Hybrid plants between Triticum aestivum var.“Chinese Spring”(CS), its ph1b mutant (CS ph1b ) and Haynaldia villosa were obtained by immature embryo culture. After selfing, the two types of hybrids showed seed settin...Hybrid plants between Triticum aestivum var.“Chinese Spring”(CS), its ph1b mutant (CS ph1b ) and Haynaldia villosa were obtained by immature embryo culture. After selfing, the two types of hybrids showed seed setting rates of 6.67% and 6.25%, respectively. The analysis of chromosome pairing behaviors at meiotic metaphase I showed that, on the average, only 1.61 chromosomes could form bivalent and trivalent in each PMC of the hybrid F 1 CS× H. Villosa , with the configuration 2 n =28=26.39I+0.79II+0.007III. However, in the hybrid F 1 CS ph1b×H. Villosa, 14.43 chromosomes per PMC were involved in bivalent and multivalent formation, with the chromosome configuration of 2 n =28=13.55I+5.95II+0.55III=0.22IV, and, in over 56% of the PMCs, 1 4 multivalents (trivalents and quadrivalents) were produced. The observation of meiotic chromosome pairing by using genomic fluorescent in situ hybridization (GISH) revealed three types of chromosomal associations: wheat wheat, wheat H. villosa and H. villosa H. villosa in PMCs for ‘ CS ph1b×H.villosa ’F 1 hybrid. The seed set of the backcross of the‘ CS ph1b×H.villosa ’F 1 with CS was 6.67% and that of‘ CS×H.villosa ’F 1 with CS or CS ph1b was only 0.45%. The chromosome number of BC 1 plants varied from 48 to 72. Robertsonian translocation chromosomes consisting of chromosome arms from wheat and H.villosa were detected by mitosis GISH in the BC1 plants from the backcross of‘ CSph1b×H.villosa’ to CS ph1b . These results led to the conclusion that the ph1b gene induced a higher level of homoeologous chromosome pairing between common wheat and H.villosa. The transfer of desirable genes from H.villosa to common wheat may be facilitated by using the ph1b gene.展开更多
文摘Hybrid plants between Triticum aestivum var.“Chinese Spring”(CS), its ph1b mutant (CS ph1b ) and Haynaldia villosa were obtained by immature embryo culture. After selfing, the two types of hybrids showed seed setting rates of 6.67% and 6.25%, respectively. The analysis of chromosome pairing behaviors at meiotic metaphase I showed that, on the average, only 1.61 chromosomes could form bivalent and trivalent in each PMC of the hybrid F 1 CS× H. Villosa , with the configuration 2 n =28=26.39I+0.79II+0.007III. However, in the hybrid F 1 CS ph1b×H. Villosa, 14.43 chromosomes per PMC were involved in bivalent and multivalent formation, with the chromosome configuration of 2 n =28=13.55I+5.95II+0.55III=0.22IV, and, in over 56% of the PMCs, 1 4 multivalents (trivalents and quadrivalents) were produced. The observation of meiotic chromosome pairing by using genomic fluorescent in situ hybridization (GISH) revealed three types of chromosomal associations: wheat wheat, wheat H. villosa and H. villosa H. villosa in PMCs for ‘ CS ph1b×H.villosa ’F 1 hybrid. The seed set of the backcross of the‘ CS ph1b×H.villosa ’F 1 with CS was 6.67% and that of‘ CS×H.villosa ’F 1 with CS or CS ph1b was only 0.45%. The chromosome number of BC 1 plants varied from 48 to 72. Robertsonian translocation chromosomes consisting of chromosome arms from wheat and H.villosa were detected by mitosis GISH in the BC1 plants from the backcross of‘ CSph1b×H.villosa’ to CS ph1b . These results led to the conclusion that the ph1b gene induced a higher level of homoeologous chromosome pairing between common wheat and H.villosa. The transfer of desirable genes from H.villosa to common wheat may be facilitated by using the ph1b gene.
