Identification of bacterial endophytes from champa rice cultivar and study of their effects on growth properties of host plant

Endophytes are symbiont microorganisms within apoplast or symplast of plants that promote growth, control phytopathogens, increase plant resistance to stress and improve plant growth conditions. The aim of this study was identification of endophytes from six rice cultivars in Khouzestan province and assessment of their effects on growth of the host plant. For this purpose, a suspension was prepared from sterilized seeds, and their endophytes were isolated in LB broth. The ability of isolates in nitrogen fixation, auxin production and phosphate solubilizing was discovered. The seeds of Champa cultivar were then infected by endophytes and growth and physiologic outcomes of this treatment were studied. As a result of this study six endophytes belong to Bacillus, Staphylococcus and Erwinia genus were isolated from them only the Erwinia sp. was able to fix N2, dissolve phosphate and produced auxin more than others. Treatment with Erwinia sp. significantly increased the fresh and dry weight of aerial parts and root and aerial part length and density of hair roots. The auxin and carbohydrate content of treated rice with Erwinia sp. had significant difference than control. No significant difference was observed for chlorophyll a and b chlorophylls in different treatments and untreated plants produced more a and b chlorophylls. While there was significant difference for carotenoid between endophyte treated samples and untreated ones. Finally based on the obtained results it can be suggested that Erwinia sp. as an endophyte has significant effect on increasing of Champa cultivar performance and improvement main characteristics of this cultivar.