昆虫病原线虫与其共生细菌共生关系的研究进展

昆虫病原斯氏和异小杆线虫与共生细菌的共生关系是这类线虫作为害虫生物防治因子的基础。从线虫共生细菌的信息、营养、抗菌和病原作用,以及线虫对共生细菌的保护和媒介作用综述昆虫病原线虫与其共生细菌的共生关系;描述这一共生关系的影响因子;同时,讨论了未来的研究方向和应用前景。     

中华卵索线虫感染棉铃虫后脂肪体结构的变化

采用组织超薄切片技术,电镜下观察研究昆虫棉铃虫Helicoverpa armigera Hǖbner脂肪体细胞的超微结构,结果表明。在中华卵索线虫Ovomermis sinensisChen感染棉铃虫后的不同寄生时期内,宿主脂肪体细胞内的线粒体、内质网、脂肪球和细胞核等细胞器在形态和结构上均有较大的病理变化,这些病理变化,与这一时期中华卵索线虫的生长发育和寄生生活等特点密切相关。     

刺果甘草中黄酮类化合物的提取与分析

With three different methods, the total flavonoids from the roots of cultivated Gtycyrrhiza pallidiflora Maxim. were determined and compared by ultraviolet-visible spectrophotometry. The results showed that the extract yield of total flavonoids in crude extracts was 4.54% by direct determination method, 4.27% by AI（ NO3）3 colorimetry method and 2.09% by AlCl3 colorimetry method. The content of total flavonoids in roots of cultivated G. pallidiflora was only 0.05%. The cultivated G. pallidiflora in Lanzhou is not unfit for the medicine source of flavonoids.     

Genetic Diversity of Soybean and the Establishment of a Core Collection Focused on Resistance to Soybean Cyst Nematode

Soybean cyst nematode （SCN; Heterodera glycines） Is one of the most Important pests affecting soybean production. The best method of control of SCN is through the development of resistant cultlvars. However, limited progress has been made in soybean breeding In China because most modern cultlvars have no resistance to SCN. The distribution and phenotype of 432 immune or highly resistant Chinese accessions were surveyed and a primary core collection was selected as a representative sample for further analyses. Using evenly distributed simple sequence repeat markers, five selection methods were applied to the primary core collection and the optimal method was chosen to establish a core collection, which consisted of 28 accessions. These encompassed 70.8% of the ailelic variation present in the overall resistant collection. The 28 accessions differed from the reference resistant accessions at the genomlc level, Indicating that Chinese resistant accessions are distinct from known resistant accessions. This applied core collection provides a rational framework for undertaking diversity surveys, using genetic variation for the investigation of complex traits and for the discovery of novel traits.     

Resolution of phylogenetic relationships of the major subfamilies of the Delphacidae （Homoptera： Fulgoroidea） using the mitochondrial ribosomal DNA

Delphacid relationships from the genus level to the subfamily have been completely resolved （among those taxa examined） using sequence data from the 3＇ end of the 12S gene. Monophyly of the non-asiracine subfamilies was strongly supported and the asiracine Ugyops was placed in the most basal position of the tree. Support levels for monophyly of the Delphacini increased after weighting transversions more heavily than transitions and after removing the cixiid outgroup from the dataset. Among the Delphacini, Conomelus and Megamelus were more closely related to each other than either was to Chloriona. These results are in agreement with the tree based on morphological characters. However, in contrast to morphological data our results strongly supported a sister group relationship between the Stenocraninae and the Kelisiinae. Although the 12S gene fragment gave some information about the species relationships within Chloriona, neither this fragment nor the 5＇ end of the 16S gene appear to be very useful for this level. Molecular evolutionary patterns provided evidence that there has been a shift in base composition from T to A during the early evolution of the non-Asiracinae. The non-Asiracinae also had comparatively fast substitution rates and these two observations are possibly correlated. In the ‘ modem＇ delphacid Chloriona, the AT content was comparatively low in regions free of constraints but this was not the case for ‘ non-modem＇ delphacids. The tRNA for valine has been translocated elsewhere, probably before the Delphacidae and Cixiidae diverged from each other.     

Demographic parameters of cotton aphid, Aphis gossypii Glover （Homoptera： Aphididae） on five cotton cultivars

Life table parameters of the cotton aphid, Aphis gossypii Glover, were estimated on five cotton cultivars （‘ Sealand＇ ,‘Siokra＇ ,＇ Vararnin＇ ,‘ Bakhtegan＇ and ‘ Sahel＇ ）. Demographic parameters of the cotton aphid were assessed at 27.5 ± 1 ℃, 65% ＋ 10% RH and a photoperiod of 14：10 （L： D）h. The shortest developmental time for the nymphal stages was 5.5 days on ‘Siokra＇ and the longest was 6.1 days on‘ Sealand＇. The highest offspring per female was 29.6 on ‘Sahel＇ and the lowest was 15.3 on ‘Sealand＇. The rm values varied from 0.272 on ‘Sealand＇ to 0.382 （day^-1） on ‘Varamin＇. Jackknife estimates of the A. gossypii parameters on these cultivars indicated the greatest developmental rate and fecundity on ‘ Varamin＇ and the poorest on ‘ Sealand＇ cultivar.     

谁会怜悯一只蚂蚁

蚂蚁阿良是一只拟黑多刺蚁,在蚂蚁的世界里,他的种族算是人高马大,而且蚁丁兴旺,是很成功的家族。阿良小时候住在地底温暖安全的家里,受到兄长们无微不至的照料,现在他已经成年,长得高大英俊,和其他兄弟姐妹们一样拥有他的家族所有的传统美德:勤劳、勇敢和虔诚——就是对蚁后——他的家族的母亲、至高无上的女神的绝对忠诚。根据与生俱来的分工,他成为一只工蚁,他每天辛勤而热诚地投入工作,只为了惟一的一个信仰:把最好的奉献给他的女神。     

小麦-黑麦代换系5A/5R与6A/6R杂交诱导同祖染色体配对与易位的研究

利用两个小麦-黑麦异源双代换系DS 5A/5R与DS 6A/6R杂交,探讨同祖染色体配对的可能性与创制小麦黑麦异源易位系.在方法上对杂种F1的减数分裂行为进行研究,观察5R与5A、6R与6A配对频率,探讨同祖染色体配对规律.实验结果看到杂交F1减数分裂中有22.91%的花粉母细胞有小麦染色体(ABD组)与黑麦染色体(R组)发生同祖配对.在F2及以后世代,通过染色体C分带、原位杂交检测,选择小麦-黑麦易位系.在F2代的45株中检测到9株有易位,易位频率为20%,是目前小麦-黑麦染色体易位频率最高的.染色体易位有的来源于同祖配对的交换,有的来源于单价体错分裂或断裂的重建.     

重组线虫抗凝肽在毕赤酵母中的表达

目的：获得具有抗凝活性的重组线虫抗凝肽（NAP）蛋白, 为新型抗凝药物的开发奠定基础。方法：将pPIC3.5K-rNAP质粒转化毕赤酵母菌株GS115,筛选出阳性菌株后,用甲醇诱导表达。收集酵母培养上清,用SDS-PAGE和Western blot分析表达产物,通过测定PT(血浆凝血酶原时间)、INR（血浆凝血酶原国际标准化比率）和APTT（活化部分凝血活酶时间）来验证其生物学活性。结果：获得了稳定表达NAP的重组酵母菌株。重组NAP被分泌表达,其分子量比预计分子量（8.7KD）稍大,约为10KD左右,可能与糖基化有关。体外活性检测证实其有较强的抗凝活性。结论：在毕赤酵母中成功表达了具有生物学活性的重组线虫抗凝肽,可用于新型抗凝药物的开发。     

梅根际丛枝菌根真菌五个中国新记录种

5种丛枝菌根真菌微刺球囊霉Glomus spinuliferum、大型无梗囊霉Acaulospora colossica、单氏内生囊霉Intraspora schenckii、巴西类球囊霉Paraglomus brasilianum和双疣盾巨孢囊霉Scutellospora dipapillosa是从梅Prunus mumeSieb.etZucc.的根围土壤中分离的中国新记录种。本文对他们的形态特征进行重新描述和图解。这5个种的标本贮藏在中国科学院微生物研究所菌物标本馆(HMAS)中。