Soil microbes are linked to the allelopathic potential of different wheat genotypes

摘要

Soil micro-circumstance and biological stress resistance were studied to validate our hypothesis that the allelopathic potential that was enhanced by breeding resulted partially from rhizophere microbes associated with the different varieties. The rhizosphere soils from four wheat genotypes with different allelopathic potential were collected so as to compare their soil micro-environments and bio-pressure tolerances. The levels of these three categories such as bacteria, fungi, and actinomycetes ranged among 1.54-26.59 x 10(6), 0.43-4.12 x 10(4), and 1.36-18.25 x 10(5) CFU/g soil, respectively. Wheat 22 Xiaoyan with greater allelopathic potential had higher levels of microorganisms than the other three genotypes having weak allelopathy. The soil microbial carbon and nitrogen analyses suggested that wheat could create an active microhabitat with high activities of key soil enzymes such as urease, catalase, sucrase, and dehydrogenase. Using the approximate concentrations detected in wheat rhizosphere soils, the leachates of all four wheat materials significantly inhibited the growth of the weed Descurainia sophia and take-all pathogen Gaeumannomyces graminis var. Tritici. Wheat exudates provided carbon and nitrogen resources for the relevant microorganism. Meanwhile, the rhizosphere soil microbes contributed to allelopathic potential of wheat by positive feedback.