Influence of rhizobacteria (Pseudomonas fluorescens) on biochemical performance of lentil (Lens culinaris) genotypes under late-sown condition in rice (Oryza sativa) fallow system

An experiment was conducted during winter season of 2018–19 and 2019–20 at Jorhat, Asom, to study effect of rhizobacteria (Pseudomonas fluorescens) on biochemical performance of lentil (Lens culinaris Medik.). The experiment was laid out in factorial randomized block design, replicated thrice. Eight genotypes (KLS 218, HUL 57, PL 406, DPL 62, DPL 15, Borpeta Local, IPL 316 and IPL 81) of lentil were used as test crops where in liquid culture rhizobacteria (2% P. fluorescens) was applied as seed treatment as well as foliar spray. After the treatment, the results showed that during the initial stages of lentil crop growth, the mean soil-moisture content was comparatively high (25.4%), but it gradually reduced up to 15.6% due to shortage of rainfall. Oxidative damage in total chlorophyll content (1.30 mg/g fresh wt.), membrane-stability index (45.6%) and in-vivo nitrate-reductase activity (1.52 μ mole NO₃ – g-1 fwhr-1) could be seen in late-sown plants over timely sown ones. The application of rhizobacteria positively altered the cellular mechanism of plants under both the sowing dates. Amongst the evaluated genotypes, the genotypes ‘DPL 62’ and ‘DPL 15’ exhibited the higher values (under both the sowing dates) in terms of biochemical characteristics like total chlorophyll content (1.74 and 1.78 mg/g fresh wt.), membrane-stability index (52.5 and 49.4%), in-vivo nitrate-reductase activity (1.95 and 1.92 μ mole NO₃ – g-1 fw/hr), SOD activity (0.99 abd 1.0 mg-1 protein) and low lipid peroxidation (3.07 and 3.12 n mole MDA g-1 fresh wt.). The results showed the genotypic superiority of ‘DPL 62’ and ‘DPL 15’ indicating that the higher stress-tolerance capability may be correlated to better antioxidative defence system under low soil-moisture condition.