EFFECT OF HOMOEOLOGOUS PAIRING PH 1- LOCUS OF TRITICUM AESTIVUM L. ON ITS F_1 - BRIDGE HYBRIDS WITH THE SPECIES (2X, 4X, 6X) TRITICUML., (2X, 4X) AEGILOPS L., AND (2X, 4X) LOLIUML. GENERA

摘要

Mono-SB Chinese Spring, mono-5B Jara, mono -5B Favorit exhibiting the deficiency of 5B-chromosome, the mutant-Ph Chinese Spring (ph1b, ph1b), mono-5A Chinese Spring, mopno-5D Chinese Spring with the genotype Ph1, Ph1 and the varieties Chinese Spring,Jara, Favorit with the genotype Ph1 Ph1 were used in the crosses with 7 species of Triticwn, 5 species of Aegilops and one species of Lolium genera to investigate the effect of the Ph1- locus on F_1 - bridge hybrids. Altogether, 117 cross-combinations were made and 98 259 florets were pollinated. The effectiveness of the locus Ph 1 was judged by the percentage of seed set of F_1- bridge hybrids. Wide variation of seed set was observed in F_1-bridge hybrids for all cross-combinations made. The deficiencyof 5B chromosome exhibited higher effectiveness (10.7% - 4. 2%) than the recessive gene ph1b (3.2%). Out of the monosomics of 5B-chromosome, mono-5B Chinese Spring exhibited the stronger effectiveness on seed set of F_1- bridge hybrids (10.7%) probablydue to the presence of the recessive crossability genes. Among the sources of the genotype Ph1 Ph1, mono-5A, -5D of the variety Chinese Spring showed higher percentage of seed set (2.4% and 1.9%), respectively than the disomic varieties Chinese Spring, Jara and Favorit (0.8%, 0.4% and 0.4%, respectively. Of the related species, three genotypes were identified as highly effective: T. monococcum L., T. dicoccoides Korn., and Ae. speltoides Taush. for obtaining the high fertile F_1 -bridge hybrids and complementary to the deficiency of 5B-chromosome and the recessive gene phlb.