【摘要】 以‘株两优06‘’株两优101‘’中早39‘’金早47‘’中嘉早17’和‘甬籼15’6个早稻品种种子为试验材料,采用标准发芽试验、低温发芽试验(12℃、15℃和18℃)和田间出苗试验等方法测定水稻种子活力。结果表明,18℃发芽4~5 d、15℃发芽5~7 d的发芽率与田间出苗率有着显著的正相关关系,其中18℃发芽4 d的发芽率与田间出苗率相关系数达到了0.932,能够有效地测定水稻种子活力。此外,18℃发芽4 d种子的内源脱落酸(abscisic acid, ABA)含量与当天的发芽率、田间出苗率呈显著的负相关关系。相比于低活力种子样品,各品种中高活力种子样品的ABA合成相关基因表达量大都显著降低,而ABA分解相关基因及ABA信号传导相关基因表达量大都显著提高。12个早稻种子样品之间ABA代谢、信号传导及其对低温胁迫响应基因表达量的差异,可能是低温胁迫下种子活力差异的重要原因。本研究结果进一步揭示了低温胁迫调控早稻种子活力的内在机制,为低温发芽试验测定早稻种子活力的方法提供了新的理论依据。更多还原

【Abstract】 Taking the seeds of six early rice cultivars‘Zhuliangyou 06’,‘Zhuliangyou 101’,‘Zhongzao 39’,‘Jinzao 47’,‘Zhongjiazao 17’and‘Yongxian 15’as materials, the seed vigor of these early cultivars was determinated by the standard germination test, low temperature germination test(12 ℃, 15 ℃ and 18 ℃) and field emergence test. The results showed that the germination percentages at 18 ℃ after 4-5 days and 15 ℃ after5-7 days had significantly positive relationship to the field emergence(FE). Especially, the correlation coefficient between germination percentage at 18 ℃ after 4 days and FE reached 0.932, revealing a fast and accurate method for measuring the seed vigor at a low temperature. The endogenous ABA content of seed at 18 ℃ after 4 days were negatively related to the germination percentages and FE. The real-time fluorescence quantitative polymerase chain reaction analysis showed the expression levels of ABA-synthesis related genes in high-vigor seeds were significantly lower than those in the low-vigor seeds. However, the most genes involved in ABAcatabolism and signal transduction related genes were highly expressed in the high-vigor seeds. Different responses in ABA metabolism and chilling signal transduction to low temperature stress might explain the seed vigor differences in the 12 early rice seed samples. The present study further reveals the internal mechanism of low temperature stress regulating seed vigor of early rice, which could provide a new theoretical basis for testing seed vigor of early rice with low temperature germination test.更多还原