不同穗型常规籼稻品种源库性状的差异

 【目的】研究不同穗型常规籼稻品种源库性状的差异,为大穗型品种遗传改良及从栽培角度调控源库提高穗重提供参考依据。【方法】在群体水培条件下,2001年、2002年分别以88个、122个常规籼稻品种为材料,测定叶面积、干物重（包括根系）、产量及其构成因素、氮素含量等,采用组内最小平方和的动态聚类方法将供试品种按单穗重从低到高依次分为A、B、C、D、E、F 6类,研究各类品种源库性状的差异。【结果】大穗型籼稻品种抽穗期和成熟期叶面积系数、绿叶重及比叶重均较大,但结实期叶面积系数下降比例小。在一定的范围内,增大叶面积系数有利于提高单穗重;大穗型籼稻品种结实期净同化率大于小穗型品种;大穗型品种库容量较大,适当增大穗重有利于库容量的提高;大穗型品种单位叶面积籽粒产量、单位叶面积库容量、单位干物质库容量、单位氮素库容量较大;影响穗重的主要叶源性状是抽穗期绿叶重、净同化率;影响穗重的主要库性状是库容量、单位叶面积库容量、单位氮素库容量、单位叶面积籽粒产量。【结论】大穗型品种叶面积系数及其构成、库容量及其构成（或库源比）显著大于小穗型品种,绿叶重、结实期净同化率是影响穗重的主要叶源性状,库容量、单位叶面积库容量、单位氮素库容量、单位叶面积籽粒产量是影响穗重主要库容性状。

Difference of Source-Sink Components in Conventional Indica Rice Cultivars with Different Panicle Weight

Objective] This study was aimed to analyze the difference of source-sink components in conventionai indica rice cultivars with different panicle weights (PW) and to provide valuable information for the cultivation and genetic improvements of lager PW cultivars. Method ] Eighty-eight and 122 conventional indica rice cultivars were solution-cultured in 2001 and 2002,respectively.Leaf area index (LAI),dry matter weight (including root,culm and sheath,leaves,panicle),nitrogen content in different organs,yield and its components were measured.Based on PW,these cultivars were classified into 6 types from low to high by the MinSSw method,to study their difference in source and sink components.Result] LAI and green leaf weight at heading and maturity stages,leaf weight per unit leaf area in large PW types of indica rice were superior to those of eultivars with small PW type,however,decline rate of LAI during grain filling period was lower in large-PW cultivar.Elevation LAI could improve PW;Cultivars with large PW showed higher net assimilation rate during grain filling period,and sink potential,grain yield per unit leaf area,sink potential per unit leaf area,sink potential per unit dry matter weight and sink potential per unit N accumulation at heading stage were also higher in cultivars with large PW than those of cultivars with small PW type,enhancing PW could improve sink potential,PW was significantly influenced by green leaf weight at heading stage,net assimilation rate,sink potential per unit area,sink potential per unit leaf area,sink potential per unit N accumulation and grain yield per unit leaf area. Conclusion ] LAI,sink and their respective components in large PW types of indica rice were superior to those of cultivars with small PW type.PW was significantly influenced by source traits including green leaf weight at heading stage,net assimilation rate,and sink traits including sink potential per unit area,sink potential per unit leaf area,sink potential per unit N accumulation,grain yield per unit leaf area.