Nucleo-cytoplasmic interactions can be studied by substituting the genome of one species into the cytoplasm of another related species by backcrossing. Kihara and Fukasawa reported the induction of cytoplasmic male sterility in Triticum by Ae. caudata and by Ae. ovata cytoplasms, respectively. Several additional cytoplasmic male sterility systems have been reported in Triticum. Several workers have suggested that a knowledge "of cytoplasmic differences among the Triticum and Aeyilops species may provide information regarding the donor of B-genome and cytoplasm to the emmer and common wheats. Because T. durum and T. aestivum plants with the cytoplasm from the A-genome donor (T. boeoticum or T. monococcum) had male sterility and highly reduced plant vigor, the assumption was made that only the B-genome donor could have contributed cytoplasm to the emmer and common wheats. Suemoto provided some preliminary data suggesting Ae. speltoides contributed cytoplasm to T. turgidum (emmer wheats) and common wheats. In this paper, we report the nucleo-cytoplasmic interactions between the cytoplasms of Ae. speltoides, amphidiploid Ae. bicornis (female)-T1. boeoticum (male) and Ae. squarrosa and the genomes of T. durum or T. aestivum. Also, we report the development of male-sterile A-lines of T. aestivum and T. durum and a male-fertile R-line of common wheat in Ae. speltoides cytoplasm. (An A-line has cytoplasmic male sterility; an R-line has a gene or genes that restore male fertility to an A-line; a B-line is a fertile counterpart of an A-line, and is used as a pollen parent to maintain the A-line.)

Text in English

Oxford

Reprints Collection