Macrophomina phaseolina (Tassi) Goid remains the prevailing causal agent of charcoal rot disease that significantly suppresses the yield of a variety of oilseed crops. Its wide host range and ability to survive under arid conditions, coupled with the ineffective use of fungicides against it, have spurred scientific endeavours for alternative avenues to control this phytopathogen. Hence, the present study aimed to provide empirical evidence of the efficacy of three fungal isolates (T2, T10 and T12) of Trichoderma harzianum as biological control agents against charcoal rot in soybean (Glycine max L.). The results of the in vitro studies revealed that all three fungal isolates significantly inhibited the growth of M. phaseolina phytopathogen, with T12 showing considerably higher inhibition effect than T2 and T10 isolates. T12 inhibited the growth of M. phaseolina in the dual culture (72.31%) and volatile production (63.36%) assays, and the hyperparasitism test indicated cell lysis following the interactions with T12 mycelia. T12 isolate was mostly effective in field experiments, observable in the attained minimum plant disease indices both in the soil incorporation (11.98%) and seed inoculation (5.55%) treatments, in comparison to isolates T2 and T10. Moreover, the stem and root lengths, as well as the seed weight, were considerably increased, as compared to the control. Hence, the findings reported in the present study supported the applicability of T12 isolate as possible alternative to fungicides for the control of charcoal rot in soybean.

Silybum marianum (L.), is an important herbal medicine. Silymarin, the active component obtained from its edible seeds, is known for its antioxidant and antimicrobial activity. This  research was aimed to study the effect of foliar application of salicylic acid (SA) at four concentrations of 1250, 2500, 5000 and 10000 μmol l-1 on the improvement of phytochemical composition, antioxidant and antimicrobial activity. Significant increase was found in the content of silibinin, silybin A and silybin B in plants treated with increasing concentrations of salicylic acid. The antioxidant activity was improved with increasing the SA concentration reaching the highest amount under 5000 μmol l-1 SA treatment (p < 0.05). Irrespective to the bacterial strain, an increasing pattern in the amount of antibacterial activity was found by increasing SA concentration. The study suggest that treatments with medium doses of SA could be a promising way to improve the health beneficial flavonolignans compounds of Silybum marianum resulting in a higher antioxidant and antimicrobial activity. Nevertheless, it should be considered that the responses to SA are highly concentration dependent and application of higher concentrations can have an adverse effect by triggering a hyper sensitive cell death pathway.

No abstract

No abstract

No abstract