Analyses On Resistance Of Wheat Cultivars (Lines) To Wheat Stem Rust And On Function Of TaBRI1 And TaSugarX

Wheat stem rust caused by Puccinia graminis Pers.f.sp.tritici Eriks.& Henn.(Pgt),has been epidemic on a large scale in the world and caused devastating yield losses.After the 1970 s,this disease was controlled effectively,but still occurs on a small scale in some countries or regions.However,a new race Ug99(TTKSK)of Pgt with strong virulence appeared in Uganda(in 1999).And then mutated constantly and spread rapidly.So far 13 variants has appeared in 13 countries.In 2016,another new race of stem rust TTTTF has joint virulence to resistance genes Sr9e and Sr13,which were used commonly in durum wheat nearly 50 years in Sicily,Italy,putting the world wheat industry into threat again.Excavating resistance materials,analyzing the population dynamics and virulence structure of Pgt,and exploring resistance genes will be able to provide relevant theoretical support for wheat disease resistance breeding and disease control.Therefore,this study started from the analysis of virulence structure of main domestic Pgt races that has been identified in our laboratory in the early stage,analyzed the resistance of main wheat cultivars(lines)in China to Pgt.Furthermore,some potential resistance genes in the interaction between Pgt and wheat were identified using transcriptome data combined with virus induced gene silencing(VIGS).And innovative research results have been achieved.All dtails as follows:1.The effectiveness of 43 monogenic lines with known resistance genes to 7 races(21C3CTHQM,21C3CTHTM,21C3CFHQC,34MKGQM,34MKGSM,34C3MTGQM and 34C3RTGQM)of Pgt was analyzed and the resistance and susceptibility of monogenic lines to the tested races were clarified.At the same time,the virulence structure of the seven tested races was also determined,which laid the foundation for the rational distribution of resistance genes and resistance reaearch of wheat cultivars to stem rust in China.Thirteen tested monogenic lines: W2619Sr9e,CnS_T_mono_deri,Eagle,Bt S30 Wst,Sr31/6~*LMPG,Federation~*4/Kavkaz,RL5405,Mq(2)5XG2919,W2691 SrTt-1,W2691Sr37,Trident,DAS15 and Fed/SrTt3 showed resitance to all tested races in whole growing season.The 7 tested races were not virulent to the genes(Sr9e,Sr21,Sr26,Sr30,Sr31,Sr31,Sr33,Sr35,Sr36,Sr37,Sr38,Sr47 and SrTt3)contained in the above 13 monogenic lines.However,9 tested monogenic lines: ISr7b-Ra,ISr8a-Ra,ISr9a-Ra,W2691Sr9b,ISr9d-Ra,CnsSr9f,CnSr9g,ISr16-Ra and W2691Sr28 showed susceptibility to all races in whole growing season.The 7 tested races were virulent to the genes(Sr7b,Sr8a,Sr9a,Sr9b,Sr9d,Sr9f,Sr9g,Sr16 and Sr28)contained in the above 9 monogenic lines.21 tesed monogenic lines: ISr5-Ra,ISr6-Ra,W2691Sr10,ISr11-Ra,W2691Sr13,MQSr14,W2691Sr15,Combination ?,LCSr18,LCSr19,LCSr20,Sw Sr22 T.B.,Exhange,Lc Sr24 Ag,Agatha/9~*LMPG,73,214,3-1/9~*LMPG,Pusa4/Edel,Cns Sr32,Compare,RL6082 and Cns Sr Tmp showed resistance to one or more tested races.The 7 tested races were different virulence to the genes(Sr5,Sr6,Sr10,Sr11,Sr13,Sr14,Sr15,Sr17,Sr18,Sr19,Sr20,Sr22,Sr23,Sr24,Sr25,Sr27,Sr29,Sr32,Sr34,Sr39 and SrTmp)contained in the above 21 monogenic lines.2.The 7 Pgt races with known virulence structure were used for the resistance identification of 211 wheat cultivars(lines)collected from the Northeast Spring Wheat Region(areas where wheat stem rust occurs frequently),middle and lower Yangtze river basin and central winter wheat planting province(where wheat stem rust spreads and is prevalent in bridge area)against stem rust at seedling stage and adult stage,and the stem rust resistance of wheat cultivars(lines)was clarified,which provides a valuable support for the screening of stem rust resistance genes.The analysis results of 21C3 CTHTM,21C3CFHQC,34MKGQM,34MKGSM,34C3 RTGQM,and 34C3 MTGQM on 75 cultivars(lines)from Gansu showed that 38 of the wheat cultivars(lines)had significant seedling resistance to the tested wheat stem rust.The analysis results of 21C3CTHQM,34MKGQM and 34C3RTGQM on 136 of these was provided by researchers from Heilongjiang,Inner Mongolia,Shandong,Shanxi,Anhui,Jiangsu,Beijing and Ningxia Academy of Agricultural Sciences 123 of the wheat cultivars(lines)had significant resistance to the tested wheat stem rust,accounting for 90.4% of the tested materials in whole growing season.3.Based on the analysis of resistance to stem rust of wheat cultivars(lines)mentioned above,the known resistance genes contained in the 211 cultivars(lines)were detected using molecular markers linked with Sr2,Sr24,Sr25,Sr26,Sr31 and Sr38.Sr31 and Sr38 with resistance to Pgt in China and Sr2 and Sr25 with resistance to Ug99 were screened,having important guiding significance in the breeding of resistance to rust.The detail results of molecular marker screening showed that Sr2,Sr25,Sr31 and Sr38 were all distributed in Chinese wheat cultivars,among which 34 wheat cultivars(lines)contained gene Sr2,2 wheat cultivars(lines)contained Sr25,50 wheat cultivars(lines)contained Sr31,37 wheat cultivars(lines)contained Sr38,and no wheat cultivars(lines)containing Sr24 and Sr26 were found.4.Based on the previous transcriptome data of wheat stem rust and wheat(Little club,LC)interactions in the laboratory,significant differently expressed Brassinosteroid(BR)receptor gene Ta BRI1(Brassinosteroid insensitive 1),sugar transporter genes: TaSTP1(Sugar transporter 1),TaSugar C(Sucrose transporter C)and TaSugar X(Sucrose transporter X)from the transcriptome results were selected to for functional verification by BSMV virus induced gene silencing(VIGS)test.The results of the silenced wheat(LC)Tabri1,TaSTP1,TaSugar C and TaSugar X using race 34MKGQM showed that the silenced Tabri1 and TaSugar X had resistance to wheat stem rust,and the silenced TaSTP1 and TaSugar C had no obvious resistance to wheat stem rust.This study provides a theoretical basis for screening resistant genes to wheat stem rust.