Application Of Wheat-Haynaldia Villosa Translocation Line T6VS·6AL And Pm21 Gene In Breeding

Common wheat is a widely cultivated food crop in the world.Wheat powdery mildew is a fungal disease caused by the infection of Blumeria graminis f.sp.tritici.Currently wheat powdery mildew is one of the most serious diseases in the world,which seriously affects wheat yelid.Therefore,discovering effective powdery mildew resistance genes and development of powdery mildew resistant wheat varieties are the most effective measures to control wheat powdery mildew.In the previous study of our laboratory,the wheat-Haynaldia villosa translocation line T6VS·6AL containing the broad-spectrum powdery mildew resistance gene Pm21 was developed,which is an important parent for domestic wheat powdery mildew resistance breeding.Previous studies showed that the wheat varieties carrying 6VS were more distributed in the southwest and northwest wheat areas,but the application status in Jiangsu Province was not investigated.This study collected some wheat lines/varieties in and outside Jiangsu Province,conducted resistance phenotype identification and molecular marker identification,and analyzed the application frequency and resistance stability of 6VS,which can provide valuable information for the reasonable distribution of the gene in production.When investigating the agronomic traits of the research materials,it was found that the materials carrying 6VS often showed the characteristics of long spikes,darker leaf color and other traits related to the high efficient use of nitrogen.In this study,we analyzed the 6VS genome sequence and found some genes related to nitrogen metabolism on the 6VS chromosome arm.At the same time,a pair of near isogenic lines were used to detect the response of materials carrying 6VS to low nitrogen stress.In this study,we also created a series of germplasm resources resistant to various diseases and new transgenic germplasm carrying Pm21 around the needs of conventional breeding and molecular breeding of Pm21,which includes the phyrameding of Pm21 and Fhb1,and the transformation of Pm21.1.Study on the application status of wheat-Haynaldia villosa translocation line T6VS·6AL in some developed varieties or linesPhenotype evaluation of powdery mildew resistance and analysis of the 6VS specific molecular markers was conducted on 275 test materials collected from Jiangsu Province and 28 materials collected from other areas.The results showed that 28 materials were resistant to powdery mildew and were detected to contain 6VS-specific bands among 28 materials from six breeding institutes.As to the 275 materials collected from Jiangsu Province,52 lines were detected to contain 6VS-specific bands.So,this result showed that 19%of the current tested lines in Jiangsu Province used T6VS·6AL in the breeding program.2.Discovery of genes related to nitrogen using efficiency on 6VS and its impact on nitrogen use efficiencyNitrogen is a component of important substances in plants,and is the most important nutrient factor for crop growth and yield formation.The wheat-Haynaldia villosa translocation line T6VS·6AL has the characteristics of long spikes and darker leaf color.This study explored the genes related to nitrogen utilization on 6VS and found that there is a family of nitrogen transport genes（NRT）with multiple members.In this study,the resistant material and susceptible material selected from the backcross population of T6VS·6AL/Yangmai 1588 were used as near-isogenic lines to evaluate the nitrogen utilization efficiency between 6VS-containing plants and 6VS-lacking plants.Under high nitrogen and low nitrogen treatment,two types of materials were compared as to the leaf color,plant height,root length,seedling fresh weight and root fresh weight.The result showed that the 6VS-carrying material has a certain tolerance to low nitrogen and the growth of the aerial parts is less affected.3.Creation of germplasm resources carrying Pm21 genePowdery mildew and Fusarium Head Blight are two important diseases of wheat.In wheat breeding,the resistance to two diseases should be taken into consideration.The’92R’ germplasms created and widely used in our laboratory carried powdery mildew resistance genes but did not carry the Fusarium Head Blight resistance genes.In order to create germplasm resources that are suitable for multiple wheat production areas and resistant to multiple diseases,the researchers of our laboratory crossed materials containing the Pm21 gene and Fhb1 gene and then used multiple main varieties for recrossing.In this study,a large number of germplasms created by the laboratory were used to identify powdery mildew and Fusarium Head Blight resistance.At the same time,these materials were subjected to molecular marker identification,Totally,21 germplasm resources showed resistance both to Fusarium Head Blight and powdery mildew were created,which provides valuable germplasm resources for breeding.Compared with traditional breeding program,genetic engineering has the advantages of high efficiency and precision.The Pm21 gene has been cloned and we can use transgenic technology to introduce Pm21 gene into more genetic backgrounds,therefore we can promote its application by genetic engineering.However,transgenic technology based on tissue culture is greatly affected by genotype,which limits the application of target genes in different genetic backgrounds.This study introduced the Agrobacterium coleoptile injection method.Using Nannong 06Y86 and GV3101 Agrobacterium strain as the material,it was found that gene could be transiently transformed when the coleoptile length ranging from 0.5 to 0.7cm and the concentration of Agrobacterium ranging from 0.9 OD to 1.2 OD.We also transformed Pm21 to different genotypes,such as Jimai22,Aikang58,Ningmai9 and Yangmai15,then the transgenic plants containing Pm21 were achieved in the genetic background of Ningmai9.However,these putative transgenic plants need to be further confirmed by more target gene-specific primers and marker gene-specific primers.