Biodiversidade e efetividade de rizóbios nativos de solos do semi-árido de Pernambuco em caupi (Vigna unguiculata L. Walp)

• Ano de defesa: 2009
• Autor(a) principal: BEZERRA, Rosemberg de Vasconcelos
• Orientador(a): STAMFORD, Newton Pereira
• Banca de defesa: SAMPAIO, Everaldo Valadares de Sá Barreto, FREITAS, Ana Dolores Santiago de, SANTOS, Maria de Fátima Vieira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural de Pernambuco
• Programa de Pós-Graduação: Programa de Pós-Graduação em Ciência do Solo
• Departamento: Departamento de Agronomia
• País: Brasil
• Palavras-chave em Português: Vigna unguiculata; Fixação biológica de nitrogênio; Biological nitrogen fixation; Microbiologia do solo
• Área do conhecimento CNPq: AGRONOMIA::CIENCIA DO SOLO
• Link de acesso: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5347

The semiarid region is characterized to show hydric deficit, high temperature and soil with salinity problem that may affect productivity of many cultivated species. The cowpea legume (Vigna unguiculata L. Walp.), have capacity to develop satisfactorily in these conditions due to its rusticity, resistance to soil salinity and to be beneficiated by the process of biological nitrogen fixation, realized by bacteria in a general sense known as rhizobia. The present work aims to estimate the diversity of cowpea rhizobia isolated from semiarid soils, by morphological characteristics; test track at high pH and salinity and select the individual that may be promising to fix nitrogen in cowpea. Results showed that takeoff of native vegetation and the establishment of monoculture crop has fundamental importance on reduction of the diversity of the cowpea rhizobia bacteria. Areas without vegetation or cropped with atriplex present low diversity, evaluated by the Margalef index, and low grade of equitability and species richness. The bacteria were more predisposed to support extreme conditions of pH in relation to sodicity and salinity, and sodicity was more detrimental in the development of bacteria. The strain NFB/REN-40 has a good potential for biological fixation of N2 in the culture of cowpea.