假俭草叶片渗透调节物质含量对冬前低温的响应及其与低温伤害的关系

在2014年11-12月冬季降温期间,田间小区试验研究了8个不同基因型假俭草的抗寒性与叶片细胞内可溶性多糖、脯氨酸,以及游离态腐胺、亚精胺、精胺等渗透调节物质含量的关系。结果表明,在冬前降温过程中,假俭草其叶片色泽持续下降,叶片相对电导率与丙二醛(MDA)的含量持续升高。基因型E02、E07、E09和E10在降温过程中的相对电导率与MDA的含量显著低于其他4个基因型,而叶片内的可溶性多糖、脯氨酸、亚精胺和精胺含量则显著高于其他4个基因型。相关分析结果表明,可溶性多糖、脯氨酸、亚精胺和精胺含量与假俭草的耐寒性存在显著正相关。因此,可溶性多糖、脯氨酸、亚精胺和精胺等渗透调节物质对增强假俭草的耐寒性有重要作用。

Response of leaf osmolyte content to low temperature in autumn,and its relationship with chilling injury in centipede grass

Cold stress is a major problem for centipede grass (Eremochloa ophiuroides) and leaf osmolyte level is generally understood to be closely related to cold tolerance, but there are few studies specifically investigating response to cold stress in centipede grass. In this study, the relationship between cold tolerance of eight different genotypes and their leaf osmolyte content was studied in yield plot experiments conducted in Jurong Jiangsu during the winter chilling period from November to December of 2014. Our results indicated that the leaf color (greenness) was consistently decreased, while the leaf electrolyte leakage (EL) and malonaldehyde (MDA) contents were consistently increased during exposure to autumn chilling. Among the 8 genotypes, the EL and MDA content of genotypes E02, E07, E09 and E10 were significantly lower than those of the other four genotypes. However, the contents of soluble sugar, proline, spermidine and spermine of these genotypes were significantly higher than those of other genotypes. A correlation analysis of the data demonstrated a positive link between cold tolerance of centipede grass and particular osmolyte contents, in particular: soluble sugar, proline, spermidine, and spermine. Therefore, those four osmolytes in leaves play important roles in enhancing cold tolerance of centipede grass.