Abstract:

【Objective】 Bacillus cereus NJSZ-13 strain is an endophytic bacterium in pine which can kill pine wood nematodes (Bursaphelenchus xylophilus). This study investigated whether this strain could induce the resistance of masson pine(Pinus massoniana) to pine wood nematodes which provides a theoretical basis for further development and utilization of this strain. 【Method】 The disease development of different treatments were observed and studied by inoculating with pine wood nematodes at four days after applying the bacterial suspension and inactivated bacterial suspension of NJSZ-13 strain on the roots of two years old masson pine seedlings. The changes of defense-related enzyme activities in masson pine were determined within 4 days after applying the bacteria and within 28 days after inoculating with pine wood nematode AMA3 strain.【Result】 The results showed that at 42 days after inoculated with pine wood nematodes, the effects of the bacterial suspension and inactivated bacterial suspension which induce the resistance of masson pine to pine wood nematode were 54% and 33%, and the disease occurrence time was delayed. After inoculation of NJSZ-13 strain, the content of MDA in the masson pine decreased, the activity of CAT decreased, and POD,SOD,PAL,PPO activities were significantly higher than those of the control. After inoculation with the pine wood nematode, the activity of the five enzymes of P. massoniana treated by the suspension and the inactivated suspension was significantly higher than that of the control, and the suspension showed higher changes in the index of massion pine than that of the inactivated suspension.【Conclusion】 Bacillus cereus NJSZ-13 strain could induce the resistance of masson pine to pine wood nematodes and the cell suspension is better.

Key words: endophytic bacteria, Bacillus cereus, Pinus massoniana, induced disease resistance, Bursaphelenchus xylophilus