Cyclocarya paliurus is only propagated from seeds which have pronounced dormancy. Overcoming seed dormancy is an important component of efficient and cost-effective seedling production of Cyclocarya paliurus. Changes ...Cyclocarya paliurus is only propagated from seeds which have pronounced dormancy. Overcoming seed dormancy is an important component of efficient and cost-effective seedling production of Cyclocarya paliurus. Changes in biochemical composition and enzyme activity were investigated during dormancy release. The activities of all the studied enzymes in the stratified seeds increased significantly, compared to those in the control samples. Of the enzymes examined, the activities of protease increased the most （413.8%）, followed by peroxidase （278.7%）, lipase （161.0%）, glucose-6-phosphate dehydrognase （149.1%） and amylase （60.6%） after 8 months of stratification. Crude fat and protein constituted the bulk of the storage reserves in mature seeds of C. pal# urus. Compared with the seeds before stratification, about 45% of the starch, 46% of the protein and 11% of the crude fat were depleted during dormancy release of C. paliurus seeds, while the soluble sugar content was enhanced by 101.5% in the germinating seeds. Correlation analysis showed, during dormancy release of C. paliurus seeds, a close positive relationship between POD and G6PDH activity as well as soluble sugar content and amylase activity, while there was a significant negative relationship between storage substances and their related enzyme activities.展开更多
Field studies were conducted to examine the effects of cerium on the growth and physiological characteristics of Cyclocarya paliurus seedlings by spraying the foliage with different concentrations of cerium nitrate. O...Field studies were conducted to examine the effects of cerium on the growth and physiological characteristics of Cyclocarya paliurus seedlings by spraying the foliage with different concentrations of cerium nitrate. Optimal concentrations of cerium nitrate improved the relative growth yield of seedling height and stems and the soluble protein and sugar content of the leaves. Cerium nitrate also increased the concentration of secondary metabolites including triterpenoids, quercetin and kaempferol, mineral elements K, P, Mg, Mn, Fe and Cu, and the activities of superoxide dismutase （SOD）, peroxidase （POX）, and phenylalanine ammonia-lyase （PAL） in the leaves. The effects of cerium nitrate on these indices were dose dependent. A concentration of 0.20 mmol/L was optimal to promote the relative growth yield of seedling height, contents of soluble sugar, kaempferol, K, P, Cu, and activities of PAL, SOD, and POX, significantly increased by 54.61%, 14.71%, 55.19%, 105.2%, 74.5%, 133.3%, 80.48%, 25.35% and 22.54%, respectively, as compared with the control. However, the maximal increase in relative growth yield of stems, contents of triterpenoid, quercetin, Mg, Mn, and Fe was attained at 1.00 mmol/L treatment, which significantly increased by 87.00%, 80.56%, 452.44%, 93.2%, 29.4%, and 133.9%, respectively, compared with control check （CK）. Correlation analysis revealed positive relationships between activities of PAL, SOD and contents of triterpenoid, quercetin and kaempferol within a certain concentration range of cerium nitrate. These resuits suggested that an appropriate concentration of cerium not only was effective in the improvement of physiological function of C. paliurus, but also increased seedling resistance. Moreover, it stimulated the synthesis of medicinal components in leaves.展开更多
基金This work is supported by the National Natural Science Foundation of China （Grant No. 30371156）in part by Grant sx （2003） 083 from the ＂Three Agriculture Engineering Program of Jiangsu Province＂.
文摘Cyclocarya paliurus is only propagated from seeds which have pronounced dormancy. Overcoming seed dormancy is an important component of efficient and cost-effective seedling production of Cyclocarya paliurus. Changes in biochemical composition and enzyme activity were investigated during dormancy release. The activities of all the studied enzymes in the stratified seeds increased significantly, compared to those in the control samples. Of the enzymes examined, the activities of protease increased the most （413.8%）, followed by peroxidase （278.7%）, lipase （161.0%）, glucose-6-phosphate dehydrognase （149.1%） and amylase （60.6%） after 8 months of stratification. Crude fat and protein constituted the bulk of the storage reserves in mature seeds of C. pal# urus. Compared with the seeds before stratification, about 45% of the starch, 46% of the protein and 11% of the crude fat were depleted during dormancy release of C. paliurus seeds, while the soluble sugar content was enhanced by 101.5% in the germinating seeds. Correlation analysis showed, during dormancy release of C. paliurus seeds, a close positive relationship between POD and G6PDH activity as well as soluble sugar content and amylase activity, while there was a significant negative relationship between storage substances and their related enzyme activities.
基金supported by National Training Programs of Innovation and Entrepreneurship for Undergraduates(201210298004)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Field studies were conducted to examine the effects of cerium on the growth and physiological characteristics of Cyclocarya paliurus seedlings by spraying the foliage with different concentrations of cerium nitrate. Optimal concentrations of cerium nitrate improved the relative growth yield of seedling height and stems and the soluble protein and sugar content of the leaves. Cerium nitrate also increased the concentration of secondary metabolites including triterpenoids, quercetin and kaempferol, mineral elements K, P, Mg, Mn, Fe and Cu, and the activities of superoxide dismutase （SOD）, peroxidase （POX）, and phenylalanine ammonia-lyase （PAL） in the leaves. The effects of cerium nitrate on these indices were dose dependent. A concentration of 0.20 mmol/L was optimal to promote the relative growth yield of seedling height, contents of soluble sugar, kaempferol, K, P, Cu, and activities of PAL, SOD, and POX, significantly increased by 54.61%, 14.71%, 55.19%, 105.2%, 74.5%, 133.3%, 80.48%, 25.35% and 22.54%, respectively, as compared with the control. However, the maximal increase in relative growth yield of stems, contents of triterpenoid, quercetin, Mg, Mn, and Fe was attained at 1.00 mmol/L treatment, which significantly increased by 87.00%, 80.56%, 452.44%, 93.2%, 29.4%, and 133.9%, respectively, compared with control check （CK）. Correlation analysis revealed positive relationships between activities of PAL, SOD and contents of triterpenoid, quercetin and kaempferol within a certain concentration range of cerium nitrate. These resuits suggested that an appropriate concentration of cerium not only was effective in the improvement of physiological function of C. paliurus, but also increased seedling resistance. Moreover, it stimulated the synthesis of medicinal components in leaves.
