硒处理对薄壳山核桃幼苗生长的影响

为探究硒对薄壳山核桃幼苗生长的影响,利用不同浓度亚硒酸钠0(CK)、0.5、5、10、20、40、80 μmol·L^-1]对薄壳山核桃幼苗进行处理,并测定相关生理指标。结果表明,低浓度硒对薄壳山核桃幼苗生长发育、生物量积累、酶活性均有促进作用,而高浓度硒抑制了幼苗生长、干物质的积累、酶活性、光合速率,且硒浓度越高,抑制作用越明显。80 μmol·L^-1 硒浓度处理后的根长较CK显著降低了55.36%(P<0.05),其他形态指标均无显著差异。硒处理显著提高了幼苗体内的硒含量,且根系>叶片。随着硒浓度的增加,叶、根内的硒含量呈先升高后降低的趋势,硒浓度≥0.5 μmol·L^-1时,其他处理均与CK存在显著差异。40 μmol·L^-1硒浓度处理下叶中的硒含量较CK显著增加了1 682倍,根中的硒含量提高了482倍。低硒浓度(≤10 μmol·L^-1)处理可以促进根中Mn²⁺、Mg²⁺含量和叶中的Zn²⁺含量的积累。当硒浓度≥5 μmol·L^-1时,会促进根中Zn²⁺含量的积累,硒浓度≥10 μmol·L^-1,促进茎中Mn²⁺含量的积累,其中在80 μmol·L^-1硒浓度处理下茎中Mn²⁺含量为CK的9.29倍。过氧化物酶(POD)、超氧化物歧化酶(SOD)活性随着硒浓度增加均呈先增后减的趋势,且在0.5 μmol·L^-1硒浓度处理下达到最高,明显高于CK,分别为1 698.63、1 912.28 U·mg prot^-1。综上,低浓度硒处理和施硒时间长短对幼苗光合作用影响不大,而高浓度硒处理会抑制光合作用。本研究结果为进一步揭示硒富集机理和硒的科学使用提供了理论依据。

Effect of Selenium Treatment on the Growth of Pecan Seedlings

In order to explore the effect of Se on the growth of pecan, pecan seedlings were treated with different concentrations of Na₂SeO₃ 0(CK), 0.5, 5, 10, 20, 40, 80 μmol·L^-1], and then the growth and physiological indexes of seedlings were measured and analyzed. The results showed that the low concentration of Se could promote growth, biomass accumulation and enzyme activity, while the high concentration of Se inhibited growth, accumulation of dry matter, enzyme activity, and photosynthetic rate. And, the higher the concentration of Se, the more obvious the inhibition effect. Treated by 80 μmol·L^-1, the root length of seedlings was significantly shorter than that of control by 55.36%, while other morphological traits were not significantly different from those of the control group. Se treatment significantly increased the Se content in the pecan seedlings. With the increase of Se concentration, the Se content in the leaves and roots of the seedlings increased at first and then decreased. When the Se concentration was higher than 0.5 μmol·L^-1, all the treatments showed significant differences to the control. Under treatment of 40 μmol·L^-1 Se, the Se content increased 1 682 times in leaves and 482 times in the roots. Low Se concentration (less than 10 μmol·L^-1) could promote the accumulation of Mn²⁺ and Mg²⁺ in roots, and Zn²⁺ content in leaves. When the concentration of Se was higher than 5 μmol·L^-1, it promoted the accumulation of Zn²⁺ in the root. When the concentration of Se was higher than 10 μmol·L^-1, more Mn²⁺ was accumulated in the stem. The content of Mn²⁺ in the stem was 9.29 times that of the control group under the treatment of 80 μmol·L^-1 Se. The activity of peroxidase (POD) and superoxide dismutase (SOD) increased at first and then decreased with the increase of Se concentration, and reached the highest level under the 0.5 μmol·L^-1 Se treatment, which were 1 698.63 U·mg prot^-1 and 1 912.28 U·mg prot^-1, respectively. Low concentration of Se and the duration of Se application had no significant effect on photosynthesis, while high concentration of Se inhibited photosynthesis. This result of study laid a foundation for further revealing the mechanism of Se accumulation and the effective use of Se.