盐胁迫对鲜食蚕豆幼苗光合特性及抗氧化酶活性的影响

Effect of Salt Stress on Photosynthesis and Antioxidant Enzyme Activities of Vicia faba L.Seedling

以鲜食蚕豆(Vicia faba L.)品种"通蚕鲜6号"为试材,采用1/2 Hoagland营养液栽培,研究不同浓度NaCl(0、50、100、150mmol·L^(-1))处理对鲜食蚕豆幼苗生长、光合特性和抗氧化酶等生理代谢的影响,为盐碱地区蚕豆的种植提供参考依据。结果表明:盐处理时,蚕豆生长呈现低浓度(50mmol·L^(-1))促进,中高浓度(≥100mmol·L^(-1))抑制,尤其是高浓度处理组植株干质量比对照组下降了64.3%,并且在高浓度时蚕豆净光合速率、蒸腾速率、气孔导度和胞间CO_2浓度也均呈降低趋势,分别下降了19.7%、56.3%、74.0%和61.2%;但是叶绿素a、叶绿素b和叶绿素(a+b)的含量在3种盐浓度处理时均出现降低趋势;在低中浓度处理时,超氧化物歧化酶(SOD)活性升高,高浓度处理时,胁迫程度加深,酶活性大幅度下降;过氧化物酶(POD)随着盐浓度升高和时间的延长均呈现升高趋势;过氧化氢酶(CAT)在低中浓度时有上升现象,低浓度上升幅度更大,在高浓度时呈先上升后下降的趋势;3个处理组的MDA含量均随盐浓度升高呈现增长趋势。

Vicia faba L. was used as material, the treatment was applied via soilless substraters pot experiment. The effect of salt stress on growth and physiology characteristics were studied. The experiment was carried out using ＇No. 6 Tongcanxian＇ to explore effects druing 12 days of NaC1 stress （0,50,100,150 mmol· L^-1 ） on biomass, net photosynthetic rate （Pn）, stomatal conductivity （Gs）, intercellular CO2 concentration （Ci）, transpiration rate （Tr）, chlorophyll （Chl）, the activity of antioxidase （SOD,POD,CAT） and the MDA content. The results showed that NaC1 stress increased plant dry weight at low salt concentration, while at high concentration the dry weight decreased 64. 3% and Pn, Tr, Gs and Ci in seedling were decreased 19.7%, 56.3%, 74.0% and 61.2%, respectively. Comparing with the control group, the chlorophyll （Chl a and Chl b） content and Chl（a＋ b） content both displayed descending. Under the lower NaC1 concentration, the activity of SOD increased, on the other hand, under the high concentration the activity decreased. The activity of POD content increased with the increasing of NaC1 concentration and time. The CAT activity was the highest when salt concentration was 150 mmol · L^-1 on the 9th day, then decreased. With increasing stress degree the MDA content increased. Growth and index of physiology could all be regarded as indexes for evaluation of Vicia faba L. in salt adaptability.