Theme 12: Forage Breeding and Genetics

Description

The genetic variation and genotype by environment interaction of crown rust resistance of annual ryegrass (Lolium multiflorum Lam.) was evaluated at two locations in Argentina, as part of the breeding programme in progress at our Institute. Forty half sib families originated from commercial tetraploid cultivars, were grown from seeds in a greenhouse during autumn 1999. At the stage of tillering initiation forty eight plants/familiy were randomly selected and transplanted as spaced plant trial in a randomized design with three replicates, at the two locations. All plants were scored for a range of morphological and phytopatological attributes. The severity of crown rust and the winter dry matter production were assessed on each plant. Crown rust resistance at both evaluation dates, was highly heritable and not affected by environment interaction. By contrast, winter dry matter showed a large family by location interaction and a high environmental influence. The results of the present study indicated that important progress in crown rust resistance in annual ryegrass can be achieved through phenotypic recurrent selection.

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Genetic Variation and Genotype by Environment Interaction of Crown Rust Resistance in Annual Ryegrass (Lolium multiflorum Lam.)

The genetic variation and genotype by environment interaction of crown rust resistance of annual ryegrass (Lolium multiflorum Lam.) was evaluated at two locations in Argentina, as part of the breeding programme in progress at our Institute. Forty half sib families originated from commercial tetraploid cultivars, were grown from seeds in a greenhouse during autumn 1999. At the stage of tillering initiation forty eight plants/familiy were randomly selected and transplanted as spaced plant trial in a randomized design with three replicates, at the two locations. All plants were scored for a range of morphological and phytopatological attributes. The severity of crown rust and the winter dry matter production were assessed on each plant. Crown rust resistance at both evaluation dates, was highly heritable and not affected by environment interaction. By contrast, winter dry matter showed a large family by location interaction and a high environmental influence. The results of the present study indicated that important progress in crown rust resistance in annual ryegrass can be achieved through phenotypic recurrent selection.