Genetic Evaluation Of New Wheat Variety Chuanmai 42

1. A new wheat variety, Chuanmai 42 (99-1572) derived from synthetics (Triticum durum x Aegilops tauschii) was bred by Sichuan Academy of Agricultural Sciences. In Sichuan Provincial and national yield trials, the yield of Chuanmai 42 increase 46.50% and 16.3% in comparison with that of the control respectively. Chuanmai 42 not only set up a new record for the average yield of Sichuan yield trials, and the first variety which yield had exceeded 6t/hm² in two years, but also is the first official released variety which derived from synthetics {Triticum durum x Aegilops tauschii) in the world.2. Chuanmai 42 was highly resistant to Chinese newly predominant races of wheat stripe rust CYR32 at adult stage. To determine the inheritance of resistance in Chuanmai 42, it was crossed and backcrossed with the susceptible Sichuan varieties of common wheat MY26 and MY335 for preparing the F₂ and BCl populations. All of F₁ hybrids of such crosses were immune or highly resistant to the Chinese stripe rust races. The segregation of resistance in F₂ and BCl populations revealed that the resistance in Chuanmai 42 to CYR32 was controlled by a single dominant gene.3. Chuanmai 42 was analyzed on its biochemical character (i.e. glutenin, gliadin and esterase). The results showed that there were polymorphisms in biochemical characters comparing Chuanmai 42 with Chuanmai 107, and Chuanyu 12. Chuanmai 42 had 1, 6+8 and 2+12 HMW-subunits, Its quality grade was 7. 5. Gliadin alleles, including Gli-Ala, Gli-Alf, Gli-Dlk, Gli-A2a and Gli-D2r, were identified in Chuanmai 42. It was also found that 50% and 53.6% polymorphisms were existed between Chuanmai 42 and both Chuanmai 107 and Chuanyu 12, but there were not difference in esterase among all materials. The appearance of 6+8 subunit and some of the gliadin pattern were delivered from one of the Chuanmai 42parent Syn-CD768, a CIMMYT synthetic hexaploid wheat Altar84/Aegilops tauschii 188. The biochemical characters was gained in present experiment, and it may be a marker for variety recognition and protection.4. The genetic variations among new wheat cultivar Chuanmai 42 and Chuanmai 107 were analyzed by RAPD, STS and SSR markers. The two varieties could be distinguished by 3 molecular markers. Ten out of 69 (14.5%) and 20 DNA bands in RAPD analysis, 4 out of 60 primer-enzyme combinations (6.7%) in STS analysis, and 15 of 57 loci (26.3%) in SSR analysis revealed genetic differences. The genetic variation between Chuanmai 42 and Chuanmai 107 revealed by SSR markers mainly distributed in Band D genome which should be derived from one of the synthetic parent of Chuanmai 42.5. Chuanmai 42 was resistance to immunity from Chinese new stripe rust races, high quality variety, was the new breakthroughs of Sichuan wheat breeding. Chuanmai 42 is a heavy and number spike variety. Chuanmai 42 is a useful genetic resource for wheat production and breeding in Sichuan.