Resistência de progênies de Stylosanthes capitata e S. macrocephala à antracnose causada por Colletotrichum gloeosporioides
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Data
2003-07
Autores
Fernandes, Celso Dornelas [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Espécies de Stylosanthes estão amplamente distribuídas em regiões tropicais e subtropicais das Américas, África e sudeste da Ásia, sendo o Brasil o principal centro de origem e diversidade do gênero, com 25 das 45 espécies descritas ocorrendo naturalmente em várias regiões do País. O gênero adapta-se a diferentes condições edafoclimáticas, apresentando melhor potencial de uso no Brasil. A antracnose, causada por Colletotrichum gloeosporioides (Penz.) Penz. & Sacc., forma anamórfica de Glomerella cingulata (Stonem.) Spauld. & Scherenk tem sido o principal entrave à ampla utilização de Stylosanthes. Em 2000, o Centro Nacional de Pesquisa de Gado de Corte (Embrapa Gado de Corte), da Empresa Brasileira de Pesquisa Agropecuária (Embrapa), lançou a cultivar Estilosantes Campo Grande, constituída por uma mistura física de populações derivadas de 11 introduções de S. capitata e seis de S. macrocephala. Tais populações foram selecionadas durante seis gerações pelo método de “bulk”. Ainda, para a composição da cultivar, misturou-se as sementes das populações selecionadas nas proporções de 80% e 20%, respectivamente. Conforme foi desenvolvida, pressupõe-se que a cultivar seja composta de indivíduos geneticamente diferentes, porém não se sabe ao certo a proporção dos mesmos, fato que dificulta saber ao longo do tempo se a composição da cultivar mantém-se ou não a mesma. Assim, realizou-se este trabalho com os objetivos de identificar a existência de variabilidade de progênies originárias da referida cultivar e selecionar germoplasma com alto grau de resistência à antracnose e performance agronômica. Este projeto foi... .
Species of the genus Stylosanthes are widely distributed in tropical and subtropical regions of the Americas, Africa, and Asia. The main center of origin and diversity is Brazil, the native habitat of 25 of the 45 described species. The genus is adapted to a variety of edaphic and climatic conditions and showed good potential as a cultivated forage in Brazil. Anthracnose, caused by Colletotrichum gloeosporioides (Penz.) Penz. & Sacc., the anamorphic form of Glomerella cingulata (Stonem.) Spauld & Scherenk, has been the main limitation to the commercial utilization of Stylosanthes. In 2000, the National Beef Cattle Research Center (Embrapa Beef Cattle), from Brazilian Agricultural Research Corporation (Embrapa) released Stylosanthes cv. Campo Grande, it is a physical mixture of hybrid-derived progenies of 11 accessions of S. capitata and six lines of S. macrocephala. The resulting populations were advanced through six generations of bulk seed production. Seeds of the two species were mixed in the proportion of 80% and 20%, respectively, to form the new cultivar. Due to its origin, the cultivar was considered as composite of genetically diverse individuals. However, the actual composition and its long-term maintenance remained unknown factors. Consequently, this project was initiated with the objective to identify the degree of variability among component progenies in the cultivar and select germplasm with a high degree of anthracnose resistance and agronomic performance. The project was carried out at Embrapa Beef Cattle, Campo Grande-MS, from 2000 to 2002. In the first instance, individual plants were raised in the green house from single seed obtained from commercial samples of the cultivar. Some 294 S. capitata plants and 124 of S. macrocephala have been established... (Complete abstract, click electronic address below).
Species of the genus Stylosanthes are widely distributed in tropical and subtropical regions of the Americas, Africa, and Asia. The main center of origin and diversity is Brazil, the native habitat of 25 of the 45 described species. The genus is adapted to a variety of edaphic and climatic conditions and showed good potential as a cultivated forage in Brazil. Anthracnose, caused by Colletotrichum gloeosporioides (Penz.) Penz. & Sacc., the anamorphic form of Glomerella cingulata (Stonem.) Spauld & Scherenk, has been the main limitation to the commercial utilization of Stylosanthes. In 2000, the National Beef Cattle Research Center (Embrapa Beef Cattle), from Brazilian Agricultural Research Corporation (Embrapa) released Stylosanthes cv. Campo Grande, it is a physical mixture of hybrid-derived progenies of 11 accessions of S. capitata and six lines of S. macrocephala. The resulting populations were advanced through six generations of bulk seed production. Seeds of the two species were mixed in the proportion of 80% and 20%, respectively, to form the new cultivar. Due to its origin, the cultivar was considered as composite of genetically diverse individuals. However, the actual composition and its long-term maintenance remained unknown factors. Consequently, this project was initiated with the objective to identify the degree of variability among component progenies in the cultivar and select germplasm with a high degree of anthracnose resistance and agronomic performance. The project was carried out at Embrapa Beef Cattle, Campo Grande-MS, from 2000 to 2002. In the first instance, individual plants were raised in the green house from single seed obtained from commercial samples of the cultivar. Some 294 S. capitata plants and 124 of S. macrocephala have been established... (Complete abstract, click electronic address below).
Descrição
Palavras-chave
Stylosanthes, Antracnose, Colletotrichum gloeosporioides, Plantas - Resistencia a doenças e pragas, Stylosanthes
Como citar
FERNANDES, Celso Dornelas. Resistência de progênies de Stylosanthes capitata e S. macrocephala à antracnose causada por Colletotrichum gloeosporioides. 2003. xi, 90 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agronômicas, 2003.