Genetic variability, correlation and path analysis study in storage life of onion (Allium cepa L.)

Abstract

The present study was under taken in onion (Allium cepa L.) to find the interrelationship of attributes studied towards post harvest losses and their direct and indirect effect of attributes towards, percentage of total losses, losses due to rotting, sprouting losses, percentage of reducing, non-preducing and total sugars coupled with a quantitative attributes viz., bulb weight, equatorial and polar diameter and 1.8.8. Data were subjected to analysis of variance, variability pattern, association among the attributes and path coefficient analysis. The bulbs of all the genotypes were kept in storage by using plastic crates in two replications. These crates were stored at ambient temperature in the well-ventilated onion storage structure. Observations on stored bulbs were recorded at 60 days intervals for the storage losses, due to rotting, sprouting, physiological loss in weight (PLW) and total losses. At each observation rotted and sprouted bulbs were discarded after recording the weight. Estimates of components of variance, heritability in broad sense, genetic advance for 13 storage attributes of 22 onion genotypes are presented in Table 1. The results indicated that in general PCV value is higher than GCV values for characters percentage of total losses, rotting losses, bulb weight, dry matter of bulb, reducing sugars and marketable yield indicated that these attributes have reacted with the environment present in the storage structure. Heritability in broad sense ranged from 1.59 (percent dry matter of bulb) to 98.27 (percent sprouting losses), high heritability coupled with high genetic advance have recorded for sprouting losses (%) (98.27 and 19.83), followed by percentage of rotting losses (93.83 and 20.84) and total losses (56.15/10.65) (Table 2). However, the high heritability was also recorded in total sugar (%), non-reducing sugars (%), marketable yield, polar bulb diameter, 1.8.8 and physical loss in weight but with very low genetic advance.