Selection and evaluation of nitrate-tolerant strains of Rhizobium leguminosarum biovar viceae specific to the lentil

Seventeen strains of Rhizobium leguminosarum biovar viceae specific to the lentil (Lens culinaris L.) were screened, using the high-yielding lentil cultivar L 4076, for their tolerance to three levels of NO _inf3 ^sup- : 0, 4, and 8 mM NO _inf3 ^sup- . Preliminary screening of this symbiosis for nodulation and N fixation in the presence of NO _inf3 ^sup- showed significant variations among the strains. The number of nodules decreased and nitrogenase activity was depressed in all strains in the presence of NO _inf3 ^sup- . Strains L-1-87, L-27-89, L-33-89, and L-40-89 tolerated 8 mM NO _inf3 ^sup- . Four strains, three tolerant of NO _inf3 ^sup- (L-1-87, L-27-89, and L-33-89), and one sensitive (L-11-89) to NO _inf3 ^sup- , were selected from preliminary screening and used in a pot experiment to assess the symbiosis in the presence of 6 mM NO _inf3 ^sup- at three stages of plant growth, viz., 40 days, 60 days, and at the final harvest. In general, the weight of nodules and C₂H₂ reduction activity was significantly higher after 60 days than after 40 days. Inoculation with strain L-1-87 produced the maximum number of nodules, and root and shoot biomass both in the presence and the absence of NO _inf3 ^sup- . Nitrate reductase activity in the tops and nodules was assayed only after 60 days and did not show significant variations among strains and NO _inf3 ^sup- treatments. The grain yields for all strains except L-11-89 were significantly higher in the presence of NO _inf3 ^sup- than in the absence of NO _inf3 ^sup- , indicating that tolerant strains contributed symbiotically fixed N to the plant's N pool, resulting in an additive effect on yield. Inoculation with strain L-1-87 produced the maximum grain yield and this strain appears to have potential use as an inoculant in the presence of high levels of soil N.     

The Rhizofiltration of Sodium from Hydroponic Fluid using Scented Geraniums

The ability of two scented geraniums, Pelargonium sp. `Frensham' and Pelargonium sp. `Citrosa' to tolerate and accumulate salt was assessed in a hydroponic system under greenhouse conditions. Rooted cuttings were exposed to a range of salt concentrations (0 to 200 mM NaCl) over a two-week period. No visible signs of phytotoxicity were observed on scented geranium plants grown in solutions up to 100 mM sodium chloride. Tolerance to salt exposure was assessed with chlorophyll a fluorescence parameters. A significant decline in the efficiency of the photosystem (Fv/Fm) was observedin Frensham plants exposed to 200 mM NaCl for 14 days. The numberand size of active reaction centers (Fv/Fo) declined with increasing NaCl treatments in both species. Total chlorophyll content of both species decreased with increasing salt treatmentas a result of significant reductions in the chlorophyll acontent. At higher levels of sodium chloride treatment, salt extrusion was observed on the petioles and the leaf lamina. An accumulation in excess of 3.7 and 2.6% of the dry weight of Frensham plants as sodium was observed in shoots and roots, respectively. The effect of the accumulated sodium on the physiology of scented geraniums was assessed through biochemicalanalysis. The determination of amino nitrogen and stress-relatedmarkers revealed an initial increase in 4-aminobutyrate, proline,asparagine, glutamine, and alanine in the root tissues. Shoot analysis showed gradual increases in asparagine, aspartate, andalanine. These data provide the first evidence for the salt tolerating and accumulating potential of Pelargonium sp. and demonstrate the efficacy of this plant species for the remediation of salt contaminated hydroponic solutions.     

The impact of cloud chemistry on photochemical oxidant formation

Photochemical smog formation at the regional scale is a phenomenon of concern in northern America and Europe. It is important to include a treatment of cloud processes in regional photochemical oxidant models because clouds may affect the overall chemistry of regional photochemical oxidant formation. This paper focuses on the development and application of a model that describes the chemistry of oxidant formation in clouds. The model consists of a chemical kinetic mechanism for the gas phase, mass transfer and thermodynamic equilibrium between the bulk gas phase and the cloud droplets, and a detailed chemical kinetic mechanism for the aqueous phase. Model simulations were conducted for typical conditions in the northeastern U.S. using (1) gas-phase chemistry only and (2) gas-phase and cloud droplet chemistry. Comparisons of these two sets of model simulations show that O₃ formation is considerably reduced in clouds despite its low solubility. The principal causes of lower O₃ formation rates are (1) the high solubility of aldehydes, which are a main source of HO₂ radicals, (2) the scavenging of radicals by cloud droplets, and (3) the lower photolytic rates inside the cloud.     

Eucalyptus planting as a response to farm management problems faced by ‘on-site’ and ‘off-site’ farmers

The success of the green revolution in the fertile and agriculturally surplus plains of western U.P. in north India led to labour shortages, and increased opportunities for off-farm investments by landowners, requiring their time and energies away from farming. These changes impelled landowners to adopt strategies which saved family labour and supervision time in cultivation. Many off-site farmers, and such on-site farmers who had a high ratio of owned land to male members in the family, resorted to tree farming, mainly eucalyptus. On the other hand, farmers in eastern U.P., with small holdings, subsistence orientation and cheap labour, showed little enthusiasm for planting eucalyptus. Based on field investigation in six villages, this paper argues that woodlot planting of eucalyptus emerged as an attractive option for landowners facing management and labour problems in western U.P., as tree farming allowed saving in family labour time and permitted greater flexibility in the timing of operations. About 60% of the total trees planted were by this category of management-constrained farmers.     

Radioreceptor assay of human chorionic gonadotropin: detection of early pregnancy

A rapid, sensitive, and specific radioreceptor assay for the determination of human chorionic gonadotropin and luteinizing hormone in plasma is described. Plasma membranes of bovine corpora lutea of early pregnancy, which bind biologically active labeled human chorionic gonadotropin, have been used as receptor. Pregnancy could be detected by assaying the gonadotropin in plasma samples obtained from day 6 to 8 after conception.     

Effect of feeding crude Red Palm Oil (Elaeis guineensis) and grain Amaranth (Amaranthus paniculatus) to hens on total lipids,cholesterol, PUFA levels and acceptability of eggs

Eggs, though a very nutritious food, also have high amounts of cholesterol and hence are not recommended to be consumed regularly by persons having hypercholesterolemia and associated cardiovascular diseases (CVD). In this context, an attempt was made in this study to reduce the cholesterol content of eggs by diet manipulation, using two naturally available and already proved hypocholesteromic agents [Red Palm Oil (RPO) and Grain Amaranth]. Thirteen experimental rations using raw and popped grain Amaranth and RPO were fed to 24 weeks old hens for a period of 6 weeks, singularly and in combinations. Total lipids, cholesterol and PUFA contents were analyzed in the experimental and control eggs. The results showed that RPO and RPO + Popped Amaranth feeding resulted in a maximum reduction in total lipids and cholesterol contents. Significant increase was observed in linoleic acid content in RPO + popped Amaranth; raw Amaranth and RPO fed groups. Acceptability studies showed that the products made from lower cholesterol eggs were well accepted.     

Molecular distinction and population structure of Indian mustard [Brassica juncea (L.) Czern.]

Genetic Resources and Crop Evolution - Rapeseed-mustard is one of the most important oilseed crops and providing a major source of edible oil in the world besides having other economic importance...