Assessment of carrot growth performance with inoculation of AsT-PGPR under arsenic infested zone

Abstract

In the present study, the maximum rhizobacterial population was observed in Nutrient Agar (NA) (average; Cfu=135×106) followed by King’s-B (average; Cfu=57×106), Soil extract agar (SEA) (average; Cfu=11×106), and Trypticase soy agar (TSA) (average; Cfu=9×106). Screening of arsenic tolerant rhizobacterial isolate revealed that about 1% of the bacterial isolate was from Nutrient Agar and King’s-B survived at 20ppb arsenic concentration, while 0.8% and 0.7% survived from TSA and SEA media respectively. 50ppb arsenic tolerant rhizobacteria were screened for plant growth-promoting activity such as IAA, Phosphate solubilization, Siderophore production, ACC deaminase activity. Maximum IAA activity was observed in rhizobacterial isolates, isolated from all different media. P- solubilizer, Siderophore producer, ACC deaminase, proline, and TSS activities were observed in the isolates of NA media followed by King’s-B media. 50ppb tolerate best suitable PGP traits producing isolates were inoculated to observe carrot plant growth in the pot experiment, Interesting and significant (p<0.05) result were observed in King’s-B media producer isolates; (Pseudomonas) induces plant length, chlorophyll-a and chlorophyll-b content of the plant after 60 days followed by 30 days.

Keywords

• Arsenic tolerant PGPR (AsT-PGPR)
• PGP traits
• Plant growth performance