Bulletin of Botanical Research ›› 2025, Vol. 45 ›› Issue (5): 827-836.doi: 10.7525/j.issn.1673-5102.2025.05.016

• Original Paper • Previous Articles    

Selection of Superior Families of Larch Resistant to Pine Wood Nematode Disease

Min ZHAO1, Feng WANG1,2,3,4, Jianan WANG2, Qi YU2, Hanguo ZHANG1, Lei ZHANG1()   

  1. 1.State Key Laboratory of Tree Genetics and Breeding(Northeast Forestry University),Harbin 150040
    2.Key Laboratory of Alien Forest Pest Detection and Control-Heilongjiang Province(Northeast Forestry University),Harbin 150040
    3.Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education(Northeast Forestry University),Harbin 150040
    4.Liaoning Provincial Key Laboratory of Dangerous Forest Pest Management and Control(Shenyang Institute of Technology),Shenyang 110001
  • Received:2024-10-16 Online:2025-09-20 Published:2025-09-28
  • Contact: Lei ZHANG E-mail:zhanglei@nefu.edu.cn

Abstract:

In this study, 18 2-year-old Larix gmelinii families were used as materials, and the seedlings were inoculated with the highly pathogenic pine wood nematode strain FSBX by peeling casing method. By calculating the anti-symptom score, insect resistance score and disease resistance score, the larch families with resistance to pine nematode disease were comprehensively screened. Physiological indicators including contents of chlorophyll, soluble sugar, soluble protein, and activities of superoxide dismutase(SOD) and peroxidase (POD) were measured at 0th, 5th, 10th and 15th day post-inoculation, respectively. The change trend of physiological indexes of larch in the process of resistance to pine wood nematode was explored. The results indicated that larch family 1311 achieved the highest disease resistance score, followed by families 1305 and 1310. Chlorophyll content of the larch families with all resistance levels initially decreased, then increased, and then decreased again. POD activity showed a pattern of first decreasing, then increasing and then slightly declined. On the 15th day, highly resistant families demonstrated significantly higher POD activity than that of the other families. SOD activity displayed an initial increase, followed by a decrease and peaking on the 10th day, and highly resistant families showed significantly higher levels than that of the other families. The soluble protein content showed a trend of decreasing first and then increasing. On the 15th day, the soluble protein content of the high-resistance family was higher than that of the other two groups, and the difference was not significant. Soluble sugar content showed a decrease-increase-decrease pattern, peaking on the 10th day for all families, and susceptible families showed higher levels than moderate-resistance families, and that moderate-resistance families showed higher levels than high-resistance families, but there was no significant difference among the three groups. In conclusion, the high-resistance families showed significant advantages in chlorophyll content, POD and SOD activity, while the contents of soluble sugar and soluble protein were generally lower than those of the other families. However, in the later stage of inoculation, the physiological indexes of high-resistance families were higher than those of medium-resistance and susceptible families, indicating that high-resistance families could maintain high resistance in the later stage of inoculation.

Key words: Bursaphelenchus xylophilus, Larix gmelinii, family selection, physiology and biochemistry, growth characteristics

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