Research And Development Of A New Type Of Coated Wheat Seads Based On A Bacterial Endophyte

Wheat is an important food crop worldwide. Keeping sustainable development of wheat production has an important significance for social stability and progress. Wheat stripe rust caused by Puccinia striiformis West f. sp. tritici Eriks et Henn and leaf rust by Puccinia triticina Eriks are constraints for sustainable development of wheat production. The control of the two diseases largely depend on chemical fungicides for wheat production at present. However, the overuse of fungicides might result in chemical residues in the environments and agro-products.Although breeding and application of wheat varieties resistant to the two diseases can be considered as an effective and ecofriendly means of controlling the two diseases, it is time-consuming and laborious to breed a new variety with both excellent agronomic traits and high resistance to the diseases. Furthermore, a newly popularized disease-resistant variety is easy to lose its resistance to the disease(s) after years of application due to the appearance of a new race virulent to the variety. Using wheat-endophytic microbes can be considered another encofriendly means of controlling wheat diseases and enhancing wheat yield. In the present study, the 16 S rDNA sequence of a bacterial endophyte(Bs-8)was amplified and a phylogenetic tree was established based on 16 S rDNA sequences for molecular identification of the bacterial endophyte.Two seed coating formulations(A and B) were prepared using strain Bs-8as a principal constituent. The seed germination safety of the two formulations was tested. Field trials of the two formulations were performed to test the efficacies of the formulations in controlling stripe rust and leaf rust and enhancing yields on multiple wheat varieties. Thestrain Bs-8 was identified as a member of Bacillus subtilis based the comparison of 16 S rDNA sequences between strain Bs-8 and other Bacillus spp. The results of seed safety tests indicated that the two formulations had no negative effects on the germination rates of the majority of wheat varieties tested. However, the see germination rates were significantly suppressed on a few varieties. The results of field tests showed that the formulation B had a significant efficacy in controlling the single infection of stripe rust or the complex infection of stripe rust and leaf rust on most of the wheat varieties tested. Furthermore, significant yield enhancements were observed on the formulaion B-treated plots compared to their respective control plots, revealing a promising application prospect of the seed coating formulation.