【作者】 赵吕权；

【导师】 朱道弘；

【作者基本信息】 中南林业科技大学 ， 森林保护学， 2011， 博士

【摘要】 滞育和翅型分化是昆虫为了适应环境时间和空间变化而采取的适应策略。丽斗蟋以若虫越冬,且具有明显的翅二型现象,本文以其为研究材料,调查了变化光周期对若虫发育的调控；探讨了环境因素及胁迫作用对翅型分化的影响、翅二型成虫飞行与繁殖发育的生理权衡及其内分泌控制机理；同时对翅二型成虫飞行与繁殖发育的能源物质权衡也进行了研究,现将结果总结如下：1.丽斗蟋若虫发育明显受光周期的影响,25℃温度条件下,3个光周期条件下的若虫发育都较慢,羽化也极不整齐,长日条件(LD16：8h)、中间日照条件(LD14：10h)和短日条件(LD12：12h)的若虫发育历期分别为206、236和230d,若虫从开始羽化到供试个体全部完成羽化所需时间分别为216、301和156d,经历短日条件的若虫转移至长日条件后能够促进其快速发育,羽化也很整齐,反方向转移则会抑制若虫发育,且羽化也极不整齐。30℃温度条件下,恒定长日条件下的若虫发育明显快于短日条件,而变化光周期对若虫发育的调控与25℃相似,这表明丽斗蟋若虫发育主要受变化光周期的调控。而变化光周期对若虫发育的影响与光周期的变化方向及低龄若虫感受的光周期类型有关。丽斗蟋若虫复杂的光周期反应模式的生态意义在于调节其生活史与季节同步。2.25℃或30℃温度条件下,长日条件(LD16：8h)、中间日照条件(LD14：10h)和短日条件(LD12：12h)下丽斗蟋成虫短翅率都较高,且三者之间无显著差异。若虫孵化后,短日条件转移至长日条件能够提高成虫长翅率,但促进效果不明显,反方向转移则对翅型分化无明显影响。若虫单只饲养时,丽斗蟋成虫长翅率为11%,密度增加为2只时,成虫长翅率增加为29.4%,而当密度增加为5只、10只时,成虫长翅率又分别降为20%和16.1%。结果表明,密度增加时,有利于成虫形成长翅型个体,但密度增加到一定范围时,高密度对形成长翅型成虫又起到了抑制作用。在若虫发育过程中,遭受胁迫作用时(附肢损伤),能够诱导丽斗蟋短翅化,且若虫发育的末龄和次末龄为胁迫作用的敏感阶段。3.长翅型个体与短翅型个体体重及产卵前期无显著差异,但长翅型个体在成虫羽化当日飞行肌显著发达于短翅型个体。长翅雌虫在成虫羽化当日,飞行肌占身体重量的11.9%,而短翅雌虫飞行肌只占4.9%；长翅雌虫在羽化后5d内,飞行肌重量增加了50%,而短翅雌虫则无明显发育过程。短翅雌虫产卵早期的产卵量显著多于长翅雌虫,而脱翅能够显著促进长翅雌虫产卵,同时诱导飞行肌降解,但短翅雌虫、长翅雌虫及脱翅雌虫的总产卵量并无差异。雄虫羽化后,长翅雄虫与短翅雄虫附腺以相似速率发育且无差异,精巢在羽化后7d内也无显著差异。4.丽斗蟋成虫羽化当日(羽化后12小时内)分别注射不等剂量保幼激素或早熟素,在注射保幼激素7d后,保幼激素能够显著促进长翅雌虫卵巢快速发育,同时诱导飞行肌降解,但不能促进卵粒形成。注射保幼激素14d后,保幼激素对卵巢及飞行肌发育无显著影响,这可能与保幼激素活性有关。短翅雌虫注射早熟素后,能够抑制卵巢发育,但抑制效果与注射的剂量有关,只有当注射剂量超过50ug时,才能对卵巢发育起到显著抑制作用。丽斗蟋长翅雄虫注射保幼激素后,对飞行肌、精巢及附腺发育皆无显著影响；短翅雄虫注射早熟素后,飞行肌、精巢及附腺发育与对照组也无显著差异,表明,丽斗蟋雄虫飞行肌与繁殖器官发育的内分泌控制机理与雌虫不同。5.以蛋白质、糖原及总脂含量为指标,比较了丽斗蟋翅二型成虫在飞行与繁殖发育间的能源物质分配差异,以探讨丽斗蟋翅二型成虫飞行与繁殖发育的能量权衡。结果表明,丽斗蟋长翅雌虫首先将获得的能源物质用于发育飞行肌,而短翅雌虫则首先将获得的能源物质用于发育卵巢；人工脱翅改变了长翅雌虫在飞行与繁殖发育之间的能源物质分配模式。长翅雄虫在成虫羽化后,飞行肌内蛋白质、糖原及总脂的含量多于短翅雄虫,但精巢与附腺内蛋白质、糖原及总脂含量与短翅雄虫无显著差异,表明,长翅雄虫在飞行与繁殖发育的能源物质分配机制与长翅雌虫不同。另外,长翅个体羽化后,飞行肌内总脂含量显著多于蛋白质与糖原,暗示丽斗蟋飞行能量主要来源于总脂。6.长翅雌虫注射保幼激素后,卵巢内蛋白质、糖原及总脂含量显著得到了提高,但飞行肌内蛋白质、糖原及总脂含量与对照组无显著差异。长翅雄虫注射保幼激素后,对飞行肌、精巢及附腺内蛋白质、糖原及总脂合成无显著影响。注射早熟素对短翅雌虫及短翅雄虫飞行肌与繁殖器官内蛋白质、糖原及总脂也无显著调控作用。更多还原

【Abstract】 Diapause and wing dimorphism is the two major season adaptation strategy of insect. Velarifictorus ornatus overwinter in the form of nymphs and has two types of wings in adult. In this paper, we studied the effect of photoperiod on the development of nymphs and the effect of environment factors and injury on the variation of wings. Meanwhile, the physiological trade-off and endocrine control the physiological trade-off between long-winged individuals and short-winged individuals were investigated. The difference in allocation of resources to egg production and flight muscle development between wing dimorphism were also studied. The results are as follows:1. Nymphal development was slow under constant photoperiods at25℃. The shortest mean duration of nymphal development was (206.2±44.0)(mean±SD) days at LD16:8h, followed by (230.3±47.4) days at LD12:12h and (236.5±93.3) days at LD14:10h. No significant difference was observed in the nymphal durations among different constant photoperiods at25℃. Nymphal development was further prolonged when nymphs were exposed to LD16:8h during the first60days and then transferred to LD14:10h or LD12:12h at25℃. Similar results were obtained when nymphs were transferred from LD14:10h to LD12:12h at60days after hatching at25℃. However, in the reverse transfer, i.e. from short days to long days, the durations of nymphal development was dramatically shortened. When nymphs were transferred from LD12:12h to LD16:8h at10,30,60or90days after hatching, the mean nymphal durations were (135.9±88.5),(80.0±5.9),(110.4±10.4) and (142.9±10.8) days respectively. When photoperiod was shifted from LD12;12h to LD14:10h at60days after hatching, the nymphal duration was (120.9±7.7) days. Nymphs exposed to those photoperiod shift developed faster than those kept at constant photoperiods. Although adults emerged more rapidly under long days than those reared under short days at30℃, changing photoperiods showed similar results on nymphal development as those at25℃. These results suggested that seasonal changing day-length controls nymphal development of V. ornatus to synchronize their life-cycle with the season.2. The percentage of brachypterous morph was more than95%when nymphs were reared at constant LD16:8h、 LD14:10h and LD12:12h at25℃or30℃. The percentage of macropterous increased when nymphs were first exposed to short photoperiod and then transferred to long photoperiod. But there was no statistics difference between the above experiments. However, in the reverse transfer, i.e. from short day to long days, The percentage of brachypters was similar to the nymphs which were reared at the constant photoperiod. In crowding experiment, percentage of macropters was11%when rearing of nymphs separately at25℃. The number of macropters increased obvious, which is higher than the nymphs reared separately, as the per container density was increased to2nymphs. But the number of macropters decreased as the per container density was increased to5or10nymphs. The results indicated that the density played an important role in the determination of wing morphs. Meanwhile, injury could induce brachypters in the phase of nymphs especially in the last instar.3. There was no difference in body weight and pre-oviposition between the two morphs, but long-winged individuals had better-developed flight muscles than short-winged individuals during and after emergence of the adult. The flight muscles at adult emergence represented11.9%of the total body weight in the long-winged female and4.9%in the short-winged female. In addition, the weight of the flight muscle of long-winged females increased by50%during the first5days, whereas the flight muscle of the short-winged variant increased only slightly after adult emergence. The process of oviposition in long-winged, short-winged, and de-alated females varied:short-winged females produced more eggs at the early stage than long-winged females, but de-alation could shorten the time until the peak of egg laying and caused histolysis of flight muscles of long-winged females. There was no significant difference in total egg production between the above three groups. In the male, unlike the female, the accessory glands of the two wing morphs enlarged continuously at the same rate. There was no difference between the two wing morphs in the mass of the testes during the first7days after adult emergence.4. Juvenile hormone and precocene were injected to long and short individuals respectively at the day of adult emergence. Topical application of juvenile hormone increased ovary and incident of flight muscle histolysis in long-winged female. Exogenous juvenile hormone stimulated ovary development but failed to elicit any significant effect on egg production. Injection of precocene restrained the ovary development of short-winged female when the dose was over50ug, but there was no effect on the ovary development when the dose was less than50ug. There was no difference in the testis, accessory gland and flight muscle development between the males which were injected acetone and the males which were injected JH. Injection of precocene elicited no influence on the testis, accessory gland and flight muscle development of short-wing male.5. Differences in resource allocation to flight muscle and reproduction organs between wing dimorphism individuals were studied by means of protein, glycogen and total lipid analysis. Long-winged females first devoted the energy to their flight muscle, while short-winged females allocated the energy to their ovary firstly. The long-winged female could reutilize the energy from the histolysis of flight muscle to development of ovary after the hind-wing was removed at the day of adult emergence. The amount of protein, glycogen and total lipid in flight muscle of long-winged male were much more than that of short-winged male, but there was no difference in testis and accessory gland between long-winged and short-winged morph. These results indicated that it was different in allocation of resources to flight muscle and reproduction organs between long-winged and short-winged individuals. On the other hand, the total lipid in flight muscle was much more than the protein and glycogen, that means lipid was the major energy for flighting.6. Topical application of juvenile hormone increased ovary and incident of flight muscle histolysis in long-winged female. Exogenous JH only raised the amount of protein, glycogen and total lipid in ovary, but failed to elicit any effect on the amount of protein, glycogen and total lipid in flight muscle. There was no effect on the amount of protein, glycogen and total lipid in flight muscle and reproduction organs after the long-winged male were injected JH and short-winged male were injected precocene.更多还原