壳寡糖对干旱胁迫下信前胡生长及叶片生理特性的影响

Effects of chitooligosaccharide on the growth and leaf physiological characteristics of Peucedanum pratense under drought stress

以信前胡盆栽幼苗作为研究材料,通过测定信前胡的株高、叶面积、生物量、含水量、根冠比和叶片抗旱相关的生理指标,研究了5、10、15 mg·L^(-1)和2 mg·L^(-1)的壳寡糖(Chitooligosaccharide,COS)溶液处理对干旱胁迫下信前胡生长和叶片生理特性的影响。结果表明,不同浓度壳寡糖对干旱胁迫下信前胡生长均有不同程度的促进作用,且随壳寡糖浓度的增加,各生长指标均表现出先增后降的趋势,均有一定的最适浓度。与单纯干旱处理相比,5、10、15 mg·L^(-1)和20 mg·L^(-1)壳寡糖处理信前胡的单株叶片数分别提高了32.5%、50.8%、29.3%和6.3%,均达到了显著水平(P<0.05);10 mg·L^(-1)和15 mg·L^(-1)壳寡糖处理信前胡的单株平均叶面积分别提高了27.3%和20.8%,均达到了显著水平(P<0.05);5、10、15 mg·L^(-1)壳寡糖处理信前胡的株高分别显著提高了17.4%、31.7%和19.6%。10 mg·L^(-1)壳寡糖处理信前胡叶片的脯氨酸含量较单纯干旱处理显著提高了11.8%,10 mg·L^(-1)壳寡糖处理信前胡叶片的H 2 O 2含量和MDA含量均较单纯干旱处理显著降低(降幅分别为46.9%和14.4%)。因此,10 mg·L^(-1)壳寡糖处理可显著缓解信前胡苗期的干旱胁迫(P<0.05)。

In this study,Peucedanum pratense seedlings was used as the research material.By measuring plant height,leaf area,biomass,water content,root-shoot ratio and physiological indexes related to drought resistance of Peucedanum pratense,the effects of chitooligosaccharide(COS)at different concentrations(5,10,15 mg·L^(-1)and 20 mg·L^(-1))on the growth and physiological characteristics in leaves of Peucedanum pratense under drought stress were studied.The results showed that the growth of Peucedanum pratense under drought stress was promoted at different concentrations of COS treatment,and with the increase of COS concentration,different growth indexes showed a trend of first increasing and then decreasing,and all had a certain optimal concentration.Compared with the single drought treatment,the number of leaves per plant in Peucedanum pratense treated with 5,10,15 mg·L^(-1)and 20 mg·L^(-1)COS were increased by 32.5%,50.8%,29.3%and 6.3%,respectively,all reaching significant levels(P<0.05),the average of leaf area per plant in Peucedanum pratense treated with 10 mg·L^(-1)and 15 mg·L^(-1)were increased by 27.3%and 20.8%,respectively,reaching significant levels(P<0.05),the plant height of Peucedanum pratense treated with 5,10 mg·L^(-1)and 15 mg·L^(-1)COS was increased by 17.4%,31.7%and 19.6%,respectively,and also reached significant levels(P<0.05).Compared with the single drought treatment,the proline content in leaves of Peucedanum pratense treated with 10 mg·L^(-1)COS was significantly increased by 11.8%.The H 2 O 2 content and MDA content in leaves of Peucedanum pratense treated with 10 mg·L^(-1)COS were significantly decreased by 46.9%and 14.4%,respectively.Therefore,the drought stress of Peucedanum pratense seedling treated with 10 mg·L^(-1)COS was significantly alleviated(P<0.05).