GENETIC CONTROL OF VARIATION IN A SELECTED POPULATION OF RUSSIAN WILD RYEGRASS (ELYMUS JUNCEUS)

Abstract

Progenies from a five-genotype diallel cross in Russian wild ryegrass, Elymus junceus Fisch., were studied to assess the pattern of genetic control for F1 seed weight and a number of seedling and adult plant characters. Variation in F1 seed weight was largely determined by the maternal parent, but some control by the pollen parent was apparent. Of the seedling characters, days to emerge, rate of leaf appearance, rate of tiller appearance, and seedling dry matter yield, only days to emerge showed additive variance which is amenable to direct selection. The other three characters could be most easily exploited by a recurrent selection program. The adult plant characters, date of inflorescence appearance, P content of the forage, and organic matter digestibility indicated strong additive control which is amenable to direct selection. Dry matter yield and seed yield also showed strong additive control which was accompanied by specific combining ability and weak maternal effects suggesting good progress should be possible by direct selection methods but crossing the selections in a diallel fashion prior to formation of synthetics might be desirable. The seedling characters, rate of leaf and tiller appearance and seedling dry matter yield were interrelated and associated with adult plant yield, thus offering the possibility of screening seedlings for these characters in a recurrent selection program for improved forage or seed yield.