模拟干旱胁迫对不同烤烟品种萌发和幼苗生长的影响

Effects of Simulated Drought Stress on Germination and Seedling Growth of Different Flue-cured Tobacco Varieties

为筛选出适合威宁县种植的耐干旱品种,对威宁县主栽烤烟品种毕纳1号、韭菜坪2号和贵烟2号进行干旱胁迫(15%PEG-6000)试验。结果表明:1)在干旱胁迫条件下,各品种种子萌发情况及幼苗生长状况均弱于正常供水处理;韭菜坪2号种子萌发状况较好,相对发芽率、发芽指数、种子活力均比毕纳1号、贵烟2号分别提高21.61%、18.22%、25.24%和26.31%、5.20%、4.26%;韭菜坪2号幼苗长势表现较好,相对幼苗鲜重、干重及过氧化氢酶活性均比毕纳1号和贵烟2号分别增加9.26%、5.53%、47.04%和11.12%、4.16%、19.03%,其幼苗长势和抗旱力增强。2)相关分析表明,相对活力指数、相对幼苗鲜重、相对幼苗干重和相对CAT活性4个指标间两两相关,其中,相对活力指数与后三者指标呈显著性正相关,同时,三者间又表现极显著正相关,因此,是较好的耐旱性评价指标。3)隶属函数分析表明,韭菜坪2号耐旱性最强,其次为贵烟2号,毕纳1号最弱。

In order to select drought-resistant tobacco varieties in Weining County,three main tobacco varieties（Bina l,Jiucaiping2 and Guiyan 2）in Weining County were selected to conduct the drought stress （15% PEG-6000）test.Results：1）under drought stress condition,seed germination and seedling growth of all the three varieties were weaker than that under normal water treatment;seed germination status of Jiucaiping 2 was good,the relative germination rate,germination index and seed vigor were higher than Bina 1 and Guiyan 2 by 21.61%,18.22%,25.24% and 26.31,5.20%,4.26% respectively;the relative fresh weight,dry weight and catalase activity were higher than Bina 1 and Guiyan 2 by 9 .2 6%,5 .5 3%, 47.04% and 11.12%,4.16%,19.03% respectively.Its seedling growth and drought force were enhanced;2 ）correlation analysis showed that the relative vigor index,relative seedling fresh and dry weight,relative CAT activity were significantly or very significantly related with each other,the relative vigor index was of a significant positive correlation with the latter three indicators,each two of which had extremely significant positive correlations.Consequently,relative vigor index was a wonderful index for evaluating the drought tolerance.3）membership function analysis showed that the Jiucaiping 2 was of the strongest drought resistance,The next was Guiyan2 and Bina 1 was the weakest.