标题：STUDY ON STRUCTURAL DIFFERENCE OF BACTERIAL FLORA IN THREE MAJOR ECOLOGICAL NICHES OF DIFFERENT INCIDENCE STAGES OF WILD P. Massoniana INFECTED WITH Bursaphelenchus xylophilus BASED ON HIGH-THROUGHPUT SEOUENCING
摘要：As one of the major forest diseases in the world today, Bursaphelenchus xylophilus is difficult to di-agnose and treat, causing huge economic losses. At present, preliminary studies have been made on the early diagnosis of Bursaphelenchus xylophilus through changes in the structure of the microbial flora. However, according to the complex wild-growing environment, there are still no related schol-ars to study and report the differences in the micro-bial flora structure with different degrees of disease and different sampling locations. In the experiment of this study, by analyzing bacteria in different eco-logical tissue parts of different disease levels of Pi-nus massoniama in the field with high-throughput se-quencing technology, it was found that the structures ofthe in vivo flora of healthy Pinus massoniana and different parts of the diseased pine affected by pine wood nematode were significantly different. The re-sults showed that the bacteria in healthy Pinus mas-soniana was mainly composed of unidentified Oxy-photobacteria, Sphingomonas leidyi, Beijerinckia sp M016010, Methylobacterium komagatae, and un-known bacteria. After inoculation with pine wood nematodes, the bacterial flora diversity in the Pinus massoniana samples increased with the increase of the infection time and disease level Along with the sharp decrease in unidentified Oxyphotobacteria, the bacteria abundance of Sphingomonas leidyi,Para-doxia multiseta, Luteibacter rhizovicinus,Burkhold-eria sp symbiont of Dicranocephalus medius,El-liptochloris bilobata,Beijerinckia sp M016010, Clostridium disporicum, Methyobacterium koma-gatae and Amantichitinumursilacus all increased. With horizontal comparison of three different tissue niches of Pinus massoniana,it was found that during the pinewood nematode infestation, the flora struc-tures of pine needles and pine branches were similar, showing a sharp decrease in the abundance of uni-dentified Oxyphotobacteria, but a significant in-crease in the abundance of Paradoxia multiseta,Burkholderia sp symbiont ofDicranocephalus me-dius, Beijerinckia sp M016010,and unknown bacte-ria. However, the structural diversity of pine stems was slightly different, which was mainly manifested by a significant increase in the abundance of Clos-tridium disporicum,Luteibacter rhizovicinus, and unknown bacteria. At the same time, after different tissue parts were infected by pine wood nematode, the flora structure of Pinus massoniana changed sig-nificantly when the first-level disease characteriza-tion occurred. From the diversity and richness of the detected flora structure, it can be seen that the bacte-rial flora structures of pine branches and pine needlesare similar, and their bacteria abundancesare higher than that of pine stems,and the abundance of the pine branches is the highest. By analyzing the differences in the bacterial flora structure in the three major ecological nichesofdiseased Pinus massoni-amna with different levels of Bursaphelenchus xy-lophilus, this study provides data support for the fur-ther use of the differences in microbial flora structure to diagnose Bursaphelenchus xyophilus in Pinus massoniana. Meanwhile, it provides technical guid-ance at the selection of sampling and detecting sites.
关键词：High-throughput sequencing;Bursqphelenchus xy-lophilus;in vivo bacteria;Pimus massonina;Disease level
