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41.
红腹锦鸡(Chrysolophus pictus)和红腹角雉(Tragopan temmminckii)均为国家Ⅱ级重点保护鸟类。作为两种同域分布的物种,其生态位重叠程度及竞争机制尚不明确。为了探究上述问题我们从2012年7月至2014年11月,在陕西省佛坪国家级自然保护区的9条样线上布设52台红外相机对这两种雉类的集群现象、日活动节律、季节性活动规律和最适活动温区进行研究。研究结果表明:(1)红腹锦鸡和红腹角雉每年8月下旬开始集群,到第二年的3、4月份集群结束,冬季集群最为频繁,而夏季则分散在其各自活动区单独活动。(2)二者皆为昼行性鸟类,活动高峰均出现在清晨和傍晚,但时间生态位存在明显分化:红腹锦鸡有两个活动高峰,分别为7:00时和17:00时;红腹角雉活动高峰为6:00时、9:00时和18:00时。(3)对两种雉类活动频次的季节性差异分析发现,春季活动最频繁,其后依次是秋季、夏季和冬季。(4)红腹锦鸡和红腹角雉选择在接近当月平均气温的时间段出来活动,红腹锦鸡活动的温度范围在﹣4℃到19℃,红腹角雉的活动温度范围是﹣1℃到22℃;但不同季节间略有差异,两种雉类在秋冬季大多选择在高于当月平均气温的时间段出来活动,而在夏季的活动温度则要略低于当月平均气温。观测数据证实了两种雉雉类有通过错峰活动减少生态位重叠导致的竞争的现象,但并未见到二者间有明显的适应性温区分化。 相似文献
42.
Vegetable Indian mustard (Brassica juncea cv. “Green Wave”) plants that control Plutella xylostella (diamondback moth) (DBM) were produced by introduction of one or two Bacillus thuringiensis (Bt) genes. A cry1Ac Bt gene associated with the nptII gene for kanamycin selection or a cry1C Bt gene with the hpt gene for hygromycin selection was introduced individually through Agrobacterium-mediated transformation of seedling explants. A cry1C line was then transformed with the cry1Ac gene to produce pyramided cry1Ac + cry1C plants. Sixteen cry1C, five cry1Ac, and six cry1Ac + cry1C plants were produced. PCR and Southern analyses confirmed the presence of the cry1C, cry1Ac or pyramided cry1Ac + cry1C genes in the Indian mustard genome. ELISA analysis showed that production of Bt proteins varied greatly among individual
transgenic plants, ranging from undetectable to over 1,000 ng Bt/mg total soluble protein. The levels of the Bt proteins were
correlated with the effectiveness of control of diamondback moth (DBM) larvae. Insect bioassays indicated that both the cry1C and cry1Ac plants were toxic to susceptible DBM. The cry1C plants also controlled Cry1A-resistant DBM while cry1Ac plants controlled Cry1C-resistant DBM, and the pyramided cry1Ac + cry1C plants effectively controlled all three types of DBM. These Bt-transgenic plants could be used either for direct control
of DBM and other lepidopteran insect pests or for tests of “dead-end” trap crops as protection of high value non-transgenic
crucifer vegetables such as cabbage. 相似文献
43.
Two types of trap, the BT Trap and PCTM pitfall cone trap, were evaluated against the most widely used method of sampling and sieving for their ability to detect
low numbers of storage mites (Acarus siro, Tyrophagus longior and Lepidoglyphus destructor) in bulk oilseed rape, under UK maritime conditions. In addition, a synthetic lure (2-nonanone) was incorporated into the
two types of trap to assess whether its presence improved trapping performance. The BT traps and PC traps were significantly
more effective in detecting low numbers of mites of all species compared with sampling and sieving. The PC trap with synthetic
lure was the most effective method. As the PC trap is already widely used for monitoring insects in cereal bulks in the UK,
extending its application to include oilseed rape, and to detect mites, would be a logical and cost effective extension of
its use.
The British Crown's right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged. 相似文献
44.
M. Teimouri Jervekani H. Karimmojeni D.C. Brainard M. Jafari 《The Annals of applied biology》2016,169(1):46-52
Egyptian broomrape (Phelipanche aegyptiaca) is a parasitic weed causing major yield loss in many field and vegetable crops. Recent observations in Iran suggest that sesame (Sesamum indicum) may serve either as a trap crop or as a host for broomrape, depending on genotype. The central objective of this research was to identify sesame genotypes that could act either as potential trap crops, or sources of genetic material for development of broomrape resistant cultivars. Seeds of 11 Iranian sesame genotypes (Ardestan, Esfarayen, Oltan, Ahvaz, Borazjan, Darab‐14, Ferdous, Kalat, Naz Tak Shakhe, Varamin and Yekta) and 10 foreign genotypes (S16, S21, S23, S25, S4, S5, S6, S7, S8 and S9) were planted with broomrape seeds in pots. At the flowering stage of sesame, tubercle number and dry weight, shoot number and dry weight and shoot height of broomrape were determined. Shoot dry weight, root dry weight and seed yield of sesame were determined at the physiological maturity. The results showed that broomrape growth varied with sesame genotype. Egyptian broomrape dry weight measured from 1.6% (S23) to 35.4% (Kalat) of the dry weight of the sesame on which it grew. Broomrape total dry weight had positive and highly correlation with the root dry weight of the sesame genotype on which it grew. When broomrape planted with the S7, S8, S9, S21 and S23 genotypes produced tubercles, but no shoots on these genotypes. Such genotypes could be used as both trap crops and as breeding‐sources for development of resistant sesame genotypes. 相似文献
45.
D. Mouillot A. Lepretre M.-C. Andrei-Ruiz F. Mouillot D. Viale 《Population Ecology》2000,42(3):293-303
The heterogeneity associated with the spatial distribution of organisms is an awkward problem in ecology because this heterogeneity
directly depends on the sampling scale. To specify the scope of the influence of sampling scale on the level of species aggregation,
we need data sets that entail excessive sampling costs in situ. To find a solution for this problem, we can use models to
simulate patterns of organisms. These models are often very complex models that take into account heterogeneity of habitats
and displacement or longevity of studied species. In this article, we introduce a new stochastic model to simulate patterns
for one taxon and we want this model to be parsimonious, i.e., with few parameters and able to simulate observed patterns.
This model is based on an aggregation–repulsion rule. This aggregation–repulsion rule is defined by two parameters. On a large
scale, the number of aggregates present on the pattern is the first parameter. On a smaller scale, the level of aggregation–repulsion
among individuals is determined by a probability distribution. These two parameters are estimated from field data set in a
robust way so that the simulated patterns reflect the observed heterogeneity. We apply this model to entomological data: four
Diptera families, namely the Sciaridae, Phoridae, Cecidomyiidae, and Empididae. The field data for the Phoridae family are
used to simulate sampling using different trap sizes. We record changes in the coefficient of variation (C) as a function of the sampling scale, and we can suggest to ecologists emergence traps of 0.6 m2, in other words a square 77 × 77 cm trap, to obtain a C value under 20%.
Received: February 28, 2000 / Accepted: October 14, 2000 相似文献
46.
Shubbir Ahmed Jun Xie David Horne John C. Williams 《The Journal of biological chemistry》2014,289(8):4546-4552
Herein, we report the development of a photocleavable analog of AP20187, a cell-permeable molecule used to dimerize FK506-binding protein (FKBP) fusion proteins and initiate biological signaling cascades and gene expression or disrupt protein-protein interactions. We demonstrate that this reagent permits the unique ability to rapidly and specifically antagonize a molecular interaction in vitro and follow a biological process due to this acute antagonism (e.g. endosome dispersion) and to release the trap upon photocleavage to follow the cell''s return to homeostasis. In addition, this photocleavable AP20187 analog can be used in other systems where the dimerization of FKBP has been used to initiate signaling pathways, offering the ability to correlate the duration of a signaling event and a cellular response. 相似文献
47.
Processive stepping of myosin Va (myoV) has been tracked by monitoring either the tail position (center of mass) or the position of one or both heads. Here, we combine these two approaches by attaching a quantum dot to one of the motor domains and a bead to the tail. Using laser trapping and total internal reflection microscopy, the position of one head and the tail are observed simultaneously as myoV moves processively on an actin filament bundle against the resistive load of the laser trap. The head moves one step (73 ± 10 nm) for every two steps of the tail (35 ± 9 nm). One tail step occurs concurrently with quantum dot-labeled head movement, whereas the other occurs with movement of the unlabeled head, consistent with a hand-over-hand model. Load increases the probability of the motor taking a back step. The back step is triggered by the motor taking a shorter forward step (head step, 68 ± 11 nm; tail step, 32 ± 10 nm), likely one actin monomer short of its preferred binding site. During a back step, the motor reverses its hand-over-hand motion, with the leading head detaching and reattaching to one of multiple actin sites behind the trailing head. After a back step, the motor can correct its mistake and step processively forward at resistive loads <0.7 piconewton or stall or detach at higher loads. Back stepping may provide a mechanism to ensure efficient cargo delivery even when myoV encounters obstacles within the actin cytoskeletal meshwork or when other motors are attached to the same cargo. 相似文献
48.
Floral biology of Aristolochia argentina (Aristolochiaceae) 总被引:2,自引:1,他引:1
The floral biology of Aristolochia argentina (Aristolochiaceae) was studied in natural populations in Córdoba, Argentina. This native vine has flowers that attract mainly scuttle fly pollinators of the genus Megaselia (Phoridae). The trap-like perianth is formed by a limb, a tube, and a basal utricle. The limb produces an odor that recalls decaying plant tissues, which apparently mimics the natural oviposition substrate of the flies. The insects stay entrapped inside the utricle for approximately 24 h, making contact with the sexual organs of the flower. When released, they can become captured again in other flowers. The mechanisms of herkogamy and protogyny are efficient. Although self-compatibility exists, as demonstrated by the high percentage of fruits produced by geitonogamy, fruits were not produced under natural or artificial autogamous conditions. Natural pollination showed significantly lower fruit set than xenogamous and geitonogamous crosses. 相似文献
49.
Population Ecology - Field studies were carried out to clarify the growth pattern, egg production and changes in the population density of the spider,Nephila clavata, in relation to food conditions. 相似文献
50.
In the predacious fungus Arthrobotrys oligospora Fres., the number and distribution of traps formed after the addition of living nematodes to the colonies were determined. At 21°C the traps were formed periodically; the mean period was 42.3±0.8 h. The periodicity was independent of light-dark (LD) cycles of 24 h (10:14). Temperature influenced the hyphal elongation but did not affect the periodic trap formation; at lower temperatures the peaks of trap formation were close together, showing partial overlapping. Induction of rhythmic mycelial growth and conidiation by chemical means was effective only in LD-cycles. The latter diurnal rhythm was weakly correlated with the trap formation and did not affect the endogenous period of approximately 42 h.Abbreviations LD
light-dark
- DD
continuous darkness
- LNM
low-nutrient medium
- CMA
corn meal agar 相似文献