甜高粱光合生理特性及其与产量的关系

Correlativity between photosynthetic physiological characteristics and biological yield of sweet sorghum strain

【目的】比较不同甜高粱品系灌浆期叶片光合生理指标的差异,揭示甜高粱生物产量和含糖锤度与灌浆期光合生理指标的相关性。【方法】以9个中熟甜高粱品系为材料,分别测定灌浆期不同品系的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci)等光合参数,并测定叶片叶绿素含量、PEP羧化酶活性等生理生化指标,以及株高、茎秆汁液含糖锤度、产量、叶面积指数等生长性状指标,同时对各指标间的相关性进行了分析。【结果】9个甜高粱品系的Pn、Tr、Gs、Ci、PEP羧化酶活性、叶面积指数(LAI)、叶绿素a(Chl a)、叶绿素b(Chl b)、总叶绿素(Chl)、氮质量分数(LNCa)、总蛋白质量分数(TP)、可溶性糖质量分数(SS)均表现出一定的差异。Pn较高的品系有"LT05"、"LT02"、"新高粱3号"、"BABUSH"、"UT84"、"MN-94",其对应数值依次为16.01,14.60,14.57,14.24,12.83和12.56μmol/(m2.s);Chl较高的品系有"新高粱3号"、"LT02"、"MN-94"、"LT05",其对应数值依次为4.63,4.36,3.98和3.91mg/g;PEP羧化酶活性较高的品系有"LT05"、"UT84"、"LT02"、"新高粱3号",其对应数值依次为23.06,21.78,18.50和17.75U/min;LAI较高的品系有"BABUSH"、"LT05"、"LT02"、"UT84"、"MN-94",其对应数值依次为3.46,3.30,2.93,2.41和2.41;生物产量较高的品系有"LT05"、"LT02"、"新高粱3号"、"MN-94",其对应数值依次为46 669.5,45 835.5,45 336.1,44 169.2kg/hm2;含糖锤度较高的品系有"新高粱3号"、"LT05"、"UT84"、"BABUSH",其对应数值依次为19.6°,17.6°,16.5°和16.3°。相关分析表明,生物产量与Pn达极显著正相关(R=0.933),与PEP羧化酶活性、LAI达显著正相关(R=0.775,0.743),与Chl a、Chl b、Chl、Gs正相关程度较高;含糖锤度与Pn、Tr、PEP羧化酶活性、LAI达显著正相关(R=0.685,0.679,0.747,0.691);生物产量和含糖锤度与其他性状均未达到显著相关。【结论】筛选出"LT05"、"LT02"、"新高粱3号"、"MN-94"为高产、高糖、高光效甜高粱种质,可以将甜高粱灌浆期叶片Pn作为选择高光效种质的一个有效指标。

[Objective] Contrastive analysis of the differences between photosynthetic physiological indexes of different sweet sorghum strains at filling stage, and their correlations between biological yield, brix and physiology index were conducted. [Method] Nine sweet sorghum strains were chosen as the experiment material. Photosynthetic parameters such as net photosynthetic rate （Pn）, transpiration rate （Tr）, cond（Gs）, intercellular CO2 concentration （Ci）, were recorded, physiological indexes such as chlorophyll content（Chl）,PEPCase activity（PEP） were determined, and agronomic traits such as plant weight, stem brix, yield,leaf area index （LAI） and their relationship were measured. [Result] There were differences in Pn, transpiration rate （ Tr）, cond （Gs）, intercellular CO2 concentration （Ci）, Chlorophyll A （Chla）, Chlorophyll B （Chlb） ,Chl,nitrogen content （LNCa） ,total protein content （TP） ,soluble sugar （SS） ,PEP,LAI of nine sweet sorghum strains. The strains with higher Pn were “LTO5”,“LTO2”,“Xingaoliang No. 3”,“BABUSH”,“UT84”, and “MN-94”, with corresponding values of 16. 01,14. 60, 14.57, 14. 24, 12. 83, and 12.56 μmol/（m2 · s）. The strains with higher Chl were “Xingaoliang No. 3”,“LT02”,“MN-94”, and “LT05” with corresponding values of 4.63,4.36,3.98,and 3.91 mg/g. The strains with higher PEP were “LTOS”,“UT84”,“LTO2”,and “Xingaoliang No. 3” with corresponding values of 23.06,21.78,18.50,and 17.75 U/min. The strains with higher LAI were“BABUSH”, “LT05”, “LT02”, “UT84”, and “MN-94” with corresponding values of 3.46,3.30,2.93,2.41 ,and 2.41. The strains with higher biological yield were “LTO5”,“LTO2”,“Xingaoliang No. 3”, and “MN-94” with corresponding values of 46 669. 5,45 835. 5, 45 336.1,and 44 169. 2 kg/hm2. The strains with higher stem brix were “Xingaoliang No. 3”,“LT05”,“UT84” ,and “BABUSH” with corresponding values of 19.6°, 17.6°, 16.5°,and 16.3°. Correlation analysis indicated that biological yield was highly significant correlated with Pn （R= 0. 933）, and significant correlated with PEP and LAI （R=0. 775 and 0. 743）,and was highly correlated with Chl a,Chl b,Chl,Gs. Brix was significant correlated with Pn, Tr,PEP and LAI （R=0. 685,0. 679,0. 747, and 0. 691）. [Conclusion] “LT05”,“LT02”,“Xingaoliang No. 3”,and “MN-94”had high biological yield, high brix and high photosynthetic efficiency. The net photosynthetic rate could be effectively used as a selection index for breeding of high photosynthetic efficiency sweet sorghum