粳稻地方品种渗入系群体农艺性状综合评价与筛选OA

[Objective]A comprehensive evaluation of agronomic traits was conducted in a set of introgression lines derived from a japonica rice landrace,aiming to screen elite lines with superior grain quality.[Method]A backcross population with two generations(BC3 F4and BC3 F5)derived from a Portuguese landrace rice Bertone(donor)and an elite japonica rice cultivar Koshihikari(recipient)was used as plant materials.Seven domestication-related traits,eight agronomic and yield traits were investigated and measured.Genetic effect analysis,correlation analysis and principal component analysis(PCA)were performed.With membership functions and index weight method,a com-prehensive evaluation value D for objectively assessing the agronomic performances of introgression lines was obtained.Lines with high D-val-ues were selected for grain quality determination.[Result]Excluding stem node color,six domestication traits showed segregation in two back-cross generations,and all agronomic traits exhibited continuous variation.The coefficient of variation(CV)was the highest for grain yield per plant(41.74%and 27.66%)and the lowest for panicle length(5.55%and 5.92%)in the two generations,respectively.Genetic variance components differed among traits,and their proportions in the total variance also varied.Dominance×environment interaction variance was the main genetic variance component in the tested populations.Correlations between grain yield per plant and four traits(basal culm thick-ness,sowing-first heading day,flag leaf length and flag leaf area)differed significantly between the two generations.Four principal compo-nents were extracted in each generation,with cumulative contribution rates of 82.903%and 77.399%,respectively.Flag leaf length and flag leaf area were common key indicators.Eight superior lines ranked among the top 30 in both generations based on the comprehensive D value were selected for quality analysis.Line 242260 showed excellent processing,appearance and eating quality,representing an elite japonica line with good eating quality.Line 242009 had superior processing and appearance quality,with low amylose content and high protein content,combining soft rice and nutrient-enhanced characteristics,making it an important germplasm accession for specialty nutrient-dense japonica rice.[Conclusion]Combining comprehensive evaluation of agronomic traits and grain quality analysis,two introgression lines with outstanding agronomic performance and distinct quality characteristics were identified.These lines provide elite germplasm resources and a theoretical ba-sis for high-yield and good-quality breeding in rice.