浙江省晚粳稻品种对PEG胁迫的反应和耐旱性鉴定

Response to PEG Stress and Drought-tolerance Identification of Zhejiang Photosensitive Japonica Rice Cultivars

为了解浙江省晚粳稻品种的耐旱性,以8个浙江省晚粳稻主栽品种为材料,比较分析了芽期不同浓度PEG处理的相对发芽率、相对芽长及相对根长的差异。结果表明,发芽高峰时间随着PEG浓度的提高逐渐推迟,PEG胁迫对发芽率、根长和芽长的抑制作用依次为芽长>发芽率>根长。25%PEG处理下芽期品种间的耐旱性存在较大差异,据此对25%PEG胁迫下不同材料的耐旱性进行隶属函数综合分析,结果显示嘉33、浙粳27和浙粳88芽期耐旱性较强,宁82芽期耐旱性较差。相对发芽率、相对芽长和相对根长与隶属值间存在极显著相关性,相对根长与相对芽长呈显著正相关。因此,相对发芽率、相对芽长和相对根长可作为8个水稻品种芽期耐旱性的评价指标,通过选择幼苗地上部达到间接选择根系的目的。研究为芽期水稻抗旱品种筛选及耐旱性遗传研究提供了理论依据。

In order to know the drought tolerance of Zhejiang photosensitive japonica rice cultivars,eight leading photosensitive japonica rice cultivars of Zhejiang province were used to analysis the differences of the relative germination rate,relative shoot length and relative root length under different PEG concentrations at the seed germination stage.Results showed that the time of peak germination was delayed when PEG concentration increased. The inhibition of PEG stress to the traits followed the order of shoot length 〉seed germination rate 〉root length. The drought tolerance at seed germination stage showed highly significant among cultivar differences under 25% PEG and according to the differences the membership function were analysis was conducted. Jia 33,Zhejing 27 and Zhejing 88 were identified to be the most drought-tolerant while Ning 82 was sensitive to drought stress. Relative germination rate,relative shoot length,and relative root length correlated with the membership function at the 0. 01 significance level,and relative root length was positively correlated with relative shoot length at the 0. 05 significance level. Therefore,for the 8 rice cultivars relative germination rate,relative shoot length and relative root length could be used to evaluate drought tolerance at the germination stage,and selection for seedling shoot could reach the purpose of indirect selection for roots.These results provide theoretical basis for screening drought-tolerant rice cultivars,and genetic studies on drought tolerance at the seed germination stage.