CAJ | 학술논문

田间条件下持续高温(而非短期高温)是导致水稻生殖生长期高温危害的重要条件, 由此推测水稻花粉母细胞减数分裂至抽穗的一段期间, 可能均为水稻的高温敏感期, 且高温诱导可能具有累积效应.本研究模拟田间典型灾害天气条件, 在人工气候箱内对杂交水稻"金优63"花粉母细胞减数分裂期进行连续3 d的热害胁迫处理, 对处理后不同发育时期的花药组织取样切片观察, 从组织、细胞水平探讨水稻受高温胁迫后花药可能出现的早期异常特征.结果表明, 受高温胁迫后, 在小孢子形成阶段, 水稻花粉母细胞发育异常、四分体无法适时分散; 在花粉粒成熟阶段, 水稻生殖细胞失去正确的排列方向、绒毡层细胞发生非正常分解、花药壁和花粉粒发生形态异常并出现败育.此外, 植株减数分裂期受高温胁迫后, 开花时花粉活力显著降低.这些结果表明, 抽穗前的高温直接导致水稻花药组织和生殖细胞异常发育, 从而减少有效花粉的形成和降低裂药与授粉性能, 可能成为田间条件下持续高温引起水稻不育的重要原因.
전간조건하지속고온(이비단기고온)시도치수도생식생장기고온위해적중요조건, 유차추측수도화분모세포감수분렬지추수적일단기간, 가능균위수도적고온민감기, 차고온유도가능구유루적효응.본연구모의전간전형재해천기조건, 재인공기후상내대잡교수도"금우63"화분모세포감수분렬기진행련속3 d적열해협박처리, 대처리후불동발육시기적화약조직취양절편관찰, 종조직、세포수평탐토수도수고온협박후화약가능출현적조기이상특정.결과표명, 수고온협박후, 재소포자형성계단, 수도화분모세포발육이상、사분체무법괄시분산; 재화분립성숙계단, 수도생식세포실거정학적배렬방향、융전층세포발생비정상분해、화약벽화화분립발생형태이상병출현패육.차외, 식주감수분렬기수고온협박후, 개화시화분활력현저강저.저사결과표명, 추수전적고온직접도치수도화약조직화생식세포이상발육, 종이감소유효화분적형성화강저렬약여수분성능, 가능성위전간조건하지속고온인기수도불육적중요원인.
A continuous high temperature (other than short-term rise in temperature) leads to heat stress in rice at the reproductive growth stage under field conditions. Hence rice can be sensitive to heat stress from meiocyte meiosis to anthesis stage, and not just at anthesis. Rice is likely to respond to heat stress in a cumulative way. Under imitated daily field microclimatic conditions for heat stress, the rice cultivar "Jinyou63" (which is a hybrid rice combination) was treated with a consecutive 3-day heat stress during meiosis in phytotron. Anther and pollen tissues at different development stages after subjected to heat stress were sampled and analyzed for transverse abnormalities. The analysis shows that under heat stress, meiocytes degenerate while tetrad cell dispersion fails at microspore formation phase. During pollen maturation phase, loss of orientation of reproductive cells, abnormal vacuolization of tapetal cells, paramorphia or abortion of anther walls and pollens are observed under heat stress. In addition, pollen activity at anthesis decreases significantly under heat stress during meiosis stage. The findings suggest that abnormalities in anther tissues and reproductive cells are caused by heat stress before heading. This decreases yield potential of active pollens and destroys dehiscence and pollination, which could be the primary cause of rice sterility under continuously high temperature field conditions.