Screening and Microcapsule Preparation of Dark Septate Endophytes for Increasing Wheat Yield Under Drought Conditions

ABSTRACT Drought is a major threat to wheat production. Utilising microbial inoculant technology to enhance crop drought resistance to achieve high yield has emerged as a promising strategy. Dark septate endophytes (DSEs) can improve plant drought resistance; however, there is little research on the DSE inoculant preparation. In this study, two dominant DSE strains, Alternaria alstroemeriae ( Aa ) and Paraphoma chrysanthemicola ( Pc ) were screened through the DSE inoculation experiment of wheat under drought stress. Finally, the optimal embedding material ratio of DSE microcapsules was obtained by measuring the embedding rate, and the degradation rate of prepared microcapsules was evaluated. The results indicated that Aa and Pc significantly increased the tiller number and biomass of wheat under drought stress, and the yield and quality indices of wheat, including spike length, spike weight, grain number, thousand grain weight and alcohol‐soluble protein and soluble sugar content in the grain, also significantly increased. The results of microcapsule preparation optimisation revealed that the optimal reagent ratio was 4% sodium alginate, 3% calcium chloride, 1% kaolin and 1% trehalose. The degradation rate of the microcapsules prepared under the optimal conditions increased significantly at 5–15 days and then stabilised. This study is highly important for improving crop productivity in arid areas and provides a theoretical basis for the microbial inoculant preparation.