Abstract
The germination of paddy seeds is vital for seedling establishment and subsequent development. Impaired rice seed germination often results from reduced levels of bioactive gibberellins (GAs) caused by environmental stress. This inhibition can be alleviated through methods such as hormone priming, nutrient priming, and osmopriming, which stimulate α-amylase activity and trigger other developmental processes. Recently, novel biopriming approaches have emerged, involving seed treatment with diverse plant growth-promoting rhizospheric microbes. Reports indicate that actinobacteria are among the least studied biopriming agents. In this study, approximately 43 actinomycete isolates were obtained from rhizospheric soils associated with the rice variety Indrayani. Data showed significant improvements in germination following seed biopriming with four multifunctional isolates, with Streptomyces ardesiacus strain I7 achieving the highest vigor index. Streptomyces antibioticus strain I4 demonstrated notable antimicrobial activity against Xanthomonas oryzae pv. oryzae (Xoo). Colonization of actinomycetes on rice roots was confirmed using scanning electron microscopy. These isolates hold potential for development into a commercial microbial consortium.