Genetic Analysis Of A New Wheat Recombinant Inbred Lines Population Derived From Wheat-Haynaldia Villosa 6VS·6AL Translocation And Huixianhong And Some Agronomic Traits

The new wheat-Haynaldia villosa 6VS-6AL translocation line 92R137 developed by Cytogenetics Institute,Nanjing Agricultural University,China is playing important roles in Chinese wheat breeding mainly due to its powerful resistance genes Pm21 and Yr26 and other beneficial traits such as sturdy stem,broad leaves and large spikes etc.An elite Chinese wheat landrace Huixianhong was selected to hybridize with 92R137,and a new RIL population including 361 F₈ was constructed by SSD method.143 polymorphic molecular markers and 10 agronomic traits were used to reveal the genetic equilibrium of the new population.Based on the result,genetic effect of 6VS·6AL and major QTLs controlling stem diameter etc were identified as the following.Of 150 polymorphic loci produced between 92R137 and Huixianhong by 140 pairs of wheat SSR and STS primers,115(76.67%) followed 1:1 segregation,while 35(23.33%) were distorted.Segregation of 3 glutenin genes followed 1:1.Based on two-year-three-location evaluation,of 9 agronomic traits involved,except the distorted resistance for powdery mildew in the population(mainly because of the little bit lower transmission rate of gametes with 6VS·6AL),the red and white glume was regular(1:1),8 other traits including plant height,stem diameter,stem wall thickness,the second basal internode length,tillers,spike length and flag leaf area were all distributed normally.The normal genetic structure of the population revealed by 150 polymorphic loci were confirmed.Two subpopulations(6VS·6AL vs 6A) were mixed based on the powdery mildew test and molecular tagging and used to reveal the genetic effect of 6VS·6AL.Significant positive effects on plant height,flag leaf area,stem diameter,stem wall thickness,stem strength and thousand grains weight were found with an increase at 2.67%,9.98%,8.16%, 5.37%,21.24%,18.92%,respectively.Significant negative effect on tillers was found with a decrease at 5.78%.No significant effect was found on the second basal internode length, protein,dry gluten and wet gluten content. Using Map Manager QTXb20,QTLs controlling stem strength were prelimiarily mapped in the loci of markers Xwmc177-2A and Xgdm68-SD etc with genetic contribution as 7.5%and 10.5%etc.QTLs controlling stem diameter were in Xgdm68-5D(12.5%), Xgwm301-2D(9%),Xgwm71-3D(7.5%),Xgwm71.1-2A(9.5%)and Xcfd80-6A/6D(13.5%) etc.QTLs controlling stem wall thickness were in Xgwm301-2D(5.5%),Xgwm570-6A(6%) and Xcfd80-6A/6D(11%) etc.QTLs controlling the second basal internode length QTL were in Xcfd80-6A/6D(5.7%),Xgwm71-3D(5%) and Xgwm46-7B(5%).QTLs controlling plant height were in Xbarc23-6AS/7A(6%) etc.QTLs controlling flag leaf area were in Xgwm 71.1-2A(5.7%),Xgwm301-2D(6.5%) and Xcfd80-6A/6D(9%).The marker NAU/xibao 15 tagging chromosome 6VS was significantly related with QTLs controlling stem diameter, stem wall thickness and flag leaf area further indicating genetic effect of 6VS·6AL.Two sets of isogenic lines(6VS·6AL vs 6A) were developed from the heterozygous F₉ lines of this population.