Study on genetic parameters in garlic (Allium sativum L.) for yield and quality traits

Garlic is an important vegetable crop grown widely throughout the world for its medicinal values and health benefits. Garlic helps to prevent and reduce the severity of common illnesses like the flu and common cold, improves blood pressure and reduces the cholesterol. The present study was undertaken to assess the genetic variability, to determine the correlation of bulb yield and its contributing components and to identify those components with significant effects on yield and using them as selection criteria. The genetic parameters of variability were estimated, comprising thirty-six genotypes in garlic at the Research Farm of Vegetable Science, UHF, Nauni, Solan, HP during the Rabi season, 2014-15 and 2015-16. Phenotypic and genotypic coefficients of variation were higher for weight of 100 peeled cloves (35.09 % and 31.07 %), bulb yield per plot (34.87 % and 33.19 %), bulb yield per hectare (34.87 % and 33.19 %), clove weight (34.50 % and 30.83 %), weight of 100 unpeeled cloves (34.22 % and 30.07 %), oleoresin content (32.69 % and 31.79 %), bulb weight (30.65 % and 30.01 %) and the number of bulbs per kg (30.21 % and 30.01 %) indicating further scope of improvement and facilitating the selection for these characters. High heritability was recorded for the characters viz., peeling index (99 %), the number of bulbs per kg (96 %), oleoresin content (95 %), bulb weight (94 %), the number of leaves per plant (92 %), bulb yield per plot (91 %), bulb yield per hectare (91 %), the number of cloves per bulb (90 %), drying percentage (86 %), neck thickness (84 %), clove length (84 %), bulb breadth (83 %), plant height (82 %) and clove weight (80 %). High genetic gain was recorded for characters viz., bulb yield per plot (65.07 %), bulb yield per hectare (65.07 %), oleoresin content (63.70%), the number of bulbs per kg (59.68 %), bulb weight (59.36 %), clove weight (56.76 %), weight of 100 peeled cloves (56.68 %), weight of 100 unpeeled cloves (52.19 %) and the number of cloves per bulb (50.04 %). An idea about interrelationships of bulb yield and its components is very helpful to improve the efficiency of breeding program using appropriate selection indices. Yield per plot was positively and significantly associated with plant height (0.445 and 0.492), the number of leaves per plant (0.381 and 0.407), days to maturity (0.497 and 0.641), neck thickness (0.375 and 0.409), bulb weight (0.966 and 1.00), bulb breadth (0.808 and 0.898), bulb length (0.852 and 0.984), clove weight (0.865 and 0.936), clove breadth (0.726 and 0.787), clove length (0.734 and 0.799), weight of 100 unpeeled cloves (0.800 and 0.873) and weight of 100 peeled cloves (0.796 and 0.861) whereas, negatively and significantly with the number of cloves per bulb (-0.448 and -0.473), the number of bulbs per kg (-0.921 and -0.960) and drying percentage (-0.374 and -0.404). Path coefficient analysis revealed a high positive and direct effect of bulb weight (2.018) on bulb yield per plot followed by weight of 100 unpeeled cloves (0.641), the number of bulbs per kg (0.309), days to maturity (0.154), peeling index (0.139), plant height (0.118), drying percentage (0.115), clove breadth (0.094), neck thickness (0.054), clove weight (0.049) and the number of leaves per plant (0.042)