02361naa a2200277 a 450000100080000000500110000800800410001910000220006024501500008226000090023252015270024165000110176865000150177965000100179465000100180465300100181465300280182465300260185265300150187865300190189365300410191270000260195370000200197970000190199977300650201819661192013-10-03       2013    bl uuuu     u00u1 u    #d1 aFREITAS, S. T. de  aShading affects flesh calcium uptake and concentration, bitter pit incidence and other fruit traits in Greensleeves apple.h[electronic resource]  c2013  aBitter pit (BP) is a physiological disorder in apple (Malus × domestica Borkh) believed to be triggered bylow Ca2+concentrations in the fruit, and which may be influenced by environmental conditions. Theobjectives of this study were to explore the effects of tree shading on total and cell wall bound fruit Ca2+content and fruit susceptibility to BP. Greensleeves (GS) apple trees were cultivated under shaded andnon-shaded conditions. The shading condition was applied 70 days after full bloom by reducing about50% of the sunlight reaching the tree canopies. Shading increased stem water potential and leaf stomatalconductance. Bitter pit was observed only in shaded fruit. Cortical Ca2+was most abundant in shadedfruit without BP symptoms, intermediary in shaded fruit with BP, and lowest in non-shaded fruit. The cellwall Ca2+concentration was higher in shaded than non-shaded fruit, but shaded fruit with and withoutBP had similar cell wall Ca2+concentrations. The degree of pectin deesterification and the expression oftwo pectin methylesterases (PME1 and PME2) were higher in shaded fruit than in non-shaded fruit. Thepercentage of total cortical Ca2+bound to the cell wall was highest in shaded fruit with BP. Shaded fruitwithout BP had lower Mg2+content and Mg2+/Ca2+ratio in cortical tissue than shaded fruit with BP. Theresults indicate that although shade increases fruit Ca2+uptake, it also enhances fruit susceptibility to BPby increasing Mg2+uptake and Ca2+binding to the cell wall in fruit cortical tissue.  aFruits  aFisiologia  aFruta  aMaça  aApple  aDeficiência de cálcio  aDesordem fisiológica  aNutrientes  aParede celular  aRadiação fotossinteticamente ativa1 aAMARANTE, C. V. T. do1 aDANDEKAR, A. M.1 aMITCHAM, E. J.  tScientia Horticulturae, Amsterdamgv. 161, p. 266-272, 2013.