Isolation and Functional Exploration of Endophytes from Different Geographical Origins of Polygonatum kingianum

To investigate the diversity composition and related characteristics of endophytes in Polygonatum kingianum, the endophytes were isolated by grinding, dilution and coating method from 7 geographical provenances. And the function of endophytes were preliminarily explored based on antagonistic plate bioassay, nitrogen-fixation, phosphate-solubilization, potassium-solubilization tests as well as seed germination-promotting experiments. The results indicated that a total of 104 strains of bacteria, 1 strain of actinomycete and 1 strain of fungus were obtained, of which the number of endophytes isolated from cultivated species in Dali Xiaguan was the largest. There were 41, 49, 35, 34 and 54 strains of antagonism to Fusarium graminearum, Fusarium oxysporum, Alternaria alternata, Polytrichosis pseudodiscoides and Colletotrichum falcatum, respectively. It should be noted that T114, T115, T116 and T117 have antagonistic effects on a variety of pathogens. Meanwhile, 8 bacterial strains could fix nitrogen, with D2−10, D2−5, and D2−15 strains showing better effects, and 2 strains solubilize potassium. In the growth promotion experiment of D2−5 strain, 10⁴ cfu/mL bacterial solution has a promoting effect on the growth of wheat. The seed germination rate, aboveground fresh weight, aboveground dry weight, root length and root fresh weight increased by 95.84%, 54.35%, 48.60%, 35.96% and 30.00% respectively compared to the control. Based on morphological characteristics D2−5 strain was identified as Kosakonia cowanii. Through preliminary functional identification, some potential probiotics have been screened.