中文摘要：

为探究钵苗机插对水稻幼穗分化期营养器官碳氮代谢以及枝梗和颖花分化、退化的影响,以大穗型杂交粳稻甬优1540为材料进行大田生产试验,以毯苗机插为对照,研究了钵苗机插方式下幼穗分化期碳氮代谢特点和枝梗、颖花分化与退化规律及差异,并探明碳氮代谢与稻穗枝梗及颖花分化与退化及产量构成的关系。结果表明：1）抽穗前25 d至抽穗阶段,钵苗机插稻株营养器官非结构性碳水化合物（NSC）质量分数显著高于毯苗机插（P〈0.05）,抽穗前25和20 d,钵苗机插全氮质量分数2015年和2014年平均分别高出毯苗机插1.82%和6.13%,但在抽穗前15 d及以后则表现相反的趋势;在抽穗前15 d及以后各期钵苗机插C/N比值显著高于毯苗机插。2）在抽穗前25~15 d,2种机插方式NSC累积量差异不明显,但在抽穗前10 d至抽穗期,营养器官NSC累积量迅速上升,累积量占单茎茎鞘总量的42.75%~50.75%累积量,钵苗机插累积量高于毯苗机插。3）钵苗机插方式下分化数和现存数显著高于毯苗机插,而退化数和退化率则表现相反的趋势;其中对二次颖花数的影响达显著水平（P〈0.05）,且对稻穗下部二次枝梗和颖花形成的影响程度高于中、上部,钵苗机插使下部二次枝梗和颖花现存数2 a平均分别增加5.24和14.21个。4）抽穗前25和20 d营养器官C/N比值与枝梗和颖花的分化/现存数呈显著或极显著的负相关,特别是跟二次枝梗和二次颖花的相关性较密切,与退化数呈正相关,而在抽穗前15 d到抽穗期则相反。千粒重和产量均表现为与穗分化期NSC积累量和抽穗后NSC运转率呈显著或极显著正相关。

英文摘要：

The high proportion of early advantaged tillering in bowl seedling mechanical-transplanting rice promotes individual growth and improves canopy＇s efficiency of solar energy utilization, which is beneficial for large panicle formation and leads to significant increase inthe total spikelet number. However, the related physiological mechanism remains unclear. In order to explore the physiological reasons for the formation of large panicle of bowl seedling mechanical-transplanting rice, with conventional blanket seedling mechanical-transplanting as the control （CK）, the hybrid japonica rice variety with large panicle Yongyou 1540 was planted in the field to investigate the features of carbon （C） and nitrogen （N） metabolism in vegetative organs, and the differentiation and degradation of branches and spikelets in young panicle differentiation stage of bowl seedling mechanical-transplanting rice. Their regularity and differences were studied, and their relationships with yield components were investigated. The results showed that the contents of non-structural carbohydrates （NSC） in vegetative organs under the 2 mechanical-transplanting methods were obviously different. The content of NSC in bowl seedling mechanical-transplanting was significantly higher than that in blanket seedling mechanical-transplanting in every growing period in panicle differentiation stage. On the 25th and 20th day before the heading, the total N content in bowl seedling mechanical-transplanting was higher than that in blanket seedling mechanical-transplanting, but the trend became opposite since the 15th day before the heading when the C/N ratio also became significantly higher than that of blanket seedling mechanical-transplanting. From the 25th to the 15th day before the heading, the difference of NSC accumulation under the 2 methods was not obvious, but from the 10th day before the heading to the heading, NSC accumulation in vegetative organs increased rapidly and that of bowl seedling mechanical-transplanting was signific