Bacterial Diversity Change after Soil Fumigation and its Effect on the Population of Root-Knot Nematode

In order to explore the effects of soil fumigation on its bacterial diversity and root-knot nematode populations, the greenhouse tomato soil with root-knot nematode disease was fumigated during the summer idle period. This experiment used the high-efficiency organic sulfur soil fumigation treatment "Wofengkang"300 kg/hm2 to fumigate on the greenhouse tomato soil with a root-knot nematode incidence rate of 64.37% and a disease index of 60.18. Soil samples were collected before and after fumigation to determine the index of bacterial diversity and the populations of root knot nematodes. The results showed that a total of 2 kingdoms, 36 phyla, 117 classes, 227 orders, 368 families and 614 genera were detected after soil fumigation and the archaea was significantly reduced by 98.42%. There was no significant difference in all phyla before and after soil fumigation (p>0.05). After soil fumigation, Gammaproteo bacteria containing multiple pathogenic genera significantly decreased by 34.36%; Xanthomonadales, the pathogens of plant fusarium wilt and canker, significantly decreased by 34.21%; Xanthomonidaceae that can infect more than 400 plant varieties significantly decreased by 41.52%; Burkholderia, which is a rhizosphere microorganism for biodegradation, biological control and promotion of plant growth in agriculture, significantly decreased by 89.62%. Generally, the high-efficiency organic sulfur soil fumigant "Wofengkang"300 kg/hm2 in plots with more serious incidence of root-knot nematode disease can significantly reduce the diversity of pathogenic microorganisms and the populations of root-knot nematodes. This can provide new measures for the effective prevention and control of greenhouse root-knot nematodes in the future and has great practical guiding significance.