外源BR诱导小白菜对霜霉病抗性的研究

Induction of Resistance to Downy Mildew in Brassica campestris ssp. chinensis L. by Brassinolide

以小白菜为材料,采用叶面喷洒的方法施用不同质量浓度的油菜素内酯(BR),研究BR对小白菜霜霉病的抗性诱导效应。结果表明,0.01～0.15mg/L BR处理均能极显著降低小白菜霜霉病的病情指数,其中,0.10mg/L BR诱导处理的病情指数最低,为29.36,极显著低于其他处理,此时抗病效果为36.60%。另外,经0.10mg/L BR诱导处理后,小白菜的株高达8.26cm,单株鲜质量达5.940g,单株干质量达0.780g,均高于其他处理和对照。研究还发现,BR处理后的第5天是诱导小白菜对霜霉病抗性效果最佳时间。

The resistance induction of brassinolide to downy mildew in pakchoi（Brassica carnpestris ssp. chinensis L. ） was studied by the method of leaf spraying. The results showed that BR treatment at 0.01-0.15 mg/L could significantly reduce the disease index of pakchoi downy mildew. The disease index of BR treatment at 0. 10 mg/L was 29.36, significantly lower than the other treatments, when the resistance effect was 36.60%. In the same treatment, the plant height（8. 26 cm）, fresh weight（5. 940 g） and dry weight （0. 780 g） of pakchoi were higher than those in the other treatments. In addition, the best time for induction of resistance by BR was the 5th day after treatment.