Chromosomal assignments of 23 biochemical loci of the rat by using rat x mouse somatic cell hybrids

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.     

不同寄主植物对云南紫胶虫自然种群的影响

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.     

大白菜相对于结球甘蓝连锁群特异SSR标记的筛选

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。     

Nymph and adult biology of Dichelops melacanthus (Dallas) (Heteroptera: Pentatomidae) feeding on cultivated and non-cultivated host plants

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.     

Patterns of species diversity on an oceanic versus a continental island mountain: a hypothesis on species diversification1

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.     

Feeding, oviposition and survival of Liriomyza trifolii (Diptera: Agromyzidae) on Bt and non-Bt cottons

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.     

The antitumor action of seminal ribonuclease tested with the plasmacytoma spleen colonization assay

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.     

Transdifferentiation of "lentoid" structures in cultures derived from pigmented epithelium was inhibited by collagen.

Cells from pigmented retina of 8- to 9-day-old chick embryos were cultured under two different conditions: on noncoated (NS) or collagen-coated (CS) substrates. Although cells on CS seemed to start dividing 2 to 3 days earlier than those on NS, their early growth rates were basically similar. Cells on CS stopped growing after attaining confluency and formed a monolayer, while cells on NS continued to grow after confluency and overlapped each other. In early growth phase, cells on both substrates became depigmented. Cells became repigmented earlier on CS than on NS. The average melanin content of cells in confluent cultures on CS was two to three times higher than that of cells on NS. By Day 30 “lentoid bodies” were formed only in cultures on NS. Immunoelectrophoretic tests showed the presence of all crystallins (α-, β-, and δ) in cultures on NS but not in cultures on CS. It is concluded that a collagen substrate inhibits “transdifferentiation” of pigmented retinal cells into lens during cell culture.     

酸沉降对森林生态系统影响的研究现状及展望

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。     

New species of Laboulbenia from Ecuador, with evidence for host switch in the Laboulbeniales

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.     

Rhodnius prolixus vitellogenesis: Dependence upon the blood source

The haemolymph-protein patterns of a Rhodnius prolixus colony, fed on human blood and of a colony fed on sheep blood, were compared by SDS-PAGE analysis. The vitellogenin-polypeptide patterns of larvae and females of both colonies were similar. However, males of the human-blood-fed colony had levels of circulating vitellogenin comparable to those of females, while males of the colony fed on sheep blood had only residual vitellogenin levels. The effect of human blood on different instars of a colony fed on sheep blood was examined. Autogeny occurs in the colony fed on human blood but not on that fed on sheep blood. When 5th-instar females from the sheep-blood-fed colony were fed on human blood, the phenomenon of autogeny was not displayed after moulting to the adult stage. Fourth-instar larvae from the colony fed on sheep blood however showed autogeny in the adult stage when fed on human blood from the 4th-instar on or in this stage only. Furthermore, first-cycle oviposition and the percentage moulting to the adult stage were increased in these groups.     

取食不同品种棉花的棉蚜对龟纹瓢虫功能反应的影响

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。     

Effect of host-plant manipulation by a gall-inducing insect on abundance of herbivores on chestnut trees

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.     

红树林湿地恢复技术的研究进展

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。     

Habitat associations of California ground squirrels and Botta's pocket gophers on levees in California

Vegetation management on levees, especially removal of trees and shrubs, might affect burrowing mammals that are considered threats to levee integrity. We evaluated habitat associations of California ground squirrels (Otospermophilus beecheyi) and Botta's pocket gophers (Thomomys bottae) on levees in the Sacramento Valley to assess the effects of levee vegetation management on these species. Using burrows as an indirect measure of mammal presence, we found that the presence of trees had a negative effect on the occurrence and abundance of ground squirrels on levees, and on the location of their burrowing activities on the levee slope, potentially because visual occlusion caused by tall woody vegetation impedes detection of predators. Similarly, trees had a negative effect on the abundance of pocket gophers on levees and on the location of their burrowing activities on the levee slope, probably because of the effect of tree cover on food availability. The conversion of woodland habitats to grasslands on levees most likely will result in increased occurrence, abundance, or both of ground squirrels and pocket gophers, and thereby increase the potential threat that their burrowing activities pose to levee integrity. © 2012 The Wildlife Society.     

湖北江汉稻区优质香稻上二化螟的为害特性

研究了二化螟Chilo suppressalis(Walker)对优质香稻鄂香1号和武香988及优质常规中稻鄂中5号的田间为害特性。结果显示,1代二化螟危害造成的枯心苗数优质香稻略低于优质常规中稻。2代二化螟危害造成的枯孕穗和白穗优质香稻鄂香1号低于常规中稻,平均每15丛7.91株。田间剥查发现优质香稻中4~5龄2代二化螟所占百分比高于常规中稻,武香988中2代二化螟蛹所占比例高于常规中稻,达46.51%。3代二化螟量优质香稻低于常规中稻。结果说明香稻受二化螟的危害集中在2代,因而香稻二化螟的防治应注意消灭1代老熟幼虫和2代幼虫。     

Predation risk and the evolutionary ecology of reproductive behaviour

A large literature exists on the effects of predation risk on foraging and survival-related behaviours. In contrast, with some notable exceptions, relatively few theoretical or experimental studies have examined the effects of predation risk on reproductive behaviours. Existing literature on risk and reproductive behaviour and suggestion directions for future study are reviewed. In particular: (1) effects on predation risk on mating behaviour; (2) the influence of spatial patchiness on interactions between risk and reproductive behaviour; (3) the potential influence of multi-species interactions on the effects of predation risk on mating dynamics; (4) the importance of looking at sets of inter-related antipredator traits; and (5) some effects of predation risk on prey population patterns due to changes in prey reproductive behaviour are discussed. To illustrate various points examples involving fish and other aquatic organisms are used.     

梨小食心虫的产卵选择性

为了准确掌握梨小食心虫的产卵特性,研究模拟室外条件下该虫在不同寄主果树的叶片、桃枝不同部位及不同品种桃果上的产卵偏好.结果表明: 梨小食心虫成虫对7种寄主果树叶片的产卵偏好由高至低依次为:桃＞樱桃＞苹果＞李＞梨＞海棠＞杏.在桃树叶片上的产卵量占总产卵量的33.5%,平均单叶卵量达8.3粒;虫卵在不同寄主叶片正、反两面的分布有所差异,苹果和海棠叶片正面卵量多于背面,桃、李、梨、杏叶背面卵量多于正面,桃叶背面卵量是正面的3.3倍,樱桃叶两面卵量差异不明显;该虫在桃枝上产卵部位选择顺序为:叶片＞托叶＞叶柄＞枝条,叶片是其主要产卵部位,占总产卵量的88.7%;梨小食心虫在桃枝上主要选择靠近顶端未展叶的前10片桃叶背面产卵,前10叶卵量占总产卵量的725%,其中第3片叶上产卵最多,占9.3%;第25叶以后仅占总产卵量的1.1%;在不同类型桃果上的产卵偏好次序为:油桃＞蟠桃＞毛桃;绒毛疏密及其特点是影响梨小食心虫在寄主果树叶片和果实上产卵选择的首要因素.     

梨小食心虫的产卵选择性

为了准确掌握梨小食心虫的产卵特性,研究模拟室外条件下该虫在不同寄主果树的叶片、桃枝不同部位及不同品种桃果上的产卵偏好.结果表明: 梨小食心虫成虫对7种寄主果树叶片的产卵偏好由高至低依次为:桃＞樱桃＞苹果＞李＞梨＞海棠＞杏.在桃树叶片上的产卵量占总产卵量的33.5%,平均单叶卵量达8.3粒;虫卵在不同寄主叶片正、反两面的分布有所差异,苹果和海棠叶片正面卵量多于背面,桃、李、梨、杏叶背面卵量多于正面,桃叶背面卵量是正面的3.3倍,樱桃叶两面卵量差异不明显;该虫在桃枝上产卵部位选择顺序为:叶片＞托叶＞叶柄＞枝条,叶片是其主要产卵部位,占总产卵量的88.7%;梨小食心虫在桃枝上主要选择靠近顶端未展叶的前10片桃叶背面产卵,前10叶卵量占总产卵量的725%,其中第3片叶上产卵最多,占9.3%;第25叶以后仅占总产卵量的1.1%;在不同类型桃果上的产卵偏好次序为:油桃＞蟠桃＞毛桃;绒毛疏密及其特点是影响梨小食心虫在寄主果树叶片和果实上产卵选择的首要因素.     

Reconstituted basement-membrane matrix modulates fibroblast activities in vitro

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.