Vol. 11, Issue 2 (2022)

Author(s):
Bhagwan Singh Dhaked, Ganesh Kumar Koli, S Triveni, R Subhash Reddy, Aman Jaiswal and Deepak Kumar Koli

Abstract:
All the potassium and zinc solubilizing bacterial isolates were subjected to further studies to understand their Plant Growth Promoting Properties (PGPR) under in vitro conditions. Pure isolates were screened for mineral phosphate solubilization, siderophore production, ammonia production, IAA production and biocontrol activity. Among four KSB isolates 3 isolates were able to solubilize phosphate on Pikovskaya’s media containing Tri calcium phosphate in the range of 7 mm to 9 mm. Among eight ZnSB isolates 2 isolates were able to solubilize phosphate on Pikovskaya’s media containing Tri calcium phosphate in the range of 8 mm to 10 mm. Among four KSB isolates, KSB - 3 were positive for ammonia production in peptone water tubes. Among eight ZnSB isolates 2 isolates ZnSB-5 and ZnSB-6 were positive for ammonia production. IAA production varied with supplementation of L- tryptophan and without supplementation of L- tryptophan. Out of four isolates KSB-1 showed maximum IAA production (2.2 µg ml^-1) without supplementation of tryptophan, Enhancement in production of IAA was observed with the supplementation of L-Tryptophan @ 10 mg per liter by KSB-1 (6.60 µg ml^-1) and IAA production for ZnSB isolates were maximum for ZnSB-5 (3.516 µg ml^-1) without supplementation of L-tryptophan and 7.51 µg ml^-1 with tryptophan. Out of four KSB isolates, KSB - 1 bacterial isolate produced siderophores moderately (++). Among eight ZnSB isolates 2 isolates ZnSB-1 and ZnSB-2 were strong (+++) for siderophore production Out of four KSB isolates, KSB-1 bacterial isolates produced HCN moderately (++) and among eight ZnSB isolates, 2 isolates ZnSB-4 and ZnSB-8 produced HCN. Antifungal activity of four potassium solubilizing bacterial isolates (KSB-1 to KSB-4) eight zinc solubilizing bacteria isolates (ZnSB-1 to ZnSB-8) were checked against Rhizoctonia solani under in vitro conditions using PDA media. Based on both characters inhibition and inhibition zone. The antifungal activity of strains tested varied with percent inhibition for KSB from 51.50 to 3.70 and for ZnSB 25.90 to 3.70.