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Field experiment was conducted during rabi season of 2008-2009 on an established plantation at Agroforestry Research Centre, Haldi, G. B. Pant University of Agriculture and Technology, Pantnagar to evaluate the effect of tree species and their spacing on yield of intercrop wheat (variety PBW-502) and soil properties. The experiment was laid out in split-plot design with 3 replications. The highest grain yield (36.0 q ha-1) was obtained under open farming system (control). The reduction in grain yield was in the range of 16 to 62% under agroforestry systems as compared to control. Poplar based agri-silvicultural system performed better as compared to other systems. Highest wheat yield was recorded in 3.0×2.5 m2 spacing under Poplar, Melia, and Leucaena based agri-silvicultural system but in the case of Eucalyptus, 3.0×2.0 m2 spacing was the best. The organic carbon was highest under Poplar (1.73%) as compared to control (0.60%). The electrical conductivity was significantly lowered under Leucaena interfaces as compared to control. Whereas, soil pH was lowered under Poplar (at 3.0×2.0 m2) and statistically similar with Leucaena (at 3.0×1.0 m2). Bulk density was significantly decreased under Leucaena and Melia interfaces at 3.0×1.0 m2 spacing. Highest available N, P2O5 and K2O content (200.42, 18.67 and 169.12 kg ha-1, respectively) were observed in the soil under Leucaena (3.0×2.0 m2). [ABSTRACT FROM AUTHOR]

Transposon, Tn917, carried on pTV1 plasmid has been used successfully to mutagenise Bacillus brevis. The transposon showed preference for insertion at an "aro" site. A second insertional event after elimination of the preferred site with ethidium bromide/acridine orange treatment has permitted isolation of Gln- mutants in B. brevis.