Qualidade sanitária e fisiológica de sementes de leucena (Leucaena leucocephala (lam.) R. de Wit.): uma leguminosa de importância para os sistemas agrícolas do nordeste.

• Ano de defesa: 2006
• Autor(a) principal: Mendes, Sandra Santos
• Orientador(a): Mesquita, João Basílio
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Sergipe
• Programa de Pós-Graduação: Pós-Graduação em Agroecossistemas
• País: BR
• Palavras-chave em Português: Transmissão de fungos; Patologia de sementes; Fisiologia de sementes; Espécies florestais; Isoenzimas
• Palavras-chave em Inglês: Fungi infection; Seeds pathology; Seeds physiology; Forests species; Isozymes
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA
• Link de acesso: https://ri.ufs.br/handle/riufs/6631

The Leucaena is a tree specie that it is able to improve the soil and can give food for animals. It is an alternative to farmer in dry periods in Northest. Seeds of leucaena (Leucaena leucocephala Lam) from two populations (Reserva Florestal Ibura and Campus da Universidade Federal de Sergipe), were collected and storage for different periods as goal their utilization as alternative culture aiming agroecosystem sustainability. The objective of this work was to evaluate the physiological and sanitary seed quality and fungi infection to seedlings obtained of seeds storage for 2, 28 and 48 months. The seeds were storage in paper bags inside a refrigerated chamber with 40% of humidity at 10 ± 1° C and the experiments carried out in Phytosanitary Clinical, Tissues Culture and Vegetal Breeding Laboratory and Seeds Laboratory of Universidade Federal de Sergipe from February through December, 2005. It was used a statistical totally randomized design with four replications. It was detected in batches of 48 and 28 months fungi from Aspergillus and Penicillium genus. For seeds storage for 2 months it was detected Pestalotiopsis, Fusarium and Curvularia genus. In concerned to infection of the fungi it was verified the Aspergillus was able to cause hypocotyls necrosis on seedlings. For seeds physiological analysis tests as Germination Speed Index (IVG), Emergence Speed Index (IVE), Electrical Conductivity (CE), Accelerate Ageing (EA), Humidity (%U) and isozymes were carried out. It was verified the seeds storage for two months presented higher values of IVG. In the CE test the seeds storage for two months and submitted to accelerate ageing during 24 hours presented the higher values of CE. The isozyme markers showed alteration in patterns of bands intensity and absence of alteration in protein subunit which permit to infer the batches besides from different provenances, probably were not genetically divergent. This fact corroborates to justify the comparison made in this work. It was observed a decreasing in values of germination with increasing storage periods which suggest vigor lost. It was recommended the storage the leucaena seeds for a period maximum of two years for the conditions of present work.