摘要
以天优998和桂农占为材料进行盆栽种植,孕穗期置于人工气候箱内进行低温处理,旨在分析不同低温强度及持续时间对水稻产量的影响及其生理机制,探明华南地区主栽水稻孕穗期的低温预警指标。低温设置为日最低温(Tmin)18℃、16℃、14℃和12℃,日较差为4℃,均匀变温,历期分别为1d、3d和5d,另设自然条件下生长的水稻为对照。结果表明,孕穗期低温使早稻倒2叶SOD和POD酶活性下降,MDA含量上升,叶绿素含量和光合速率下降,造成光合同化物减少。同时,颖花受精率和可育率下降。每穗总粒数减少、结实率及千粒重降低是造成天优998和桂农占产量降低的主要原因。经Tmin≤16℃处理3d,天优998和桂农占产量显著下降,籽粒发育形成过程明显受阻,倒2叶光合能力降低(P<0.05)。温度越低,持续时间越长,受害越严重。杂交稻组合天优998比常规稻桂农占耐低温的能力略弱。日最低温度为16℃持续3d的低温可作为华南地区早稻孕穗期低温冷害指标。
Low temperature,especially occured at booting stage,would cause sterility of rice florets and became one of restricting factors of rice yield.In order to evaluate the effect of low temperature on yield of rice,and ascertain the low temperature warning indicator at booting stage in South China,a controlled experiment was conducted with two cultivars,Tianyou 998 and Guinongzhan at four daily minimum temperature levels （18,1 6,14,and 12℃,diurnal temperature range is 4℃,nutural air temperature as CK）with three durations （1 ,3,and 5 d）.The results showed that under the low temperature treatment during the booting stage of early-season rice,SOD and POD enzyme activities of the second leaf from top decreased,MDA content increased,SPAD value and photosynthetic rate declined,the percentage of pollen fertility and spikelet-fertilized rate decreased.The number of grains per panicle,seed-setting rate, and 1000-grain weight decreased,leading to a reduction in grain yield.When T min ≤ 1 6℃ （3 d）,the grain yield of Tianyou 998 and Guinongzhan significantly decreased,as well as development progress of grains and photosynthesis of the second leaf from top（P 〈0.05）.The lower temperature and longer duration have a greater influence on the damage to rice.The cold-tolerance of hybrid rice Tianyou 998 was weaker than the conventional rice Guinongzhan.The critical temperature for chilling damage was the daily lowest temperature 1 6℃ （3 days）.
出处
《中国水稻科学》
CAS
CSCD
北大核心
2014年第3期277-288,共12页
Chinese Journal of Rice Science
基金
国家科技支撑计划资助项目(2011BAD32B02)
华南农业大学农学院金穗创新计划资助项目
关键词
水稻
低温
产量
孕穗期
生理机制
rice
low temperature
yield
booting stage
physiological mechanism
