Effects of Feeding Stress of Phthorimaea operculella on Species Diversity and Abundance of Potato Rhizosphere Culturable Bacteria

Purpose The physiological response of potato to the feeding stress of Phthorimaea operculella was studied through the diversity of rhizosphere culturable bacteria, so as to provide scientific basis for the interaction of plant-boring insect-rhizosphere microorganism and the management of P. operculella.

Methods Indoor potted potato “Qingshu No.9” was inoculated with the 3rd instar P. operculella larvae of potato tuber moth. Soil samples were taken from the rhizosphere of potato under feeding stress for 3, 7 and 14 days, and soil bacteria were isolated and cultured on LB medium. Morphological characteristics and 16S rRNA sequencing were used to identify the species of bacteria, and the composition and diversity of culturable bacteria were analyzed.

Results P. operculella feeding stress changed the composition and diversity of rhizosphere soil bacterial. For 3 days-feeding stress, three species of bacteria were specific compared with the control (Rossellomorea aquimaris, Streptomyces longisporoflavus, and Microbacterium algeriense); for 7 days-feeding stress, there were two species more than that of control (R. oryzaecorticis and Paracoccus marcusii); and for 14 days-feeding stress, there were two more species (Chryseobacterium indologenes and Brucella rhizospha). The relative abundance of rhizosphere soil culturable bacteria of potato changed after the feeding of P. operculella, and the greatest change was at 3 days-feeding stress. On the 3, 7, 14 days-feeding stress, the relative abundance of Actinomycete bacteria increased by 23.49%, 12.56% and 28.06%, respectively; and the relative abundance of Arthrobacter bacteria increased by 103.50%, 65.37% and 28.57%, respectively.

Conclusion The feeding stress of P. operculella affects the species and diversity of the rhizosphere bacteria community of potato, and the relative abundance of bacteria in Arthrobacter increases obviously. The results provide a basis for the response of potato rhizosphere to pest feeding stress and the screening of functional bacteria in potato rhizosphere.