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1.
以9个大白菜品种和10个结球甘蓝品种为试材,对位于芸薹属A基因组10个连锁群的207对SSR引物进行PCR筛选,共筛选出33个大白菜相对于结球甘蓝的特异SSR标记,涉及了大白菜的10个连锁群,其中位于A1连锁群3对,A2连锁群4对,A3连锁群5对,A4连锁群2对,A5连锁群3对,A6连锁群4对,A7连锁群2对,A8连锁群1对,A9连锁群2对,A10连锁群7对。为进一步利用SSR标记鉴定结球甘蓝—大白菜异附加系奠定了基础。  相似文献   

2.
The biology of the pentatomid Dichelops melacanthus (Dallas) feeding on cultivated and non-cultivated plants was studied in the laboratory. Nymph mortality varied from approximately 60 on corn (seed mature) to 77% on wheat (ear immature); no nymphs survived on seedlings of corn or wheat. Nymph developmental time on soybean, corn or wheat (seed, pod or ear) varied from 25.5 to 32.8 days. Body weight at adult emergence was similar and greater on most foods than on wheat ear. Nymphs fed preferentially on soybean (pod immature). On non-cultivated hosts, nymphs showed high mortality (73%) on crotalaria (pod immature); on tropical spiderwort (stem) all nymphs died. Nymphs took longer time to develop on crotalaria and/or on spiderwort than on soybean. Body weight at adult emergence did not differ on crotalaria or soybean. Survivorship decreased with time on most foods, with approximately 50% of adults alive at day 30. On corn and wheat seedlings approximately 80% of adults were dead on day 20. Adult longevity ranged 31-43 days, except on corn and wheat seedlings < 15 days. Females % ovipositing peaked ( approximately 76%) on soybean (pod or seed immature), and was minimum ( approximately 9%) on wheat ear (immature); no females reproduced on seedlings of corn or wheat. Preoviposition period was shorter ( approximately 12 days) on soybean (immature pod or seed) and longer ( approximately 37 days) on wheat (ear immature). Fecundity was similar and higher on all foods than on wheat (ear immature). Body weigh gain occurred on all foods, but on corn and wheat seedlings. Adults fed preferably on soybean (pod immature and seed mature); wheat (seedling) was the least preferred food.  相似文献   

3.
不同寄主植物对云南紫胶虫自然种群的影响   总被引:7,自引:1,他引:6  
研究了云南紫胶虫(Kerria yunnanensis)在聚果榕、南岭黄檀、钝叶黄檀和偏叶榕上的发育、存活和繁殖情况.结果表明:在自然条件下,云南紫胶虫在钝叶黄檀上的种群初始密度最高,为181.17头·cm-2,聚果榕上最低,为145.27头·cm-2;雄虫占的比例以在南岭黄檀上最少,为0.19,偏叶榕和聚果榕上最多,为0.24;从幼虫到成虫的累积死亡率,南岭黄檀上最高,为90.03%,偏叶榕上最低,为87.05%;完成世代时间以在南岭黄檀上最长,为156 d,聚果榕上最短,为140 d;平均怀卵量以在南岭黄檀上最高,为536粒,聚果榕上最低,为345.86粒;虫体质量以在南岭黄檀上最大,为12.62 mg,偏叶榕上最小,为9.03 mg;世代净增值率以在南岭黄檀上最高,为48.51,聚果榕上最小,为32.79.综合比较4种不同寄主植物,南岭黄檀是云南紫胶虫夏季世代种群生长发育和繁殖最适宜的寄主.  相似文献   

4.
Rossi W 《Mycologia》2011,103(1):184-194
Ten new species of Laboulbenia from Ecuador are described. These are L. barraganii, parasitic on Platamops sp. (Salpingidae); L. biformis, parasitic on Diploharpus rossii Moret (Carabidae); L. davidsonii, parasitic on Odontocheila spp. (Carabidae); L. gregaria, parasitic on Philonthus sp. (Staphylinidae); L. micrandra, parasitic on Lobrathium sp. (Staphylinidae); L. mycotreti, parasitic on Mycotretus spp. (Erotylidae); L. opima, parasitic on Chrysodinopsis sp. (Chrysomelidae); L. otongaensis, parasitic on Diploharpus iridescens Moret (Carabidae); L. tapiae, parasitic on Priocera sp. (Cleridae); and L. trogacti, parasitic on Trogactus sp. (Staphylinidae). Laboulbenia barraganii is the first of the Laboulbeniales to be reported on beetles of the family Salpingidae. L. biformis displays a moderate dimorphism associated with the position on the host insect. L. davidsonii, which is very different from the other species of Laboulbenia reported so far on the Cicindelinae but similar to a group of species parasitic on Galerita spp., provides evidence for the occurrence of host switch in Laboulbeniales.  相似文献   

5.
本文以GK12、33B和SGK3213种转基因棉和对应的3种常规棉泗棉3号、33及石远321为材料,通过室内测定,研究了取食转基因棉的棉蚜却h/sgossypiiGlover对龟纹瓢虫Propylaea japonica Thunberg1—4龄幼虫功能反应的影响。结果指出,龟纹瓢虫对来自转基因棉田蚜虫的捕食量大多高于常规棉田,且捕食量随猎物密度的增加而增大。在1、2龄幼虫期,龟纹瓢虫取食转双价基因棉田蚜虫的数量多高于取食转单价基因棉田的蚜虫数量,但是在3、4龄幼虫时,龟纹瓢虫取食转双价棉田蚜虫的数量多低于取食转单价棉田的蚜虫数量。龟纹瓢虫对来自转基因棉田棉蚜的捕食功能反应符合HollingII型。龟纹瓢虫1龄幼虫取食GK12和SGK3212个转基因棉田蚜虫的最大日捕食量大于对照,处理时间短于对照;龟纹瓢虫P.japonica2、3龄幼虫取食33B和SGK3212个转基因棉田蚜虫A.gossypii的日最大捕食量大于对照,处理时间短于对照;4龄时取食转基因棉田蚜虫的数量都大于对照,处理时间均短于对照,其中取食转双价基因棉SGK321棉田蚜虫的日最大捕食量小于取食单伊棉田蚜虫的日最大捕食量。  相似文献   

6.
红树林湿地恢复技术的研究进展   总被引:11,自引:0,他引:11  
本文从红树林育苗造林技术、次生林改造技术和红树植物引种试种与种源选择的研究等方面试述红树林湿地恢复技术的研究进展,并针对我国的目前现状,提出今后亟待加强研究的如下几个方面:加强红树植物引种扩种,恢复植被,提高红树林生态工程质量的原理研究;监测外来引进种对我国红树林湿地的生态影响;研究半红树植物在沿海防护林体系工程建设中的作用;加强红树植物对潮汐水位适应能力的研究;开展红树人工林生态恢复过程中的综合定位观测等。  相似文献   

7.
The effects of Bt transgenic cottons (Bt-I expressing cry1Ac and Bt-II expressing cry1Ab and cry2Ab or cry1Ab and cry1Fa) and non-Bt cottons on feeding, oviposition and longevity of adults, and development and survival of Liriomyza trifolii larvae were studied under laboratory conditions; and infestation on four Bt and two non-Bt cotton traits were investigated under field conditions. Laboratory choice and no-choice tests showed that L. trifolii adults were capable of distinguishing between Bt cottons and non-Bt cottons. In a choice test on younger plants (4-5 leaves), the adults were found more often and made more feeding punctures (FP) on non-Bt cottons than on Bt cottons. On older plants (8-9 leaves), adults made the most FP on non-Bt cotton followed by those on Bt-II cottons and the least on Bt-I cotton. The females oviposited more eggs (6.7 eggs per leaf) on non-Bt cotton than on Bt-I (1.7 eggs per leaf) and Bt-II (0.8 eggs per leaf) cottons on younger plants and oviposited similar numbers of eggs (0.7-1.3 eggs per leaf) on non-Bt and Bt cottons on older plants. In a no-choice test, the females also fed more FP on non-Bt cottons than on Bt cottons on both younger and older plants. The females oviposited more eggs (15.6 eggs per leaf) on non-Bt cotton than on Bt-I (8.2 eggs per leaf) and Bt-II (6.5 eggs per leaf) cottons on younger plants and similar numbers of eggs (2.5-3.3 eggs per leaf) on non-Bt and Bt cottons on older plants. Larval and puparial survivals were not different among Bt and non-Bt cottons. The occurrence and damage of leafminers on cottons in the field showed that L. trifolii infested more plants and leaves and had more mines on non-Bt cotton than on Bt cottons.  相似文献   

8.
酸沉降对森林生态系统影响的研究现状及展望   总被引:14,自引:0,他引:14  
刘菊秀 《生态学杂志》2003,22(5):113-117
酸沉降影响下物质循环及其不平衡研究;酸沉降对土壤理化性质的影响;森林水化学方面的研究;酸沉降下重金属的活化研究;酸沉降对植物生长的影响研究;酸沉降和气候变化对森林的影响;模拟酸雨对土壤理化性质和植物生长的影响;酸沉降下土壤风化问题的研究;运用模型对酸化问题的研究;森林土壤人为和自然的酸化;酸沉降临界负荷的研究;酸沉降和其它污染物对植物的联合影响;酸化土壤恢复研究等方面介绍了酸沉降对森林生态系统影响的研究现状,并阐明了今后研究的方向及应该注意的问题。  相似文献   

9.
A panel of 18 rat x mouse somatic cell hybrid clones segregating individual rat chromosomes in different combinations was used to assign 23 biochemical loci to rat chromosomes. The chromosomal locations for these 23 loci were determined as follows: GOT1 on rat chromosome 1; HAGH on 2; ACP2, ADA, GANC, ITPA, and SORD on 3; LDHB on 4; PEPB on 7; GLB1 and HEXA on 8; IDH1 on 9; UMPH2 on 10; GUSB on 12; FH and PEPC on 13; PEPS on 14; ESD and NP on 15; DIA4 on 19; and PP on 20. In addition, ACP1 and GLO1 were reassigned to rat chromosomes 6 and 20, respectively. The chromosomal assignments of these loci extends the known syntenic homologies among rats, mice, and humans.  相似文献   

10.
Cellular growth and collagen biosynthesis were compared in dermal calf fibroblasts cultured on plastic or on a reconstituted basement membrane gel, termed matrigel. This matrix, extracted from Engelbreth-Holm-Swarm tumors, consists mainly of laminin, entactin, type IV collagen, and heparan sulfate proteoglycan. The multiplication rate of fibroblasts grown on matrigel was stimulated compared to that of monolayered cells cultured on plastic, and these cells formed multilayers after 4 days. Protein and collagen biosynthesis was reduced in fibroblasts cultured on matrigel. A higher proportion of the newly synthesized collagen (40%) was incorporated to the extracellular matrix in cultures grown on matrigel than in those grown on plastic (14%). Type III collagen was the preferential collagen type deposited on matrigel, and the ratio of type III:type I collagens secreted in the medium was also slightly higher in cultures grown on matrigel. Partially processed collagen was more abundant in fibroblasts grown on matrigel than in cells cultured on plastic. Finally, cells grown on matrigel exhibited a higher catabolic activity than cells grown on plastic. In this experimental model, the reconstituted basement-membrane matrix seems to influence the activities of fibroblasts significantly.  相似文献   

11.
We investigated plant-mediated effects of the stem gall wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae), on other herbivores on the chestnut tree Castanea crenata. In the early season, leaves emerged earlier and in greater numbers on galled shoots than on ungalled shoots. On galled shoots the leaf to shoot biomass ratio was lower and the leaves were physically different. In May and June the concentration of nitrogen in leaves was higher on galled shoots than on ungalled shoots. In July, the water content of leaves was lower on galled shoots. In May and June, the number of aphids, Myzocallis kuricola Matsumura (Homoptera: Aphidoidea), on leaves was higher on galled shoots than on ungalled shoots, but the opposite was true at the end of July. Laboratory experiments showed that aphid fecundity and body weight decrease were higher in May and June when aphids fed on leaves on a galled shoot than when they fed on those on ungalled shoots. In contrast, aphid performance in July was greater on ungalled leaves than on galled leaves. Our findings suggest that gall initiation in a chestnut tree affected aphid performance by affecting host plant quality.  相似文献   

12.
D. BAINES 《Ibis》1989,131(4):497-506
Data on the breeding success of Lapwings Vanellus vanellus on unimproved and improved grassland, with comparative data for arable land, were obtained from a study on 760 Lapwing clutches. The study was undertaken in the Eden Valley, Cumbria, and Teesdale, Co. Durham, between 1985 and 1987. First clutches were larger on unimproved grassland with a mean of 3.73 eggs compared to 3.61 eggs on improved grassland. In contrast, replacement clutches were larger on improved areas (3.90 eggs) than on unimproved (3.47 eggs). On average, 40% of eggs laid on unimproved pastures hatched compared to only 17% on improved pastures. No significant difference in hatching success was found between unimproved and improved meadows with 32% and 22% of eggs hatching, respectively. Overall, 73% of unsuccessful first clutches were replaced on unimproved pastures, whereas on meadows and improved pastures combined, only 32% were replaced. Survival of small chicks was highest on unimproved areas. Production on unimproved areas was sufficient to replace adult losses and so maintain numbers, whereas on improved land production was too low to maintain existing breeding densities. Hatching success on unimproved areas was similar for the four species of wader considered. On improved areas, Redshank hatching success was relatively high, with 54% of pairs producing chicks, compared to 35% for Lapwing and 23% for Curlew.  相似文献   

13.
鸟类群落研究进展   总被引:31,自引:3,他引:28  
崔鹏  邓文洪 《动物学杂志》2007,42(4):149-158
鸟类群落的研究一直是鸟类生态学研究的重要领域,研究内容主要集中在以下几个方面:群落的组成结构、集团结构、生态位与种间关系、动态与演替、群落与栖息地关系以及城市化对鸟类群落影响。群落的组成与结构、动态与演替以及群落与栖息地关系的研究是过去20年间的研究热点,但有关城市化对鸟类群落影响的研究还比较少。本文在总结国内外鸟类群落生态学研究的基础上,重点讨论了目前的研究热点和今后的发展趋势,以期促进我国鸟类群落生态学的研究。  相似文献   

14.
Abstract. The vegetation on a wet mountain slope on Haleakala (an oceanic island) is compared with that on Kinabalu (a continental island) to examine relationships between regional floristic richness and α- and β-diversities. The two mountains are similar in their constant tropical climate, generic and family-level floristic elements and geological age of the summit regions, but different in regional floristic richness (rich on Kinabalu vs. poor on Haleakala). α-diversity of canopy and subcanopy tree species was much higher on Kinabalu than in comparable zones on Haleakala. Average turnover rate of species (as logarithmic community similarity) on the slope was one order of magnitude greater on Kinabalu than on Haleakala (0.127 vs. 0.017 per 100 m alt.). While there were genera with wide altitudinal ranges on both mountains, a large proportion of the genera was differentiated into parapatric altitudinal congeners on Kinabalu. By contrast, most genera are altitudinally monotypic on Haleakala. The number of sympatric congeners per genus, and the frequency of multi-specific genera per plot were high on lower slopes but decreased with increasing altitude on Kinabalu, whereas the values were low across all altitudes on Haleakala. These patterns suggest that sympatric and parapatric species radiation was less on Haleakala than on Kinabalu. This may be related to Haleakala's initially poor and disharmonic flora.  相似文献   

15.
浙江海岛鸟兽地理生态学的初步研究   总被引:6,自引:1,他引:5  
对浙江洞头岛及舟山五岛的鸟兽调查表明,海岛动物的种数较相邻大陆为低,但种群密度却高于大陆,岛上的某些种类出现生态位扩展的现象。舟山五岛兽类的种数和岛屿面积呈正相关,其关系式为S=2.12A~(0.29),但种群密度随着岛屿面积的增大而下降。文中据此提出了保护和发展岛屿动物资源的某些措施。  相似文献   

16.
Yields of Bacterial Cells from Hydrocarbons   总被引:15,自引:13,他引:2       下载免费PDF全文
A strain of Nocardia and one of Pseudomonas, both isolated on pristane (2,6,10,14-tetramethylpentadecane), gave cell yields of approximately 100% on n-octadecane and pristane. Both organisms grew more rapidly on the n-octadecane than on the pristane. A mixed culture, isolated on 3-methylheptane, whose two components were identified as species of Pseudomonas and of Nocardia, gave approximately 100% cell yields and grew with generation times of about 5 hr on n-heptane, n-octane, and 2-methylheptane. The generation time on 3-methylheptane was 8.6 hr and the cell yield was only 79%. A strain of Pseudomonas isolated from naphthalene enrichments and one from phenanthrene enrichments both gave a cell yield of 50% on naphthalene. The phenanthrene isolate gave a cell yield of 40% on phenanthrene. A Nocardia species isolated on benzene gave a 79% cell yield on benzene. The generation times of the bacteria isolated on aromatic hydrocarbons were related to the solubility of the aromatic hydrocarbons on which they were grown; the more insoluble hydrocarbons gave slower growth.  相似文献   

17.
The diet choice of omnivores feeding on two adjacent trophic levels (either plants and herbivores or herbivores and predators) has been studied extensively. However, omnivores usually feed on more than two trophic levels, and this diet choice and its consequences for population dynamics have hardly been studied. We report how host-plant quality affects the diet choice of western flower thrips feeding on three trophic levels: plants (cucumber or sweet pepper), eggs of spider mites and eggs of a predatory mite that attacks spider mites. Spider mites feed on the same host plants as thrips and produce a web that hampers predator mobility. To assess the indirect effects of spider mites on predation by thrips, the thrips were offered spider-mite eggs and predatory-mite eggs on cucumber or sweet pepper leaf discs that were either clean, damaged by spider mites but without spider-mite web, or damaged and webbed. We show that, overall, thrips consumed more eggs on sweet pepper, a plant of low quality, than on cucumber, a high quality host plant. On damaged and webbed leaf discs (mimicking the natural situation), thrips killed more predator eggs than spider-mite eggs on sweet pepper, but they killed equal numbers of eggs of each species on cucumber. This is because web hampered predation on spider-mite eggs by thrips on sweet pepper, but not on cucumber, whereas it did not affect predation on predatory-mite eggs. We used the data obtained to parameterize a model of the local dynamics of this system. The model predicts that total predation by the omnivore has little effects on population dynamics, whereas differential attack of predator eggs and spider-mite eggs by the omnivore has large effects on the dynamics of both mite species on the two host plants.  相似文献   

18.
The antitumor action of bovine seminal ribonuclease was evaluated with a quantitative assay based on the production of tumor foci in the spleens of mice injected with plasmacytoma cells. The antitumor action depended on the integrity of the catalytic site, and on the dimeric structure of the enzyme. A working hypothesis is proposed, based on these results, and on previous results obtained studying the antitumor action of seminal RNAase in vitro on cell cultures. According to this hypothesis, the antitumor action is based on the ability of seminal RNAase to interact at specific receptor sites on the tumor cell membrane, as well as on its RNA degrading ability.  相似文献   

19.
Two new species of Leporinus are described from tributaries of the Rio Amazonas in Brazil. One species is known from the Jari and Tapajós River basins, and is identified on the basis of a gas bladder reduced in size, a dark midlateral stripe on the body, dark transverse bars on the dorsum, a subinferior mouth, three teeth on the premaxilla, four teeth on the dentary and 16 scale rows around the caudal peduncle. The second new species is known from the Tocantins, Xingu and Tapajós River basins, and is identified on the basis of three dark longitudinal stripes on the body, a subinferior mouth, three teeth on the premaxilla, four teeth on the dentary and 12 scale rows around the caudal peduncle. In addition, Leporinus striatus is redescribed based on type and additional specimens from the Río de La Plata, Amazonas, Orinoco, Atrato, Magdalena and Sinu River basins. Leporinus striatus is identified on the basis of four dark longitudinal stripes on the body, a subterminal mouth, three teeth on the premaxilla, four teeth on the dentary and 16 scale rows around the caudal peduncle.  相似文献   

20.
棉田亚洲玉米螟生物学的研究   总被引:1,自引:0,他引:1  
亚洲玉米螟为棉花上一种重要的钻蛀性害虫。该虫产卵于棉抹中下部主茎叶和果技叶上,但二、三代代次之间产卵部位有明显差抖。幼虫可为害棉株的嫩头、叶柄、蕾、花、铃、茎秆等多个器官,棉花同-器官上各龄幼虫之间的分布、以及同龄幼虫在棉花不同器官之间的分市.均存在显差异。1头幼虫一生破坏棉花器官的单位效二代为3.373个.三代为2.202个。二年的试验结果表明,田间二代亚洲玉米螟种群趋势指数差异大。三代幼虫越冬场所广泛。  相似文献   

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