Study On Characteristics Of Physiologic Race Of Wheat Stripe Rust In Gansu Province

The breakdown of the resistance of wheat cultivars was caused by the occurrence and development of new races of PST. Cansu Province is conducive to the disease and new races of the fungus were detected very frequently.As an obligate fungus, the race identification and the virulence analysis of PST were complicated and time consuming. Purificated and separated monospore strain of CY33,CY32,Su11-4, Su11-7 which collected from Gansu Province is to analysis inter-single spores'difference, and screened out comparatively ideal varieties as to add supplementary differential host provide evidence for epidemic forecast and further research of wheat stripe rust physiological races.The results are as follows:1. Thrity-five wheat stripe rust physiological races of CY33,CY32,Su11-4,Su11-7 were purificated and separatedwhich collected from different regions of Cansu Province,and analysised the inter-single spores'difference and variation.One handred eighteen samples were collected from Gansu province and identified hosts respectively, the result showed that there is great difference in single spores,thrity-one races and pathotypes were mainly detected.Hy pathotypes reached the frequency of about 26.3%,CY32 reached the frequency of about 7.6%;Su11 pathotypes reached the frequency of about 50.8%,CY33 reached the frequency of about 11.7%;CY33(F.R), Su11-4(F.R),Su11-4(F.R),CY32(F.R) pathotypes reached the frequency of about 6.8%,5.1%,4.3%,3.4% respectively,appearing individual rust physiological race had pathogenieity to Guinong22,T.spelta album,Zhong4.2. Though the research on the resistance to stripe rust of twenty predominant cultivars and wheat variety resources in nurseries period in Gansu province. Result shows that Longjian9343,Zhong4,92R137 and 92R178 displayed good resistance to both dominant pathotypes of Pst CY33 and CY32. Zhongliang17, Xiannong4 and Shi9511 have higher resistant,HY8 had weak pathogenieity to Tian94-3,which had strong toxieity to most of wheat varieties in production. CY33(F.R) had weak pathogenieity to 863-3,Yumai54;Yumai54 has high resistant for Shui11-7(F.R);but so susceptible to other pathotypes;all the wheat stripe rust physiological race had highest pathogenieity to wheat varieties Mianyang26, Longyuan31,Lantian13, Yumai21 and Lantian15;all the wheat stripe rust physiological race had higher pathogenieity to wheat varieties Tao157,Shi7816 and Yangmai5.3. The resistance to stripe rust of thrity-one Yr genes and twenty near-isogenic lines in nurseries period in Gansu province. Result shows that all the wheat stripe rust physiological race had no toxieity to wheat varieties Guinong775,P1178383,Mega and T.spelta album which are most of new lines and antigens,which is the a series of high resistant materials.Yr10/6*Avocet S,Yr18/3* Avocet S,Yr24/3*Avocet S,YrSk/3* Avocet S,Jupateco R(yr18) is the effective stripe- rust-resistant genes.Yr7/6*Avocet S,Yr11/3*Avocet S,Yr12/3*Avocet S,Yr17/6* Avocet S represented susceptable to all pathotypes in the nurseries plantstage,both CY33(F.R),CY32(F.R) pathotypes,so VYr-7,VYr-11,VYr-12,VYr-17 is the virulent- gene of the all pathotypes.4. According to response of pathotype of wheat stripe rust in predominant cultivars,wheat cultivars(lines), wheat variety resourees,Yr genes,Near-isogenie lines,the cultivar which can be differential host initially were analyzed.The results showed that Shi9511,863-13,Tian94-3, Yumai54,Xiannong4,YrSp/6*Avocet S and Yr15/6* Avocet S can be the potentially differential host initially,but as potentially differential host still need to verified.Yr18/3*Avocet S,Yr24/3*Avocet S,YrSk/3* Avocet S,Yr10/6*Avocet S,Jupateco R(yr18) still resistence,can be the accessorial differeltial cultivars to monitor and forecast the new physiological races.The best way to monitor The physiological race is that genes survey instead of tradition survey, which have significance detection for solving resistance loss and breeding strategies.