Structural Changes Of Chromosomes 2V, 4V And 6V Of Haynaldia Villosa Induced By Chromosome 3C Of Aegilops Triuncialis

Haynaldia viIlosa (2n=2X=14, VV), a close relative of wheat, played important roles in wheat improvement mainly due to its disease resistance and high protein genes. Powdery mildew resistance gene Pm21 mapped on 6VS of Haynaldia villosa had been successfully transferred into wheat by Cytogenetics Institute, Nanjing Agricultural University, China and widely used in current wheat breeding programs in China. To further transfer, fine map and utilize the beneficial genes mapped on 2V, 4V and 6V of Haynaldia villosa, gamatocidal chromosome 3C ofAegilops triunciaIis added in Norin26 was selected and crossed to the wheat- H. viUosa DS2V(2D), DA4V and DS6V(6A) and hybrids F₁ were then self pollinated. Chromosome C-banding, genomic in situ hybridization (GISH), meiotic analysis combined with molecular markers were applied to detect the chromosome variations derived from hybrids F₂ and F₃ of these crosses. The results were as the following. For chromosome 2V, total 7 lines with structural changes including one small segmental translocation T6BS-6BL-2VS, two Robertsonian translocations (preliminarily designed as T3DS·2VLand T2VS·7DL), one intercalary translocation T2VS·2VL-W-2VL, one deletion Del 2VS·2VL-, one monotelosomic Mt2VS and one iso-arm chromosome 2VS·2VS lines were developed. Wheat SSR marker Xwmc25-120 tagging 2VS and STS marker NAU/STSBCD135-1(2BL) tagging 2VL were used to confirm the alien chromatins involved in the seven lines. Three lines T2VS·7DL, Mt2VS and 2VS.2VS showed the tufted bristles on the glume ridge like the donor DS2V (2D), while T3DS·2VL without this trait, therefore, genes controlling the tufted bristles might be mapped on 2VS. For chromosome 4V, total 7 lines with structural changes including 4 homozygous translocations and 3 lines involved monotelosomic 4VL were developed. Of them, T4VS·4VL-4AL was a kind of complementary translocation induced by gametocidal chromosome. Its breakage point was mapped between marker Xgwm637and Xpsr115. This line also showed high resistance to WSSMV and might be a new germplasm for wheat improvement.The other translocations were T4VL·5AL, T4VS.6AL and T4VS·W?, respectively.For chromosome 6V, one new homozygous deletion line with sensitivity to powdery mildew and one homozygous translocation T6VS.4AL with high resistance were developed. Analysis of four melecular markers (CINAU15, NAU/xibaol6, 6VS-381, CINAU18-723) loacated on 6VS and one melecular marker 6VL-358 on 6VL confirmed that Del.6VS-2 was a new terminal deletion and the breakpoint was between marker CINAU15 and NAU/xibaol6. Powdery mildew test combined marker analysis on Del.6VS-2 and Del.6VS-1 indicated that the powdery mildew resistance gene Pm21 might be located between FL0.58 and melecular marker NAU/xibaol6, which provided important information for isolating of this gene.