黄瓜枯萎菌粗毒素对不同抗性黄瓜种子萌发及幼苗胁迫作用研究

Seed germination and growth of various resistant cucumber seedlings under Fusarium oxysporum crude toxin stress

利用黄瓜枯萎菌粗毒素处理不同抗性品种黄瓜,研究粗毒素对黄瓜种子萌发及幼苗生长的影响,结果表明:粗毒素对不同抗性的黄瓜胚根生长和侧根分化均有抑制作用,且随处理浓度增加,抑制作用愈加明显,但粗毒素对感病品种的抑制作用强于抗病品种。粗毒素胁迫使黄瓜胚根的细胞膜透性、MDA含量、可溶性糖含量增加,其中感病品种的细胞膜透性和MDA含量高于抗病品种,但可溶性糖含量低于抗病品种。在粗毒素处理36 h内,抗感品种黄瓜幼苗的PAL、PPO和POD酶活性均呈现先升高后降低的趋势,其中PAL和PPO的峰值出现在粗毒素处理12 h,而POD的峰值出现在粗毒素处理24 h,抗病品种的3种酶活性峰值高于感病品种。表明抗病品种对黄瓜枯萎菌粗毒素胁迫的抵抗能力强于感病品种。

The effect of Fusarium oxysporum crude toxin stress on seed germination and growth of various resistant cucumber seedlings were researched.The results show that radicle growth and lateral root amount of various resistant cucumber seedlings are suppressed by F.oxysporum crude toxin.The more concentrated the toxin is,the more germination and growth are suppressed.However,the degree of suppression of susceptible varieties is higher than that of resistant varieties.Under F.oxysporum crude toxin stress,cell membrane permeability,MDA and soluble sugar contents increase.Cell membrane permeability and MDA content of susceptible varieties are higher than those of resistant varieties,but the soluble sugar content is lower.Under F.oxysporum crude toxin stress for 36 h,PAL,PPO and POD activity initially increases but subsequently drops.PAL and PPO peak value occurs after 12 h of continuous stress,but POD peaks after 24 h.Peak values of PAL,PPO and POD of resistant varieties are higher than those of susceptible varieties.The capability of resistance to F.oxysporum crude toxin of resistant varieties precede that for susceptible varieties.