Evolution in indigenous west African rice

The genus Oryza contains two cultivated species,O. sativa L., the Asiatic rice, andO. glaberrima Steud. which is limited to Africa. Despite much taxonomic work on the relationships of the wild species of the genus, they are still imperfectly known and there has not been unanimous agreement on nomenclature. Most of the species group into complexes the delimitation of which is a matter of opinion. This paper presents results from experimental work, and a theory for the evolution of African cultivated rice is put forward based on taxonomic studies.     

Genetic control of streptococcus-induced hepatic granulomatous lesions in mice

Hepatic granulomatous lesions were induced in mice by a single intraperitoneal injection of 3 mg of disrupted Streptococcus pyogenes cell-wall material. Mice carrying the H-2 ^b or H-2 ^k haplotypes were highly susceptible to the induction and three weeks after the injection produced numerous granulomas. In contrast, mice of the H-2 ^d haplotype were resistant and produced only a few hepatic granulomas. Resistance was inherited as a dominant trait and in the backcross generation segregated together with the H-2 ^d phenotype. Testing of the H-2-recombinant mice indicated that the putative gene(s) determining resistance/susceptibility is located to the right of the S and to the left of the D region. Thes location corresponds to the recently described gene cluster consisting of tumor necrosis factor (TNF) and lymphotoxin genes and several BAT sequences. The known effect of TNF on granuloma formation in mice is consistent with a possible effect of TNF genes, and their variants, on S. pyogenes-inducibility of hepatic granulomas in mice. Address correspondence and offprint requests to: M. B. Zaleski.     

Efficacy of combined application of Trichoderma asperellum NG T158, Aloe vera leaf extract and poultry manure for the management of Colletotrichum lindemuthianum causing anthracnose disease on cowpea

Anthracnose disease is a major constraint for the production of cowpea, accounting for significant yield losses in Nigeria. Trials were conducted in 2016 and 2017 to evaluate an integrated approach in the management of anthracnose disease on cowpea. The experiment was conducted in a screenhouse with ten treatments and three replications in a completely randomised design using a susceptible cowpea variety IT07K-298-9. Ten varieties of cowpea were evaluated for seed-to-plant transmission of pathogen with respect to disease incidence, severity, and yield. The highest yield of 12–14 pods per plant was observed in treatment of Trichoderma asperellum and poultry manure combined. Seed treatments using T. asperellum and soil amendment with poultry manure had a significantly (P?=?0.05) lower disease incidence of 8.4–10.5%. This study showed the potential of combining naturally occurring organic products in the ecosystem that compete favourably with synthetic fungicides in the management of anthracnose disease of cowpea.