation involved phenotypic characterization of 84 gladiolus genotypes based on 18 DUS descriptors to estimate genetic variation and identify desirable genotypes for hybridization. Considerable variability was observed among the genotypes for most of the traits and principal component analysis revealed that the first two principal components explained most of the existing variation (>98%) in the germplasm. Genotypic coefficient of variation exhibited a wide range from 7.80% (androecium length) to 37.11% (duration of flowering) while, phenotypic coefficient of variation ranged from 8.12% (androecium length) to 37.61% (duration of flowering). Strong broad sense heritability estimates (>95%) were observed for the characters viz., bract length, flower width, tepal length, tepal width, style length, time of beginning of flowering and duration of flowering. Seventy four pair wise inter-trait combinations showed significant and positive genotypic and phenotypic correlations among 153 possible trait combinations. Mahalanobis D2 statistic analysis revealed that genotypes of the cluster II and V to be highly distinct and hybridization between them might have better chance to obtain desirable recombinants. Ward’s cluster analysis confirmed that the cv. Victor and cv. Malaviya Shatabdi to be highly diverse for the selected traits. It is concluded that the above genotypes may be utilized in crossing programme to obtain better progenies. Characterized data of gladiolus germplasm would assist the breeders in varietal identification, conservation and their sustainable utilization during breeding programme.