Evaluating the effects of cold water diffusates against Xanthomonas oryzae Pv. Oryzae causing bacterial leaf blight (BLB) in rice

Abstract

The crude extracts of 63 plants were used for testing antibacterial activity against Xanthmonas oryazae Pv. oryzae that causes bacterial leaf blight (BLB) in rice plants. Only ten aqueous extracts of botanicals (Thuja orientalis, Prunus domestica, Citrus limon, Allium sativum, Vitis vinefera, Mangifera indica, Phyllanthus emblica, and Terminalia chebula) showed maximum activity against Xanthmonas oryazae in a plate agar diffusion assay. On a detached leaf, in a glasshouse and in a field assay, two potential plant extracts, namely Allium sativum, and Citrus limon showed maximum efficacy in terms of controlling BLB lesions in rice. After isolation through fractionation of the crude extract of Allium sativum, the bioactive compound was purified and characterized as 8-amino(-8-butoxyoct)-2-(enyldisulfanyl)-3-(2hydroxy-4-methoxyphenylprop-1-enyl) benzene-1,3-diol.

Keywords:

• Xanthomonas oryzae
• phytochemical studies
• botanicals
• BLB
• rice