Investigating early vigour in upland rice (Oryza sativa L.): Part I. Seedling growth and grain yield in competition with weeds
Investigating early vigour in upland rice (Oryza sativa L.): Part I. Seedling growth and grain yield in competition with weeds
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DOI：
10.1016/j.fcr.2009.05.008
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发表时间：
2009-09
影响因子：
5.8
通讯作者：
O. Namuco;J. Cairns;David E. Johnson
中科院分区：
文献类型：
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作者：
O. Namuco;J. Cairns;David E. Johnson
据报道，水稻幼苗的快速生长与提高的耐受杂草竞争的能力有关，这是直播水稻作物的主要限制因素。为了探索生长差异和杂草竞争对产量的影响，在田间和温室实验中种植了20个不同的亚洲水稻品种。不同品种之间的粮食产量发生在该领域，经过单手除草，杂草竞争减少粮食产量的60%以上，与无杂草的地块。在无杂草区产量最高的四个品种中，有三个品种在同一季节与杂草竞争时产量也最高。然而，有些品种，在与杂草的竞争中，与无杂草的条件相比，产量相对较差。水稻生物量在28天与谷物产量在与杂草的竞争，并减少杂草生物量。品种间幼苗生长存在显著差异。Sabita和NSG 19积累了两倍的总干物质和叶面积每苗播种后12天（DAS）的一些最不活泼的品种。两季田间试验中与杂草竞争的籽粒产量与温室试验中12DAS时的秧苗生物量呈显著正相关。6DAS叶面积对12DAS干物质积累的直接影响最大。叶面积在6 DAS，反过来，与较高的比叶面积，更大的干物质分配到叶在4 DAS，更大的胚胎，更重的种子，和更早的光自养生长。超过90%的水稻幼苗总生物量的变化在12 DAS与研究的参数。水稻幼苗的6 DAS叶面积和干物质是容易测量的性状，有可能用作大规模筛选水稻抗杂草竞争力的间接工具。
Rapid seedling growth of rice is reported to be associated with improved ability to tolerate weed competition, which is a major constraint in direct-seeded rice crops. To explore differences in growth and the effects of weed competition on yield, 20 diverse Asian rice cultivars were grown in the field and in greenhouse experiments. Differences in grain yield occurred between cultivars in the field and, after a single hand weeding, weed competition decreased grain yields by more than 60% compared with weed-free plots. Three of four cultivars producing the largest grain yields in weed-free plots also had the largest yields in competition with weeds in the same season. Some cultivars, however, had relatively poor yields in competition with weeds compared with weed-free conditions. Rice biomass at 28 days was correlated with grain yield in competition with weeds, and with reduced weed biomass. Substantial differences in seedling growth were found among cultivars. Sabita and NSG19 accumulated twice the total dry matter and leaf area per seedling by 12 days after sowing (DAS) as some of the least vigourous cultivars. Grain yields in competition with weeds in field experiments in two seasons significantly correlated with rice seedling biomass at 12 DAS in greenhouse experiments. Leaf area at 6 DAS had the greatest direct effect on seedling dry matter accumulation at 12 DAS. Leaf area at 6 DAS, in turn, was associated with higher specific leaf area, greater dry matter partitioning to leaves at 4 DAS, larger embryos, heavier seeds, and earlier onset of photo-autotrophic growth. More than 90% of the variation in total rice seedling biomass at 12 DAS was associated with the parameters studied. Leaf area at 6 DAS and dry matter of rice seedlings are easily measurable traits that have potential to be used as an indirect tool for mass screening of rice for competitiveness against weeds.