D2 Analysis and Direct & Indirect Selection Parameter for Yield and Its Components in Gladiolus (Gladiolus Grandiflorus L.)

Abstract

The present investigation “D2 Analysis and Direct & Indirect Selection Parameters for Yield and Its Component in Gladiolus (Gladiolus grandiflorus L.)” was carried out with twenty five diverse genotypes gladiolus at HRC (Horticultural Research Center) Sardar Vallabhbhai Patel university of Agriculture and technology, Meerut.(U.P.). Observation were recorded on various characters viz., days to 50% corm sprouting, days to completely corm sprouting, plant height, number of leaves per plant, length of longest leaf, width of longest leaves, stem girth, days to spike emergence, flowering duration, number of spike per plant, spike length, spike weight, number of florets per plant, flower diameter, fresh weight of corm and yield of corm. Analysis of variance revealed substantial amount of for all the 16 characters studied. It indicates the wide spectrum of variability among the genotype. Present study indicates that the GCV and PCV were higher (>20 %) observed for number of spike per plant, moderate for flowering duration, days to 50% corm sprouting, days to complete corm sprouting, number of leaves per plant at 30 days, width of longest leaf, floret diameter, fresh weight of corm, number of floret per spike, stem girth and spike weight and low (10- 20%) for number of leaves per plant at 60 days, length of longest leaf, yield of corm, plant height at 30 days, number of leaves per plant at 90 days, plant height at 60 days, spike length, days to spike emergence, plant height at 90 days. Further the present findings exhibited that the estimate of PCV were magnitude higher than their corresponding GCV for all the character indicating the important role of environment the expression of characters. So that character would be more effective to improve the crop. High heritability was recorded for all the characters taken under study. High heritability coupled with high genetic advance observed number of spike per plant only indicating that the heritability is due to additive gene action and simple selection for these traits could be practiced for improving it. Corm yield per plant revealed positive and significant correlation with fresh weight of corm, number of leaves at 90, 60 and 30 days, flowering duration, number of spike per plant, width of longest leaf, length of longest leaf, stem girth, spike weight, plant height at 60 and 90 days, days to spike emergence, plant height at 30 days and floret diameter both at phenotypic and genotypic level. Path coefficient analysis revealed that plant height at 90 days and days to completely corm sprouting recorded the high direct effect on yield of corm along with highly significant correlation in the desirable direction towards corm yield indicated the true and perfect relationship between yield of corm yield and these characters suggesting direct selection based on the characters would help in selecting the high yielding genotypes in gladiolus. Mahalanobis (D2) static revealed considerable genetic diversity Among the five clusters, cluster I was the largest including 9 genotypes followed by cluster II had 6 genotypes, cluster III had 5 genotype, cluster IV had 4 genotype and cluster V had 1 genotypes each. Based on results obtained from the study it can be concluded in general that, there was parallelism between genetic and geographic diversity. The maximum intra-cluster distance was because of wide genetic diversity among its genotypes. The highest inter-cluster distance was revealed between cluster III and V. I clearly indicates that the genotypes are included in these clusters are having broad spectrum of genetic diversity and could very well be used in crossing program of gladiolus for improving the yield of corm. The least inter cluster distance was observed between clusters I and II. It is suggested that, crosses among the parents belonging to most divergent clusters would be expected to manifest maximum heterosis and also wide variability of genetic architecture.