Analysis on Genetic Relationship of Oxya chinensis and Oxya japonica from Xuzhou and Pingshan, China

Genetic relationship among Oxya chinensis populations and Oxya japonica populations collected from Xuzhou City, Jiangsu Province and Pingshan County, Hebei Province, China were analyzed by random amplified polymorphic DNA （RAPD） markers. A total of 125 DNA bands ranging from 200 to 2 200 bp were amplified by 10 random primers in DNA samples from 43 grasshopper individuals. One hundred and twenty-three （99%） of these bands were polymorphic. Shannon＇s index showed that the genetic, diversity within O. chinensis （0.3432） was higher than that of O. japonica （0.2781）. Nei＇s genetic distance between O. chinensis population and O. japonica population from the same area was less than that between populations from two different areas. The dendrogram based on Nei＇s genetic distance of RAPD markers was constructed using the unweighted pair group method with the arithmetic average （UPGMA） and Neighbor-Joining （NJ） methods. Cluster analysis indicated that all the individuals were grouped into two main clusters. O. chinensis populations from Xuzhou and Pingshan formed one cluster, and O. japonica populations from the two regions belonged to another cluster. The results demonstrated that RAPD can detect within species, and among closely related species. polymorphisms to distinguish minor difference among individuals

重金属镉和铬在中华稻蝗(Oxya chinensis)体内的组织分布

为研究重金属在中华稻蝗(Oxya chinensis)自然种群体内的累积分布,以山西省代县水稻田中华稻蝗为研究对象,用火焰原子吸收法测定中华稻蝗不同组织部位的镉和铬含量。研究结果表明:镉和铬在中华稻蝗自然种群不同组织部位的富集量不同,且雌雄间存在一定的差异。镉在雌虫体内的富集顺序为中肠>后肠>前肠>翅>头>卵巢>足>体壁;在雄虫体内为中肠>前肠>后肠>足>头>体壁。镉在雌雄中华稻蝗消化道内均有较高的富集并以中肠的累积量最高,雌虫为6.7984mg·kg-1,雄虫为3.3477mg·kg-1,且与其他组织部位间存在显著差异(P<0.001)。中华稻蝗雌虫各组织部位对铬的累积浓度依次为中肠>足>体壁>头>卵巢>前肠>翅>后肠,中华稻蝗雄虫体内铬浓度的分布依次为足>体壁>中肠>头>前肠>精巢>后肠。多因素方差分析结果表明,自然条件下雌雄中华稻蝗对重金属镉和铬的累积具有组织特异性,两种重金属在中华稻蝗体内的累积规律有所不同。

溴氰菊酯对中华稻蝗(Oxya chinensis)SOD及GSH-Px活性的影响

采用酶活性分析法研究了溴氰菊酯对中华稻蝗SO D及G SH-Px活性的影响。结果表明,溴氰菊酯作用于中华稻蝗时,其体内SO D及G SH-Px活性发生变化。随着溴氰菊酯浓度的提高,SO D活性变化的趋势表现为先增大后减小。当浓度为0.02、0.14、0.26μg·μL-1时,浓度相同、不同性别的中华稻蝗SO D活性差异显著。随着溴氰菊酯浓度的提高,雄性中华稻蝗G SH-Px活性先增大后减小;而雌性中华稻蝗G SH-Px先减小后增大。当浓度为0.02、0.14μg·μL-1时,浓度相同、不同性别的中华稻蝗G SH-Px活性差异显著。溴氰菊酯作为化学农药对中华稻蝗的生理生化有着明显的作用,当处理剂量较低时,中华稻蝗对其为应激适应,在浓度较高时为应激损伤。

铬在中华稻蝗(Oxya chinensis)体内的累积及对抗氧化系统的影响

昆虫体内的重金属主要是通过消化途径实现代谢过程的。本文中以不同浓度六价铬(Cr6+)溶液(0、7.5、15、30mg·L-1)培育的小麦对中华稻蝗(Oxya chinensis)从4龄若虫开始进行慢性染毒,待其发育到成虫时分别测定虫体、粪便、小麦叶片内的Cr含量以及成虫体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPx)和总抗氧化能力(T-Aoc)。结果显示,生长于0、7.5、15、30mg·L-1Cr6+溶液中的小麦,其叶片中Cr浓度分别为5.77、6.85、9.88、18.33μg·g-1。随着Cr6+浓度的增加,虫体内和粪便中Cr的累积量也逐渐增大,在30mg·L-1时达到最大值。中华稻蝗体内SOD活力随着处理浓度的增加,变化不明显,未达到显著水平。而CAT、GPx活力和T-Aoc随着处理浓度的增加,呈先升高后降低的趋势,在7.5mg·L-1时达到最大值。本文结果表明,中华稻蝗体内的Cr含量随着染毒浓度的增加而增大,是对环境中重金属Cr污染的一种间接反应。通过测定中华稻蝗体内的Cr含量,可以对环境中Cr污染进行评估;同时,中华稻蝗抗氧化酶系统在机体防御过氧化物损伤方面起着重要作用。

中华稻蝗(Oxya chinensis)对重金属镉的累积及排泄

为了研究重金属镉(Cd)在植食性昆虫体内的累积和排泄规律,通过Cd慢性染毒的方法,用不同浓度Cd溶液培养的麦苗饲喂中华稻蝗(从4龄若虫至成虫),采用原子吸收法测定Cd在中华稻蝗(Oxyachinensis)整虫和中肠的蓄积及Cd在其粪便和蜕中的排泄量。研究结果表明,Cd在中华稻蝗整虫和中肠中的累积规律相似,即随着麦苗中Cd含量的增加,整虫和中肠中Cd的累积量明显升高,且各处理间存在显著差异(P<0.05)。部分Cd可以通过粪便的排泄和蜕皮过程而排出体外。用不同Cd浓度的麦苗饲喂中华稻蝗后,其粪便和蜕中的Cd排泄量与对照组相比显著升高(P<0.05),且各处理间差异显著(P<0.05)。中华稻蝗整虫、中肠、粪便和蜕中的Cd含量与食物(麦苗叶片)中的Cd含量存在显著的剂量-反应关系,其相关系数分别为:整虫0.977、中肠0.920、粪便0.967、蜕0.840。研究结果可为进一步研究Cd在中华稻蝗体内积累和排泄的动态变化规律提供理论和实验依据。

秦岭南北5地中华稻蝗(Oxya chinensis)的亲缘关系

选择秦岭南北５地中华稻蝗（Ｏｘｙａ ｃｈｉｎｅｎｓｉｓＴｈｕｎｂｅｒｇ） 的每地雌雄各１２ 个个体的１３个形态特征进行测量， 取每一地同一性别不同个体的平均值分别形成雌雄的原始数据矩阵。用自然对数的绝对值对雌雄原始数据矩阵分别进行标准化后， 用ＰＣＴ距离系数和离差平方和法进行聚类。用欧氏距离系数和单链法、全链法等聚类方法进行验证。结果表明： 汉中和安康一线沿秦岭山脉南麓汉江两岸的中华稻蝗距离较近， 应为一个地理宗或居群； 秦岭山脉北麓的眉县至长安一线的中华稻蝗距离较近， 应为一个地理宗或居群； 黄土高原另一侧的延安地区的中华稻蝗应为一个地理宗或居群。

Oxidative stress related enzymes in response to chromium(VI) toxicity in Oxya chinensis (Orthoptera: Acridoidae)

The toxic effects of Cr（Vl） on antioxidant enzymes of Oxya chinensis（Orthoptera： Acridoidae） were determined. Changes in the activities of the antioxidant enzymes superoxide dismutase（SOD）, catalase（CAT）, and guaiacol peroxidase（GPx） were measured in O. chinensis insects injected with Cr（VI）. Fifth-nymphs of O. chinensis insects were injected with Cr（VI） with different concentrations （0, 75, 150, 225, 300, 375, 450 mg/kg of body weight）. The results showed that Cr（VI） led to the change of SOD, CAT, and GPx activities at different concentrations, which revealed that： （1） The oxidative stress of SOD increased with the increase of Cr （VI） concentration. （2） With the increase of Cr （VI） concentrations, CAT activities for females increased at lower concentrations, but decreased at higher concentration range, which indicated that antioxidant system of O. chinensis was not influenced by the presence of Cr （VI）. A very similar response to Cr（VI） effect for males indicated that Cr（VI） concentrations were not high enough to damage O. chinensis in terms of CAT. （3） The GPx activity for females increased in all treatments, which revealed that the damage power of Cr（VI） was increased with the increase of Cr（Vi） concentrations in terms of GPx, but the effect was not so remarkable. There was not a consistent trend of GPx activities for males in all treatments of Cr（VI）. Cr（VI）-induced changes in antioxidant enzymes were different for SOD, CAT and GPx, of which the tendency was that activities generally changed with increase of concentrations of Cr（VI） suggesting SOD, CAT, and GPx could serve as indices of oxidative stress to some extent.

Accumulation of cadmium and copper by female Oxya chinensis (Orthopera: Acridoidea) in soil-plant-insect system

One purpose of this research is to present accumulation of cadmium （Cd） and copper （Cu） by female Oxya chinensis （Orthopera： Acridoidea） in a simulated soil-plant-insect ecosystem treated with Cd. Fourth-instar nymphs of O. chinensis had been fed on wheat （Triticurn aestivum） seedlings contaminated with Cd and Cu for one month. In the ecosystem, the Cd concentration in wheat seedlings rose greatly with the increasing of Cd in the soil, but the Cu concentration in wheat seedlings was not found elevated. There was a highly significant difference（P〈0.05） in Cd concentrations of wheat seedlings and not any significant difference（P〉0.05） in Cu concentrations of wheat seedlings. The Cd and Cu concentration in different body part-head, thorax, abdomen, and hind femur, varied under different Cd concentrations in soil. There were significant differences （P〈0.05） in the four parts of Cd and Cu accumulations with all treatments. The order of Cd accumulation was thorax 〉abdomen 〉head 〉hind femur and the Cu was abdomen 〉thorax 〉 head〉hind femur. The results indicated that Cd and Cu were accumulated from the soil to grasshoppers through the plant; that is to say, Cd and Cu in environment could be transported to animal or human via food chain.

小翅稻蝗(Oxya yezoensis Shiraki)翅多型现象浅释

对小翅稻蝗翅型构成的季节变化 ,长翅型、短翅型产卵前期间的差异及光周期对翅型分化的影响进行了调查 ,结果表明 ,小翅稻蝗存在着明显的翅多型现象 ,相对翅长 (前翅长 /后足腿节长 )最长可达 1 .4 9,最短只有 0 .50 ,翅长呈连续性双模态分布。早期羽化的个体大多为长翅型 ,随着季节的推移 ,羽化成虫短翅率逐渐增加。长翅型雌成虫的产卵前期间为4 2 .7± 1 3.1日 ,短翅型为 1 5.3± 6.4日 ,短翅型雌成虫的产卵前期间显著短于长翅型。不同的光周期短翅成虫出现的比例不同 ,光照短于 LD1 2 :1 2时 ,几乎全为短翅型 ,LD1 4 :1 0短翅率为 66.8% ,LD1 6:8则长翅率达 62 .1 % ,光照长于LD1 8:6时 ,几乎全为长翅型。

Comparative Study of Malathion Toxicity and General Esterases in Larvae and Adults from a Field Population of Oxya chinensis (Thunberg) (Orthoptera: Acridoidea)

The susceptibility of Oxya chinensis to malathion was compared in larvae and adults from a field population, collected from Jinyuan outskirt, Shanxi Province. The results showed that Oxya chinensis was more susceptible to malathion in the adult stage than in the larval stage. The LD50 values for malathion susceptibility of Oxya chinensis were 4.94 and 2.44 mg g-1 body weight in the larvae and adults respectively. The results indicated that the larvae were 2.02-fold less susceptible to malathion than the adults. The general esterases and the kinetics were characterized and compared between the two life stages and between females and males. Larval preparations of Oxya chinensis were more active than adult preparations in females and males. The larvae showed 1.18-, 1.49-, and 1.17- fold higher specific activities than the adults in females with α-NA, α-NB and β-NA respectively. In males, the ratios were 1.34-, 1.70-, and 1.06-fold. Female preparations were more active than those of males in the adults. The reverse results were observed in the larvae where male preparations were more active than female preparations. Kinetic studies showed that Km values of general esterases hydrolyzing α-NA, α-NB, and β-NA in the adult stage were 1.36-, 1.32- and 1.39-fold respectively, higher than those in the larval stage in females. In males, the ratios were 1.24-, 2.14-, and 1.20-fold. The esterase from male insects had a higher affinity (lower Km value) to the substrate than those from females. The results also showed that the Vmax values of general esterase hydrolyzing α-NA, α-NB, and β-NA in the two stages were similar. From the results of bioassays and biochemical analyses, it has been inferred that a higher level of resistance to malathion in larvae than in adults would appear to result from differences in the expression of resistance mechanisms in these two life stages. Enhanced esterase activities appeared to play a major role in resistance to malathion in both larvae and adults. From the analysis of inhibition in vitro, the esterases in the two life stages were B-type, and carboxylesterases were predominant enzymes in the composition of the esterases in the two stages.

Comparisons of Properties of Acetylcholinesterase from Two Field-Collected Populations of Oxya chinensis Thunberg(Orthoptera:Acrididae)and the Role of Acetylcholinesterase in the Susceptibility to Malathion

In this study, acetylcholinesterase (AChE) was extracted from two field-collected populations of Oxya chinensis (XinxiangCity, Henan Province and Changzhi City, Shanxi Province). AChE activities were decreased when concentrations of ATCincreased, showing a characteristic phenomenon of substrate inhibition at high concentration in both populations. Suchinhibition occurred at relatively low concentration for AChE from Xinxiang population but relatively high for AChE fromChangzhi population. The kinetic study showed that there were no significant differences between the two populations inthe Km values. The Km value in Changzhi population was only 1.09-fold higher than that in Xinxiang population. However,significant differences were observed between the two populations in Vmax values. The Vmax value in Changzhi populationwas 1.32-fold higher than that in Xinxiang population. The inhibition study in vitro showed that the AChE from bothpopulations exhibited similar rank order in sensitivity to inhibition by three OPs, as determined by comparison of theirbimolecular rate constants (ki), from the most potent inhibition to the least was chlopyrifos-oxon > paraoxon >demeton-s-methyl for AChE from the two populations and that the ki values in Xinxiang population were lower than those in Changzhipopulation. The I50 values of AChE from Xinxiang population were 4.84-, 2.66-, and 1.92-fold less sensitive to inhibition byparaoxon, chlopyrifos-oxon, and demeton-s-methyl. These results were consistent with the results in bioassay. It isinferred that AChE insensitivity to OP insecticides plays an important role in the differences of insusceptibility of Oxyachinensis to malathion between the two populations.

中华稻蝗（Oxya Chinesis Thunberg）胚胎发育过程中耗氧率变化的研究

用ＳＫＷ－３型华氏呼吸仪对中华稻蝗（ＯｘｙａＣｈｉｎｅｓｉｓＴｈｕｎｂｅｒｇ）卵发育过程中的耗氧率进行了测定研究（培养条件：恒温２５℃），并同步用染色法研究了胚胎形态的变化．结果发现，中华稻蝗卵发育的耗氧率曲线形状在种内，特别是同一居群内具有一定的稳定性，但总的耗氧量在不同的地区。

The Susceptibilities of Oxya chinensis(Orthoptera:Acridoidea) to Malathion and Comparison of the Esterase Properties from Three Collected Populations in Tianjin Area,China

The susceptibilities of Oxya chinensis to malathion were studied in three populations collected from outskirt of Tianjin, China, using bioassays and biochemical analysis. Populations were chosen to represent different exposure to insecticides： BDG （Beidagang; low exposure）, BD （Baodi; high exposure previously but low exposure now）, and JN （Jinnan; high exposure）. The results showed that the LD50 values of BD and JN populations were 3.95- and 12.02-fold and 3.64- and 10.07- fold higher than that of BDG population in females and males, respectively. The LD50 values in females were higher than those in males. The results of biochemical analysis indicated that the esterase （EST） activities in JN population were higher than those in BD and BDG populations. They showed that when α-NA, α-NB, and α-NA were used as substrates, females＇ EST activities of JN population were 1.11-, 1.30-, and 1.14-fold and 1.39-, 1.59-, and 1.54-fold higher than those of BD and BDG populations, respectively. When α-NA, α-NB, and β-NA were used as substrates, males＇ EST activities of JN population were 1.13-, 1.12-, and 1,00-fold and 1.20-, 1.14-, and 1.07-fold higher than those of BD and BDG populations, respectively. The results also showed that the specific activities of the females were higher than those of the males in the BD and JN populations, whereas the specific activities of the males were higher than those of the females in the BDG population. The results of bioassay were consistent with those of biochemical analysis. Thus, it was inferred that the elevated ESTs activities might play an important role in conferring the differences of susceptibility of O. chinensis to malathion in the three collected populations. Enzyme kinetic studies indicated that the Km and Vmax values were different among the three collected populations and between the females and the males. The observed changes in the kinetic parameters might be explained by differential expression patterns of isozymes so that the insect esterases have different affinities and maximum velocities toward the same substrate.

Study on Insecticidal Activities and Effect on Three Kinds of Enzymes by 5-Aminolevulinic Acid on Oxya chinensis

Insecticidal activities and effects on three enzymic activities caused by 5-aminolevulinic acid （ALA） on Oxya chinensis were studied. Fourth-instar nymphs of O. chinensis were treated with different doses ofALA （A1,250 mM; A2, 450 mM; A3,750 mM; A4, 1 000 mM）. Mortality and the activities of acetylcholinesterase （ACHE）, glutathione S-transferase （GSTs）, and glutathione peroxidase （GPx） were determinated. The mortality of O. chinensis rose with an increasing dose of ALA. The mortality of high-dose treatments A3 and A4 reached 66.19 and 80.21%, respectively. The value of LD50 was 3.61 （3.29-3.93） mg·g^-1 body weight （95% confidence interval）. Biochemical studies showed that the activities of AChE and GPx in the A4 treatment declined by 51.53 and 42.82% in the female, and 42.65 and 43.85% in the male compared to the control, respectively, and the degree of decline reached a significant level at P 〈 0.05. Meanwhile, the GSTs activities of O. chinensis enhanced with increasing dose of ALA. The GSTs activities of female and male O. chinensis in the A4 treatment remarkably increased by 171.05 and 97.42% compared to the control （P〈 0.05）. ALA had an obviously toxic effect on O. chinensis. Moreover, ALA caused the photoinactivation of AChE and GPx, which induced nerve transmission blocking and the capability to defend oxidation damage declining. Meanwhile, a high dose of ALA could activate GSTs, which caused a feedback inhibition of the insect to the phototoxic substance.

小稻蝗Oxya intricata(Stàl)一畸形个体记述(直翅目:斑腿蝗科)

记述了采自湖北黄冈市黄州区龙王山的小稻蝗 Oxya intricata(Stal)一畸形个体 ,与正常个体的主要区别是左侧前翅明显短缩 ,近卵形 ,鳞片状 ,翅脉异常 ,侧置 。

A Photosensitivity Insecticide, 5-Aminolevulinic Acid, Exerts EffectiveToxicity to Oxya chinensis (Orthoptera: Acridoidea)

5-Aminolevulinic acid （ALA）, a major photosensitivity insecticide, has attracted increasing attention as a new type of highly efficient, environmental friendly pesticide to be used to control the pest. To examine whether or not ALA acts effectively to grasshopper, Oxya chinensis and elucidate the detoxification mechanism of ALA, the susceptibility to ALA was assessed in O. chinensis and two major metabolic detoxification enzymes including glutathione S-transferases （GSTs） and general esterases （ESTs）-specific activities were compared in different development stages and different body sections of O. chinensis treated by ALA and the control. The results showed that the ALA exhibited obvious toxicity to the grasshopper in different development stages. In the low-dose treatment （0.0597 mmol L-1）, the mortalities of O. chinensis reached a significant level （55.5% in the 1st instar nymphs, 61.4% in the 2nd instar nymphs, 71.4% in the 3rd instar nymphs, and 64.4% in the 4th instar nymphs. But, there was no dose-dependent toxic effect. Thereby, we proposed that ALA has the potential for acting as photosensitivity insecticide for controlling O. chinensis. GSTs activity assays using CDNB and DCNB as substrates indicated that the thorax and abdomen of the different instar nymphs treated by ALA showed 1.52-5.56 fold significantly increased GSTs activities compared with the control. However, for the ESTs-specific activity assay, there was no significant difference between O. chinensis treated by ALA and the control within different instar nymphs, when a-NA, a-NB and b-NA were used as substrates. Therefore, GSTs-mediated metabolic detoxification as evidenced by significantly increased GSTs activities might contribute to protect against oxidative damage and oxidative stress by ALA in O. chinensis.

Comparative Studies of Substrate and Inhibitor Specificity of Glutathione S-Transferases in Six Tissues of Oxya chinensis(Thunberg)(Orthoptera:Acrididae)

Specific activity, substrate specificity, and kinetic parameters （Km and Vmax） of glutathione S-transferases （GSTs） towards three substrates, 1-chloro-2,4-dinitrobenzene （CDNB）, 1,2-dichloro-4-nitrobenzene （DCNB）, and p-nitrobenzene chloride （pNBC） were investigated in six tissues （foregut, midgut, hindgut, fat body, hemolymph, and muscle） of Oxya chinensis. In addition, the inhibition in vitro （ethacrynic acid, and Cibacron Blue 3GA） of Oxya chinensis in the six tissues was also investigated. Glutathione S-transferase activity was detected in all the six tissues examined. The rank order of GST activities towards CDNB was fat body 〉 midgut 〉 hindgut 〉 muscle 〉 foregut 〉 hemolymph both in females and males. Glutathione S-transferase activities in the fat body in females and males were 1.3- to 10.4-fold and 1.1- to 10.0- fold higher than those in the other tissues. The rank order of GST activities towards the other substrates changed slightly. From these results, it was inferred that GSTs in the fat body and midgut played important roles in detoxifying xenobiotics including insecticides and plant allelochemicals in O. chinensis. In the three substrates examined, CDNB seemed to be the best substrate, followed by pNBC and DCNB. The kinetic parameters of GSTs were different among the six tissues. This suggested that GSTs in different tissues have various affinities and catalytic efficiency to substrates. In vitro inhibition study showed that the median inhibition concentration （IC50） values of the two inhibitors to GSTs from the six tissues were different. The results suggested that the two inhibitors have different inhibition potency to GSTs from the different tissues. The observed changes in kinetic parameters and inhibition in vitro among the six tissues of the insect might suggest that the number and structure of isoenzymes and their rate of expression varied for the different tissues.

中华稻蝗 (Oxya chinensis)种群间体型分化与染色体核型均一性研究(英文)

本文研究了 16个具有地理隔离的中华稻蝗 (Oxyachinensis)种群形态特征和染色体核型关系。种群标本采集地北自嫩江 (4 8°N ,12 5°0 8′E) ,南至福州 (2 6°N ,119°12′E)。这 16个中华稻蝗种群的个体大小有显著差异 ,以在北纬 4 0°附近为界可将这 16个种群分为两组。南方组 (体长LB (♀ ) =35 39±11 61mm ,LB (♂ ) =2 8 86± 8 0 0mm)中华稻体长显著大于北方组 (LB (♀ ) =2 5 81± 5 61mm ,LB (♂ ) =2 1 2 4± 5 81mm )。与种群间体长分化相反 ,其染色体特征显示高度均一性。染色体数目、相对长度和着丝点位置均无明显区别。核仁组织者 (NORs)均位于M8和S10 两条染色体。在L1、L2 、S10 染色体各有一条C 带端带 ,另在M8有一条居间带。雄性外生殖器形态亦显示出高度一致性。本研究结果表明中华稻蝗群体间体型大小分化应为种内变异。

Different survival of chromium-exposed Oxya chinensis among allozyme genotypes

The goal of the present study was to compare the different survival of Oxya chinensis exposed to chromium（VI） among allozyme genotypes to gain a better understanding of the relationship between the genetic variations and environmental disturbance. This study analyzed the occurrence of genotypes in O. chinensis population exposed to Cr（VI）. O. chinensis samples were collected at Yuanping, Shanxi Province, China and used in acute toxicity tests. Specimens were assigned to Cr（VI） exposure （LDs0：291.0 mg/kg） for 24 h. The genetic composition of both dead and survived specimens was analyzed with horizontal starch gel electrophoresis in four enzymes （GPI, PGM, LDH, and ME）. The results indicated that under Cr（VI） exposure, specimens with different genotypes had various mortalities at the four loci in laboratory conditions, and there was a genetic basis for tolerance in O. chinensis during acute exposure to Cr（VI）.

镉锌处理麦苗对中华稻蝗(Oxya chinensis)体内锌、镉水平及生化指标的影响

为了研究Cd、Zn污染对中华稻蝗生理生化的影响,选用不同浓度Cd、Zn溶液(Cd0+Zn0,Cd20+Zn0,Cd20+Zn50,Cd20+Zn100,Cd20+Zn200)mg·L-1培养麦苗饲喂中华稻蝗(Oxya chinensis)进行慢性染毒,测定麦苗和虫体(4龄若虫)中Cd与Zn蓄积量、虫体中丙二醛(MDA)含量、超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GPx)活性和总抗氧化能力(T-Aoc)。研究结果显示,在Cd浓度恒定的情况下,随Zn处理浓度的增大,麦苗和虫体中Zn含量显著上升,(Cd20+Zn200)mg·L-1处理组麦苗和虫体Zn含量分别为对照组的2.03和1.63倍;Cd含量呈先升高后降低趋势,在(Cd20+Zn100)mg·L-1处理组达到最高值,分别为10.40、4.35μg·g-1,(Cd20+Zn200)mg·L-1处理组下降到7.36、3.35μg·g-1。在Cd和Zn联合作用下,随着Zn浓度的增加,中华稻蝗体内的MDA含量升高。SOD表现出先升高、后降低的趋势。与对照组相比,Cd单一处理组GPx活性增加,随着Zn的加入,其GPx活性降低。T-Aoc在(Cd20+Zn100)mg·L-1处理组活性最高。研究结果表明,低浓度Zn的加入可以增加中华稻蝗对Cd的富集,Cd和Zn的联合作用能够引起中华稻蝗脂质过氧化损伤。