Peaches are subject to flesh softening during postharvest storage and transport,which affects the storage life of the fruit and causes huge economic losses.Previous research has demonstrated that postharvest brassinol...Peaches are subject to flesh softening during postharvest storage and transport,which affects the storage life of the fruit and causes huge economic losses.Previous research has demonstrated that postharvest brassinolide treatment can maintain flesh firmness,ascorbic acid and soluble solids contents,and enhance disease resistance in peach fruits.This study assessed the influence of postharvest brassinolide treatment on the expression of key genes involved in cell wall degradation and the phenylpropanoid pathway in peach fruits by real-time fluorescence quantitative polymerase chain reaction(qPCR).The results showed that brassinolide dipping inhibited the gene expression of pectate lyase 1,polygalacturonase 21 and pectin methylesterase 1,and significantly enhanced the gene expression of peroxidase,cinnamoyl-CoA reductase,phenylalanine ammonia lyase and caffeoyl-CoA-O-methyltransferase 5 in peach fruits.It also increased the gene expression levels of chaleone synthase,chaleone isomerase,dihydroflavonol-4-reductase and flavanone 3-hydroxylase at the early stage of storage.These findings imply that brassinolide can suppress the expression of key genes involved in cell wall degradation and enhance the expression of key genes involved in the phenylpropanoid pathway,thereby delaying peach fruit softening and enhancing disease resistance.展开更多
The rheological properties in the supernatant of peach gum from Prunnus dulcis were discussed in order to provide more scientific technical parameters and references for developing peach gum as a kind of medicinal gum...The rheological properties in the supernatant of peach gum from Prunnus dulcis were discussed in order to provide more scientific technical parameters and references for developing peach gum as a kind of medicinal gum.The rheological properties in the supernatant of peach gum were comparatively studied in different material ratios,temperatures,shaking times,pH values and salinities.The results show that,1) the mathematical model of shear rate with material ratio and shear stress is Y=0.069X12+0.035X2 -1.174,R2=0.942;2) the mathematical model of shear rate with temperature and shear stress is Y=4.936X12+0.023 2X2-1.688,R2=0.937;3) the mathematical model of shear rate with shaking time and shear stress is Y=0.005 192 X13-0.140 73X12+1.249 045X1+ 0.036 546 X2-3.644 29,R2=0.954 3;4) the effects of pH value on the rheological properties in the supernatant of peach gum are comparatively complicated with a varying range of 3-11 and the shear rate shows a change trend of saddle model;5) the mathematical model of shear rate with the concentration of NaCl and shear stress is Y=-0.037 44X1+0.012 93 X2,R2=0.998;6) the mathematical model of shear rate with the concentration of CaCl2 and shear stress is Y=0.025 789X1+0.016 19X2,R2 =0.999;and 7) the mathematical model of shear rate with the concentration of sorbic acid potassium and shear stress is Y=0.079 5X1+0.017 3X2,R2=0.998.The results show that the material ratio,temperature,shaking time,pH value significantly affect the rheological properties in the supernatant of peach gum,and the concentrations of NaCl and CaCl2 also significantly affect the rheological properties expect the concentration of sorbic acid potassium.展开更多
Differential thermal analysis was utilized to determine midwinter hardiness of stem tissues and flower buds of mei flower (Prunus mume) and David’s peach (Prunus davidiana). Low temperature freezing exotherms were fo...Differential thermal analysis was utilized to determine midwinter hardiness of stem tissues and flower buds of mei flower (Prunus mume) and David’s peach (Prunus davidiana). Low temperature freezing exotherms were found to occur at -35℃ in Green Calyxs’ David’s peach and -18℃ in mei flower. A Low temperature exotherm was produced by the freezing of deep supercooling water which was detected in the wood tissues but not in the bark. Freezing processes of the wood and those of the bark appeared to be independent. Deep supercooling points of both species were found to be closely related to freezing injury and to their respective distributions.展开更多
文摘Peaches are subject to flesh softening during postharvest storage and transport,which affects the storage life of the fruit and causes huge economic losses.Previous research has demonstrated that postharvest brassinolide treatment can maintain flesh firmness,ascorbic acid and soluble solids contents,and enhance disease resistance in peach fruits.This study assessed the influence of postharvest brassinolide treatment on the expression of key genes involved in cell wall degradation and the phenylpropanoid pathway in peach fruits by real-time fluorescence quantitative polymerase chain reaction(qPCR).The results showed that brassinolide dipping inhibited the gene expression of pectate lyase 1,polygalacturonase 21 and pectin methylesterase 1,and significantly enhanced the gene expression of peroxidase,cinnamoyl-CoA reductase,phenylalanine ammonia lyase and caffeoyl-CoA-O-methyltransferase 5 in peach fruits.It also increased the gene expression levels of chaleone synthase,chaleone isomerase,dihydroflavonol-4-reductase and flavanone 3-hydroxylase at the early stage of storage.These findings imply that brassinolide can suppress the expression of key genes involved in cell wall degradation and enhance the expression of key genes involved in the phenylpropanoid pathway,thereby delaying peach fruit softening and enhancing disease resistance.
基金Project(2006BAD18B02) supported by the 11th Five-Year Plan of National Key Technology R&D Program of ChinaProject(07006B) supported by Youth Fund of Central South University of Forestry and Technology,ChinaProject(080929) supported the Education Fund of Hunan Province,China
文摘The rheological properties in the supernatant of peach gum from Prunnus dulcis were discussed in order to provide more scientific technical parameters and references for developing peach gum as a kind of medicinal gum.The rheological properties in the supernatant of peach gum were comparatively studied in different material ratios,temperatures,shaking times,pH values and salinities.The results show that,1) the mathematical model of shear rate with material ratio and shear stress is Y=0.069X12+0.035X2 -1.174,R2=0.942;2) the mathematical model of shear rate with temperature and shear stress is Y=4.936X12+0.023 2X2-1.688,R2=0.937;3) the mathematical model of shear rate with shaking time and shear stress is Y=0.005 192 X13-0.140 73X12+1.249 045X1+ 0.036 546 X2-3.644 29,R2=0.954 3;4) the effects of pH value on the rheological properties in the supernatant of peach gum are comparatively complicated with a varying range of 3-11 and the shear rate shows a change trend of saddle model;5) the mathematical model of shear rate with the concentration of NaCl and shear stress is Y=-0.037 44X1+0.012 93 X2,R2=0.998;6) the mathematical model of shear rate with the concentration of CaCl2 and shear stress is Y=0.025 789X1+0.016 19X2,R2 =0.999;and 7) the mathematical model of shear rate with the concentration of sorbic acid potassium and shear stress is Y=0.079 5X1+0.017 3X2,R2=0.998.The results show that the material ratio,temperature,shaking time,pH value significantly affect the rheological properties in the supernatant of peach gum,and the concentrations of NaCl and CaCl2 also significantly affect the rheological properties expect the concentration of sorbic acid potassium.
基金This project was supported by the National Natural Science Foundation of China
文摘Differential thermal analysis was utilized to determine midwinter hardiness of stem tissues and flower buds of mei flower (Prunus mume) and David’s peach (Prunus davidiana). Low temperature freezing exotherms were found to occur at -35℃ in Green Calyxs’ David’s peach and -18℃ in mei flower. A Low temperature exotherm was produced by the freezing of deep supercooling water which was detected in the wood tissues but not in the bark. Freezing processes of the wood and those of the bark appeared to be independent. Deep supercooling points of both species were found to be closely related to freezing injury and to their respective distributions.
