Phoma herbarum: A Potential Biocontrol Agent Against Weeds, that Promotes Wheat Growth

Abstract

The usage of chemical weedicide adversely affects the soil fertility and environment. Hence, in order to reduce the use of chemical weedicide, current study was aimed to isolate plant pathogenic microorganisms from diseased weeds and evaluate their potential as a bioherbicide in wheat field. Twelve bacterial and thirty-one fungal isolates were screened to determine their bioherbicidal activity against prevalent weeds (Avena fatua, Phalaris minor, and Chenopodium album) by using detached leaf assay and in-vitro seed testing methods. Among the forty-three isolates, two potential isolates were selected for further studies. Potential fungal isolates DGL 8C and DGL 7A with significant bioherbicidal activity were molecularly (ITS sequencing) identified as Phoma herbarum R21 (GenBank ID- ON705696) and K_NESO2 (GenBank ID- ON705704). Phoma herbarum R21 was chosen for further research due to its superior herbicidal effect and positive influence on wheat growth. Effective herbicidal activity (up to 90%) of potential isolate was obtained in pre-germination testing, compared to control. Cell free culture filtrate (CFCF) treatment showed nonspecific inhibition in the germination of weeds and wheat. While, CFCF selectively deteriorated the target weeds in post-germination treatment. Phoma herbarum R21 enhanced the growth of Durum wheat varieties Poshan and Tejas, as it promoted the growth of shoot, root, and fresh weight up to 88% compared to control. Phoma herbarum R21 significantly inhibited the growth of phytopathogenic fungi up to 57%. In this study, Phoma herbarum R21 was identified as a potential bioherbicide against the weeds of wheat along with its growth promoting and antifungal activities.