四种天牛的核型比较研究

为弄清天牛的核型特征, 补充我国天牛染色体分类特征和天牛细胞分类学的基础研究空缺, 本文以4种沟胫天牛亚科天牛为研究对象, 选取天牛的分裂旺盛组织精巢（卵巢）和中肠, 在不同的条件下进行天牛染色体玻片的制备和观察。结果显示： 4种天牛染色体数目均为 2n = 20, 性别决定机制为Xy_p。其中, 云斑白条天牛Batocera lineolata的核型公式： 4L+5M+Xy_p, 大型染色体4对, 中型染色体5对, 性染色体为小型; 榉白背粉天牛Olenecamptus cretaceus marginatus、 中华八星粉天牛Olenecamptus octopustulatus chinensis（粉天牛属）和桑天牛Apriona germari的核型公式均为： 5L+4M+Xy_p, 大型染色体5对, 中型染色体4对, 性染色体为中型。粉天牛属的榉白背粉天牛和中华八星粉天牛的核型指数非常相近; 桑天牛的染色体公式虽然与粉天牛属相同, 但长度和着丝粒位置明显不同。     

天牛染色体核型研究及其核型快速检测在检疫中的应用

本文研究了天牛科3亚科9族20种的染色体核型。在所研究的20种天牛核型中,染色体以10对为主,其性染色体决定机制以Xyp为主。这种性别决定机制被认为是最原始的形式。Xyp,是大X染色体和小y染色体形成的降落伞状（parachute-like）的二价体。在细胞减数分裂中,雄性细胞呈现单倍体数目。研究发现,20种染色体中1/2种类其雄性单倍体数目为10,并且由Xyp型性染色体的性别决定机制。生物活细胞在24 h内均能制作成核型玻片。由于不同生物种类间的核型差异显著,本文对应用核型检测方法检测和鉴定有害生物的可行性进行探讨。     

光肩星天牛与星天牛种间竞争行为研究

光肩星天牛Anoplophora glabripennis和星天牛Anoplophora chinensis是我国两种重要的林业蛀干害虫,存在很多共同的寄主植物。为了阐明两种星天牛之间的物种竞争关系,本文采用行为观察试验,研究两种星天牛寄主危害部位、异种危害寄主识别和种间争斗行为等试验。结果显示,光肩星天牛和星天牛在寄主植物上的取食危害部位有很大差异,光肩星天牛主要取食寄主植物的枝条上部,取食面积为2 390.0 mm^2,占整个寄主植物取食面积的69.3%,星天牛主要取食寄主植物的树干上部,取食面积为3 140.0 mm^2,占整个寄主植物的96.6%;两种星天牛都能识别异种天牛危害过的寄主,对其具有显著的回避性,其中光肩星天牛对星天牛危害过的寄主取食量平均值为420.8 mm^2,显著低于健康寄主取食量平均值2 518.8 mm^2,同样,星天牛对光肩星天牛危害过的寄主取食量平均值为436.8 mm^2,显著低于健康寄主取食量平均值1 803.5 mm^2,而对同种天牛危害过的寄主没有显著的选择性;两种星天牛之间争斗共发生34次,其中星天牛获胜30次,表现出更强的竞争力。两种星天牛之间存在显著的种间竞争关系,并且能够识别对方物种的存在,其对寄主的感受机制和植物免疫反应机制需要进一步的试验研究。     

光肩星天牛种群间及其近缘种遗传关系的RAPD研究

利用RAPD技术对采自中国和美国的星天牛属Anoplophora 5个种及8个光肩星天牛Anoplophora glabripennis (Motschulsky)地理种群共13个样品进行了遗传相似性分析。选用了Operon公司生产的引物H系列20个,L系列20个,Q系列11个共51个引物,最后从40个引物中筛选出26个具有多态性的引物作为第一组用于星天牛属种间和光肩星天牛种群间分析,从31个引物中筛选出19个具有多态性的引物作为第二组单独用于光肩星天牛种群分析。根据第一组引物实验获得的RAPD聚类图及遗传距离表明,各个地理种群的光肩星天牛和黄斑星天牛A. nobilis都聚在一起,形成一个大的分枝,而四川星天牛A. freyi、楝星天牛A. horsfieldi和星天牛A. chinensis均在此分枝之外。来自美国纽约和芝加哥的光肩星天牛种群聚于中国光肩星天牛种群之外的另一个独立的分枝上。分布在我国宁夏、内蒙古和河北的光肩星天牛以及宁夏黄斑星天牛和山东、陕西的光肩星天牛分别聚在一起,而甘肃的光肩星天牛与甘肃的黄斑星天牛则聚于另一枝,且它们之间的遗传距离很近,仅为0.1324,说明这两者之间有着极其相近的亲缘关系,由此推断光肩星天牛和黄斑星天牛的差异很小,遗传关系难以区分,进一步证实了它们很可能是同一个种下的两个不同的型。第二组引物实验得到了相似的结果,来自中国的6个光肩星天牛种群全部聚于同一枝中并分成两小枝： 分布于我国宁夏、河北、山东、甘肃的光肩星天牛聚在一起,内蒙古和陕西的光肩星天牛则成另一枝,而分布于美国纽约和芝加哥的光肩星天牛仍聚于中国光肩星天牛种群之外的一个单独的分枝上。但是美国光肩星天牛与中国光肩星天牛之间的遗传距离最近的为0.4578, 最远的为0.5960。由此认为,本研究中采自美国的两个光肩星天牛种群的样本和采自中国的光肩星天牛种群的样本之间存在显著差异,遗传关系较远。有必要从中国和世界其他天牛分布地采集更多样本做进一步DNA 分析。     

聚集性信息素和植物源信息素对松墨天牛的联合诱捕作用

我们评价了聚集性信息素和植物源信息素对松墨天牛Monochamus alternatus Hope(Coleoptera:Cerambycidae)在林间的联合诱捕作用,以期研制出更优的引诱剂控制松墨天牛成虫的危害。结果显示,樟子松墨天牛M.galloprovincialis雄虫挥发出来的聚集性信息素2-undecyloxy-1-ethanol对松墨天牛雌雄成虫均有引诱效果,而且樟子松墨天牛性信息素与植物源信息素之间相互增效作用十分显著,比性信息素或植物源信息素单独使用效果提高4⁵倍。松墨天牛雌虫卵巢发育情况显示,成虫期在浙江地区大约持续4个月,松墨天牛成虫期可以分为两个阶段,第一个阶段为取食期(卵巢未成熟),从5月9日到7月9日;第2个阶段为产卵期(卵巢成熟),从6月3日到9月18日,两个阶段在一段时期有重叠。聚集性信息素和植物源信息素联合应用将在防控松墨天牛危害,遏制松材线虫病传播方面发挥重要作用。     

2种辉蝽的精巢和染色体研究(半翅目:蝽科)

通过探讨中国蝽科Pentatomidae辉蝽属Carbula的红角辉蝽Carbula crassiventris(Dallas,1849)和北方辉蝽C.putoni(Jakovlev,1876)的精巢形态和染色体的核型及减数分裂行为,为蝽科昆虫的细胞分类学提供新资料。采用显微形态解剖法和染色体制片法对其精巢和染色体进行观察。结果表明:2种精巢的位置、外被颜色、形状及精巢叶的数目都一致;染色体组成均为2n(♂)=14(12A+XY),具有X-Y性别决定机制。在减数分裂过程中,常染色体前减数分裂,性染色体后减数分裂且无交叉;在中期-Ⅱ,常染色体排列成环状而性染色体在环中央形成假二价体。但是,2个物种在弥散期常染色体的去固缩程度,终变期常染色体双交叉的个数及中期-Ⅰ常染色体和性染色体的排列方式都各不相同。本文证实了蝽科昆虫的减数分裂行为在不同属间、种间可不相同,而且具有一定的属、种间特异性;同时为精巢在蝽类昆虫分类中的作用提供新的资料。     

聚集信息素和寄主植物挥发物对光肩星天牛和星天牛的引诱作用

【目的】光肩星天牛Anoplophora glabripennis和星天牛A.chinensis经常混合发生,危害共同的寄主,且共享相同的聚集信息素。本研究旨在评价聚集信息素和寄主植物挥发物对这两种星天牛的引诱作用。【方法】通过取食面积法,测定了两种星天牛对复叶槭Acer negundo、青皮垂柳Salix babylonica和苦楝Media azedarach 3种寄主枝条的室内取食偏好性;采用动态顶空吸附法结合气相色谱-质谱联用技术(GC-MS)分析了寄主植物挥发物成分;通过在浙江余姚和慈溪的野外诱捕试验,分析了聚集信息素和植物挥发物对两种星天牛的诱捕效果。【结果】室内选择性和非选择性取食试验结果都显示,光肩星天牛最喜食的寄主植物是复叶槭,其次是青皮垂柳,再次是苦楝;而星天牛对这3种寄主植物的选择顺序与光肩星天牛相反,最喜食苦楝,其次是青皮垂柳,再次是复叶槭。寄主植物挥发物成分中,以萜烯类和芳香族化合物居多,每种寄主挥发物都有几种特有的成分,且不同寄主植物的挥发物中多种成分之间存在显著性差异。野外林间诱捕试验结果显示,聚集信息素与苦楝混合配方MK(4-庚氧基丁醇+4-庚氧基丁醛+莰烯+顺-3-己烯-1-醇+罗勒烯+β-石竹烯)、聚集信息素M(4-庚氧基丁醇+4-庚氧基丁醛)、苦楝配方K(莰烯+顺-3-己烯-1-醇+罗勒烯+β-石竹烯)和柳树配方L(壬醛)都同时诱捕到了光肩星天牛和星天牛。其中,聚集信息素与苦楝混合配方MK对光肩星天牛和星天牛的诱捕效果最好,都表现出比单独使用信息素或者植物挥发物更高的诱捕效果;聚集信息素诱捕到的光肩星天牛和星天牛中雌虫比例更高,而植物挥发物诱捕到的光肩星天牛和星天牛中雄虫比例更高。【结论】本研究进一步证实了聚集信息素4-庚氧基丁醇和4-庚氧基丁醛是光肩星天牛和星天牛共享的信息素;同时,壬醛、莰烯、顺-3-己烯-1-醇、罗勒烯和β-石竹烯是光肩星天牛和星天牛共享的植物挥发物。聚集信息素和植物挥发物联合使用可以应用于光肩星天牛和星天牛的林间监测技术。     

云南省西部庭蚱属一新种及其染色体记述（直翅目：蚱科）

记述采自云南省西部怒江峡谷庭蚱属1新种,即怒江庭蚱Hedotettix nujiangensis Zheng sp.nov.。该种染色体数目2n(♂)=13,性别决定机制为XO型,全部为端部着丝粒染色体,性染色体大小位于第4位。模式标本保存于西南林业大学昆虫标本室。     

新疆主要造林树种对光肩星天牛的抗性

利用网室接种和树干套笼接种光肩星天牛Anoplophora glabripennis(Motschulsky)成虫的方法,于2005年～2006年在新疆光肩星天牛的发生疫区,进行10种主要造林树种对其抗性的测定试验。结果显示:2种接种试验结果基本一致,各试验树种都不同程度地受到光肩星天牛的危害,表现出不同的抗虫性。根据孵化幼虫数综合分析,判断出试验树种的抗性高低的顺序为:桑树、沙枣>胡杨、圆冠榆、新疆杨、白榆、箭杆杨>复叶槭、旱柳、馒头柳。另外根据网室内试验树种上出现的羽化孔判断,光肩星天牛在新疆巴音郭楞蒙古自治州1年发生1代。     

利用管氏肿腿蜂防治光肩星天牛技术研究

光肩星天牛Anoplophora glabripennis是我国重大的森林害虫,对我国造林绿化和林业生态工程建设造成了严重危害。由于其为蛀干害虫,隐蔽性生活,难以防治。利用天敌开展生物防治是控制天牛的重要措施,作者研究探讨了利用管氏肿腿蜂Sclerodermus guani防治光肩星天牛技术。测定了管氏肿腿蜂对光肩星天牛1～3龄幼虫的室内控制作用,研究了林间防治防治技术。结果表明,在室内试验条件下,管氏肿腿蜂由于是抑性外寄生性,其产卵之前的刺蛰可造成天牛幼虫直接死亡,对1、2、3龄幼虫的平均致死率分别为100％、92．10％和87．29％;可寄生3龄天牛幼虫。在管氏肿腿蜂防治光肩星天牛小幼虫的林间试验中,管氏肿腿蜂对光肩星天牛小幼虫的致死率为27．79％-37．87％,平均为32．51％,放蜂比例以蜂虫比8-10：1的寄生率最高。     

Increased divergence but reduced variation on the Z chromosome relative to autosomes in Ficedula flycatchers: differential introgression or the faster-Z effect?

Recent multilocus studies of congeneric birds have shown a pattern of elevated interspecific divergence on the Z chromosome compared to the autosomes. In contrast, intraspecifically, birds exhibit less polymorphism on the Z chromosome relative to the autosomes. We show that the four black-and-white Ficedula flycatcher species show greater genetic divergence on the Z chromosome than on the autosomes, and that the ratios of intraspecific polymorphism at Z-linked versus autosomal markers are below the neutral expectation of 75%. In all species pairs, we found more fixed substitutions and fewer shared polymorphisms on the Z chromosome than on the autosomes. Finally, using isolation with migration (IMa) models we estimated gene flow among the four closely related flycatcher species. The results suggest that different pattern of evolution of Z chromosomes and autosomes is best explained by the faster-Z hypothesis, since the estimated long-term gene flow parameters were close to zero in all comparisons.     

The C-banded karyotypes of the four British species of Notonecta L. (Heteroptera: Notonectidae)

Chromosome preparations were made from mid-gut and ovarian cells of adult Notonecta glauca L., N. obliqua Thunberg, N. maculata F. and N. viridis Delcourt, using the acetic acid dissociation, air-drying method (Crozier 1968) with Giemsa staining. C-banding was obtained by treatment with barium hydroxide and salt-sodium citrate (2xSSC). The karyotypes of the first three species are very similar, with 11 pairs of autosomes plus XY sex chromosomes (plus sometimes a small 12th autosome pair in N. glauca), and the sequence of chromosome sizes very similar. However, the four longest pairs of autosomes, and the X chromosomes, have characteristic C-band patterns, which differ between the species. The karyotype of N. viridis is more distinct, with one pair of long autosomes, while the remaining chromosomes are much shorter. The long autosomes have distinct C-bands, but these are present in only one of the shorter pairs, as faint terminal bands. In warm conditions the long autosomes of N. viridis appear rod-like, but in cold conditions they have one end heavily condensed, giving a tadpole-like appearance.     

松墨天牛成虫标本保存及其DNA提取质量比较

【目的】探讨适合DNA提取的天牛成虫标本保存方法。【方法】采用SDS-蛋白酶K消化法对液氮中冷冻保存、无水乙醇-20℃冷冻保存、无水乙醇室温保存和干标本室温保存且保存时间在2年以上的松墨天牛Monochamus alternates Hope成虫标本基因组DNA进行提取,并对不同保存方式提取的DNA样本进行了质量比较和分析。【结果】在上述常见的松墨天牛成虫标本4种保存方式中,以液氮中冷冻保存效果最佳,其次为无水乙醇-20℃冷冻保存,插针干标本室温保藏效果最差。利用昆虫线粒体基因CO I和CO II的通用引物从上述DNA中均能够成功扩增出目的片段,测序结果证实扩增片段符合预期。【结论】液氮和无水乙醇-20℃冷冻保存适合松墨天牛成虫标本长期保存,且不影响后续的PCR扩增和测序。     

Intraspecific chromosome variation between different populations ofCtenomys dorbignyi (Rodentia, Ctenomyidae) from Argentina

We used banding techniques to analyze the karyotypes of 17 individuals ofCtenomys dorbignyi Contreras and Contreras, 1984, from populations in Corrientes (Mbarigüí, the type locality, and Sarandicito) belonging to the previously known range of the species, and Entre Ríos (Tiro Federal and Paso Vera) representing a new geographically isolated group of populations. All known populations have 2n=70 although the extreme geographic isolation of the different localities suggested the possibility of chromosomal divergence. We found three different karyomorphs; two of them (Mbarigüí and Sarandicito) had 6 pairs of biarmed autosomes and 28 pairs of telocentric autosomes, with an FN=80. Pair 20 (telocentric) was the carrier of the only detected NOR. However, pair 2 was clearly different in each of these two, being metacentric in Sarandicito and submetacentric in Mbarigüí. The third fixed karyomorph differed significantly from the others, showing 8 pairs of biarmed autosomes and 26 pairs of telocentric autosomes, with an FN=84. Pair 3 (biarmed) was the carrier of the single NOR detected. The NOR carrier also showed a marked heteromorphism (Corrientes vs Entre Ríos) evidenced by differences in the length of the short arm. These observations revealed a chromosomal polytypism that was expected owing to the disjunct geographic distribution of the species.     

Comparison of the nuclear organiser region activity in four taxa of the family Canidae

Four species of the family Canidae were cytogenetically studied. The activity of NORs was detected with the use of silver staining. The number of NORs was characteristic for a given karyotype. For the dog found on autosomes 7, 17, 20 and on sex chromosome (Y), for the racoon dog on autosomes 1, 4, 13 and on sex chromosome (Y), for the silver fox only on autosomes 8, 9, 13 and for the blue fox on autosomes 13, 15, 17, 18, 20 and 22. The results demonstrate that NOR activity is similar in all the analysed species of the Canidae. Simultaneously, NOR activity for a medium-sized chromosome pair is distinctly higher than for two other autosome pairs (the longest and the smallest pair). Considerable variability was observed within individuals.     

A new chromosomal race (2n=44) of Nannospalax xanthodon from Turkey (Mammalia: Rodentia)

A new karyotype for blind mole rats was recorded in Tunceli province in Eastern Turkey. The karyotype contained 44 chromosomes, including 13 biarmed pairs, 7 acrocentric pairs, and one heteromorphic pair with a submetacentric and an acrocentric homologue in the autosomal complement (FNa=69). The X chromosome was submetacentric and the Y chromosome medium-sized subtelocentric (FN=73). Distinct dark centromeric C-bands were observed on most of the biarmed and three pairs of the acrocentric autosomes. The NORs were detected on short arms of three subtelocentric pairs and one acrocentric pair of autosomes. The diploid number of chromosomes and the karyotype characteristics observed are obviously unique among hitherto studied populations of blind mole rats and the complement can be evaluated as a new chromosome race of Nannospalax xanthodon. The distribution ranges of individual chromosome races of the species recorded in Eastern Anatolia are revised and possible interracial hybridization is discussed in respect of the finding of a new race.     

Chromosome numbers, sex determining systems, and patterns of the C-heterochromatin distribution in 13 species of lace bugs (Heteroptera, Tingidae).

The karyotypes, sex chromosome systems, and male meiotic patterns in 13 species belonging to 10 genera of the family Tingidae were studied. Data on eleven species, one subgenus, and 5 genera are presented for the first time, and the chromosome formula of Acalypta parvula is revised. Karyotypes of all species included six pairs of autosomes. Most of the species displayed an XY sex chromosome system, in four species, belonging to genera of Acalypta and Kalama, the X0 system was found. Male meiosis is chiasmatic for autosomes. Sex chromosomes are achiasmatic and undergo pre-reductional meiosis. Using C-banding technique, for the first time constitutive heterochromatin was localized on chromosomes in all the species studied. The heterochromatin was found either in telomeres or in some species in interstitial locations, evidencing that a quite substantial redistribution of chromosome material within chromosomes might occur without fragmentations or fusions. In two species, a supernumerary (B) chromosome was found. In addition, the male reproductive system of four species was examined and the number of testicular follicles was determined as two per testis.     

Karyotypes of two rare rodents, Hapalomys delacouri and Typhlomys cinereus (Mammalia, Rodentia), from Vietnam

Karyotypes of Hapalomys delacouri (Rodentia, Muridae) and Typhlomys cinereus (Rodentia, Platacanthomyidae) from Vietnam are described for the first time. The diploid karyotype of Hapalomys delacouri is 38 (NFa=48), consisting of six pairs of bi-armed and 12 pairs of acrocentric autosomes decreasing in size; plus a large metacentric X chromosome and Y chromosome, also metacentric, that is equal in size to the largest pair of acrocentric autosomes. The newly described karyotype differs significantly from that reported for Hapalomys delacouri from northern Thailand. The latter record very likely represents a different species of Hapalomys, possibly the taxon Hapalomys pasquieri described from north-central Laos.The diploid karyotype of Typhlomys cinereus is 38 (NF=48), consisting of five pairs of meta- to submetacentric and 14 pairs of acrocentric chromosomes varying in size from large to small; sex chromosomes were not defined.     

Description of the karyotype of Rhagomys rufescens Thomas, 1886 (Rodentia, Sigmodontinae) from Southern Brazil Atlantic forest

Rhagomys rufescens (Rodentia: Sigmodontinae) is an endemic species of the Atlantic forest from Southern and Southeastern Brazil. Some authors consider Rhagomys as part of the tribe Thomasomyini; but its phylogenetic relationships remain unclear. Chromosomal studies on eight specimens of Rhagomys rufescens revealed a diploid number of 2n = 36 and a number of autosome arms FN = 50. GTG, CBG and Ag-NOR banding and CMA(3) /DAPI staining were performed on metaphase chromosomes. Eight biarmed and nine acrocentric pairs were found in the karyotype of this species. The X and Y chromosomes were both acrocentric. Most of the autosomes and the sex chromosomes showed positive C-bands in the pericentromeric region. The X chromosome showed an additional heterochromatic block in the proximal region of the long arm. Nucleolus organizer regions (NORs) were located in the pericentromeric region of three biarmed autosomes (pairs 4, 6 and 8) and in the telomeric region of the short arm of three acrocentrics (pairs 10, 12 and 17). CMA (3) /DAPI staining produced fluorescent signals in many autosomes, especially in pairs 4, 6, and 8. This study presents cytogenetic data of Rhagomys rufescens for the first time.