Molecular marker (AFLP)-based Manihot and cassava numerical taxonomy and genetic structure analysis in progress: Implications for their dynamic conservation and genetic mapping.

Producao Cientifica/CENARGEN/199

The primary genepool of cassava (Manihot esculenta Crantz).

The cultivated genepool comprises all comercial stocks of the crop besides all ingenous landraces and folk varieties of the domesticate.Suplemento. Edição dos Resumos do IV International Scientific Meeting of the Cassava Biotechnology Network, Salvador,1998

Identificação e ocorrência de begomovírus em algodoeiro em regiões de Goiás.

O objetivo do trabalho é verificar se o vírus do mosaico comum do algodoeiro em regiões de Goiás é um begomovírus. Foram localizadas e coletadas 69 plantas com aparentes sintomas de begomovírus

The primary gene pool of cassava (Manihot esculenta Crantz).

A crop gene pool comprises three distinct categories of gene suppliers, primary, secondary, and tertiary gene pools. The primary gene pool (GP-1) is composed of gene reservoirs that cross easily with the domesticate and the crosses produce fertile offspring regularly. The secondary (GP-2) and tertiary (GP-3) gene pools comprise gene sources that cross with variable degrees of diffilculty with the crop species, this implies less close genetic distances. The GP-1 is further subdivided in cultivated and wild gene pools. The cultivated gene pool englobes commercial stocks of the crop besides indigenous landraces and folk varieties of the domesticate. The wild GP-1 of a crop comprises putative ancestors and closely related species that show a fair degree of fertile relationships with the domesticate. Two Douth American wild subspecies of cassava (M. flabellifolia and M. peruviana) are natural members of the wild GP-1 of the species. Another Brazilian species (M. pruinosa) is so close morphologically to the two wild subspecies of cassava that it may turn out another member of the wild GP-1 of the indigen. The GP-2 of cassava is more difficult to delimit as few species have been tested for genetic compatibility. Biosystematic crosses carried out between the crop and a number of wild species suggest a dozen of them as components of the GP-2, the majority are Brazilian species

Conservacao e uso sustentavel de recursos geneticos de Manihot.

Recursos geneticos de especies brasileiras de Manihot (Euphorbiaceae) foram estudados numa abordagem interdisciplinar que visou a produzir conhecimentos em areas de pesquisa pouco exploradas ou em areas cujo conhecimento e considerado carente. Nesta comunicacao apresentam-se sequencialmente resultados das seguintes pesquisas inter-relacionadas: 1. estudos etnobotanicos da mandioca na Amazonia brasileira; 2. estudos taxonomicos de especies silvestres da Amazonia brasileira; 3. estudos sobre a origem geografica da mandioca; 4. estudos de mapas ambientais georeferenciados aplicados a distribuicao ecogeografica de especies; 5. estudos de tecnicas de conservacao ex situ de especies, em especial o estabelecimento de protocolos para a quebra da dormencia e melhorar os indices de germinacao de sementes, conservacao de sementes a longo prazo em temperatura sub-zero, regeneracao de eixos embrionarios e conservacao de vitroplantulas; 6. producao de germoplasma-semente em campos de polinizacao aberta e por polinizacao controlada

Domestication syndrome is investigated by proteomic analysis between cultivated cassava (Manihot esculenta Crantz) and its wild relatives

Cassava (Manihot esculenta Crantz) wild relatives remain a largely untapped potential for genetic improvement. However, the domestication syndrome phenomena from wild species to cultivated cassava remain poorly understood. The analysis of leaf anatomy and photosynthetic activity showed significantly different between cassava cultivars SC205, SC8 and wild relative M. esculenta ssp. Flabellifolia (W14). The dry matter, starch and amylose contents in the storage roots of cassava cultivars were significantly more than that in wild species. In order to further reveal the differences in photosynthesis and starch accumulation of cultivars and wild species, the globally differential proteins between cassava SC205, SC8 and W14 were analyzed using 2-DE in combination with MALDI-TOF tandem mass spectrometry. A total of 175 and 304 proteins in leaves and storage roots were identified, respectively. Of these, 122 and 127 common proteins in leaves and storage roots were detected in SC205, SC8 and W14, respectively. There were 11, 2 and 2 unique proteins in leaves, as well as 58, 9 and 12 unique proteins in storage roots for W14, SC205 and SC8, respectively, indicating proteomic changes in leaves and storage roots between cultivated cassava and its wild relatives. These proteins and their differential regulation across plants of contrasting leaf morphology, leaf anatomy pattern and photosynthetic related parameters and starch content could contribute to the footprinting of cassava domestication syndrome. We conclude that these global protein data would be of great value to detect the key gene groups related to cassava selection in the domestication syndrome phenomena