Fig. 7. (a) Linear regression between biological parameters of pea plants grown in sandy clay loam soil treated with varying concentrations of kitazin and inoculated with R. leguminosarum RP1; nodule number vs. root length (R² = 0.96), nodule number (90 DAS) vs. nodule biomass (R² = 0.94), nodule number (130 DAS) vs. nodule biomass (R² = 0.77), nodule number vs. shoot length (90 DAS) (R² = 0.90), nodule biomass vs. root dry biomass (90 DAS) (R² = 0.95), nodule biomass vs. LHb content (R² = 0.87), seed yield vs. nodule biomass (R² = 0.99), shoot dry biomass vs. total chlorophyll content (R² = 0.78), seed yield vs. total chlorophyll (R² = 0.95). (b) Loading (A) and score (B) plots showing the principal component analysis (PCA) of various parameters of pea plants under kitazin stress and bio inoculated with R. leguminosarum RP1 strain. Here, SVI seedling vigor index, RL root length, SL shoot length, RFW root fresh weight, SFW shoot fresh weight, RDW root dry weight, SDW shoot dry weight, chl total chlorophyll, corot carotenoid content, NDB nodule biomass, LHb leghaemoglobin content, SY seed yield, GP grain protein, RN, root nitrogen, SN shoot nitrogen, RP root phosphorous, SP shoot phosphorous, R pro, root proline, S pro shoot proline, L pro leaf proline, G pro grain proline, APX ascorbate peroxidase, GPX guaiacol peroxidase, POD peroxidase, CAT catalase and MDA malondialdehyde.