Bio-efficacy of Trichoderma isolates and Bacillus subtilis against root rot of muskmelon Cucumis melo L. caused by Phytophthora drechsleri under controlled and field conditions

Abstract

Root rot of muskmelon caused by Phytophthora drechsleri (Tucker) is considered the most important disease limiting muskmelon production in Pakistan. In this study, three molecularly characterized isolates of Trichoderma (T. harzianum HK, T. harzianum HM, T. asperellum TH) and phenotypically characterized isolate of Bacillus subtilis were evaluated against P. drechsleri under laboratory conditions. The different antagonism assays such as, dual culturing, non-volatile, volatile metabolites and field conditions were tested. The results showed that all tested isolates of Trichoderma and Bacillus subtilis significantly (p<0.001) inhibited the mycelial growth of the pathogen. In all dual cultures, T. asperellum TH showed maximum mycelial inhibition followed by T. harzianum HK, T. harzianum HM and Bacillus subtilis. Non-volatile metabolites were more effective against pathogens than volatile metabolites. Under field conditions, percent disease incidence was decreased while percent plant survival, dry root and shoot weight significantly (p<0.001) were increased by the application of To (combination of all tested Trichoderma isolates and B. subtilis) followed by T. asperellum TH during both growing seasons. It is suggested that bio-control agents can be used for the sustainable management of root rot of muskmelon. (Cucumis melo L.

Bacillus velezensis CE 100 Inhibits Root Rot Diseases (Phytophthora spp.) and Promotes Growth of Japanese Cypress (Chamaecyparis obtusa Endlicher) Seedlings

“…In particular, PGPR secretes auxins, such as indole-3-acetic acid (IAA), which improve the growth of shoots and roots by increasing root surface area, which in turn, promote nutrient uptake [ 23 , 24 , 28 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. Specifically, Bacillus species possess significant inhibitory activity against various phytopathogens, including Phytophthora capsici [ 40 , 41 ] and Phytophthora drechsleri [ 42 ]. In addition, Bacillus species are known to produce auxins, which promote plant growth [ 31 , 32 , 33 , 34 , 35 ].…”

​Induction of Systemic Resistance against Phytophthora Blight in Pigeonpea Through the Interaction of Plant Growth Promoting Rhizobacteria: In vivo and in vitro Study

“…Out of 7 antagonists S-18 (39.6%) isolate showed the highest mycelial growth inhibition against the test fungus as compared to others (Table 3). Similar studies were conducted by (Anjum et al 2019) reported the bioactivity of biocontrol agents against Phytophthora drechsleri infection was studied in vitro. T. asperellum (47.3%) showed the highest growth rate of Phytophthora drechsleri in potato dextrose.…”

A systematic review about biological control of phytopathogenic Phytophthora cinnamomi

“…Moreover, these treatments also presented plant growth-promotion traits, demonstrated by the increase in dry root and dry shoot weights. However, the most efficient treatment was the combination of all biocontrol agents, which showed the minimum percent of disease incidence (20%) and the highest survival rate of plants (80%), as well as the higher dry root and dry shoot weight [46]. Their results suggest that Trichoderma spp.…”

“…This subsection will present some works investigating the use of bacteria and fungi tested as biocontrol agents against Phytophthora species. Looking for biological approaches to control the root rot of muskmelon caused by Phytophthora drechsleri (Tucker), Anjum and colleagues (2019) [46] obtained Trichoderma isolates (T. harzianum HM, T. harzianum HK, and T. asperellum TH) and isolated B. subtilis from soil samples collected at the Research Area of the University of Sargodha. All biocontrol agents tested showed mycelial inhibition against P. drechsleri to some degree in dual culture in vitro assays.…”