College of Plant Protection, Yangzhou University, Yangzhou 225009, China.
CSIRO Agriculture and Food, PMB2, Glen Osmond, SA 5064, Australia.
J Appl Microbiol. 2023 May 2;134(5). doi: 10.1093/jambio/lxad101.
Develop quantitative assays (qPCR) to determine the wheat rhizosphere competence of inoculant strains Bacillus amyloliquefaciens W10 and Pseudomonas protegens FD6, and their suppressive efficacies against the sharp eyespot pathogen Rhizoctonia cerealis.
Antimicrobial metabolites of strains W10 and FD6 decreased in vitro growth of R. cerealis. A qPCR assay for strain W10 was designed from a diagnostic AFLP fragment and the rhizosphere dynamics of both strains in wheat seedlings were compared by culture-dependent (CFU) and qPCR assays. The qPCR minimum detection limits for strains W10 and FD6 were log 3.04 and log 4.03 genome (cell) equivalents g-1 soil, respectively. Inoculant soil and rhizosphere abundance determined by CFU and qPCR were highly correlated (r > 0.91). In wheat bioassays, rhizosphere abundance of strain FD6 was up to 80-fold greater (P < 0.001) than strain W10 at 14 and 28 days postinoculation. Both inoculants reduced (P < 0.05) rhizosphere soil and root abundance of R. cerealis by up to 3-fold.
Strain FD6 exhibited greater abundance in wheat roots and rhizosphere soil than strain W10 and both inoculants decreased the rhizosphere abundance of R. cerealis.
开发定量检测方法（qPCR），以确定生防菌解淀粉芽孢杆菌 W10 和荧光假单胞菌 FD6 在小麦根际的定殖能力及其对禾谷丝核菌病原菌的抑制效果。
W10 和 FD6 菌株的抑菌代谢物在体外抑制了禾谷丝核菌的生长。W10 菌株的 qPCR 检测方法基于一个诊断性 AFLP 片段设计，通过培养依赖（CFU）和 qPCR 检测，比较了这两种菌株在小麦幼苗根际的动态变化。W10 和 FD6 菌株的 qPCR 最小检测限分别为 3.04 和 4.03 个基因组（细胞）当量 g-1 土壤。CFU 和 qPCR 检测到的接种土壤和根际丰度高度相关（r > 0.91）。在小麦生物测定中，FD6 菌株在接种后 14 和 28 天的根际丰度比 W10 菌株高 80 倍（P < 0.001）。两种生防菌都将禾谷丝核菌的根际土壤和根际丰度降低了 3 倍（P < 0.05）。
FD6 菌株在小麦根系和根际土壤中的丰度大于 W10 菌株，两种生防菌都降低了禾谷丝核菌在根际的丰度。
