Nodule formation in legumes is a process that starts with root infection by rhizobia. The present study assessed the population and infectivity of the indigenous rhizobial strains in rainforest soils of Nigeria. Soils were collected from three sites -IdiAyunre, Orile-Ilugun (OI) and the University of Ibadan Teaching and Research Farm (UITRF) -and analysed for physico-chemical properties and rhizobial population. Soybean varieties TGx1448-2E and TGx1456-2E and a cowpea variety IT89KD-288 were planted as trap crops on each of the soils, and rhizobia were isolated from their nodules. Infectivity assay was conducted using eight varieties of soybean and a cowpea variety. Most probable number estimate of the rhizobial population showed that the UITRF had significantly higher rhizobial population than the other two locations. OI and the UITRF soils planted with TGx1448-2E had significantly higher nodules and number of strains than other treatments. Among the 70 slow-grower strains isolated, only nine were infective. Three of the nine strains -IDC8, TRC2 and OISa-6e -nodulated at least seven of the eight soybean varieties used for infectivity test. Indigenous rhizobial infectivity of the studied locations was low, and cultivation of grain legume may require rhizobial inoculation for high productivity.

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The effect of traditional shade-drying method on the seed germination and vigour of two varieties of tomato was investigated. The experiment was conducted at the seed testing laboratory of The National Centre for Genetic Resources and Biotechnology (NACGRAB), Ibadan, Nigeria in July 2015. The seed samples were dried for one week in the drying chambers and thereafter evaluated for germination and vigour tests. The experiment was carried out in a completely randomized design with three replications, in 2 x 2 factorial scheme. Two varieties of tomato (Ibadan local and Alausa) and two drying methods: traditional (shade-drying with an electric fan at a temperature between 23.5 to 32.3°C) and mechanical (seed dryer at 35°C) were evaluated. The germination Short Research Article