硒提高马铃薯幼苗抗寒性生理研究

低温胁迫是影响我国南方冬闲田马铃薯种植的一大阻碍因素，发生在马铃薯植株生长发育前期。以马铃薯品种金湘为试材，研究不同硒浓度（1、3、5 mg·L^-1）和适宜浓度的喷硒次数（1、2、3 次）对马铃薯幼苗抗寒性的影响。结果表明：外源喷施1、3、5 mg·L^-1 亚硒酸钠处理均可以提高低温胁迫下马铃薯叶片中叶绿素含量，降低叶片相对电导率以及丙二醛（MDA）、H2O2 含量，且3 mg·L^-1 的喷施效果最佳。低温胁迫下喷施3 mg·L^-1 亚硒酸钠溶液1～3 次的幼苗叶绿素含量高于未喷硒对照，MDA 和H2O2 含量均降低，且喷施2 次时效果最好。综上，适宜的喷硒浓度（3 mg·L^-1）和次数（2 次）能在一定程度上降低低温胁迫所带来的伤害，从而提高马铃薯幼苗的抗寒性。

Studies on Physiology of Cold Tolerance Improved by Selenium in Potato Seedling

Low temperature stress is a major obstacle to potato growth and development especially duringthe early stage in winter fallowing fields in southern China．Taking potato variety‘Jinxiang’as test material，this paper studied the effects of spraying Na₂SeO₃ with different selenium concentrations（1，3，5 mg·L^-1） anddifferent times（1，2，3）on cold resistance of potato seedlings respectively．The results showed that exogenousspraying of 1，3，5 mg·L^-1 selenium solution could increase the chlorophyll contents of potato leaves，reducethe relative conductivity，contents of MDA and hydrogen peroxide of leaves under low temperature stress．Theeffect of spraying 3 mg·L^-1 was the best．The chlorophyll content of seedlings by spraying 3 mg·L^-1 seleniumsolution for 1-3 times was higher than that of without selenium spraying under low temperature stress，and thecontents of malondialdehyde and hydrogen peroxide were all decreased．The effect of spraying twice was the best．To sum up，the suitable selenium concentration（3 mg·L^-1）and spraying times（twice） can reduce the damagecaused by low temperature stress to certain extent，thus having improved the cold resistance of potato seedlings．