不同抗旱性油菜种子萌发期抗旱指标比较研究

The comparative study on drought resistance index of rape with different drought resistance in germination

采用不同浓度（8％一25％）的PEG一6000高渗溶液，对田间表现为不同抗旱等级的5份油菜品种进行种子萌发期渗透胁迫试验，统计分析相对发芽率、相对根长和相对芽长3个指标的变化规律及其与材料萌发期抗旱性的关联度，筛选油莱萌发期的抗旱性鉴定指标。PEG一6000浓度为19％时，不同抗旱性材料的相对发芽率平均为60．6％，变异系数为51％，强抗旱材料达到90％以上。相对根长平均为57．3％，变异系数为17．9％，强抗旱材料达到70％以上。各材料间差异显著。相对发芽率、相对根长与材料萌发期抗旱性的相关度〉0．9。相对发芽率、相对根长可作为油菜萌发期抗旱性鉴定的可靠指标。PEG一6000浓度为19％时，相对发芽率〉90％、相对根长〉70％的材料，可初步认定具有较强的抗旱性。

For studying the drought resistance index of rape in germination, this paper investigated the germination of rape varieties with different drought resistance under PEG 6000 stress condition with the concentration ranging form 8 % to 25 %. The change rule of three indexes, i.e. relative germination rate, root length, bud length, and its correla tion with drought resistance were statistically analyzed. The results showed that in 19 % concentration of PEG 6000, the relative germination percentage of different materials averaged at 60.6 % with a coefficient of variation 51% and the rela tive germination of the strong drought resistance materials exceeded 90 % . The relative root length averaged at 57.3 % with a coefficient of variation 17.9%, and the relative root length of the strong drought resistance materials exceeded 70 % . The correlation coefficient between relative germination percentage, root length and the drought resistance of rape in sprouting period were larger than 0.9. The relative germination percentage of seeds and the relative root length were the reliable indexes identified as strong for idenfication of drought resistance of rape in sprouting period . The materials could be preliminary drought resistance, if whose relative germination was over 90 % and relative root length was over 70 % under the 19% concentration of PEG 6000.