Most of the legume crops are affected by metal stress present in the soil mainly due to contaminated agrochemicals and sewage sludge. The effect of aluminium, and heavy metals copper, iron and molybdenum on growth and activity of enzymes of fast and slow growing rhizobial sps. was studied. Sinorhizobium meliloti RMP 5 was found to be more tolerant to metal stress than Bradyrhizobium BMP 1 . Both the strains were extremely sensitive to Al than other metals. Al was much more deleterious for the enzymatic activities (nitrate reduction, nitrite reduction, nitrogenase and uptake hydrogenase) of strain RMP 5 and BMP 1 . Cu showed inhibitory effect on growth and enzyme activities of Bradyrhizobium strain at all concentrations. However, in S. meliloti RMP 5 all the tested enzymatic activities increased up to the concentration of 0.1 mM Cu. Fe enhanced the growth and enzyme activities of S. meliloti RMP 5 and Bradyrhizobium BMP 1 up to 100 mM concentration. Mo enhanced all the tested enzymatic activities of S. meliloti RMP 5 up to 1 mM. Nitrate and nitrite reduction activities of Bradyrhizobium BMP 1 increased up to 1 mM concentration. However, nitrogenase and hydrogenase activities of Bradyrhizobium BMP 1 got enhanced only up to 0.5 mM Mo. Both Fe and Mo are the key components of the enzyme nitrogenase and nitrate reductase and enhanced the growth and enzyme activities of both the sps. The study of physiology of nitrogen fixing ability of both fast and slow growing rhizobial strains reported that the supplementation of Mo and Fe in soils along with the biological formulations will enhance the process of symbiotic nitrogen fixation.

Finding promising purple tea germplasm that would target new tea products for diversification and value addition boost the tea industry’s economic growth. Accordingly, 10 tea germplasm viz. TRA St. 817, TRA St. 293, TRA St. 400, TRA 177/3, TRA 376/2, TRA 376/3, TRA 427/7, TRA P7, TRA P8, and TV1 were evaluated in terms of gas exchange parameters, multiplication performance, and biochemical markers such as chlorophyll, carotenoids, and anthocyanin content, which are related to the purple tea quality. The investigated gas exchange and biochemical parameters revealed significant differences. Germplasm TRA St.817 was physiologically more efficient (24.7 μmol m–2 s–1), followed by TRA St. 293, exhibiting the highest net photosynthesis, water use efficiency (19.02 μmol mmol–1), carboxylation efficiency (0.73), chlorophyll fluorescence or photochemical efficiency of PSII (0.754) and mesophyll efficiency (ci/gs ratio: 2.54). Net photosynthesis was positively correlated with water use efficiency, carboxylation efficiency, mesophyll efficiency, and photochemical efficiency of PSII (r = 0.965**, 0.937**, 0.857**, 0.867**; P = 0.05), respectively, but negatively correlated with the transpiration ratio (r = −0.878**; P = 0.05) based on Pearson correlation analysis. The total anthocyanin content (4764.19 μg.g–1 fresh leaf weight) and carotenoid content (3.825 mg.g–1 fresh leaf weight) were highest in the TRA St.817 germplasm, followed by germplasm TRA St. 293 (2926.18 μg.g–1 FW). In contrast, total chlorophyll content was significantly low (1.779 mg.g–1 fresh weight), which is very suitable for manufacturing purple tea. The highest carotenoid concentration in TRA St. 817 was 3.825 mg.g–1 FW, followed by TRA P8 (3.475 mg.g–1 FW), favoring the formation of more volatile flavor constituents. The promising germplasm, TRA St 817, has a multiplication success rate of 91.4% through cleft grafting. The outcome reveals that TRA St.817 is a promising germplasm that can be used to make speciality teas, i.e., purple tea.

A study was undertaken to evaluate the quality characteristic of tea (Camellia sinensis L.) seed oil. The oil content ranged between 20.84 and 21.90 per cent. Smoke point, iodine value, saponification value, calorific value, refractive index, oil density, oil colour and oil pH were in the range of 247.29 - 251.53 (oC), 82.74 - 85.65 (g I 100-1 g), 185.33 - 185.72 (mg KOH g-1), 6822.53-6891.05 (J per 100 g), 1.46 (at 40 0C), 0.92 - 0.94 (g per cm3), 4.45 - 4.47 (Y+5R) and 4.62 - 4.64, respectively. The oxidation parameters, i.e., peroxide value, ranged from 1.17 - 2.63 meq kg-1. The tea seed oil has PUFA/SFA ratio 0.82 - 1.31 closer to WHO recommended value. Besides, antioxidant activity in term of DPPH free radical scavenging activity ranged between 6.30 - 7.14 per cent, β-carotene 4.62 - 12.93 mg kg-1 and α-tocopherol 90.49 - 366.52 mg kg-1. Highest oleic acid content was found in TSS 1, whereas highest α-tocopherol was found in TS 557. The results open up the possibilities of extracting oil from these bi-clonal seed stocks, which will diversify the use of tea.

A total of 92 soybean nodulating rhizobia were isolated from different agro regions and screened for sensitivity against 8 rhizobiophages. Only 33 showed susceptibility with phage strains. Nineteen rhizobial isolates selected, including 9 isolates having high lytic behaviour and 10 resistant to all phages, were subjected to study on symbiotic effectiveness. Strains ALSR12, KNSR16, USDA123 and USDA94 showed highly significant interaction with host plant grown under axenic conditions. Strains USDA123 and ANSR12 had distinct lytic reaction with phage strain SR1 and SR2, respectively. Plaques formed by SR1 on USDA123 were quite clear with sharp margin, whereas central halo was surrounded by turbid concentric by SR2 on strain ALSR12. In view of generation time varying from 9.2 h (USDA94) to 12.6 h (ALSR12), they were marked as slow grower. Of the different carbon sources used, arabinose served as a potent carbon source for supporting highest growth of these strains. As compared to the other strain, ALSR12 was able to grow at 45°C and capable to tolerate a higher range of acidity and alkalinity. Strains ALSR12 and USDA123 showed highest resistance level with the antibiotics streptomycin and gentamicin, respectively. Ex-planta N 2 -ase activity was determined only in USDA94 and ALSR12. This study provides means for conducting a systematic and scientific investigation towards obtaining a reliable understanding of the bradyrhizobial diversity in terms of their physiological behaviour.

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