荒漠环境下10种沙拐枣的生理特征比较研究

目前,土地荒漠化形势严峻,严重威胁生态系统安全。而植物对防治土地荒漠化发挥重要的作用,因此筛选合适的物种进行荒漠恢复重建则显得极为重要。沙拐枣因其抗逆性强而成为新疆荒漠区主要的优势物种,其生理生态响应被广泛研究,但是系统、定量的比较不同种沙拐枣抗逆性的研究较为缺乏。为此本文以吐鲁番沙漠植物园中栽培的10种沙拐枣为试验材料,测定同一生境下不同种沙拐枣的7个抗逆生理指标,利用方差分析其种间差异,并结合主成分分析综合评价不同种沙拐枣的抗逆性。结果表明,不同种沙拐枣在同一生境下各生理指标表现出显著性差异(P<0.01);其中头状沙拐枣、乔木状沙拐枣、小沙拐枣的SOD、POD含量均表现较低水平,抗逆性较差;泡果沙拐枣以高脯氨酸含量表现良好抗逆性;小沙拐枣H₂O₂含量最高,不利于细胞正常代谢;综合分析抗逆性由强到弱为泡果沙拐枣>艾比湖沙拐枣>密刺沙拐枣>淡枝沙拐枣>奇台沙拐枣>心形沙拐枣>红果沙拐枣>乔木沙拐枣>头状沙拐枣>小沙拐枣,该结果与沙拐枣在新疆的生态分布极为吻合。试验数据可为荒漠植物沙拐枣的引种栽培和抗逆性筛选提供基础数据和科学依据。

Examination and comparison of the physiological characteristics of ten Calligonum species in a desert environment

Desertification is a serious issue and especially so in Xinjiang,where it is a significant threat to ecosystem security.As plants play an important role in the prevention and control of desertification,screening suitable species for restoration projects is an important task.Calligonum is a dominant species in the desert region of Xinjiang and its resistance to drought and salt stress has been thoroughly researched.However,there are few quantitative analyses comparing the resistance of different Calligonum species.In this study,ten Calligonum species grown in the Turpan desert botanical garden were selected and their physiological characteristics analysed.Seven physiological indexes were measured.Species' differences were examined using variance analysis,while their resistance was evaluated using principal component analysis.The results showed that the species' physiological indexes in the same habitat showed significant differences (P＜0.01).Superoxide dismutase (SOD) and peroxide enzyme (POD) contents were the lowest for C.caput-medsae,C.arborescens and C.pumilum,all of which showed poor resistance.Proline content was the highest for C.junceum,with strong resistance.H2O2 content was the highest for C.pumilum,which is not conducive for normal cell metabolism.The combined resistance analysis produced the following species' order:C.junceum＞C.ebi-nurcum ＞C.densum＞C.leucocladum＞C.klementzii＞C.cordatum＞C.rubicundum＞C.arborescens＞C.caputmedsae＞C.pumilum.Calligonum species have different resistance mechanisms with different protective enzyme contents.These results are confirmed by the ecological distribution of Calligonum in Xinjiang.This experiment thus provides a scientific basis for screening and introducing Calligonum species to remedy desert conditions.