Adaptation to heterogeneous environments. III.* The inheritance of response to spacing in flax and linseed (Linum usitatissimum)

Abstract

Random F+3 families from two crosses of varieties of Linum usitatissimum were grown at two spacings and the following determined: (a) the characteristics of the families at each spacing; (b) the response of these characteristics to spacing, measured as the value at wide spacing divided by the value at close spacing.

There were significant differences between the families for the characters at each spacing and for their responses. The heritability values for response, calculated from between-family variances, were significant and relatively high for all characters measured.

There was no clear effect of spacing on genetic correlation between the characters, but low genetic correlations between the same character in the two spacings showed that high heritabilities in two spacings may be achieved by independent gene action. Genetic correlations between response characters were character and cross-dependent: there was no evidence of general stability of the genotypes.

A separate experiment showed that there was no evidence for the induction of heritable changes by the application of different spacing treatments in the previous generation.

_________________ *Part II, Aust. J. Agric. Res., 27: 519 (1976).