GrainGenes

II. 45 Effects of the very early gene, ea_k, on yield and its components in barley.

S. Yasuda. The Ohara Institute for Agricultural Biology, Okayama Univ., Kurashiki 710, JAPAN.

Takahashi and Yasuda (1970) and Yasuda (1977) have shown that very early gene, mat-a⁸ of X-ray induced mutant Mari is allelic to the gene ea_k in a Japanese two-rowed cultivar Kinai 5. In this experiment, the effects of the early genes from Kinai 5 and Mari on yield and its components were studied in the same genetic background. In order to introduce two different earliness genes each from Kinai 5 and Mari into late cultivars, Bonus and Tochigi Golden, the former two varieties were each backcrossed five times with the latter two late varieties. Four early lines thus obtained and their recurrent parents were sown in a field in fall with three replications, and reared under conventional cultural method.

As shown in Fig. 1, the effects of the ea_k on various characters did not differ with their origins. However, the early lines were 17 or more days earlier in heading time, and significantly less in culm length, ear-length, number of grains per ear and grain yield per unit area than those of the recurrent parents. Furthermore, the early lines were always longer in their rachis internodes, and more in number of ears per unit area only in the genetic background of Bonus. No effects of the earliness genes are recognized on weight of 1000 kernels, however. From these results, it will be concluded that in spite of the slight increase in number of ears per unit area, the grain yield of the early lines are decreased considerably, without exceptions, which is doubtless due to the marked decrease of the number of grains per ear.

Fig. 1. Relative values of differences between the early lines and their recurrent parents

References:

Takahashi, R. and S. Yashuda. 1970. Barley Genetics II 388-408.

Yasuda, S. 1977. Ber. Ohara Inst. landw. Biol. Okayama Univ. 17:15-28.

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