不同穗型常规籼稻品种物质生产与分配的差异及原因分析

Difference of dry matter accumulation and distribution in conventional indica rice cultivars with different panicle weight

在群体水培条件下,2001、2002年分别以88、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,研究各类品种物质生产与分配的差异及其原因。结果表明:①大穗型籼稻品种抽穗期、结实期、成熟期群体干物质生产量和个体干物质生产量大;②大穗型品种成熟期茎鞘干重比例较大,穗干重比例及经济系数小于中等穗型品种;③单穗重受生物产量和经济系数的共同影响,生物产量特别是单穗生物量对穗重的作用显著大于经济系数对穗重的作用;④大穗型水稻品种播种到抽穗天数、全生育期天数较长,生育期、干物质生长率均是影响干物质生产的重要因素,干物质生长率特别是个体干物质生长率对干物质生长量影响较大;⑤大穗型品种单穗茎鞘重、单穗绿叶重、单穗叶面积大,结实期单穗叶面积下降速度慢。单穗根源、单穗氮源、单穗叶源、单穗碳源优势明显是大穗型品种干物质积累多、穗重大的主要原因。

A total of 88 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 and panicle）,nitrogen content in different organs,yield and its components were measured.Based on panicle weight（PW）,these cultivars were classified into 6 types from low to high by the MinSSw method,to study their difference and its causes in dry matter accumulation and distribution.The population dry matter accumulation（DMA） and individual DMA at heading,grain filling and maturity stages were higher in cultivars with large PW than those in cultivars with small PW.The ratio of culm and sheath dry weight to entire plant DMA（PDMA） at mature stage was higher in cultivars with larger PW types compared with cultivars with smaller PW,while the ratio of panicle to PDMA at maturing stage was small in the cultivars with large PW than those with medium PW,and cultivars with large PW showed lower harvest index.The contribution of biomass,especially individual biomass,to PW was significantly greater than that of harvest index to PW.Rice cultivars with large PW showed longer growth duration especially days from sowing to heading.The effects of both growth duration and dry matter growth rate on PW were significant.The dry matter growth rate,especially dry matter growth rate of individual,was more influential to dry matter accumulation.Leaf area,dry weight of leaf and culm and sheath,were larger in the cultivars with large PW than those with small PW,and Leaf area declined less during grain filling period in the cultivars with large PW.Root traits,N accumulation,Leaf area,dry weight of culm and sheath in the cultivars with large PW were higher than those with small PW,which was main factors enhancing dry matter accumulation and panicle weight in large PW.