旱稻297非结构性碳水化合物的生产与产量构成因子的关系

以旱稻297为试验材料,比较了在不施氮肥和150 kg hm-2的施氮量下旱稻297非结构性碳水化合物的生产能力、运转特点及其与产量构成因子的关系,分析了旱稻297氮肥投入与碳水化合物生产和产量形成间的关系。试验结果表明,开花前储藏的非结构性碳水化合物对产量的贡献率为32%~54%,施氮降低了开花前非结构性碳水化合物对产量的贡献率,相对而言开花后光合产物对产量的贡献率略有提高;开花前非结构性碳水化合物的转移效率为48%~65%,施氮后转移效率略有降低;总体而言,施氮降低了开花前后分配给单个籽粒的非结构性碳水化合物的数量,导致千粒重降低;在一定的范围内,随着开花期叶片中可溶性糖浓度的提高,结实率显著提高,但是随着穗中淀粉浓度的提高,结实率显著降低。因此,施氮后非结构性碳水化合物积累不足和转移效率降低同时限制了千粒重和结实率的提高,而叶片中可溶性糖浓度偏低和穗中淀粉浓度偏高限制了结实率的提高,是限制产量提高的主要原因。此外,旱稻297花后光合产物生产能力较低,是限制产量提高的又一原因。

Relationship of Non-Structure Carbohydrate Production and Yield Components of Aerobic Rice, Handao 297

In the system of “aerobic rice”, one of the problems is that the grain yield can not be improvedunder a relatively high N application rate. Production and translocation of non-structure carbohydrate (NSC) contributed greatly to grain yield. Moreover, nitrogen influenced these two procedures a lot through affecting photosynthesis and C metabolism. There have been many studies on the contribution of pre-anthesis and post-anthesis NSC to grain yield on wheat, lowland rice, etc., but little was done on aerobic rice. Therefore, production and translocation of NSC of HD297 was studied in a field experiment to explain the constraints for improving grain yield of HD297 under a relatively high N application rate. The results showed that the contribution of pre-anthesis NSC to grain yield was 32–54% and decreased slightly with 150 kg N ha^-1. The translocation efficiency of NSC before anthesis was 48–65%. Compared with 0 kg N ha^-1 treatment, the translocation efficiency of NSC decreased with 150 kg N ha^-1. The amount of NSC supply to each spikelet decreased with 150 kg N ha^-1, and thus reduced the thousand-grain weight. The percentage of filled grains increased with higher concentration of water-soluble carbohydrate (WSC) in leaf and decreased with higher concentration of starch in panicle. Therefore, the low percentage of filled grains and thousand-grain weight were related to the poor NSC accumulation and translocation, which were the main limit factors for improving the grain yield with 150 kg N ha^-1. Furthermore, the low production of photosynthetic assimilation after anthesis was another reason of yield limitation.