复硝酚钠对低温下黄瓜种子萌发和幼苗耐寒性的影响

为缓解低温胁迫对黄瓜(Cucumis sativus L.)幼苗的伤害,以黄瓜中农106为试验材料,研究不同浓度复硝酚钠(CSN)浸种对低温胁迫下黄瓜种子萌发及萌发后生长的影响,以及CSN灌根处理对黄瓜幼苗壮苗效果及幼苗耐寒性的影响。结果表明,适宜浓度的CSN浸种能显著提高低温胁迫下黄瓜种子的发芽率、发芽势、发芽指数、活力指数、侧根数和鲜重,以50 mg·L^-1浓度效果最佳。在黄瓜育苗过程中,100 mg·L^-1的CSN灌根处理能显著提高穴盘苗质量和壮苗指数,低温胁迫下CSN通过促进矿质元素吸收,提高幼苗叶绿素含量、净光合速率、根系活力、可溶性蛋白含量和抗氧化酶活性,提高生长素(IAA)和油菜素内酯(BR)含量,降低活性氧和丙二醛(MDA)含量以提高幼苗的耐寒性。本研究为培育黄瓜壮苗和提高黄瓜幼苗耐寒性提供了新方法,也为复硝酚钠在设施蔬菜上的应用提供了技术支持。

Effect of Compound Sodium Nitrophenolate on Seed Germination and Seedling Cold Tolerance of Cucumber Under Low Temperature

In order to alleviate the damage of cucumber (Cucumis sativus L.) seedlings under low temperature, a cold-sensitive cucumber genotype (cv. Zhongnong 106) was used in this study to investigate the effects of compound sodium nitrophenolate (CSN) on seeds germination and seedling growth of cucumber under low temperature via soaking seeds or root application to the substrate of CSN. The results showed that soaking seeds with appropriate concentration of CSN significantly improved the germination rate, germination index, vigor index, number of lateral roots and fresh weight of cucumber during low temperature, and the optimal concentration of CSN was 50 mg·L^-1. Moreover, during the growth of cucumber seedling, addition of 100 mg·L^-1 CSN in substrate could significantly improve the quality and seedling index of seedlings exposed to low temperature, and enhance cold tolerance by increasing the mineral elements absorption, chlorophyll content, net photosynthetic rate, soluble protein content, proline content, root activity, the activities of antioxidant enzyme (superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase), the contents of IAA and BR but reducing the content of hydrogen peroxide and malondialdehyde. This study provides a new method for cultivating strong cucumber seedlings and improving the cold tolerance of cucumber seedlings, and offers technical support for the application of CSN in the cultivation of protected vegetables.