P T C Gomes

University of Brasília, Brasília, Distrito Federal, Brazil

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Publications (6)6.17 Total impact

  • P T C Gomes, N M A Nassar
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    ABSTRACT: Cassava (Manihot esculenta) is a principal food for large populations of poor people in the tropics and subtropics. Its edible roots are poor in protein and lack several essential amino acids. Interspecific hybrids may acquire high protein characteristics from wild species. We analyzed 19 hybrids of M. esculenta with its wild relative, M. oligantha, for crude protein, amino acid profile, and total cyanide. Some hybrids produced roots with high protein content of up to 5.7%, while the common cultivar that we examined had just 2.3% crude protein. The essential amino acids alanine, phenylalanine, and valine were detected in the hybrids. The sulfur-containing amino acids cysteine and methionine were found at relatively high concentrations in the roots of 4 hybrids. The proportion of lysine in one hybrid was 20 times higher than in the common cultivar. The levels of total cyanide ranged from 19.73 to 172.56 mg/kg and most of the roots analyzed were classified as "non-toxic" and "low toxic". Furthermore, 2 progenies showed reasonable levels of cyanide, but higher protein content and amino acid profile more advantageous than the common cassava.
    Genetics and molecular research: GMR 01/2013; 12(2):1214-1222. · 0.99 Impact Factor
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    ABSTRACT: A new species of Manihot has been collected from Fortaleza, Ceará state, Brazil. It was grown at the living collection in the experimental station, University of Brasilia since 1980 and left for natural reproduction. It bred true during all these years giving rise to identical typical plants of the ancestor one. The closest species to it is M. glaziovii. Apparently this new species was formed by sporadic hybridization between M. glaziovii and cassava itself in its natural habitat, Ceará. It possesses morphological marker gene of the latter one which is ribbed fruit that is found only in cassava. Interspecific hybrids produced experimentally between M. glaziovii and cassava showed similar morphological markers. Exam of its ovules revealed formation of multiple embryos, an indicator of apomixis. Grafting it with common cassava was compatible, giving increased root size up to seven times. KeywordsApomixis–Caatinga vegetation–Grafting–Interspecific hybridization– Manihot glaziovii –Multiembryonic ovule
    Genetic Resources and Crop Evolution 01/2011; 58(6):831-835. · 1.59 Impact Factor
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    ABSTRACT: Cross incompatibility of wild Manihot species with cassava (M. esculenta) can impede their utilization for improving this cultigen. We tested whether compatibility could be determined based on electrophoresis results. Manihot pilosa, M. glaziovii, M. reptans, and M. cearulescens were tested. These species were allowed to hybridize with cassava to determine whether hybridization coincides with the similarity index based on electrophoresis analysis. Gene markers of leaf shape, stem surface, disk color, and fruit shape were used to confirm hybridization. Manihot pilosa and M. glaziovii successfully hybridized with cassava, while the others failed to do so under natural conditions. This result coincided with the similarity index from electrophoresis.
    Genetics and molecular research: GMR 01/2010; 9(1):107-12. · 0.99 Impact Factor
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    ABSTRACT: Cassava hybrids from interspecific crosses with Manihot caerulescens Pohl, M. pseudoglaziovii Pax and Hoffmann and M. dichotoma Ule showed a very high iron and zinc content in both roots and leaves, e.g. 98.15mgkg−1 in roots of the interspecific hybrid cassava-M. caerulescens versus 12.17mgkg−1 in a cassava cultivar. This promising results show the potential of wild Manihot species for micronutrient enhancement of cassava.
    Genetic Resources and Crop Evolution 01/2010; 57(2):287-291. · 1.59 Impact Factor
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    ABSTRACT: An interspecific hybrid between cassava and Manihot glaziovii acquired an apomixis gene from the parent M. glaziovii. This hybrid was exposed to open pollination during three subsequent generations. Seven sibs and the maternal progenitor of the fourth generation were genotyped using six microsatellite loci previously developed for cassava. All sibs were identical with each other and with their maternal progenitor. Sibs of selfed M. glaziovii proved to be identical when examined with these microsatellite loci. The chromosome complement of the apomictic clone was 2n = 38. We observed multi-embryonic aposporic embryo sacs.
    Genetics and molecular research: GMR 01/2009; 8(4):1323-30. · 0.99 Impact Factor
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    ABSTRACT: Wild Manihot species are sources of useful characters to improve the crop. However, their incompatibility with cassava may impede their utilization for improving the cultigen. This study examined the possibility of detecting their compatibility judging from electrophoresis results. Four Manihot species, namely M. pilosa, M. glaziovii, M. reptans and M. cearulescens, were used. These species were allowed to hybridize with cassava to give an idea of how much this hybridity coincides with similarity index of electrophoresis analysis. Gene markers of leaf shape, stem surface, disk color, and fruit form were used to detect hybridity. Species M. pilosa, M. glaziovii had successful hybridization while others failed under natural conditions. This result coincides with the similarity index of electrophoresis.