RESUMEN
Late blight caused by Phytophthora infestans (Mont.) de Bary is a constraint to both potato and tomato crops in Nicaragua. The hypothesis that the Nicaraguan population of P. infestans is genotypically and phenotypically diverse and potentially subdivided based on host association was tested. A collection of isolates was analyzed using genotypic markers (microsatellites and mitochondrial DNA haplotype) and phenotypic markers (mating type, virulence, and fungicide sensitivity). The genotypic analysis revealed no polymorphism in 121 of 132 isolates of P. infestans tested. Only the Ia haplotype and the A2 mating type were detected. Most of the tested isolates were resistant to metalaxyl. The virulence testing showed variation among isolates of P. infestans. No evidence was found of population differentiation among potato and tomato isolates of P. infestans based on the genotypic and phenotypic analysis. We conclude that the Nicaraguan population of P. infestans consists of a single clonal lineage (NI-1) which belongs to the A2 mating type and the Ia mitochondrial DNA haplotype. Moreover, based on the markers used, this population of P. infestans does not resemble the population in countries from which potato seed is imported to Nicaragua or the population in neighboring countries. The data presented here indicate that the NI-1 clonal lineage is the primary pathogen on both potato and tomato, and its success on both host species is unique in a South American context.
Asunto(s)
Variación Genética/genética , Phytophthora infestans/genética , Enfermedades de las Plantas/microbiología , Solanum lycopersicum/microbiología , Solanum tuberosum/microbiología , Alanina/análogos & derivados , Alanina/farmacología , Carbamatos/farmacología , ADN/genética , ADN/aislamiento & purificación , ADN Mitocondrial/genética , Genotipo , Haplotipos , Repeticiones de Microsatélite/genética , Nicaragua , Fenotipo , Phytophthora infestans/clasificación , Phytophthora infestans/efectos de los fármacos , Phytophthora infestans/aislamiento & purificación , Semillas/microbiologíaAsunto(s)
Dieta , Estrógenos no Esteroides/uso terapéutico , Isoflavonas , Neoplasias de la Próstata/prevención & control , Proteínas de Soja/uso terapéutico , Animales , Estrógenos no Esteroides/administración & dosificación , Finlandia/epidemiología , Humanos , Japón/epidemiología , Masculino , Fitoestrógenos , Preparaciones de Plantas , Neoplasias de la Próstata/epidemiología , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: In this study, we investigated whether dietary intervention could inhibit tumor growth of an androgen-sensitive human prostatic cancer. METHODS: LNCaP cells were transplanted subcutaneously in nude-mice. The animals were then put on different diets and tumor take, tumor growth and prostate specific antigen (PSA) secretion were studied during 9 weeks. RESULTS: Palpable tumors developed in 75% of the tumor-cell injected sites in animals fed a control diet (corn starch, sucrose, etc.) whereas, for animals given rye bran (RB), ethyl acetate extraction from rye bran supplemented cellulose based diets (CCEE), palpable tumors were seen in only 30% and for soy protein based diets (SCC) 50% of the transplantation sites, respectively. The tumors that grew to palpable size in the rye (RB) and soy (SCC) groups were smaller and secreted less PSA than those in the control group. In the rye and soy groups tumor cell apoptosis was increased, but cell proliferation was unaffected. Addition of fat to the rye diet reduced its effect on prostate cancer growth. CONCLUSIONS: Factors in rye bran and soy protein may inhibit prostate cancer growth. The effect is more apparent for rye than for soy. Further studies are needed to identify the effective substances and to explore the mechanism of action.