不同种源油蒿形态与生理特征对干旱胁迫的响应

Morphology and Physiology Characteristic Responses of Different Provenances of Artemisia ordosica to Drought Stress

【目的】了解干旱胁迫对不同种源油蒿的形态和生理特征的影响,同时比较不同种源油蒿的抗旱能力,为我国干旱、半干旱地区引种提供理论依据。【方法】以毛乌素沙地、库布齐沙漠、草原荒漠过渡带的3个种源油蒿为材料,进行不同水分处理,研究在适宜、轻度干旱、重度干旱情况下不同种源油蒿株高、基径、叶面积、比叶面积、叶绿素a(Chla)、叶绿素b(Chlb)、叶绿素(a+b)[Chl(a+b)]、类胡萝卜素(Car)、叶绿素a/b(Chla/b)、类胡萝卜素/叶绿素(Car/Chl)、可溶性糖、淀粉、非结构性碳水化合物(NSC)的变化。【结果】3个种源地油蒿形态特征、光合色素含量以及NSC对干旱胁迫响应趋势一致,表现为随着干旱胁迫加剧:1)油蒿的株高、基径、叶面积和比叶面积呈现逐渐减小趋势,其中在重度干旱情况下,库布齐沙漠油蒿的株高、叶面积、基径大于毛乌素沙地和草原荒漠过渡带油蒿,而比叶面积小于毛乌素沙地和草原荒漠过渡带油蒿;2)油蒿叶片的Chla,Chlb,Chl(a+b),Car,Chla/b和Car/Chl呈现先增大后减小的趋势,其中在重度干旱情况下,库布齐沙漠油蒿叶片的Chla,Chlb,Chl(a+b)大于毛乌素沙地和草原荒漠过渡带油蒿叶片,而3个种源地油蒿的Car含量以及Car/Chl相差不大,Chla/b表现为草原荒漠过渡带最大,毛乌素沙地其次,库布齐沙漠最小;3)油蒿叶片可溶性糖、淀粉和NSC含量呈现先减小后增大的趋势,其中在重度干旱情况下,草原荒漠过渡带油蒿叶片的可溶性糖、淀粉和NSC含量均大于库布齐沙漠和毛乌素沙地油蒿叶片,而库布齐沙漠油蒿叶片的可溶性糖、淀粉和NSC含量又大于毛乌素沙地油蒿叶片;在轻度干旱情况下,库布齐沙漠油蒿叶片的可溶性糖、淀粉和NSC含量大于草原荒漠过渡带和毛乌素沙地油蒿叶片。【结论】从3个种源地油蒿株高、基径、叶面积、比叶面积、Chla、Chlb、Chl(a+b)、Car、Chla/b、Car/Chl、可溶性糖、淀粉、NSC等指标比较中,推测来自库布齐沙漠的油蒿较毛乌素沙地、草原和荒漠过渡带油蒿具有更强的抗旱性。

[ Objective ] In this study, we investigated effects of drought stress on morphology and physiology characteristics of Artemisia ordosica and compare with the drought-resistant ability of three different provenances of A. ordosica, to provide a theoretical basis for the introduction of the species to China＇s arid and semi-arid area. [ Method ] Three different provenances of A. ordosica were collected from Mu Us Sandy land, Kubuqi desert, and Desert-steppe transitional zone, and subjected to different soil moisture to investigate the changes of plant height, stem size, leaf area, Sla, content of Chla, Chlb, Chl（a ＋ b） and Car, Chla/b and Car/Chl and content of starch, soluble sugars and NSC. [ Result] The response of morphology characteristics, photosynthetic pigment content, and contents of starch, soluble sugars and NSC of three different provenances of A. ordosica to drought stress was consistent. Namely, as the drought stress increased, 1 ）plant height, stern diameter, leaf area and SLA, showed a trend of gradual decrease. The plant height, stem size, and leaf area of A. ordosica from Kubuqi desert were greater than those from Mu Us Sandy land and Desert-steppe transitional zone under the severe drought stress. However Sla of the provenance from Kubuqi desert was less than that from Mu Us Sandy land and Desert-steppe transitional zone. 2）Chla,Chlb,Chl（a＋b）,and Car contents、Chla/b and Car/Chl of A. ordosica leaves showed a trend of first increase and then decrease under drought stress. Contents of Chla,Chlb,Chl（ a＋b） of A. ordosica leaves from Kubuqi desert were higher than A. ordosica from Mu Us Sandy land and Desert-steppe transitional zone under the severe drought stress. However there were no significant differences in contents of Car and Car/Chl of the three different provenances. The Chla/b of A. ordosica from Desert-steppe transitional zone was greatest,followed by that from Mu Us Sandy land,and then by that from Kubuqi desert. 3 ） Contents of starch,soluble sugars and NSC of three different provenances leaves showed a trend of first decrease and then increase. Contents of starch,soluble sugars and NSC of A. ordosica from Desert-steppe transitional zone were higher than A. ordosica from Kubuqi desert and Mu Us Sandy land under severe drought stress,and contents of starch,soluble sugars and NSC of A. ordosica from Kubuqi desert were higher than those of A. ordosica from Mu Us Sandy land. Contents of starch,soluble sugars and NSC of A. ordosica from Kubuqi desert were higher than those of A. ordosica from Mu Us Sandy land and Desert-steppe transitional zone under slight drought stress.[Conclusion]Through the comparison of morphology and physiology characteristics of three different provenances of A. ordosica,we find that the drought resistance of A. ordosica from Kubuqi desert is stronger than A. ordosica from Mu Us Sandy land and Desert-steppe transitional zone.