Genetic variability studies for yield attributes and resistance to foliar diseases in groundnut (arachis hypogaea l.).

Twenty eight F2 populations (crossed in an 8 × 8 diallel fashion without reciprocals) of groundnut were evaluated in randomized block design with three replications for variability, heritability and genetic advance during rabi 2009-10. Observations on sixteen characters were recorded. Analysis of variance revealed highly significant differences among the genotypes for all the characters except number of mature pods per plant and pod yield per plant. High GCV accompanied by high heritability and high GAM were obtained for percentage of leaves affected by foliar diseases per plant and number of immature pods per plant indicating predominant role of additive gene action and amenability for phenotypic selection in early generations. For late leaf spot and rust severities and harvest index moderate GCV and high heritability and GAM was observed. Moderate GCV, heritability and GAM were registered for plant height at harvest, number of primary branches per plant, number of leaves per plant at harvest, number of mature pods per plant, kernel weight per plant indicating that additive and non-additive gene actions have a role in their inheritance and phenotypic selection would be effective to some extent. For days to 50% flowering and days to maturity, GCV was low, heritability was high and GAM was low. For sound mature kernel percentage and shelling out-turn all the genetic parameters were low indicating larger role of non-additive gene action and selection would be effective in later segregating generations.

Inhibition of Aspergillus flavus colonization and aflatoxin (AfB1) in peanut by methyleugenol.

Methyleugenol is naturally occurring substance in oils and fruits and in various foods as flavoring agent. Effect of this methyleugenol in inhibiting A. flavus colonization and aflatoxin production on peanut pods and kernels has been studied. Spray of methyleugenol (0.5%) on peanut pods and kernels checked the colonization of A. flavus and aflatoxin synthesis. This chemical can be used as both prophylactic or post infection spray on peanut pods before storage. It is the first report on the inhibition of A. flavus by methyleugenol on peanut.