百脉根对干旱胁迫的生长、生理生态响应及其抗旱性评价

Growth,Physiological Ecology Responses of Lotus corniculatus Materials to Drought Stress and Evaluation of Drought Resistance

以不同来源的百脉根幼苗为试验材料,采用盆栽控水法研究各百脉根材料对干旱的生长、生理生态响应,并利用隶属函数法综合评价其抗旱性。研究结果表明:(1)连续干旱导致百脉根材料幼苗死亡、株高和干物质受到抑制、根冠重量比较对照显著提高。(2)随着干旱胁迫时间的延长,百脉根材料的相对含水量呈降低趋势,相对电导率值和MDA含量呈增加趋势,SOD活性呈先升高后降低的趋势。(3)干旱28d后,各百脉根材料的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、水分利用效率(WUE,除材料B04、B05和B08外)、最大光化学量子效率(Fv/Fm)、光化学量子产量和光化学猝灭系数(qP)均下降;非光化学猝灭系数(NPQ,除B12、B02和B01外)升高。(4)利用隶属函数法综合幼苗生长、生理生态等16个指标评价出8个百脉根材料间的抗旱性顺序为B08>B04>B05>B18>B03>B12>B02>B01。

There were eight Lotus corniculatus materials were taken as the studied objects, which came from natural distribution area. Growth, physiological characteristics were investigated under water controlled conditions to unveil the possible mechanisms of seedlings of L. corniculatus materials in response to drought stress and to screen out the drought resistant materials. The results showed that： （1）Continuous drought caused L. corniculatus seedlings death, inhibition of plant height and dry matter, and its weight ratio of root to shoot was significantly higher than the plants grown under the well-watered condition. （2） As the extension of drought-affected time, the relative water content of L. corniculatus deceased, the relative conductivity and MDA content increased, SOD activity increased firstly and then decreased. （3） After drought 28 day, Net photosynthetic rate（Pn）, stomatal conductance（Gs）, transpiration rate（Tr）, water use efficiency（WUE, except B04, B05 and B08）, maximum photochemical efficiency（Fv/Fm）, actual photochemical quantum yield and photochemical fluorescence quenching coefficient （qe） decreased, non photochemical fluorescence quenching eoefficient（NPQ, except B12, B02 and B01） increased. （4）According to the results of subordinate function value analysis, the drought resistance of eight L. corniculatus materials was in the order of B08 〉B04 〉B05 〉B18〉B03 〉B12 〉B02 〉B01.