Generation mean analysis of inheritance of insensitivity to ozone injury in two crosses of beans(Phaseolus vulgarisL.)

Abstract

The inheritance of bean (Phaseolus vulgaris L.) foliar insensitivity to ozone (03) was studied using generation mean analyses (GMA) as the genetic design. The following GMAs were evaluated: ‘Bush Blue Lake (BBL) 290’ x PI 304833, and ‘BBL 254’ x PI 300657. The six populations (P,, P2, F,, F2, F, x P,, and F, x P2) comprising a GMA from each cross were planted in 15 cm plastic pots as a randomized complete block design with three replications. When unifoliate leaves were about two-third expanded and maximally sensitive to 03 they were fumigated with non-filtered ambient (NF) + 0.06 ppm 03 concentration in open top field-fumigation chambers. Data on percent leaf 03 injury were recorded. The mean rated values of the incidence of O, injury in the F, generation were lower than the mid-parent values in both crosses, suggesting that insensitivity may be dominant over sensitivity. A genetic model with additive-dominance effects was fitted to generation means in ‘BBL 290’ x PI 304833, and ‘BBL 254’ x PI 300657 and...