查询词典 populations

Results show that the insect community structure in the Bt fields differed sharply from that in the CV fields. The populations of the Lepidopterous pests, such as cotton bollworm, corn borer, diamond bollworm and cotton leaf caterpillar, decreased significantly in the BT fields, while the populations of non-target pests with piercing-sucking mouthparts, such as leaf bugs, cotton spider mites, cotton aphids and whiteflies, increased obviously. Much more predators, such as spiders and ladybirds, and much less parasitiods of Helicoverpa armigera were observed in the BT fields.

结果表明，与常规棉田相比，Bt棉田棉铃虫、玉米螟、金刚钻、棉小造桥虫等鳞翅目害虫种群数量显著降低，而盲蝽象、红蜘蛛、棉蚜、烟粉虱等非靶标刺吸式害虫种群数量显著增加；蜘蛛、瓢虫等捕食性天敌种群数量显著增加，而棉铃虫的寄生性天敌种群数量则显著下降。

On the sampling scale of 20 m, the road effects on different dominant populations were demonstrated in their spatial distribution patterns. There were significant increases in the biomass of Schima superba population, the number of individuals and biomass of Litsea rotundifolia population (P.05) along the parallel direction to road, respectively, while those of other populations had no significant difference.

优势物种20 m取样尺度的空间分布格局反映了不同种群对旅游路径干扰的不同响应，其中荷木的生物量、豺皮樟的个体数和生物量在远离旅游路径方向上均呈显著增长趋势，其他物种的个体数和生物量变化不显著。

Most species' populations were decline in last fifty years, especially since the last 1980's, the populations such as Alpine Musk Deer, Przewalski's Gazelle and Red Deer etc. declined dramatically;(5) Desertification and grassland degredation are obviously affected by climate change on macrographic scale, anthropogenic activities is an important driving role for desertification, herbing, land-development and urbanization have majority impact to biodiversity spatial pattern and its loss.

祁连山区动物资源组成成分复杂，总体上缺乏自身特有的种类，哺乳动物区系特点不很突出，既包含了东部黄土高原和东南湿润地区的兽类成分，又不乏青藏高原特有种类，同时还与新疆的动物区系有一定的联系，近50年来尤其自上个世纪80年代以来，多数种类的种群数量呈下降趋势，其中以马麝、普氏原羚、马鹿等物种的数量下降的最为显著；（5）土地沙漠化和草地退化在宏观尺度上受气候因素影响较大，人类活动对荒漠化的加速发展起着重要的驱动作用，尤其是放牧、土地开发和城镇化建设对生物多样性资源减少以及空间分布格局影响较大。

TO examine whether there is SD system in natural populations of Drosophila melanogaster in China, we surveyed a few populations of D.

在此基础之上，进一步从北京北安河地区的黑腹果蝇群体中筛选得到一个SD果蝇品系。

Furthermore, out of 497 fAFLP markers, 80 special bands were found to be able to distinguish the four groups from each other and may be applied for germplasm characterization and molecular assistant classification of Meretrix clam.4 Molecular classification of two species of Meretrix clam based on fAFLP and ITS sequences4.1 The results of fAFLP maker analysis of S, G and W showed that each group had their own specific loci among which there were 53 special loci in W group, much more than those of S group (14) and G group (21). Among the 53 loci, nine were all dominant loci. These unique loci could be taken as molecular markers to distinguish W from other groups. The genetic similarity indexes and distance matrix between S and G groups were 0.9585 and 0.0424 respectively, but the genetic similarity indexes and distance matrix between W group and S or G group was 0.7939 or 0.7941, and 0.2308 or 0.2305 respectively. The results revealed that significant difference existed between W and S or G groups in molecular genetic structure. The phylogenetic trees by the methods of UPGMA and NJ also indicated that S and G populations were very closely related, while W population was a relatively independent cluster, lying beyond the species which S and G belong to.4.2 The internal transcribed spacer region of the rDNA from S group, G group and W group were PCR amplified and sequenced. The results showed that the size of ITS ranged between 1266-1269bp in W group, while those in G and S groups were 1614bp and 1520bp respectively. The GC content ranged 62.32-62.62% in W group while it was 61.77% in G group. The genetic distances between three populations of W group were 0.001～0.003, but it was 0.110 or 0.147 respectively between W group and G group or S group. Phylogenetic trees by NJ method also showed that G group was very closely related to S group, while W group was a relatively independent cluster.

在457个总扩增位点中找出了53个W的特有位点，远多于S群体(14)和G(21)群体，而且在53个特有位点中有9个出现频率为100%的位点，这些位点可以作为区分其它2个群体的特征性标记；S– G群体特有的位点有112个，其中有4个位点出现频率为100%，可作为S– G群体区别于W群体的特征性标记。S群体和G群体间的遗传相似性系数为0.9585，遗传距离只有0.0424，在NJ和UPGMA法构建的亲缘关系的树状图上均首先聚在一起，说明二者的亲缘关系很近，应属于种内群体间的关系；而W与S和G的遗传相似性系数均较小(0.7939和0.7941)，相对遗传距离很大而且十分相近(0.2308和0.2305)，在亲缘关系树状图上单独分出一支，也表明W与S和G群体间的亲缘关系较远。4.2 ITS序列比较分析通过对白壳文蛤、山东文蛤和广西文蛤的ITS序列扩增电泳、PCR-RFLP分析和ITS序列分析发现，W的ITS序列长度在1266-1269 bp，而S和与G的ITS序列总长度分别为1520 bp和1614 bp；从ITS1和ITS2长度来看，W分别为739-741 bp和316-317 bp，S为895 bp和414 bp，G为987 bp和416 bp；而从ITS碱基组成来看，W的GC含量在62.32-62.62%之间，而G群体为61.77%。W的3个壳色不同群体间的遗传距离仅0.001、0.002和0.003，S与G群体间的遗传距离是0.010，说明W群体内变异很小，而S与G群体间已出现明显的遗传分化，但还均属于种内群体间的遗传变异；而W与G和S的遗传距离分别达到0.110、0.147，两个类群差异显著，已远超出种内群体间的遗传变异。

We conducted removal experiments in open populations of Microtus ochrogaster and M.pennsylvanicus to test for potential interspecific competition between coexisting populations in bluegrass and tallgrass prairie in east-central IL, USA.

我们对美国伊利诺斯州中东部的蓝草和高草牧场共生的橙腹田鼠和草原田鼠开放种群进行了去除实验，以测定潜在的种间竞争。

The phenotypic mean values for the three populations and the midparental heterosis values for the two backcross populations were used for quantitative trait locus mapping and analysis, the genetic basis and correlations betweent the traits were analysed.

将三个群体的表型值和两个回交群体的中亲优势值进行了数量性状位点(quantitative trait locus，QTL)的检测及效应分析，初步分析了持绿性、充实度和产量等农艺性状的遗传基础和各性状间的相关关系。

When applying monose that was easily utilized by HPB as substrate, the competition for common feed among different populations restrain their exertion of co-metabolism. While applying complex organic compounds including greese, ester and protein as substrate, the co-metabolism among different populations could be exerted and therefore the hydrogen-producing ability of HPB was enhanced via their cooperation.

以单糖为底物时，由于菌种间的竞争作用，抑制了高效HPFB的产氢能力，混合菌种协同作用不能有效地发挥；以复杂的有机物为底物时，菌种间的共代谢协同作用是可能积极地发挥，进而提高高效HPB的产氢能力。

Furthermore, it was found that some microsatellite loci of the three breeds deviated from Hardy-Weinberg equilibrium, where the majority of the variance in the Oncorhynchus mykiss was within populations (80.7%), and small proportion was among populations (19.3%).

在Hardy-Weinberg平衡条件下，进行了P检验，发现3个群体均有位点发生了显著偏离；对3个群体进行了Fst值计算，表明群体间存在着一定程度的遗传分化，但遗传变异绝大部分存在于品种内。

With the seeds from nine natural Cyclocarya paliurus populations as test materials, their phenotypic traits, including 1000-seed weight, seed size, seed diameter, seed thickness, and seed diameter/thickness ratio, were investigated, and the phenotypic diversity among and within the populations were studied by the methods of ANOVA analysis, hierarchical cluster analysis, and correlation analysis.

以青钱柳分布区内的9个天然群体种子为试材，对种子千粒重、体积、直径、厚度和径厚比5个表型性状进行了系统的比较分析，采用方差分析、相关分析及聚类分析等方法对群体间和群体内的表型多样性进行探讨。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。