Interspecific hybridization between urdbean (Vigna mungo (L.) Hepper) and adzukibean (Vigna angularis (Willd.) Ohwi and Ohashi)

Summary To introduce resistance to fungal and viral diseases into urdbean (Vigna mungo), it was crossed with adzukibean (Vigna angularis) to achieve an interspecific hybrid between the two species by using different non-conventional breeding methods. Partial success was obtained with the use of UV irradiated pollen, intraspecific hybrids as parents and spray of immuno-suppressants on the female parent under glass house conditions and to the extent of callusing in aseptic culture.     

Interspecific compatibility barriers,development of interspecific hybrids through embryo rescue and lineage of Trifolium alexandrinum (Egyptian clover)—important tropical forage legume

Genetic improvement of Trifolium alexandrinum L. is hampered because of narrow genetic base and lack of interspecies compatibility information. The study was envisaged to understand the interspecies incompatibility and the affinity between T. alexandrinum and 22 species of the genus representing different sections and to develop interspecific crosses. Development of interspecific hybrids with T. resupinatum, T. lappaceum, T. subterraneum, T. vesiculosum and T. echinatum, through embryo rescue, revealed their affinity with T. alexandrinum. Failure of pollen germination or restricted pollen tube growth showed its distant relatedness with T. clypeatum, T. balansae, T. purpureum, T. leucanthum, T. hirtum, T. pilulare and T. hybridum. Pollen tubes reached up to ovule among the crosses with T. alpestre, T. repens and T. nigrescens, whereas it travelled up to ovary among the crosses with T. angustifolium, T. grandiflorum and T. dasyurum indicating need of manipulation to overcome barrier. Thus, incompatibility of T. alexandrinum with many Trifolium species could be overcome through embryo rescue with intensive crossing. Egyptian clover ecotype ‘Fahli’ was more compatible with other species than ‘Mescavi’.     

Differentiation antigens on bovine mononuclear phagocytes identified by monoclonal antibodies

Five monoclonal antibodies (MAb) produced against cell surface antigens on bovine mononuclear phagocytes (MPh) were characterized. None of the MAb recognized erythrocytes, thrombocytes, B lymphocytes or resting or activated T lymphocytes. Two MAb (IL-A22 and IL-A24) reacted with the majority of monocytes and granulocytes in peripheral blood, with 20-40% bone marrow cells comprising myelo-monocytic cells, and with a proportion of mature macrophages. Reactivity of the remaining three MAb was restricted to MPh: one of these (IL-A25) was apparently specific for pulmonary macrophages, whereas the molecules recognized by the other two (IL-A23 and CH16A) were expressed on subpopulations of blood monocytes and tissue macrophages. None of the MAb inhibited adherence of MPh to plasma-coated gelating surfaces or Fc-mediated rosette formation. One of the MAb, IL-A24, which reacts with MPh and granulocytes, inhibited antigen-specific proliferative response or peripheral blood mononuclear leukocytes (PBM) to the soluble antigen, keyhole limpet hemocyanin (KLH) but did not inhibit responses to concanavalin A or allogeneic leukocytes. This MAb was shown to react with two polypeptides of approximately 75 kD and 110 kD on the surface of peripheral blood monocytes.     

Allelopathy of gymnospermous trees

The present paper reviews the available literature on the allelopathy of gymnosperms which constitute the famous boreal forests known for their high quality timber and other products of great commercial importance. Nineteen genera belonging to six of the seven taxonomic families of conifers comprising one of the most dominating and largest group of present day gymnosperms, are reported to show the phenomena of allelopathy. The available information signifies the role these mighty trees play in determining the understorey vegetation, ecological succession and forests dynamics besides causing regeneration problems to the donor trees. The allelochemicals, identified from these plants, responsible for such interactions have also been summarised. In most of the cases the leaching of phenolics from the litter predominantly of tree needles, which remain on the ground for a longer time due to slow decomposition rate, are held responsible for these interactions.     

Predictive models for biomass and carbon stocks estimation in Grewia optiva on degraded lands in western Himalaya

Grewia optiva Drummond is one of important agroforestry tree species grown by the farmers in the lower and mid-hills of western Himalaya. Different models viz., monomolicular, logistic, gompetz, allometric, rechards, chapman and linear were fitted to the relationship between total biomass and diameter at breast height (DBH) as independent variable. The adjusted R² values were more than 0.924 for all the seven models implying that all models are apparently equally efficient. Out of the six non-linear models, allometric model (Y = a × DBH ^b ) fulfils the validation criterion to the best possible extent and is thus considered as best performing. Biomass in different tree components was fitted to allometric models using DBH as explanatory variable, the adjusted R² for fitted functions varied from 0.872 to 0.965 for different biomass components. The t values for all the components were found non-significant (p > 0.05), thereby indicating that model is valid. Using the developed model, the estimated total biomass varied from 6.62 Mg ha^?1 in 4 year to 46.64 Mg ha^?1 in 23 year old plantation. MAI in biomass varied from 1.66–2.05 Mg ha^?1 yr^?1. The total biomass carbon stocks varied from 1.99 Mg ha^?1 in 4 year to 15.27 Mg ha^?1 in 23 year old plantation. Rate of carbon sequestration varied from 0.63–0.81 Mg ha^?1 yr^?1. Carbon storage in the soil up to 30 cm soil depth varied from 25.4 to 33.6 Mg ha^?1.     

Rubidium-strontium, uranium, and thorium-lead dating of lunar material

Rubidiuom and stronztiulm concentrations and strontium isotopic compositions have been measutred on whole rock samples and density fractions of microgabbro. Density fractionis on two rocks define isochrons of 3400 and 4500 million years with large uincertainties owing to low enrichment of radiogenic strontium. Lead from fine surface material is highly radiogenic. An age of 4750 million years has been calculated from the ratio of (207)Pb/(206)Pb. The concentrations of uiranium, thorium, and lead isotopes are consistent with the evolution of lead in a 4700-million-year-old closed system characterized by the ratios of uranium to lead and of thoriunm to lead in this sutrface material.