Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain...Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain obscure.This study aimed to examine whether and how MC and PPD affect the leaf morpho-physiological characteristics,and thus final cotton yield.PPD of three levels(D1:2.25 plants·m^(-2),D2:4.5 plants·m^(-2),and D3:6.75 plants·m^(-2))and MC dosage of two levels(MC0:0 g·ha^(-2),MC1:82.5 g·ha^(-2))were combined to create six treatments.The dynamics of nonstructual carbohydrate concentration,carbon metabolism-related enzyme activity,and photosynthetic attributes in cotton leaves were examined during reproductive growth in 2019 and 2020.Results Among six treatments,the high PPD of 6.75 plants·m^(-2)combined with MC application(MC1D3)exhibited the greatest seed cotton yield and biological yield.The sucrose,hexose,starch,and total nonstructural carbohydrate(TNC)concentrations peaked at the first flowering(FF)stage and then declined to a minimum at the first boll opening(FBO)stage.Compared with other treatments,MC1D3 improved starch and TNC concentration by 5.4%~88.4%,7.8%~52.0% in 2019,and by 14.6%~55.9%,13.5%~39.7% in 2020 at the FF stage,respectively.Additionally,MC1D3 produced higher transformation rates of starch and TNC from the FF to FBO stages,indicating greater carbon production and utilization efficiency.MC1D3 displayed the maximal specific leaf weight(SLW)at the FBO stage,and the highest chlorophyll a(Chl a),Chl b,and Chl a+b concentration at the mid-late growth phase in both years.The Rubisco activity with MC1D3 was 2.6%~53.2% higher at the flowering and boll setting stages in both years,and 2.4%~52.7% higher at the FBO stage in 2020 than those in other treatments.These results provided a explanation of higher leaf senescence-resistant ability in MC1D3.Conclusion Increasing PPD coupled with MC application improves cotton yield by enhancing leaf carbohydrate production and utilization efficiency and delaying leaf senescence.展开更多
本研究旨在确定大菱鲆(Scophthalmus maximus L.)的最适饲料糖脂比,并探究其对碳水化合物和脂肪的利用能力。实验采用5种不同糖脂比饲料(碳水化合物∶脂肪的比值为2.01、1.53、1.25、0.96、0.71),分别投喂5组大菱鲆幼鱼(D1、D2、D3、D4...本研究旨在确定大菱鲆(Scophthalmus maximus L.)的最适饲料糖脂比,并探究其对碳水化合物和脂肪的利用能力。实验采用5种不同糖脂比饲料(碳水化合物∶脂肪的比值为2.01、1.53、1.25、0.96、0.71),分别投喂5组大菱鲆幼鱼(D1、D2、D3、D4、D5)。将初始体质量为(7.00±0.35)g的大菱鲆幼鱼随机分到15个养殖圆桶中,每桶40尾大菱鲆进行养殖实验。养殖期间采用饱食方式进行投喂,每天投喂2次,养殖周期56 d。研究显示,D4组大菱鲆的增重率(WGR)、蛋白质效率(PER)、饲料利用率(FER)以及特定生长率(SGR)均显著高于其他组(P<0.05)。D4组肠道中脂肪酶和胰蛋白酶的活性显著高于其他组(P<0.05),D3组淀粉酶活性显著高于其他组(P<0.05)。D3和D4组血浆中甘油三酯(TG)含量显著高于其他组(P<0.05);D4组总胆固醇(T-CHO)、高密度脂蛋白(HDL-C)和低密度脂蛋白(LDL-C)的含量均显著高于其他组(P<0.05)。D3组肝脏中糖代谢相关酶的葡萄糖激酶基因(gk)的表达量显著高于D1组(P<0.05);D3和D4组丙酮酸激酶基因(pk)的表达量显著高于其他组(P<0.05),D4组磷酸果糖激酶1基因(pfk)的表达量显著高于其他组(P<0.05)。D5组磷酸烯醇丙酮酸羧化酶基因(pepck)、果糖双磷激酶1基因(fbpase)和葡萄糖-6-磷酸酶基因(g6pase)的表达量均显著高于其他组(P<0.05)。D4组脂代谢相关基因过氧化物酶体增殖物激活受体-γ共激活因子1α基因(pgc1α)和磷脂酸磷酸化酶1基因(lipin1)的表达量显著高于其他组(P<0.05);D5组过氧化物酶体增值物激活受体基因α(pparα)的表达量显著高于其他组(P<0.05);D4和D5组脂蛋白酯酶基因(lpl)的表达量显著高于其他组(P<0.05);D3、D4和D5组肝X受体基因(lxr)的表达量显著高于其他组(P<0.05)。研究结果显示,饲料糖脂比在0.96~1.25之间时大菱鲆幼鱼表现出最优生长性能。展开更多
为研究饲料中碳水化合物类型对大菱鲆(Scophthalmus maximus L.)生长性能以及糖脂代谢的影响,实验设计了4种含有不同类型碳水化合物(葡萄糖、蔗糖、β-葡聚糖、淀粉)的等氮等能饲料,选取体质量为(7.03±0.15)g的大菱鲆幼鱼,进行为期...为研究饲料中碳水化合物类型对大菱鲆(Scophthalmus maximus L.)生长性能以及糖脂代谢的影响,实验设计了4种含有不同类型碳水化合物(葡萄糖、蔗糖、β-葡聚糖、淀粉)的等氮等能饲料,选取体质量为(7.03±0.15)g的大菱鲆幼鱼,进行为期8周的养殖,测定了大菱鲆的生长性能、表观消化率、全鱼常规组成、形体、肝脏切片组织形态、血清生化、糖原含量、糖代谢、脂代谢、能量代谢等指标。研究表明:淀粉组的特定生长率、增重率、蛋白质效率均显著高于蔗糖组和葡萄糖组(P<0.05),葡萄糖组的饲料系数最高且显著高于其他3组(P<0.05)。与葡萄糖组和蔗糖组相比,淀粉组和β-葡聚糖组的干物质和蛋白质的表观消化率有显著提高(P<0.05)。葡萄糖组肝脏切片脂滴面积占比较其他3组显著增加(P<0.05)。相较于其他组,葡萄糖组的血清甘油三酯、葡萄糖、总胆固醇及肝糖原含量显著增加(P<0.05),而蔗糖组肌糖原含量显著降低(P<0.05)。蔗糖组的葡萄糖激酶、丙酮酸激酶、磷酸果糖激酶基因相对表达量较其他3组显著上调(P<0.05),而葡萄糖组的1,6-二磷酸果糖酶和6-磷酸葡萄糖酶基因相对表达量显著降低(P<0.05)。葡萄糖组和蔗糖组的脂肪酸合酶、固醇调节元件结合蛋白1、脂酰辅酶A氧化酶基因相对表达量显著低于β-葡聚糖组和淀粉组(P<0.05)。β-葡聚糖组和淀粉组的柠檬酸合酶、异柠檬酸脱氢酶1、二氢硫辛酰胺琥珀酰转移酶基因相对表达量显著高于葡萄糖组和蔗糖组(P<0.05)。研究结果表明,与葡萄糖、蔗糖等结构简单的碳水化合物相比,大菱鲆幼鱼对淀粉、β-葡聚糖等结构复杂的碳水化合物的利用能力更强。在本实验条件下,淀粉是饲料中最适合大菱鲆幼鱼生长的碳水化合物来源。展开更多
基金supported by the National Natural Science Foundation of China(grant no.31960385)the Natural Science Foundation of Jiangxi,China(grant no.20212BAB215009)。
文摘Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain obscure.This study aimed to examine whether and how MC and PPD affect the leaf morpho-physiological characteristics,and thus final cotton yield.PPD of three levels(D1:2.25 plants·m^(-2),D2:4.5 plants·m^(-2),and D3:6.75 plants·m^(-2))and MC dosage of two levels(MC0:0 g·ha^(-2),MC1:82.5 g·ha^(-2))were combined to create six treatments.The dynamics of nonstructual carbohydrate concentration,carbon metabolism-related enzyme activity,and photosynthetic attributes in cotton leaves were examined during reproductive growth in 2019 and 2020.Results Among six treatments,the high PPD of 6.75 plants·m^(-2)combined with MC application(MC1D3)exhibited the greatest seed cotton yield and biological yield.The sucrose,hexose,starch,and total nonstructural carbohydrate(TNC)concentrations peaked at the first flowering(FF)stage and then declined to a minimum at the first boll opening(FBO)stage.Compared with other treatments,MC1D3 improved starch and TNC concentration by 5.4%~88.4%,7.8%~52.0% in 2019,and by 14.6%~55.9%,13.5%~39.7% in 2020 at the FF stage,respectively.Additionally,MC1D3 produced higher transformation rates of starch and TNC from the FF to FBO stages,indicating greater carbon production and utilization efficiency.MC1D3 displayed the maximal specific leaf weight(SLW)at the FBO stage,and the highest chlorophyll a(Chl a),Chl b,and Chl a+b concentration at the mid-late growth phase in both years.The Rubisco activity with MC1D3 was 2.6%~53.2% higher at the flowering and boll setting stages in both years,and 2.4%~52.7% higher at the FBO stage in 2020 than those in other treatments.These results provided a explanation of higher leaf senescence-resistant ability in MC1D3.Conclusion Increasing PPD coupled with MC application improves cotton yield by enhancing leaf carbohydrate production and utilization efficiency and delaying leaf senescence.
文摘本研究旨在确定大菱鲆(Scophthalmus maximus L.)的最适饲料糖脂比,并探究其对碳水化合物和脂肪的利用能力。实验采用5种不同糖脂比饲料(碳水化合物∶脂肪的比值为2.01、1.53、1.25、0.96、0.71),分别投喂5组大菱鲆幼鱼(D1、D2、D3、D4、D5)。将初始体质量为(7.00±0.35)g的大菱鲆幼鱼随机分到15个养殖圆桶中,每桶40尾大菱鲆进行养殖实验。养殖期间采用饱食方式进行投喂,每天投喂2次,养殖周期56 d。研究显示,D4组大菱鲆的增重率(WGR)、蛋白质效率(PER)、饲料利用率(FER)以及特定生长率(SGR)均显著高于其他组(P<0.05)。D4组肠道中脂肪酶和胰蛋白酶的活性显著高于其他组(P<0.05),D3组淀粉酶活性显著高于其他组(P<0.05)。D3和D4组血浆中甘油三酯(TG)含量显著高于其他组(P<0.05);D4组总胆固醇(T-CHO)、高密度脂蛋白(HDL-C)和低密度脂蛋白(LDL-C)的含量均显著高于其他组(P<0.05)。D3组肝脏中糖代谢相关酶的葡萄糖激酶基因(gk)的表达量显著高于D1组(P<0.05);D3和D4组丙酮酸激酶基因(pk)的表达量显著高于其他组(P<0.05),D4组磷酸果糖激酶1基因(pfk)的表达量显著高于其他组(P<0.05)。D5组磷酸烯醇丙酮酸羧化酶基因(pepck)、果糖双磷激酶1基因(fbpase)和葡萄糖-6-磷酸酶基因(g6pase)的表达量均显著高于其他组(P<0.05)。D4组脂代谢相关基因过氧化物酶体增殖物激活受体-γ共激活因子1α基因(pgc1α)和磷脂酸磷酸化酶1基因(lipin1)的表达量显著高于其他组(P<0.05);D5组过氧化物酶体增值物激活受体基因α(pparα)的表达量显著高于其他组(P<0.05);D4和D5组脂蛋白酯酶基因(lpl)的表达量显著高于其他组(P<0.05);D3、D4和D5组肝X受体基因(lxr)的表达量显著高于其他组(P<0.05)。研究结果显示,饲料糖脂比在0.96~1.25之间时大菱鲆幼鱼表现出最优生长性能。
文摘为研究饲料中碳水化合物类型对大菱鲆(Scophthalmus maximus L.)生长性能以及糖脂代谢的影响,实验设计了4种含有不同类型碳水化合物(葡萄糖、蔗糖、β-葡聚糖、淀粉)的等氮等能饲料,选取体质量为(7.03±0.15)g的大菱鲆幼鱼,进行为期8周的养殖,测定了大菱鲆的生长性能、表观消化率、全鱼常规组成、形体、肝脏切片组织形态、血清生化、糖原含量、糖代谢、脂代谢、能量代谢等指标。研究表明:淀粉组的特定生长率、增重率、蛋白质效率均显著高于蔗糖组和葡萄糖组(P<0.05),葡萄糖组的饲料系数最高且显著高于其他3组(P<0.05)。与葡萄糖组和蔗糖组相比,淀粉组和β-葡聚糖组的干物质和蛋白质的表观消化率有显著提高(P<0.05)。葡萄糖组肝脏切片脂滴面积占比较其他3组显著增加(P<0.05)。相较于其他组,葡萄糖组的血清甘油三酯、葡萄糖、总胆固醇及肝糖原含量显著增加(P<0.05),而蔗糖组肌糖原含量显著降低(P<0.05)。蔗糖组的葡萄糖激酶、丙酮酸激酶、磷酸果糖激酶基因相对表达量较其他3组显著上调(P<0.05),而葡萄糖组的1,6-二磷酸果糖酶和6-磷酸葡萄糖酶基因相对表达量显著降低(P<0.05)。葡萄糖组和蔗糖组的脂肪酸合酶、固醇调节元件结合蛋白1、脂酰辅酶A氧化酶基因相对表达量显著低于β-葡聚糖组和淀粉组(P<0.05)。β-葡聚糖组和淀粉组的柠檬酸合酶、异柠檬酸脱氢酶1、二氢硫辛酰胺琥珀酰转移酶基因相对表达量显著高于葡萄糖组和蔗糖组(P<0.05)。研究结果表明,与葡萄糖、蔗糖等结构简单的碳水化合物相比,大菱鲆幼鱼对淀粉、β-葡聚糖等结构复杂的碳水化合物的利用能力更强。在本实验条件下,淀粉是饲料中最适合大菱鲆幼鱼生长的碳水化合物来源。
