不同基因型大白菜对外源钙敏感性鉴定评价

为探讨大白菜钙敏感性鉴定的便捷指标,以20个大白菜品种为试材,研究不同钙水平对大白菜不同生育期干烧心指数及植株生长量、叶片叶绿素含量及钙含量的影响。结果表明:不同基因型大白菜干烧心指数差异较大,总体上均随钙水平的升高明显降低,而相同钙水平下则随生育期延长而升高;幼苗期钙水平0 mmol·L~(-1)和莲座期、结球期钙水平0.5mmol·L~(-1)处理的干烧心指数聚类结果基本一致。采用多元逐步回归分析建立的幼苗干烧心指数回归模型中,仅幼苗期0.5mmol·L~(-1)与4.0 mmol·L~(-1)钙水平下的植株鲜质量及叶片叶绿素含量相对值入选,且以入选变量为参数进行聚类分析的结果与幼苗期干烧心指数聚类结果完全一致,均可将参试大白菜品种分成钙敏感型、钙迟钝型和中间型3类,说明幼苗期0.5mmol·L~(-1)和4.0 mmol·L~(-1)钙水平下的大白菜植株鲜质量与叶片叶绿素含量相对值可作为大白菜品种钙敏感性鉴定的便捷指标。

Identification and Evaluation of Sensitivity to Exogenous Calcium in Different Genotypes of Chinese Cabbage

In order to probe convenient indexes for identifying Chinese cabbage〔Brassica campestris L. ssp. pekinensis（Lour）Olsson〕calcium sensibility，this paper took 20 varieties of Chinese cabbage as test material，and studied the effects of different calcium levels on leaf tip burn index at different growth stages of Chinese cabbage and plant growth，leaf chlorophyll content，leaf calcium content．The results showed that there were bigger differences in the leaf tip burn indexes among Chinese cabbage of different genotypes．Generally，the leaf tip burn index decreased obviously with the increase of calcium levels．While，it increased with the extension of growth period under the same calcium level．Clustering analysis indicated that Chinese Cabbage leaf tip burn index of seedling stage at the calcium level 0 mmol·L^-1 was consistent with that of rosette and knot stage at calcium level 0.5 mmol·L^-1．The leaf tip burn index regression model established by regression analysis indicated that only the relative fresh weight and relative leaf chlorophyll content of plants treated at the seedling stage with calcium levels of 0.5 mmol·L^-1 and 4.0 mmol·L^-1 were selected．Results of clustering analysis using the selected variables as parameters were consistent with those of the leaf tip burn index of seedling stage by clustering analysis． Both clusters could classify Chinese cabbages into 3 categories：calcium sensitive，dullness，and intermediate type．All these data suggested that the relative fresh weight and relative leaf chlorophyll content of plants treated with calcium levels of 0.5 mmol·L^-1 and 4.0 mmol·L^-1 at the seedling stage could be used as convenient criteria to identify calcium resistant Chinese cabbage varieties．