Screening and biodiversity analysis of cultivable inorganic phosphate–solubilizing bacteria in the rhizosphere of Hydrilla verticillata

each large branch is divided into two small branches. The first subclade of the first major con- tains three genera (Priestia, Bacillus and Exiguobacterium), and the second subclade contains two genera (Ciceribacter and Asticcacaulis). The first subclade of the second subclade includes one genera (Comamonas), and the second subclade includes three genera (Acinetobacter, Ser- ratia and Aeromonas). The evolutionary distance and kinship of 28 IPB strains in the evolu- tionary tree are shown in Fig 1 and Table 1. Analysis of phosphate-solubilizing characteristic After the screening and purification of the NBRIP medium, 28 IPB strains with a good phos- phate-solubilizing effect were obtained. The OD600, DIP and phosphate-solubilizing efficiency of the culture solution are provided in Table 2. Table 2. Incubation time, OD600, DIP and phosphate-solubilizing efficiency. Strain Number Incubation Time (d) i pH ii OD600 iii DIP (mg/L) iv Phosphate-solubilizing Efficiency CK - 7.0 - 0.23 ± 0.01 f - SWIP-1 4 5.9 1.049 29.28 ± 1.32 c 37% SWIP-3 3 5.3 2.105 38.53 ± 1.74 b 49% SWIP-5 6 6.0 0.695 32.50 ± 1.63 c 45% SWIP-6 4 6.5 1.729 19.84 ± 0.79 d 25% SWIP-7 4 4.9 0.405 49.26 ± 1.48 ab 62% SWIP-8 5 5.0 1.457 44.67 ± 0.88 b 56% SWIP-9 6 6.2 0.221 25.83 ± 0.26 cd 33% SWIP-10 3 5.7 2.208 32.69 ± 0.33 c 41% SWIP-11 5 6.4 1.422 22.27 ± 0.35 d 29% SWIP-12 3 5.2 2.122 39.30 ± 0.39 b 50% SWIP-13 4 6.5 1.760 21.92 ± 0.66 d 28% SWIP-15 5 6.7 1.491 2.19 ± 0.05 e 3% SWIP-16 5 5.4 1.464 33.91 ± 1.21 c 43%

SWIP-18 3 5.1 2.175 35.54 ± 0.89 bc 45% SWIV-1 5 6.6 1.195 14.26 ± 0.14 de 18% SWIV-2 5 6.1 1.165 31.48 ± 0.47 c 39% SWIV-3 4 5.5 1.714 33.37 ± 0.50 c 42% SWIV-7 4 6.2 2.263 24.45 ± 0.38 cd 32% SWIV-10 5 6.3 1.231 24.37 ± 0.49 cd 30% SWIV-11 5 5.2 1.373 39.15 ± 0.96 b 49% SWIV-12 5 5.8 1.356 32.61 ± 0.49 c 41% SWIH-1 5 5.1 1.486 41.28 ± 0.84 b 51% SWIH-2 5 5.3 1.438 37.55 ± 0.58 b 49% SWIH-3 4 6.7 1.748 2.94 ± 0.06 e 4% SWIH-5 3 6.1 2.408 28.48 ± 0.58 c 36% SWIH-7 4 6.4 1.757 20.83 ± 0.31 d 26% SWIH-8 4 6.0 1.804 29.13 ± 0.87 c 37% SWIH-9 4 4.8 1.463 55.74 ± 0.56 a 71% Note: CK: not inoculated. i. Incubation time: the time corresponding to the best phosphate-solubilizing effect of the strain in NBRIP medium. ii. pH: the pH corresponding to the best phosphate-solubilizing effect of the strain in the NBRIP liquid medium. iii. OD600: the OD corresponding to the best phosphate-solubilizing effect of the strain in the NBRIP liquid medium. iv. the maximum DIP value of sample after subtracting the CK DIP value in the NBRIP liquid medium. In the same column, different letters a, b and c indicate significant differences (P < 0.05), the same letters indicate non-significant differences (P > 0.05), and data containing letters such as ab are not significantly different from those containing a and those containing b. https://doi.org/10.1371/journal.pone.0297047.t002 PLOS ONE Screening and biodiversity analysis of cultivable inorganic phosphate–solubilizing bacteria

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