Genetic Basis And Combining Ability Analysis Of The Rice Restorer Line Yazhan

Yazhan is a restorer line bred from multiple generations of self-cross after the cross between Huazhan and Zhanhui 15,and its combination showed good performance in yield,rice quality and blast resistance,it can be used as one of the current excellent parents.To anlysis its genetic basis,Yazhan Huazhan and Zhanhui 15 were used as the experimental materials.By investigating agronomic traits,combining SSR primer screening and second-generation resequencing analysis,genetic composition of Yazhan were studied.A t the same time,In order to make a better comprehensive evaluation of the utilization value of Yazhan,7 restorer lines were selected as controls and matched with 18 sterile lines.this study produced 144 hybridized combinations following the incomplete diallel hybridization 8×18(NCII).These materials were analyzed for the combining ability and the genetic parameters of 8 agronomic traits.The main research results are as follows:1.The plant height of Yazhan was signifi cantly lower than Zhanhui 15,and the yield was not different from the parent lines.some fragments in chromosome 1,3,4,5,and 10 in the genome of Yazhan were mainly from Zhanhui 15,segments in chromosome 2,6,8.9,11 and 12 mainly come from Huazhan,and the chromosomes 1,5.and 6 had the most variation.In terms of genomic similarity,Yazhan was more similar to the male parent(Huazhan).Yazhan has more SNP s and Indel numbers than parents,and genetic diversity has increased.Yazhan and Huazhan carried the Wxb genotype.while Zhanhui 15 carried the Wxa genotype.The amylose contents of Yazhan and H uazhan were significantly lower than Zhanhui 15.Yazhan and Huazhan carried the Pita blast resistance gene,and Zhanhui 15 carried the Pita susceptibility gene.2.The plant height,effective panicle number,spike length,1000-grain weight and yield per plant of hybrid combination were largely female-dependent.while the total grain number was largely male-dependent.The grain number and seed setting rate were genetically contributed by both parents.Changhui 871.Changhui T025 and Yazhan are good parents for the preparation of high-yield hybrid rice.Quan 9311 A/Yazhan,Wuxiang A/Yazhan.Taifeng A/Yazhan.Xintai A/Yazhan are the better combinations of Yazhan.The combination of Yazhan and male sterile lines with short growth period was more prominent,and Changhui T025 was more suitable for male sterile lines in long growth period.The analysis of Yazhan's genetic basis provides some theoretical reference for elucidating the genetic composition of Yazhan and determining the main genetic sources of its important agronomic traits.And the determination of combining ability of Yazhan is helpful to accelerate its application in breeding,while the analysis of special combining ability is beneficial to the digging of excellent combinations,and provides some scientific basis for the breeding of hybrid rice restorer lines.