大蒜根系分泌物对烟草青枯病的影响

为探讨大蒜根系分泌物对烟草青枯病菌的抑菌活性，采用抑菌圈法和盆栽试验研究了大蒜根系分泌物及其主要成分对烟草青枯病的影响。结果表明：大蒜根系分泌物浓度为1g/mL时，对烟草青枯病菌抑制效果最好，其抑菌率为53.67%。大蒜根系分泌物4种成分的抑菌效果由强到弱依次为：2,6-二异丙基苯酚>二烯丙基二硫>2,6-二叔丁基对甲酚>邻苯二甲酸二丁酯。其中，2,6-二异丙基酚对烟草青枯病菌的抑制作用最强，在1和5mmol/L时的抑菌率分别为99.66%和100.00%；在盆栽试验中也具有较好的防治效果，接种后7 d和14 d后，其防效分别为34.75%和31.35%。因此，大蒜根系分泌物及其成分均对烟草青枯病有明显的抑制作用。本研究揭示了大蒜作为轮作或间作作物对烟草青枯病的防控机理，以及大蒜根系分泌物和2,6-二异丙基酚作为烟草青枯病防治剂的潜力。

Effects of Garlic Root Exudates on Ralstonia solanacearum

To investigate the antibacterial activity of garlic root exudates on Ralstonia solanacearum, the effect of garlic root exudates and their main components were tested against tobacco bacterial wilt (R. solanacearum) by inhibition zone method and pot trials. The results showed the inhibitory rate of 1 g/mL crude garlic root exudate extract was higher than those of the other extracts, with the inhibitory rate of 53.67%. The inhibitory effects of the four components, from the strongest to the weakest, were as follows: 2,6-diisopropylphenol＞diallyl disulfide ＞2,6-di-tert-butyl-p-cresol＞dibutyl phthalate. 2,6-diisopropylphenol had the greatest inhibitory effect, with the inhibitory rates of 99.66% and 100.00% at 1 mmol/L and 5 mmol/L, respectively. 2,6-diisopropylphenol had good control effects in the pot trials, with the efficacies of 34.79% and 31.35% at 1 mmol/L and 5 mmol/L at 7 and 14 days after inoculation, respectively. Therefore, the garlic root exudates and its components had significant inhibitory effects against tobacco bacterial wilt. The above results revealed the control mechanism of garlic as a rotation or intercropping crop on tobacco bacterial wilt, and the potential of garlic root exudates and 2,6-diisopropylphenol as a control agent for bacterial wilt in tobacco fields.