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Universidade de Brasília (2011)

Controle genético de caracteres agronômicos em Quinoa (chenopodium quinoa willd)

Rocha, Juliana Evangelista da Silva

Titre : Controle genético de caracteres agronômicos em Quinoa (chenopodium quinoa willd)

Genetic control of agronomic characters in Quinoa

Auteur : Rocha, Juliana Evangelista da Silva

Université de soutenance : Universidade de Brasília

Grade : Doutorado em Agronomia 2011

Quinoa, originated from the Altiplano between Bolivia and Peru, is an example of potential species which has shown outstanding performance by the pioneer work aiming at nutritional quality and biomass to protect the soil In Brazil, the research started in the 1990’s, by Embrapa in collaboration with Universidad de Brasília (UnB). Promising results stimulated the continuation of research efforts until it was possible to adapt the crop to the Brazilian Savannah. The first selected genotypes, however, had limiting factors, as in the case of BRS Piabiru, first cultivar released for cultivation in Brazil. In sequence, BRS Syetetuba was acquired, possessing short plant cycle and large, saponin-free, grains, becoming an option to farmers. For quinoa to be inserted in the agricultural system, varieties should meet desirable agronomic characteristics, such as short- to mid-cycle, high grain yield, plant height suitable to combine harvest and large, high quality grains. In general, these are complex in their genetic expression, resulting from interaction of various components, not being found simultaneously in progenies derived from existing germless. Thus, controlled hybridizations were conducted to increase grain size, in association with other characters. In the absence of records for artificial hybrids being employed in Brazil, for quinoa breeding, induced crosses, by emasculation with alcohol and artificial handling of flowers resulted hybrids among selected genotypes. The F1 hybrids were identified by morphological characters such as the presence of pigment in plant parts and the character was tested for genetic inheritance, confirming dominance over absence. Pleiotropy for as a tool in selection. From controlled hybridizations among divergent genotypes, agronomic and physic-chemical characters were studied in F2 for genetic components. Plant height and protein content were less influenced by environment, creating real opportunities for gain from selection. It has been demonstrated the value of genetic conditioners in characters with economic interest in quinoa, governed by quantitative effects, that might contribute to genotypic enhancement and cultivar acquisition.


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