Abstract: The effects of basal selenium fertilizer on alfalfa forage yield and anti-oxidation were studied to investigate the ability and mechanism of micro-element Se on resist adverse environment of alfalfa. Results showed that selenium application as basal fertilizer could increase the yield of alfalfa. The yield of alfalfa was maximum in different growth periods when Se was 0.45 kg穐m^-2, whereas the forage yield was decreased when Se was more than 0.45 kg穐m^-2. The POD, CAT and SOD activities in alfalfa leaves of different growth stages were first increased then decreased when Se increased and reached its maximum value when Se was 0.45 kg穐m^-2. The MDA contents in alfalfa leaves were first decreased then increased when Se increased and reached its minimum value when Se was 0.35 kg穐m^-2. Conclusions were that Se enhanced alfalfa anti-oxidation abilities when Se was low, whereas Se restrained anti-oxidation abilities when Se was higher.

Key words: Selenium (Se), Alfalfa (Medicago saliva L.), Forage yield, Anti-oxidation

摘要： 为探讨微量元素硒对紫花苜蓿(Medicago saliva L.)抵抗逆境环境的能力和机理,通过田间试验研究了不同基施硒肥用量对其草产量及抗氧化作用的影响。结果表明:适量施硒可提高紫花苜蓿草产量,各生育期均以施硒量为0.45 kg·hm^-2草产量最高,当施硒量再增加,草产量增幅反而降低;不同生育期其叶片中过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性随施硒量的增加均呈现先升高后降低的趋势,以施硒量为0.45 kg·hm^-2(Se4)时达到最大值;其叶片中丙二醛(MDA)含量随施硒量的增加先降低后升高,其中施硒量为0.35 kg·hm^-2时,MDA含量最低。说明在施硒量较低时,硒提高了紫花苜蓿抗氧化作用的能力,而施硒量较高时,硒对其抗氧化能力起抑制作用。

关键词: 硒, 紫花苜蓿, 草产量, 抗氧化作用