【作者】 栾军波；

【导师】 刘树生；

【作者基本信息】 浙江大学 ， 农业昆虫与害虫防治， 2008， 博士

【摘要】 近20年来,B型烟粉虱Bemisia tabaci广泛入侵世界各地,并在一些入侵地取代了危害不严重的土著烟粉虱,对生产造成了巨大的危害,而且入侵区域还在不断扩大。深入研究B型烟粉虱竞争取代土著烟粉虱的机制,对于解释B型烟粉虱的广泛入侵并取代土著烟粉虱的现象和规律,以及对其进一步入侵和地域扩张并取代土著烟粉虱的预警,将会提供重要的理论依据。本文系统地研究了B型烟粉虱竞争取代土著ZHJ2型烟粉虱的潜能及其行为机制,同时还结合本实验室已开展的B型烟粉虱竞争取代土著ZHJ1型烟粉虱和AN型烟粉虱的工作,研究了B型烟粉虱竞争取代土著ZHJ1型烟粉虱和AN型烟粉虱的行为机制。结果如下:(1)使用摄像机观察和记录烟粉虱在活体植物上的交配行为研发了一套用于观察和记录烟粉虱在活体植物上交配行为的摄像系统,经验证该系统可以准确、连续地观察和记录该虫在较自然状态下的求偶和交配行为。该系统成本低、操作简单,可以满足在活体植物上进行大量连续观察的需要,为开展烟粉虱交配行为观察和不同生物型交配行为互作研究提供了技术支撑。(2)B型烟粉虱、ZHJ1型烟粉虱、ZHJ2型烟粉虱的羽化节律与首次交配时间和交配频率B型烟粉虱和ZHJ1型烟粉虱羽化高峰出现在每日光照开始后1～2h,ZHJ2型烟粉虱的出现在光照开始后1～4h,羽化高峰期雌虫比例为50%～60%:对于这三个生物型而言,90%的成虫在光照开始后1～6h内羽化,雌虫比例约60%,只有少数成虫在夜间无光时段内羽化。三个生物型烟粉虱最早的交配出现在羽化后2～6h,并且56%～73%的雌虫在羽化后12h内至少交配1次。雌雄虫都可交配多次,大多数交配事件发生在日间,约1/5的交配事件发生在晚间。(3)B型烟粉虱与ZHJ2型烟粉虱的生殖隔离程度与同型雌雄虫之间的交配次数和频率相比,B型烟粉虱和ZHJ2型烟粉虱之间的交配次数显著减少,交配频率显著下降。这表明,B型和ZHJ2型存在交配前部分生殖隔离。尽管二者部分个体可以互相交配,但交配后的雌虫只产生雄性后代,所以,B型和ZHJ2型能发生交配的个体之间还存在交配后完全生殖隔离。因此,B型和ZHJ2型之间的生殖隔离关系属于交配前部分生殖隔离兼交配后完全生殖隔离。(4)B型烟粉虱与ZHJ2型烟粉虱在棉花上的竞争取代过程当B型烟粉虱与ZHJ2型烟粉虱以3:20的比例在棉花上开始竞争,在未喷施吡虫啉乳油的情况下,B型经过6代完全取代了ZHJ2型,并伴随着B型雌虫比例的上升和ZHJ2型雌虫比例的下降;在喷施吡虫啉乳油的情况下,B型取代速度加快,经过5代完全取代了ZHJ2型,也伴随着B型雌虫比例的上升和ZHJ2型雌虫比例的下降;B型单一种群中,雌虫比例稳定在55%～60%;ZHJ2型单一种群中,雌虫比例稳定在50%左右。(5)B型烟粉虱竞争取代ZHJ2型烟粉虱的行为机制详细的交配行为分析揭示了中国B型烟粉虱与ZHJ2型烟粉虱之间存在非对称交配互作。B型雌虫比ZHJ2型雌虫具有更强的性接受能力。B型雄虫能更频繁、更有效地向B型雌虫或ZHJ2型雌虫求偶。与ZHJ2型雄虫干扰B型雄虫的求偶相比,B型雄虫对ZHJ2型雄虫求偶的干扰更频繁和有效。而且,B型雄虫干扰ZHJ2型雄虫求偶比B型雄虫干扰另一B型雄虫的更成功,而对于ZHJ2型雄虫却恰恰相反。B型雄虫具有交配后保卫行为,可阻止其它雄虫的求偶,并且对ZHJ2型雄虫求偶的阻止比对B型雄虫求偶的阻止更有效。然而,ZHJ2型雄虫每次与雌虫交配后就离开,未表现有交配后保卫行为,这便有利于其它雄虫对交配过的雌虫进行求偶。ZHJ2型雄虫的存在促进B型雄虫更频繁地求偶。然而,B型雄虫的存在却减少了ZHJ2型雄虫对ZHJ2型雌虫的求偶。这些求偶互作行为使得ZHJ2型雄虫的存在提高了B型雌雄之间的交配次数,相反,B型雄虫的存在使得ZHJ2型雌雄之间的交配次数减少。同时观察表明,另一生物型雄虫的存在导致了B型后代雌性比例提高,ZHJ2型后代雌性比例下降。B型和ZHJ2型之间的交配并未影响交配的雌虫的后代性比。B型或ZHJ2型的交配时间未受到同型或另一型雄虫共存的影响。因此,作为B型和ZHJ2型之间非对称交配互作的结果,交配次数的不对称变化导致了B型后代雌性比例的上升,ZHJ2型后代雌性比例的下降,这表明B型具有取代ZHJ2型的潜力,揭示了B型与ZHJ2型在棉花上竞争取代现象的行为机制,即B型在室内条件下能够取代ZHJ2型,并伴随着B型雌虫比例的上升和ZHJ2型雌虫比例的下降,这种取代与两个生物型之间的非对称交配互作导致的后代性比变化密切相关。(6)B型烟粉虱竞争取代ZHJ1型烟粉虱和AN型烟粉虱的行为机制详细的交配行为分析也揭示了中国B型烟粉虱与ZHJ1型烟粉虱之间、澳大利亚B型烟粉虱与AN型烟粉虱之间均存在非对称交配互作。B型雌虫比ZHJ1型雌虫和AN型雌虫具有更强的性接受能力。B型雄虫能更频繁、更有效地对同型雌虫或另一型雌虫求偶。与ZHJ1型雄虫和AN型雄虫干扰B型雄虫的求偶相比,B型雄虫对ZHJ1型雄虫和AN型雄虫求偶的干扰更频繁和有效。而且,B型雄虫干扰ZHJ1型雄虫和AN型雄虫求偶比B型雄虫干扰另一B型雄虫的更成功,而对于ZHJ1型雄虫却恰恰相反。B型雄虫具有交配后保卫行为,可阻止其它雄虫的求偶,并且对ZHJ1型雄虫和AN型雄虫求偶的阻止比对B型雄虫求偶的阻止更有效。然而,ZHJ1型雄虫和AN型雄虫每次与雌虫交配后就离开,未表现有交配后保卫行为,这便有利于其它雄虫对交配过的雌虫进行求偶。ZHJ1型雄虫和AN型雄虫的存在促进B型雄虫更频繁地求偶。然而,B型雄虫的存在却减少了ZHJ1型雄虫和AN型雄虫对其同型雌虫的求偶。这些求偶互作行为使得ZHJ1型雄虫或AN型雄虫的存在提高了B型雌雄之间的交配次数,相反,B型雄虫的共存使得ZHJ1型雌雄之间或AN型雌雄之间的交配次数减少。同时观察表明,另一生物型雄虫的存在导致了B型后代雌性比例提高,ZHJ1型和AN型后代雌性比例下降。B型或ZHJ1型或AN型的交配时间未受到同型或另一型雄虫共存的影响,因此,作为B型与ZHJ1型之间、B型与AN型之间非对称交配互作的结果,交配次数的不对称变化导致了B型后代雌性比例上升,ZHJ1型和AN型后代雌性比例下降,这也揭示了B型竞争取代ZHJ1型和AN型的行为机制。本研究的主要创新之处(1)首次自主设计组装了一套经济可靠的录像观察和记录装置,可连续几天详细记录烟粉虱成虫在活体植物上较自然状态下的求偶和交配行为。(2)首次通过严格的试验,证明了B型烟粉虱和ZHJ2型烟粉虱之间存在交配前部分生殖隔离兼交配后完全生殖隔离。(3)首次证明了B型烟粉虱具有竞争取代土著ZHJ2型烟粉虱的潜能,并揭示了非对称交配互作是室内条件下B型烟粉虱竞争取代土著ZHJ2型烟粉虱的行为机制。(4)首次证明了非对称交配互作是中国和澳大利亚两地B型烟粉虱竞争取代土著ZHJ1型烟粉虱和AN型烟粉虱的行为机制。更多还原

【Abstract】 The B biotype of Bemisia tabaci has spread to much of the rest of the world from its presumed origin in the Mediterranean-Asia Minor-North Africa in the past 20 years and has displaced some indigenous biotypes of this species in the regions of invasion. During the processes of invasion and displacement,the B biotype has caused considerable damage to a range of crops.Revealing the mechanisms underlying the displacement of indigenous biotypes by the B biotype will contribute to explain why the B biotype has such a strong capacity to invade and displace indigenous biotypes, which can provide us with critical theoretical bases to predict whether the B biotype can spread further and displace other indigenous biotypes.This research is aimed to find out the potential of the B biotype to displace the indigenous ZHJ2 biotype and its underlying behavioural mechanisms,and in addition,to study the behavioural mechanisms underlying the displacement of indigenous biotypes ZHJ1 and AN by the B biotype,based on the previous findings from our laboratory that the B biotype could displace indigenous biotypes ZHJ1 and AN.The results are summarized as follows:(1) Observing and recording copulation events of whiteflies on plants using a video cameraA cost-effective,efficient,and reliable video recording system for observing and recording the mating behaviour of whitefly on live plants was developed.With this novel method,a large number of accurate and continuous recordings of courting and mating behaviour of this insect on live plants could be made under more natural condition,and the mating interactions between biotypes of B.tabaci could be observed in detail.(2) Diurnal patterns of adult emergence,pre-copulation intervals and copulation frequencies of biotypes B,ZHJ1 and ZHJ2In biotypes B and ZHJ1,the peak of emergence occurred during the first 2 h of the photophase and in biotype ZHJ2,it occurred during the first 4 h of the photophase. The percentage of females remained 50-60%during the peaks of emergence.In these three biotypes,over 90%of the adults emerged during the first 6 h of the photophase, throughout which the percentage of females remained approximately 60%,and only small proportions of the adults emerged during the scotophase. Continuous observations using the video recording system showed that in the three biotypes,the earliest copulation events occurred 2-6 h after emergence and 56-73%of females copulated at least once by 12 h after emergence.Both females and males copulated multiple times over the first three days.Most of the copulation events occurred during the photophase,while approximately one-fifth of the events occurred during the scotophase.(3) Reproductive compatibility between biotypes B and ZHJ2When adults of biotypes B and ZHJ2 were placed in one arena,mating could occur between the two biotypes.However,the number of events and frequency of copulation between the biotype B and ZHJ2 decreased significantly compared with those between females and males of a given biotype being placed in one arena, demonstrating a degree of pre-mating partial reproductive isolation between these two biotypes.Although some of the adults of the biotype B and ZHJ2 copulated with each other,mated females produced only male progeny,demonstrating a post-mating complete isolation in reproduction between the two biotypes in cases where copulation has happened.Thus,both pre-mating partial reproductive isolation and post-mating complete reproductive isolation existed between these two biotypes.(4) Competitive displacement between biotypes B and ZHJ2 on cottonThe mixed cohorts began with 13%B and 87%ZHJ2,and 50%females.In the treatment without insecticide application,the B biotype had totally displaced ZHJ2 by the sixth generation.During the process of competition and displacement,the female ratio of B increased,while that of ZHJ2 decreased with time.In the treatment where the insecticide imidacloprid was applied after the second generation,the B biotype had totally displaced ZHJ2 by the fifth generation,and during the process of competition and displacement,the female ratio of B increased,while that of ZHJ2 decreased.In cohorts with ZHJ2 only,the female ratio remained at 50%or so throughout.(5) Behavirouai mechanisms underlying the displacement of the indigenous biotype ZHJ2 by the B biotypeDetailed analysis of mating behaviour revealed asymmetric mating interactions between biotypes B and ZHJ2.The B biotype had higher sexual activity than the ZHJ2 biotype in that B females were more receptive to males,and B males more frequently and efficiently courted female of B or ZHJ2.Besides,B males interfered more intensely with courtship initiated by rival males of another biotype than did ZHJ2.B males interfered more successfully with courtships initiated by rival males of ZHJ2 than by males of the same biotype.In contrast,ZHJ2 males interfered more successfully with courtships initiated by males of the same biotype than those initiated by B males.B males could guard females post copulation,and more effectively inhibited courtships from a ZHJ2 male than from a B male during guarding.However, ZHJ2 males separated from females post copulation so that another male had access to court the female.All these behavioural differences between the two biotypes had the consequences that copulation events between B males and females increased in the presence of ZHJ2,while copulation events between ZHJ2 males and females decreased in the presence of B.Also,in the presence of rival males of another biotype, female ratio in the offspring of the B biotype increased while female ratio in the offspring of the ZHJ2 biotype decreased.Copulation duration within the biotype B or ZHJ2 was not influenced by the presence of another male of either biotype,and reproduction of females was not affected by mating between the two biotypes when males of the two biotypes were available.Therefore,we can conclude that as the consequence of asymmetric mating interactions between biotypes B and ZHJ2, asymmetric change of copulation events resulted in the increase of female offspring of the B biotype and decrease of female production of the ZHJ2 biotype.Our data demonstrated that the B biotype had the potential to displace the ZHJ2 biotype under laboratory caged conditions and revealed that asymmetric mating interactions between the two biotypes were the major behavioural mechanism underlying the displacement.(6) Behaviroual mechanisms underlying the displacement of indigenous biotypes ZHJ1 and AN by the B biotypeDetailed analysis of mating behaviour revealed asymmetric mating interactions between biotypes B and ZHJ1,or B and AN.The B biotype had higher sexual activity than the two indigenous biotypes in that B females were more receptive to males,and B males more frequently and efficiently courted female of the B biotype or another biotype.Besides,B males interfered more intensely with courtships initiated by rival males of another biotype than did indigenous biotypes.The B males interfered more successfully with courtships initiated by rival males of another biotype than by males of the same biotype,while indigenous males interfered more successfully with courtships initiated by males of the same biotype than by rival males of the B biotype. B males from both China and Australia could guard females post copulation,and more effectively inhibited courtships from indigenous males than from B males during guarding.However,indigenous males separated from females post copulation so that another male had access to court the females.All these behavioural differences between the biotypes had the consequences that copulation events between B males and females increased in the presence of indigenous males,while copulation events between the indigenous males and females decreased in the presence of B males.Also, in the presence of rival males of another biotype,female ratio in the offspring of B increased while female ratio in the offspring of the indigenous biotypes decreased. Copulation duration within each of the three biotypes was not influenced by the presence of another male,thus,we can conclude that as the consequence of asymmetric mating interactions between biotypes B and ZHJ1 or between B and AN, asymmetric change of copulation events resulted in the increase of female offspring of B biotype and decrease of female production of biotypes ZHJ1 and AN.These observations revealed the behavioural mechanisms underlying the widespread invasion and displacement of indigenous biotypes ZHJ1 and AN by the B biotype.Major new findings of this study:(1) We developed a cost-effective,efficient,and reliable video recording system for observing and recording the mating behaviour of whitefly on live plants.With this novel system,a large number of accurate and continuous recordings of courting and mating behaviour of this insect can be made on live plants under more natural condition.(2) We demonstrated that both pre-mating partial reproductive isolation and post-mating complete reproductive isolation between biotypes B and ZHJ2 of B. tabaci.(3) We found that under laboratory caged conditions the B biotype had the capacity to displace the indigenous biotype ZHJ2 in a short period of time and that the asymmetric mating interactions between the two biotypes were the behavioural mechanism underlying the displacement.(4) We revealed that the asymmetric mating interactions between biotypes B and ZHJ1,or between biotypes B and AN were the behavioural mechanisms underlying the displacement of the indigenous biotypes ZHJ1 and AN by the B biotype in China and Australia.更多还原