花后人为模拟倒伏对超级稻生长、产量和品质的影响

Influence of artificial lodging at grain-filling stage on plant growth, yield and quality of super rice

  • 摘要: 倒伏是水稻实现高产优质的主要限制因子之一。以‘南粳9108’为材料,研究人为模拟倒伏对超级稻物质生产和分配、产量和产量构成因素以及稻米品质的影响及其与倒伏发生时期的关系,探讨倒伏对水稻生长、产量和品质的影响,为超级稻抗倒栽培提供依据。试验设3个处理,分别为正常植株(CK)、抽穗后15 d倒伏(AL15)和抽穗后30 d倒伏(AL30),成熟期测定水稻物质积累与分配、产量和产量构成以及稻米主要品质性状。结果表明,与正常生长水稻相比,AL30和AL15处理使水稻地上部各器官生物量下降,总生物量分别显著降低7.3%和24.3%。从物质分配看,AL15处理使水稻生物量在生殖器官中的分配比例显著下降,而AL30处理植株响应不显著。AL30和AL15处理使水稻产量分别显著下降8.3%和36.4%。抽穗后倒伏造成的产量损失主要与饱粒率和饱粒千粒重下降有关。AL30处理使饱粒率和饱粒千粒重分别显著下降5.6%和3.3%,AL15处理分别极显著下降30.8%和6.7%。水稻结实期倒伏导致饱粒重下降主要与糙米变小,稻谷充实程度明显降低有关。从稻米品质看,AL30和AL15处理使水稻整精米率分别下降7.5%和14.7%,达显著和极显著水平;AL30处理对稻米蛋白质和直链淀粉含量均无显著影响,但AL15处理使稻米蛋白质含量极显著增加20.2%;RVA谱数据表明,结实期倒伏水稻崩解值减少而消减值增加,但均未达显著水平。以上结果表明,结实中后期发生倒伏对超级稻‘南粳9108’籽粒产量和稻米品质影响较小,但结实早期倒伏将使物质生产和籽粒灌浆均受到抑制,最终导致产量大幅下降,同时稻米加工和食味品质亦呈变劣趋势。

     

    Abstract: Rice lodging has been one of the main constraints to high yield and good quality rice production in China. Because lodging not only makes mechanized harvesting difficult, it also impedes assimilate, water and nutrient transport in grains, limiting the realization of rice yield potential. Lodging conditions under high humidity are prone to diseases and pests, resulting in poor grain quality. In recent years, the potential risk of rice lodging has been increasing because of the release of high-yielding varieties characterized by large panicle, increased nitrogen fertilizer application and shifts from labor-intensive to simplified planting techniques such as direct-seeding or seedling broadcasting. In addition, extreme weather conditions, such as typhoon accompanied with heavy rains at late growth stage, has been another main reason behind lodging, often affecting large areas of croplands. Therefore, it was of utmost importance to further study the mechanisms of lodging-resistance of rice and the related regulation strategies. In this experiment, the effect of artificial lodging at grain-filling stage on plant growth, yield and grain quality of super rice ('Nanjing 9108') was investigated by comparing plants with normal growth (CK), artificial lodging after 30 days of heading (AL30) and artificial lodging after 15 days of heading (AL15). Compared with CK, AL30 and AL15 artificial lodging treatments decreased dry matter production of aboveground organs of 'Nanjing 9108', which resulted in decrease in total dry matter production by 7.3% (P < 0.05) for AL30 and 24.3% (P < 0.01) for AL15. The proportion of biomass distribution in reproductive organs decreased for AL15, but had no significant change for AL30. AL30 and AL15 artificial lodging treatments decreased grain yield by 8.3% (P < 0.05) and 36.4% (P < 0.01), respectively. Yield loss caused by lodging at grain-filling stage was mainly associated with decreases in filled-grain rate and 1000-full-grain weight. Filled-grain rate and 1000-full-grain weight decreased by 5.6% (P < 0.05) and 3.3% (P < 0.05) for AL30, and by 30.8% (P < 0.01) and 6.7% (P < 0.01) for AL15. Lodging-induced decrease in grain weight was mainly associated with smaller brown rice, which was attributed to poorer grain filling at grain-filling stage. Head rice rate decreased by 7.5% (P < 0.05) for AL30 and 14.7% (P < 0.01) for AL15. AL30 treatment had no effect on protein or amylose contents of rice grain, but AL15 increased protein content by 20.2% (P < 0.05). Artificial lodging had no significant effect on RVA profile of rice grain. The results suggested that the effect of plant lodging at late grain-filling stage (30 days after heading) on yield and grain quality of 'Nanjing 9108' super rice was relatively small. In contrast, plant lodging at early grain-filling stage (15 days after heading) inhibited dry matter production and grain-filling process, resulting in yield loss and grain quality deterioration.

     

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