摘要
采用溶液培养方法，设Mn^2＋浓度为0、0．05、0．50、5、30、50mg／L，探讨了2种大豆品种（浙春2号、东北大豆854—11）的幼苗光合特性对不同锰浓度的响应。结果表明，低锰浓度提高了大豆叶片的初始荧光（Fo）、最大荧光（Fm）、PSⅡ原初光能转化效率（Fv／Fm）、潜在光化学活性（Fv／Fo）和光化学猝灭系数（qP），高锰降低了Fo、Fm、Fv／Fm、Fv／Fo、qP。随着锰营养的增加，非光化学猝灭系数（qN）增大。适量的锰浓度显著提高了大豆的净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs），降低了气孔阻力（Rs）和细胞间CO2浓度（Ci），随着锰浓度的逐渐增大，降低了Pn、Tr、Gs，提高了Rs、Ci。0．50mg／L下的锰浓度有最大的Fo，5mg／L下的锰浓度有最大的Fm、qP、Fv／Fm、Fv／Fo，表明0．50～5mg／L的锰浓度有利于大豆的光合作用。在50mg/L的锰浓度下，两个大豆品种有最大的qN、Rs、Ci和最小的Tr、Pn，此时两个品种大豆耗散了过剩的激发能，降低了大豆叶片的光合速率，对大豆已产生了一定的伤害。两个品种大豆光合特性对锰的响应存在着基因型差异，浙春2号较东北大豆耐锰胁迫。
With two soybean （ Glycine max） varieties, Dongbei 854-11 （ DB854-11 ） and Zhechun No. 2 （ZC2） as experimental materials, the responses of photosynthetic characteristics in soybean leaves to different manganese （Mn） concentration （0, 0.05, 0.5, 5, 30, 50 mg/L ） were studied. The results showed that minimal fluorescence （ Fo）, maximum fluorescence （Fm）, maximal photochemical efficiency of PS Ⅱ （Fv/Fm）, the potential activities of PS Ⅱ （Fv/Fo）, photochemical quenching （qP） were enhanced with low concentration of Mn, but the Fo, Fm, Fv/Fm, Fv/Fo, qP were reduced with high concentration of Mn. With the increasing of Mn concentration, non-photochemical quenching coefficient （qN） was increased. Appropriate concentration of Mn significantly increased photosynthetic rate （Pn）, transpiration rate （ Tr）, stomatal conductance （Gs） and decreased stomata resistance （Rs） and intercellular CO2 concentration （Ci）. With the increasing of Mn concentration, Pn, Tr and Gs in soybean leaves were reduced, while Rs, Ci increased. Fo reached the maximum value at the concentration of 0.5 mg/L Mn^2＋ , but Fm, qP, Fv/Fm, Fv/Fo was maximum at 5 mg/L Mn^2＋ , which indicated that for the photosynthesis was promoted when the concentration of Mn^2＋ between 0.5 mg/L and 5 mg/L. Under 50 mg/L Mn^2＋ treatment, qN, Rs, Ci reached the maximum and Tr, Pn reduced to the minimum. The negative effect on soybean growth was resulted from the dissipation of excess light energy and reduction of photosynthetic rate. There was a genotypic difference between the two varieties of soybean. Zhechun No. 2 was more Mn-tolerant than Dongbei 854-11 soybean.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2007年第6期1135-1142,共8页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金(30540056)资助
关键词
锰浓度
大豆
光合特性
基因型差异
Mn concentration
soybean
photosynthesis
genotype difference
