Heritability Studies of Late Leaf Spot Resistance in Valentia Type Groundnut Varieties.

The knowledge about heritability and genetic advance in the breeding material is necessary to decide on a breeding procedure to be chosen and determining effectiveness of selection. The objective of this study was to estimate heritability and genetic advance for late leaf spot resistance (LLS). Breeding materials including F₁, F₂, and backcrosses to susceptible BC₁P₁ and resistant parents BC₁P₂ along with their respective parental lines of crosses between M₃ × ICGV-SM 02501, Valencia C × ICGV-SM 02501 and Redbeauty × ICGV-SM 03590 were evaluated in CRD with three replications at the experimental field of National Semi-Arid Resources Research Institute (NaSARRI) of the National Agricultural Research Organization (NARO). Spreader row technique was used to maximize leaf spot inoculum pressure under natural conditions and late leaf spot severity was assessed using a modified nine point scale (1-9). Broad-sense heritability and genetic advance estimates for LLS disease score were moderate in Redbeauty × ICGV-SM 03590 and Valencia C × ICGV-SM 02501, and high in M3 × ICGV-SM 02501, while narrow-sense heritability estimates were low in Redbeauty × ICGV-SM 03590 and Valencia C × ICGV-SM 02501 and high in M3 × ICGV-SM 02501 cross. The results suggest that the best strategy for obtaining LLS resistant genotypes is selection of the disease score trait in advanced generations (F3 or F4) for the Cross between M3× ICGV-SM 02501, followed by selection in the following generations with higher endogamy levels in other crosses.