Effect of vernalization on flowering and true seed production behaviour of garlic (Allium sativum) under North Indian Plains

Abstract

The effect of vernalization on reproductive potential of garlic (Allium sativum L.) especially on flowering and its true seed production behaviour which includes bolting behaviour, scape colour, flower colour, bulbil colour, number of bulbils per umbel, scape length and number of seeds per umbel were studied under North Indian Plain conditions. The thirteen ‘seed producing’ garlic genotypes which produce true seed under USA (long day) conditions were used in the present study and were given vernalization treatment at 4oC for two months before sowing. In control treatment, garlic bulbs were kept at room temperature before sowing. The vernalization of garlic bulbs at 4oC (for two months) resulted in bolting, umbel formation and true seed production in nine genotypes, whereas non-vernalized did not result into bolting, i.e. no true seed production was observed. Out of nine true seed producing garlic genotypes, the maximum seed setting was observed in genotypes 5366, 5351 and 5477 having values of 20.0, 18.0 and 13.0 seeds per umbel. The seed received from these genotypes were further sown but they did not germinated. These genotypes can be used in breeding programme, if these are sown under long day conditions. The highly significant and positive correlation was observed between number of seeds per umbel and scape length (r= 0.99); significant and positive correlation for number of seeds per umbel and number of bulbils per umbel (r=0.58); significant and positive correlation for number of bulbils per umbel and scape length (r=0.61). It was and also observed that when vernalization treatment was given to the 13 different genotypes of the garlic; out of them, nine complete genotypes produce flowers and after bulbil removal process resulted in true seed production. True seed production in garlic has the practical significance as it generates genetic variation which can be exploited in garlic breeding.