籼稻桂华占、八桂香花后营养器官干物质流转与籽粒灌浆关系

以桂华占和八桂香2个籼稻品种为材料,研究籼稻花后不同部位器官物质积累、运转与籽粒生长的动态特征及相互关系。结果表明:(1)叶、叶鞘、节间干物质流转存在一定差异,倒2叶鞘对籽粒的贡献超过倒3叶鞘和倒1叶鞘,倒3节间对籽粒的贡献超过倒2节间和倒1节间;(2)不同部位籽粒的灌浆速率和拐点粒重呈现UPG(上部籽粒)MPG(中部籽粒)BPG(下部籽粒)变化趋势,拐点时间和活跃灌浆时间及持续灌浆时间均呈现BPGMPGUPG变化规律,UPG启动早,灌浆速率大,BPG的灌浆速率小,灌浆时间滞后,籽粒粒重呈现UPGMPGBPG;(3)叶片、叶鞘及节间干物质运转速度和运转率都与籽粒起始灌浆势呈正相关,其中器官间与起始灌浆势的相关系数大小表现为节间叶鞘叶片,不同叶位间与起始灌浆势的相关系数大小表现为倒2叶倒3叶倒1叶,其中节间干物质运转对籽粒生长的作用大于叶鞘,叶片干物质运转与籽粒生长的相关性最小。倒1节鞘物质输出与BPG生长时间上同步,倒2节鞘与MPG生长同步,倒3节鞘与UPG生长同步。

Relationship between post-anthesis dry matter remobili- zation from culm, leaf in different position and grain growth of Indica rice varieties Baguixiang and Guihuazhan

Field experiments were conducted to investigate carbon and nitrogen accumulation & translocation and grain growth after flowering with two indica rice Baguixiang and Guihuazhan as material in 2008 and 2009. The main results are as follows.(1)There were some differences in post-anthesis dry matter remobilization among leaves blade,sheath and internode of the quality rice in different positions. The contribution of the second leaf sheath from top(SS)to the grain was greater than the first leaf sheath from top(FS)and the third leaf sheath from top(TS)and the contribution of the third internode from top(TI)to the grain was more than the first internode from top(FI)and the second internode from top(SI);(2)Differences of the grain in various parts were presented in grain filling rate and initial grain filling potential. Filling rate and grain weight at the inflexion point claimed as: UPG(upper position grains)>MPG(middle position grains)>BPG(basal position grains). Upper position grain showed earlier initial filling potential,higher filling time rate while lower position grain lower filling rate,lagging filling time,and grain weight showed UPG>MPG>BPG;(3)Dry matter translocation rate and efficiency of leaf blade and sheath and internode post-anthesis were proportional to grain were correlated with initial grain filling potential. The corrational between organs and grain initial were displayed as follows:internode>leaf sheath>leaf,and the correlation coefficients in different parts showed inverted 2 from top>3 from top>1 from top. The effect of dry matter remobilization of internode on grain growth was much more than leaf sheath,and least of leaves. The first internode from top and lower position grain growth occurred with synchronicity. The same case happened to the second internode from top and the middle position grain,the third internode from top and basal position grain.