Genetic Analysis And QTL Mapping Of Main Agronomic Traits And Barley Yellow Mosaic Disease Resistance In Recombinant Inbred Lines

Barley is the fourth largest cereal crop in the world,which is not only widely used for food and feed,but also used for malting and brewing.New barley varieties of high-quality and high-yielding are the foundation for the stable and development of barley industry,genetic studies on main agronomic traits and resistance in barley is helpful to explore the barley germplasm resources and new varieties.In the present study,Yangnongpi 5 is high-yielding and high-resistant to Barley Yellow Mosaic Virus,Riyin 3 is the susceptible variety to Barley Yellow Mosaic Virus.A recombinant inbred lines(RILs)were construct by using Yangnongpi 5 and Riyin 3,the main agronomic traits and resistance of Barley Yellow Mosaic virus were investigated in three years.The genetic map of RILs was constructed by screening SSR markers with polymorphic between its parents,QTL mapping were carried out on 6 major agronomic traits and resistance to Barley Yellow Mosaic.The main results are as follows:1.A total of 109 SSR markers were screened from 1176 pairs of barley SSR markers,and the whole genome was scanned by screened polymorphic markers.The population linkage map of 108 pairs of molecular markers was successfully constructed.The number of linkage groups is equal to the number of barley chromosomes.The total length of the map is 1065.13 cM.The average distance between the markers is 9.86 cM,and the number of markers in each linkage group varies from 8 to 27.2.The difference of plant height,main panicle length,spike length,the number of grains per spike and thousand-grain weight with barley yellow mosaic and the Disease-free field in parents of Yangnongpi 5 and Riyin 3 were significant.The difference of panicle number per panicle was not significant.The plant height,the length of the main spike,the length of the spike,the number of spikelets per panicle,the number of spike per plant and the number of grains per plant in disease nursery were significantly different between the years,genotype and year and genotype interaction.There was no significant difference between the other five traits in genotype,except that the number of spike per plant was not significant in no-disease fields.3.There were significant positive correlations between the height of the plant height and the length of the main panicle,the length of the intemode,the number of grains per spike and the grain weight.And there was a significant positive correlation between the length of the main spike and the length of the shoots and the number of spikelets per panicle.There was a significant positive correlation between the panicle internode length and the other four traits except the panicle number per plant.Barley barley yellow mosaic did not change the direction of the correlation between the main agronomic traits,but the size and significance of the correlation between the traits were changed.4.In the barley yellow mosaic virus nursery,the resistance index of barley yellow mosaic disease in 2014-2016 was negatively correlated with plant height,internode length per panicle,panicle number per panicle number and 1000 grain weight.The negative correlation of the number 2 traits was extremely significant,which was positively correlated with the main panicle length and the number of grains per spike.The resistance of barley yellow mosaic disease to the main agronomic traits in different years was consistent,but the degree of influence was different.5.In this study,48 QTLs for agronomic traits and 6 barley yellow mosaic were detected.QTLs were distributed on 7 chromosomes of barley,and there were five hot spots.There were 16 QTLs for stable agronomic traits detected in at least two environments.There were five main QTLs in 16 stable QTLs:qMSL-2H,qMSL-4Ha,qTFIL-6H,qGPS-2Ha and qGPS--2Hb,The highest contribution rates were 40.90%,19.99%,26.84%,38.94%and 14.54%,respectively.qMSL-2H,qTFIL-6H and qGPS-2Ha could be detected in four different environments,and qMSL-2H,qGPS-2Ha is located at the same site.qRYM--2Ha was stable in the first phase of 2014,the first period in 2016,the third phase of 2016,and the qRYM-2Hb was stable in the third year of the year.The qRYM-2Hb was similar to the locus of Ryml6 Hb,which may be its allele,which needs to be further validated.qRYM-2Ha may be a new resistance site.