Endophytic Bacteria and Their Effects on Improve Growth of Rice

Abstract

Thirteen isolates were obtained from the rice roots of Khao Jow Hawm Suphan Buri variety and tested for plant growth promotion ability. All of these isolates were able to solubilize tricalcium phosphate (Ca3(PO4)2) in the range of 421.7-465.9 µg/ml to produce auxin and gibberellin in the ranges of 8.0-21.9 µg/ml and 143.7-292.1 µg/ml, respectively. Overall, the results showed that the isolate KJHSB-9 was the most efficient. Sequence analysis of the PCR product indicated that the 16S rDNA gene of the isolate KJHSB-9 was 98% identical to the same region of Bacillus safensis. The KJHSB-9 was inoculated onto Pathum Thani 1 and Khao Jow Hawm Suphan Buri rice varieties to examine the plant growth promotion ability in pot experiments. The results indicated that the application of N and P fertilizers with the endophytic bacteria KJHSB-9 resulted in enhanced height of rice, number of tillering, number of ears/plants, and grain yield by 5.83%, 42.62%, 43.27% and 38.42% respectively, when compared with the control. Moreover, the results indicated that the application of N and P fertilizers with KJHSB-9 resulted in enhanced height of rice, number of tillering, number of ears/plants, and grain yield by 3.15%, 22.56%, 2.55% and 9.94%, respectively, when compared with the application of N and P without KJHSB-9.