Improvement Of Translocation Lines With Small Ha Haynaldia Villosa Chromosome Fragment Carrying PM21Gene Resistante To Powdery Mildew

Haynaldia villosa L.(syn. Dasypyrum villosum L.,2n=14, VV) is an annual cross-pollinated herb, a wild relative of common wheat and native to the Mediterranean coast and the Caucasus. It has the resistance to powdery mildew, rusts, eyespot, wheat streak mosaic virus and other diseases, meanwhile with more spikelets, frost and drought tolerance, high grain protein content. Through the wide hybridization between wheat and Haynaldia villosa and chromosome manipulation, the amphiploid, alien addition, substitution and translocation lines have been developed and contributed to wheat genetic improvement. Alien addition and substitution lines usually carry a complete chromosome, which is accompanied by undesirable agronomical traits, making them hard to be used in breeding. At the present time, small alien fragment lines carrying target genes will be the most valued materials in breeding.A terminal translocation line nj-1and a small interstitial translocation line nj-2carring the powdery mildew resistance gene Pm21were developed by Cytogenetic Institution, Nanjing Agricultural University, showed high resistance to powdery mildew. Athough nj-1and nj-2are small fragment translocations with high resistance to powdery mildew, but still cannot be directly used by breeders. On the one hand, these two translocation lines were poor on economical traits; on the other hand, they could not be used as hybrid parent directly for not adapting to different ecological wheat growing regions. In order to improvement of their agronomical traits, these small alien fragment translocation lines were crossed and backcrossed to main publized wheat varieties from different ecological areas (Yangmai158, Yangmai20, Zhen02166, Zhou9823, Cheng9023and Zheng9694).71heterozygous and19homozygous plants with small alien fragment chromosome carring the Pm21gene identified by using mitotic and meiotic chromosome GISH, powdery mildew evaluation and PCR analysis using the primer CINAU15-902, which specific to Pm21.Their characters of agronomical traits, such as stem length, number of effective ears, ear length, number of spikelets, number of effective spikelets and grain number per ear were surveyed and compaired with their parents.