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Micropropagation of an orchid Dendrobium strongylanthum Rchb.f.
61-64.Views:442A simple and reliable procedure for in vitro propagation of an orchid Dendrobium strongylanthum Rchb.f. was studied. Protochorm was induced from seed explants on 1/2 MS medium supplemented with 0.2 mg/L NAA. A mass of protochorm could be multiplied on proliferated medium of 1/2 Ms containing 0.5 mg/L V-6-BA. And bud differentiation of green global body was cultured in the same media, 2-2.5 cm shoots were formed after 30 day of culture. Addition of mashed banana and 0.5 mg/L NAA to 1/2 MS medium promoted root formation and vigorous growth. The plantlets were acclimatized and transplanted to compound materials of humus:sawdust (1:1) in greenhouse, the survival rate was more than 98%.
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Experiments on the Resistance or Pepper Cultivars to Macrophomina phaseolina
74-75.Views:212The ashy stern blight of pepper (Capsicum annuum) is often caused by Macrophomina phaseolina. Serious wilt disease occurred between 1994 and 1996 of pepper plants in Hungary. In 1996-98 screening experiments were made on many pepper cultivars. Culture (Knopp) solution experiments, pot experiments, greenhouse and field trials were carried out. We determined the incidence of disease by visual examinations, testing on PDA culture, and light microscope. There were significant differences in susceptibility of cultivars and breeding materials.
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Prevalence of banana diseases and post-harvest losses in Kenya, and biocontrol potential of arbuscular mycorrhizal fungi against Fusarium wilt
62-73.Views:633The demand for bananas (Musa spp.), which is ranked as the most important fruit crop in Kenya has been on the rise owing to both their dietary contribution and income generation. Meeting this demand has however been hampered by losses during production or post-harvest. This study assessed banana disease and post-harvest losses in leading producing counties in Kenya namely; Kisii, Nyamira and Embu. The study also assessed the efficacy of Rhizophagus irregularis in controlling Fusarium oxysporum f.sp. cubense. Structured questionnaires were used to collect data on post-harvest losses. Disease scoring tables, charts and photos were used to confirm observed symptoms and hence, disease occurrence and severity. AMF biocontrol efficacy experiment was conducted using tissue culture bananas grown in the greenhouse. The study revealed that most smallholder farmers were unaware of the causes or the prevalence of post-harvest losses. The findings also revealed a significant difference (p<0.05) in the severity of banana diseases across various cultivars from the three counties. The AMF treated bananas showed a significant difference (p<0.05) in plant height, total leaf area and chlorosis in comparison to other treatments. The study also revealed a reduction of Fusarium’s pathogenic effects including chlorosis, reduced leaf surface area and eventual necrosis.
