A significant proportion of indigenous rhizobia from India associated with soybean (<Emphasis Type="Italic">Glycine max</Emphasis> L.) distinctly belong to <Emphasis Type="Italic">Bradyrhizobium</Emphasis> and <Emphasis Type="Italic">Ensifer</Emphasis> genera

The diversity among 269 rhizobia isolated from naturally occurring root nodules of soybean collected from two different agro-ecological regions of India, based on RFLP and sequences of the intergenic spacer (IGS) between the 16S and 23S rRNA genes, growth rate, and indole acetic acid production, revealed their significant, site-dependent genomic diversity. Among these bacteria, nine IGS genotypes were identified with two endonucleases. They were distributed into five divergent lineages by sequence analysis of each IGS representative strain, i.e., (1) comprising IGS genotypes I, II, III, and reference Bradyrhizobium yuanmingense; (2) with genotype IV and strains of unclassified bradyrhizobia genomic species; (3) including genotypes V, VI, and Bradyrhizobium liaoningense; (4) with IGS genotype VII and Bradyrhizobium elkanii strains; and (5) comprising IGS genotypes VIII, IX, and different Ensifer genus bacteria. Host-specificity test revealed that all rhizobia-nodulated soybean and cowpea and only part of them formed nodules on Arachis hypogeae and Cajanus cajan. The great diversity of soybean nodulators observed in this study emphasises that Indian soil is an important reservoir of nitrogen-fixing rhizobia.     

Effect of dietary ligands and food matrices on zinc uptake in Caco-2 cells: implications in assessing zinc bioavailability

The kinetics, depletion/repletion of zinc, and effects of dietary ligands/food matrices on (65)Zn uptake was studied in Caco-2 cells. The uptake of zinc showed a saturable and nonsaturable component, depending upon the media zinc concentrations. Intracellular depletion increased zinc uptake, whereas zinc loading did not. Phytic acid and histidine inhibited zinc uptake, while tannic acid, tartaric acid, arginine, and methionine increased zinc uptake. Tannic acid at a 1:50 molar ratio promoted zinc uptake from wheat- and rice-based food matrices. Further, Caco-2 cells responded similarly with zinc and iron uptake when fed Indian bread prepared from low- and high-extraction wheat flour, representing low and high phytate content. However, inclusion of tea extract or red grape juice as a source of polyphenols enhanced the uptake of zinc while decreasing that of iron. These results suggest that the Caco-2 cells predict the correct direction of response to dietary ligands even from complex foods.     

Ammonia-oxidizing bacterial and archaeal communities in tropical bioaugmented zero water exchange shrimp production systems

Journal of Soils and Sediments - Ammonia oxidation is an important process in the removal of ammonia generated from feed and metabolic wastes in aquaculture systems. Considering the biogeochemical...     

Haematological changes in domestic fowl experimentally infected with the cestode Raillietina tetragona (Molin, 1858)

Haematological alterations in domestic fowl following three levels of infection with 20, 50 and 100 cysticercoids of Raillietina tetragona (Eucestoda) have been studied over a period of 8 weeks. The infected birds showed significant haemoglobin depression. There was no significant change in the packed cell volume (PCV), RBC counts or mean corpuscular haemoglobin (MCH). In all three levels of infection, the calculated mean corpuscular volume (MCV) increased, while the mean corpuscular haemoglobin concentration (MCHC) decreased considerably. Macrocytic anaemia along with hypochromia could be noticed during different periods of infection. Total white cell count diminished significantly in infected birds. There was a significant lymphocytopenia concurrent with a significant increase in the percentage of heterophilic elements. Eosinophilia was not a consistent feature. Erythrocyte sedimentation rate (ESR) increased significantly in infected birds. The changes in the blood picture were more pronounced in birds infected with 50 and 100 cysticercoids.     

广东湛江红树林国家级自然保护区湿地鸟类资源现状及保护对策

广东湛江红树林国家级自然保护区位于祖国大陆最南端的湛江市，分布有全国最大面积的红树林。由于地处西伯利亚一澳大利亚候乌迁徙路线，每年都有大量的候乌飞经此地。如何保护这些珍贵鸟类及其栖息地是保护区的主要工作之一。本文介绍了湛江红树林保护区鸟类资源的基本情况，并提出了一些可行的措施。     

Antibacterial effects of Coscinium fenestratum

Antibacterial activity of Coscinium fenestratum is mainly due to the presence of berberine.     

International seminars,workshops and conferences organized by ICRAF

This paper gives brief accounts of the nine international seminars, workshops and conferences organized by ICRAF during the period from 1979 to early 1987.Principal Scientist, ICRAF