Early Heading Mutants of T. monococcum and Ae. squarrosa, A- and D-Genome Ancestral Species of Hexaploid Wheat.

Abstract

Two induced mutants for early heading in diploid species of Triticum monococcum and Aegilops squarrosa, A- and D-genome ancestral species common to common wheat, were analyzed for the genetic behavior of the heading trait. The T. monococcum mutant headed earlier than its wild type under the long-day condition with vernalization treatment, whereas the Ae. squarrosa mutant headed under the short-day condition without any difference from the long-day one. These results indicate that the former is a mutant for narrow-sense earliness, and the latter, for photoperiod sensitivity. Earliness of both mutants was found to be controlled by a recessive gene. These early-heading mutants could be useful sources for the breeding of heading earliness of common wheat, as well as for genetic analysis for the determination of heading time.