M M Yamada

Publications (2)2.18 Total impact

• Article: Photosynthesis, chloroplast ultrastructure, chemical composition and oxidative stress in Theobroma cacao hybrids with the lethal gene Luteus-Pa mutant

  B. C. Rehem, A. -A. F. Almeida, I. C. Santos, F. P. Gomes, C. P. Pirovani, P. A. O. Mangabeira, R. X. Corrêa, M. M. Yamada, R. R. Valle
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  ABSTRACT: The Theobroma lethal character Luteus-Pa segregates in a 3:1 ratio, expresses in recessive homozygosis, initially inducing leaf chlorosis and finally provoking seedlings death. The objective of this work was to evaluate gas exchange, chlorophyll fluorescence emission, chemical composition and oxidative stress of wild and mutant seedlings resulting from the crosses Pa 30 × Pa 169 and its reciprocal, aiming to elucidate the seedlings death induced by Luteus-Pa. At 15 day after emergence (DAE) differences began to appear between the wild type and mutant. Mutant seedlings showed: (1) lack of photosynthesis and alterations in chloroplast morphology; (2) lower level of three abundant groups of proteins in leaves; (3) decrease in the content of chloroplastidic pigments (4) decrease in peroxidases activities and increase in leaf polyphenol oxidase activity; (5) decrease in carbohydrate and concentration of some nutrients and low dry mass in all plant parts. In leaves of mutant seedlings of both crosses damages occurred in the system responsible for the photochemical phase of photosynthesis. Variations in growth parameters and subsequent seedling death up to 60 DAE were related to exhaustion of cotyledonary reserves, inactive photosynthetic apparatus and oxidative stress. Additional key wordscacao–lethal gene–mutants–Parinari–photosystem II
  Photosynthetica 04/2012; 49(1):127-139. · 1.00 Impact Factor
• Source

  Available from: Alex-Alan Furtado Almeida

  Article: Genetic mapping of Theobroma cacao (Malvaceae) seedlings of the Parinari series, carriers of the lethal gene Luteus-Pa.

  B C Rehem, A-A F Almeida, R X Corrêa, A S Gesteira, M M Yamada, R R Valle
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  ABSTRACT: The lethal gene 'Luteus-Pa' is found in cacao genotypes (Theobroma cacao) of the Parinari (Pa) series, from Peru. Seedlings affected by this gene have yellowing leaves and subsequently die. We mapped this gene based on microsatellite markers and RAPDs, in order to elucidate the inheritance of 'Luteus-Pa' and investigate possible lethal mechanisms. DNA samples of genitors were amplified with 87 SSR and 64 RAPD primers. The SSR primers amplified 65 RAPD primers, giving 179 polymorphic bands. After screening with SSR and RAPD markers, we selected 20 SSR primers, two SSR primers with ESTs and 22 RAPD primers that were polymorphic for genitors Pa 30 and Pa 169. Only two of the 22 RAPD primers and three of the 20 SSR primers were informative and polymorphic in the analysis of the bulk samples of progenies. Among these, primer RAPD E11 produced a band linked to the lethal gene (38.5 cM); none of the SSRs were associated with 'Luteus-Pa'.
  Genetics and molecular research: GMR 01/2010; 9(3):1775-84. · 1.18 Impact Factor