Genetic variability and correlation studies on vegetative and floral characters of gladiolus (Gladiolus grandiflorus)

The study was undertaken on genetic variability and correlation of vegetative and floral characters of gladiolus (Gladiolus grandiflorus) during November 2011 to June 2013. Ten varieties, Jester, Candyman, Poppy Tears, Summer Sunshine, Wedding Bouquet, Hunting Song, Pacifica, American Beauty, Red Ginger and White Prosperity, were evaluated. The variation was high for spike length (89.67–109.83), followed by days taken for spike emergence after sprouting (60.00–89.00) and plant height (53.47–71.20 cm). Highest phenotypic and genotypic variances were observed for fresh weight of spike (234.87 and 213.78), respectively. The estimates of phenotypic coefficient of variation were higher than genotypic coefficient of variation for all the traits. Maximum phenotypic coefficient of variation and heritability were observed for cormel weight (43.32 and 96.90%). Genotypic coefficient of variance showed variation from 3.77 to 42.64 for diameter of second floret and cormel weight, respectively. However, maximum genetic advance was observed in fresh weight of spike (28.74). The high heritability was associated with high genetic advance of mean for cormel weight, indicating the possible role of additive gene action. The magnitude of genotypic correlation was higher than their corresponding phenotypic correlation for most of the traits, indicating a strong inherent linkage between various traits. At genotypic level, days for sprouting of corms exhibited highly significant and positive correlation with number of florets/spike, fresh weight of spike and vase-life but significant and positive correlation with fresh weight of spike at phenotypic level.