Cultivar differences in the number of differentiated spikelets and percentage of degenerated spikelets as determinants of the spikelet number per panicle in relation to dry matter production and nitrogen absorption
Cultivar differences in the number of differentiated spikelets and percentage of degenerated spikelets as determinants of the spikelet number per panicle in relation to dry matter production and nitrogen absorption
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DOI：
10.1080/00380768.2003.10410029
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发表时间：
2003-06
影响因子：
2
通讯作者：
T. H. Ansari;Yoshinori Yamamoto;Tetsushi Yoshida;A. Miyazaki;Yulong Wang
中科院分区：
文献类型：
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作者：
T. H. Ansari;Yoshinori Yamamoto;Tetsushi Yoshida;A. Miyazaki;Yulong Wang
摘要近年来育成的高产品种的株型有从多穗、小穗型（穗数型）向多穗、大穗型（穗重型或超穗重型）转变的趋势，每穗小穗数对每平方米小穗数的贡献率也随之增加。为此，以22个不同株型的粳稻和籼稻品种为材料，通过田间试验，分析了品种间每穗分化颖花数（NDS）和决定每穗颖花数的退化颖花率（PDGS）的差异，与直到穗形成阶段和/或穗形成阶段期间所产生的干物质和所吸收的氮（N）的量有关。籼型品种的NDS、退化小穗数（NDGS）和每穗存活小穗数（NSS）均显著高于粳稻品种，其主要原因是二次枝梗上的小穗。粳稻和籼稻的NDS分别为83.9-149.6和133.1-229.9。粳稻的PDGS为15.3 ~ 26.8%，籼稻为7.2-38.1%，平均值分别为21.6%和27.0%。相关分析表明，在籼、粳两个品种群体中，高NDS使每穗NSS数和NDGS数均增加，且NDGS显著增加了PDGS。两种生态种的NSS与PDGS的关系不密切。幼穗期（幼穗期：上级茎上1-2 mm长的幼穗）和抽穗期的干物质积累量及其在幼穗期至抽穗期的增长量与NDS相关，而吸氮量除幼穗期外与NDS相关性相似。两种生态品种在YPS或抽穗期的干物质或单茎吸氮量的变化范围相似，但在相同干物质量下，籼稻的NDS显著高于粳稻，即，SPE-D或SPE-N（单位干物质或含氮量的分化小穗生产效率）在籼稻品种中高于粳稻品种。在籼稻和粳稻品种组中，SPE-D和SPE-N与YPS和抽穗期的干物质和吸氮量以及YPS至抽穗期的增加量呈高度负相关。这些结果表明，在YPS和抽穗期，随着SPE-D或SPE-N的降低，每茎干物质或吸氮量的增加也增加了NDS。我们得出的结论是，从穗数穗重类型的植物类型的变化可能带来的NDS和NSS的增加，伴随着减少单位量的干物质生产的小穗生产效率和N吸收每茎不考虑生态种。
Abstract The plant type in high-yielding cultivars (HYC) bred in recent years has tended to change from a higher number of panicles with smaller stems and panicles (panicle number type) to a lower number of panicles with larger stems and panicles (panicle weight type or superpanicle weight type) with a concomitant increase of the contribution ratio of the spikelet number per panicle to the number of spikelets per square meter. Therefore, field experiments were conducted by using twenty-two rice cultivars with different plant types belonging to both japonica and indica ecospecies to analyze cultivar differences in the number of differentiated spikelets per panicle (NDS) and the percentage of degenerated spikelets (PDGS) which determines the number of spikelets per panicle, in relation to the amount of dry matter produced and nitrogen (N) absorbed until and / or during the panicle formation stage. The NDS, number of degenerated spikelets (NDGS) and surviving spike lets per panicle (NSS) were significantly higher in the indica cultivars than in the japonica ones mainly due to the spike lets on the secondary rachis branches. The NDS ranged from 83.9–149.6 and 133.1–229.9 in the japonica and indica cultivars, respectively. The PDGS ranged from 15.3 to 26.8% in the japonica cultivars and 7.2–38.1% in the indica ones with averages of 21.6 and 27.0%, respectively. Correlation showed that the higher NDS increased the number of both NSS and NDGS per panicle and that the latter one significantly increased the PDGS in both indica and japonica cultivar groups. The NSS was not closely related to the PDGS in both ecospecies. The amount of dry matter per productive stem (per stem) at YPS (young panicle stage: young panicle 1–2 mm long on superior stems) or heading and its increase during the period from YPS to heading were correlated with the NDS, and the amount of absorbed N per stem showed similar correlations with the NDS except at YPS. The amount of dry matter or absorbed N per stem at YPS or heading showed a similar range in both ecospecies, but for the same amount of dry matter, the NDS was remarkably higher in the indica than in the japonica cultivars, i.e., SPE-D or SPE-N (production efficiency of the differentiated spikelets per dry matter or N content) was higher in the indica than in the japonica cultivars. SPE-D or SPE-N showed a high and negative correlation with the amount of dry matter or absorbed N per stem at YPS or heading and their increase during the period from YPS to heading in both indica and japonica cultivar groups. These results imply that the increase in the amount of dry matter or absorbed N per stem at YPS and heading also increased the NDS with decreasing SPE-D or SPE-N. We concluded that the changes in the plant type from panicle number to panicle weight type may be brought about by the increase of NDS and NSS with a concomitant decrease in the spikelets production efficiency per amount of dry matter produced and N absorbed per stem irrespective of ecospecies.