Low temperature induced spikelet sterility in rice. I. Nitrogen fertilisation and sensitive reproductive period
Low temperature induced spikelet sterility in rice. I. Nitrogen fertilisation and sensitive reproductive period
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DOI：
10.1071/ar03075
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发表时间：
2003-01-01
影响因子：
--
通讯作者：
Blamey, FPC
中科院分区：
文献类型：
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作者：
Gunawardena, TA;Fukai, S;Blamey, FPC
水稻穗发育过程中的低温会增加小穗不育性。田间大量施氮 (N) 会加剧这种影响。在温室实验中检查了低温和氮肥诱导的小穗不育，以阐明所涉及的机制。在两个温室实验中，在穗发育过程中，在 5-7 天的时间内施加 12 小时的低温（18/13°C）和高（28/23°C）昼夜温度，以确定低温和氮肥对小穗不育的影响。在一项实验中，50% 的阳光与低温一起照射，以研究减少太阳辐射和低温的相加效应。在同一实验中通过分蘖去除处理来检查由于施氮肥而增加分蘖的效果。分别在抽穗和收获时记录花粉粒数和小穗不育性。虽然在不施氮的情况下，低温对小穗不育性没有显着影响，但在施氮的情况下，由于每个花药饱满的花粉粒数量减少，低温大大增加了小穗不育性。小穗不育性与每个花药饱满的花粉粒数量密切相关。小孢子发育早期（小穗分化后期-花粉母细胞阶段）和高峰期（第二次减数分裂阶段-外壁形成早期）期间的低温导致花粉产量严重减少，主要是由于花粉总产量减少。与低温不同，遮光的影响相当小。由于施氮量高，分蘖增加，单株小穗数增加，低温条件下小穗不育性增加。在出现分蘖时去除分蘖减少了每株植物的小穗总数，并维持了每个花药大量充盈的花粉粒，这反过来又降低了小穗不育性。每个花药充盈的花粉粒数决定了柱头上截获和发芽的花粉粒数。结论是，氮增加了每株植物的分蘖和小穗数量，这反过来又减少了每个花药饱满的花粉粒数量，导致低温条件下小穗不育性增加。
Low temperature during panicle development in rice increases spikelet sterility. This effect is exacerbated by high rates of nitrogen (N) application in the field. Spikelet sterility induced by low temperature and N fertilisation was examined in glasshouse experiments to clarify the mechanisms involved. In two glasshouse experiments, 12-h periods of low (18/13degreesC) and high (28/23degreesC) day/night temperatures were imposed over periods of 5-7 days during panicle development, to determine the effects of low temperature and N fertilisation on spikelet sterility. In one experiment, 50% sunlight was imposed together with low temperature to investigate the additive effects of reduced solar radiation and low temperature. The effect of increased tillering due to N fertilisation was examined by a tiller removal treatment in the same experiment. Pollen grain number and spikelet sterility were recorded at heading and harvest, respectively. Although there was no significant effect of low temperature on spikelet sterility in the absence of applied N, low temperature greatly increased spikelet sterility as a result of a reduction in the number of engorged pollen grains per anther in the presence of applied N. Spikelet sterility was strongly correlated with the number of engorged pollen grains per anther. Low temperature during very early ( late stage of spikelet differentiation-pollen mother cell stage) and peak ( second meiotic division stage-early stage of extine formation) microspore development caused a severe reduction in engorged pollen production mainly as a result of reduced total pollen production. Unlike low temperature, the effect of shading was rather small. The increased tillering due to application of high rates of N, increased both spikelet number per plant and spikelet sterility under low temperature conditions. The removal of tillers as they appeared reduced the number of total spikelets per plant and maintained a large number of engorged pollen grains per anther which, in turn, reduced spikelet sterility. The number of engorged pollen grains per anther determined the numbers of intercepted and germinated pollen grains on the stigma. It is concluded that N increased tillering and spikelet number per plant and this, in turn, reduced the number of engorged pollen grains per anther, leading into increased spikelet sterility under low temperature condition.