Soybean Bacterial Endophytes against Anthracnose Disease Collected from Karnataka State: An in-vitro Study

Endophytes trigger various defence mechanisms within their host plants, engaging primary and secondary protective pathways. This investigation primarily aimed to isolate bacterial endophytes from diverse agroecological regions in Karnataka. Subsequently, these endophytes were assessed for their inhibition against Colletotrichum truncatum using the in-vitro streak plate technique. A total of 43 bacteria isolated from soybean plants and key endophytes showing the inhibition against C. truncatum were in different zones namely, DHW-9(87%), BID-2(85%), BID-13(85%), BID-14(82.50%), DHW-15(80%), BID-15(75%),and BID-16(75%) exhibited notable efficacy against C. truncatum in decreasing order. Among these, the DHW-9 (Stenotrophomonas maltophilia strain P4-32) bacterial endophytes isolated from the North Transition Zone (Dharwad) were highly effective against the pathogen, possibly due to employing many direct and indirect mechanisms. Furthermore, the inhibition potential of the bacterial endophytes varies with and within the place of agroecological zones. In conclusion, it has been observed that the bacterial endophyte DHW-9 inhibited the progression of anthracnose disease caused by C. truncatum in controlled in vitro. Hence, it is imperative to conduct additional experiments, including pot and field studies, to explore its potential to enhance the growth and yield of soybean plants.