Identification Of Stripe Rust Resistance In 95 Wheat Native Cultivars And Genetic Diversity Analysis Based On SSR Marker

Wheat stripe rust(yellow rust),caused by Puccinia striiformis West.f.sp.tritic is one of the most important diseases on wheat throughout the world.Planting resistant cultivars is the most effective and economical methods to control this disease.But resistant wheat cultivar gradually lost its resistance traits in several years because of the narrow genetic background.Genetic diversity is the fundamental element of biodiversity,including the genetic differentiation between populations in a species and the genetic variation among individuals within a population.Genetic diversity analysis is helpful for efficient utilization of the germplasm resources and genetic improvement.95 wheat cultivars and advanced lines were assessed for resistance stripe rust in adult stage by using five prevalent races(CY29,CY31,CY32,Su-1,Su-14).Genetic diversity was used to investigate by SSR marker.The main results are as follows:1.95 wheat cultivars were assessed for resistance stripe rust in adult stage by using race 31,race32 and mixed races(CY29,Su-1,Su-14),recorded infection type,severity,and incidence respectively.The results indicated that 15 cultivars were immune and nearly immune to CY31,73 cultivars were high resistance and moderate resistance,7 cultivars were medium susceptibility and high susceptibility.To CY32,16 cultivars were immune and nearly immune,71 cultivars were high resistance and moderate resistance,8 cultivars were medium susceptibility and high susceptibility.To mixed races,14 cultivars were immune and nearly immune,76cultivars were high resistance and moderate resistance,5 cultivars were medium susceptibility and high susceptibility.Overall evaluation of identification result by three times.9 cultivars were immunity,77 cultivars were resistance and 9 cultivars were infection.2.28 primers out of 108 SSR markers in genome A,B and D of wheat were used to investigate the genetic diversity of 95 wheat cultivars.The 28 primers are steady,high resolution and polymorphic amplification profiles.The results showed that 28 SSR primers produced 227 distinctive bands in total and 193 of them were polymorphic,accounted for 81.6%.Each primer amplified 2 to 15 polymorphic bands with the average of 6.9.The value of allelic polymorphism information content(PIC)ranged from 0.54 to 0.95 on an average of 0.80 per primer.The greatest PIC was prime wms124 and the smallest PIC was wmc491.3.The genetic similarity(GS)among 95 wheat Native Cultivars was calculated according to SSR data.The GS varied from 0.54 to 0.96 with an average of 0.75.The GS between wheat Xiaosanyuehuang and Honglaomai was the greatest(0.96),while the GS between wheat Daqingmang and Huzhuhong,Daqingmang and Wujiangzhuo,Mahuaban and Galaohan,Huoqiu and Zhahong,Huoqiu and Wujiangzhuo,Bailanghuimai and Shanmai,Bailanghuimai and Laotutou,Liuyuehuang and Baiqimai,Liu,vuehuang and Baiqitou were the smallest(0.54).The results indicated that lower genetic diversity and narrow genetic basis.Broaden the genetic basis become the main problem for plant breeding.4.The result showed that cultivars tested in GS 0.69 could be clustered into Three groups and ten subgroups.SGI was divided into 2 subtypes.The first subtype contained 3 cultivars such as Hongdongmai,Kashibaipi,Chushanbao;The second subtype contained 12 cultivars such as Geerhongmai,Dahuangpi,Zhahong.The SGâ…¡was divided into 3 subtypes.The first subtype contained 5 cultivars such as Daqingmang,Guangtou,Mahuaban;The second subtype contained 3 cultivars such as Laoqimai,Hongpixiaomai,Xiaobaimai;The third subtype contained 9 cultivars such as Dabaimai,Baimazha,Yizhimai.SGâ…¢was divided into 5 subtypes.The first subtype contained 18 cultivars such as Tumangmai,Baiqiumai,Qiangchangmai,The second subtype contained 15 cultivars such as Fumai,Honggoudou,Baibiansui;The third subtype contained 17 cultivars such as Meiqianwu,Wangshuibai,Huangshuibai;The forth subtype contained 11 cultivars such as Zhushimai,Kangdingxiaomai,Baimangmai;The fifth subtype contained 4 cultivars such as Chike,Dixiuzao.Shengen,Songruimai.This is partly accordance wih the previous classification.SSR markers can reveal more genetic variation among genotypes.