运城盐湖十种耐盐植物体内无机及有机溶质含量的比较研究

Comparative Study on the Content of Inorganic and Organic Solutes in Ten Salt tolerant Plants in Yuncheng Saltlake

运城盐湖的 1 0种耐盐植物体内的有机及无机溶质含量差异较大。总无机溶质含量在各种植物间的变化幅度小于总有机溶质 ,其中双子叶植物 (除二色补血草外 )地上部 K+ 含量及 K/Na比均低于单子叶植物 ,而双子叶植物地上部的Na+ 含量明显高于单子叶植物。双子叶植物 (除二色补血草外 )的 Na/Cl>1 ,而单子叶植物的 Na/Cl≈ 1。二色补血草的二价离子 Ca2 +和 Mg2 +含量较高。单子叶植物的可溶性糖及游离氨基酸含量高于双子叶植物 (除枸杞外 ) ,碱莞、盐角草、盐地碱蓬、碱地肤、二色补血草的脯氨酸含量均较低 ( <7μmol/g FW) ,且脯氨酸占游离氨基酸的比例高于其它植物。另外还计算了各种溶质占 COP的百分比 ,并讨论了它们在植物渗透调节过程中的作用。

In higher salt tolerant plants adaptation to saline conditions is associated with osmotic adjustments leading to the accumulation of low molecular weight solutes. This thesis mainly treats with the capacity of salt tolerant plants from Yuncheng saltlake to accumulate soluble solutes. Yuncheng saltlake (350°E, 110°N) located in the south of Shanxi Province and at the foot of Zhongtiao Mountains. With the elevation of 320m, the mean annual precipitation of 600mm and evaporation of 1734mm. Serious salinized soil because of strong evaporation is becoming apparently into the restrictive factor of the vegetation growth and development in the area. All plants (eight dicotyledons and two monocotyledons) in this study were collected on low lying land in May 2000. Inorganic soluble solutes were extracted by distilled water from dried and pulverized plant materials. Further, K +, Na + and Ca 2+ were determined by emission spectrum in a AtomScom 25 inductived coupled plasm atomic emission spectrometry (ICP AES); NO - 3 was measured by colorimetry with sulfanilamide reagent and Cl - by tiltration with Hg(NO 3) 2. Organic constituents were analyzed with fresh samples. Soluble sugars (SS) were extracted with 80% ethanol and then determined with anthrone/sulfuric acid; Following extraction in distilled water, prolines and amino acids (AA) were determined with ninhydrin reagent and organic acids (OA) with NaOH. Furthermore, some indices were performed for water contents, succulent degrees, total contents of inorganic solutes ,total contents of organic solutes, ratios for K/Na、Na/Cl、Pro/AA and AA: SS: OA, COP (calculated osmotic potential) and the percentages of each solute in COP. The results are as following: 1) The water contents and succulent degrees in above grounds of dicotyledonswere higher than those of monocotyledons, especially,those of Tripolium vulgare , Salicornia europaea,Suaeda salsa , Kochia scoparia respectively over 80% and over 6.3; 2) The variations of total organic solutes were much wider than that of total inorganic solutes within different plants . Dicotyledons (except Limonium bicolor ) contained lower levels of K + and lower ratios of K/Na in above grounds than monocotyledons, while the former accumulated much larger quantities of Na + than the latter, but distinct differences between Na + and K + in monocotyledons, as had been reported by several authors, were not found. The Na/Cl ratios in dicots (except Limonium bicolor ) were 1, but the values in monocots was about 1. Higher Ca 2+ and Mg 2+ levels were found to be a feature of Limonium bicolor , NO - 3 occurred in lowest concentration in all these species and it was more greatly in monocotyledons than in dicotyledons; 3) The quantities (mmol/gFW ) of total organic solutes were less than that of total organic solutes in each species . The accumulations of soluble sugars and amino acids in monocotyledons were more than those in dicotyledons (except Lycium chinense ). The contents of soluble sugars (SS) and amino acids (AA) and organic acids (OA) in Tripolium vulgare , Salicornia europaea presented in the order SS>OA>AA, in Artemisia lavandulaefolia SS>AA>OA, in other plants AA>SS>OA. Dicotyledons contained higher pro/AA ratios than monotyledons, this indicated that other amino acids except prolines were greatly synthesied or built up in monocots under saline conditions. Proline levels in Tripolium vulgare , Salicornia europaea, Suaeda salsa , Kochia scoparia, Limonium bicolor were considerably lower (<7μmol/gFW), but the pro/AA ratios were higher than other plants; 4) The percentages of total inorganic solutes in COP (the total osmotic potential of each solute which was determined) of dicots(>75%) were higher than that of monocots (<75%),especially in Tripolium vulgare ,Salicornia europapea , Suaeda salsa and Kochia scoparia , whose total inorganic solutes accounted for over 95% of COP. Among these inorganic solutes, Na + made greatest contributions to cop in dicotyledonous plants an