首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
This investigation concerned the question of whether honeybees collect bacteria that are beneficial for humans from the flowers that contribute to formation of their honey. Bacteria originating from the types of flowers involved, and found in different anatomic parts of the bees, in larvae, and in honey of different types, were sampled during a 2-year period. 16S rRNA sequencing of isolates and clones was employed. A novel bacterial flora composed of lactic acid bacteria (LAB) of the genera Lactobacillus and Bifidobacterium, which originated in the honey stomach of the honeybee, was discovered. It varied with the sources of nectar and the presence of other bacterial genera within the honeybee and ended up eventually in the honey. It appeared that honeybees and the novel LAB flora may have evolved in mutual dependence on one another. It was suggested that honey be considered a fermented food product because of the LAB involved in honey production. The findings are seen as having clear implications for future research in the area, as providing a better understanding the health of honeybees and of their production and storage of honey, and as having clear relevance for future honeybee and human probiotics.  相似文献   

2.
引入西方蜜蜂对中蜂的危害及生态影响   总被引:33,自引:9,他引:33  
杨冠煌 《昆虫学报》2005,48(3):401-406
作者阐述自1896年中国引进西方蜜蜂Apis melliferaL.的优良品种如意大利蜂Apis mellifera ligusticaSpinola和喀尼阿兰蜂Apis mellifera Carnica Pollmann以来,使当地的东方蜜蜂Apis cerana F.受到严重危害,其分布区域缩小75%以上,种群数量减少80%以上。使山林植物授粉总量减少,导致植物多样性减少。文中提出: 建立自然保护区保存本地蜜蜂遗传特性,和采用基因转移等技术,培育具有西方蜜蜂优良生产性能的中蜂新品种,逐步恢复中蜂的种群数量。  相似文献   

3.
Aims Exploring flowering patterns and detecting processes are essential when probing into the nature of reproductive traits during the life history and the interactions among different evolutionary clades. Such patterns are believed to be influenced by many factors, but quantifying these impacts at the community-level remains poorly understood.Methods We investigated the flowering patterns based on long-term herbarium records in a given area from subtropical forest regions in southern China. We obtained 5258 herbarium voucher specimens collected from the Dinghushan National Nature Reserve (DNNR) belonging to 166 families, 943 genera and 2059 species and examined the month when each species was flowering during the period 1920–2007.Important findings The results showed that plants flowered sequentially almost throughout the whole year, showing the characteristics of subtropical evergreen broad-leaved forests. Flowering spectrums of the entire flora and the four life forms exhibited a clear unimodality that is probably typical of subtropical forest communities. Flowering patterns of the DNNR were positively correlated with mean rainfall, mean air temperature and mean sunshine duration. Median flowering dates of the 38 large species-rich families ranged from early April to late August; 25 families exhibited significant unimodal distribution patterns, whereas the remaining families were unclear or bimodal. Median flowering dates of the 10 most species-rich genera ranged from middle May to later July. While the results are consistent with climatic factors playing a general role in flowering patterns, median flowering dates varied significantly among species-rich families and genera, suggesting that phylogenies could provide specific constraints in subtropical forests.  相似文献   

4.
We here explore the use of a Bayesian approach to island biogeography for disentangling the evolutionary origins of a continental-scale floristic pattern, the enigmatic ‘Rand Flora’. The existence of disjunct distributions across many plant lineages between Macaronesia–northwest Africa, Horn of Africa–southern Arabia and east–south Africa has long intrigued botanists, but only now can we start analysing it within a statistical framework.Phylogenetic and distributional data from 13 plant lineages exhibiting this disjunct distribution were analysed to estimate area carrying capacities and historical rates of biotic exchange between areas. The results indicate that there has been little exchange between southern Africa and the northern African region, and that this exchange occurred via east Africa. Northwest Africa–Macaronesia shows the smallest carrying capacity but highest dispersal rate with other regions, suggesting that its flora was built up by immigration of lineages, probably from the Mediterranean region and western Asia. In contrast, southern Africa shows the highest carrying capacity and lowest dispersal rate, suggesting a flora formed by in situ diversification.We discuss further improvements of the method for addressing more complex hypotheses, such as asymmetric dispersal between regions or repeated cyclical events.  相似文献   

5.
Compilation of alien flora from phytogeographically distinct regions is of immediate relevance not only for better understanding the patterns of plant invasion but also for explicating the processes promoting invasion at local, regional or global scales. Despite being at higher risk of invasion by plants because of its European colonial past, south Asia has received very little attention in respect of characterization of its alien flora. This paucity of baseline data necessitated compilation of the first catalogue of alien flora from the Kashmir Himalaya—a phytogeographically distinct south Asian region nestled in the northwestern folds of Himalayan biodiversity hotspot. Total alien flora of the region is represented by 571 plant species, belonging to 352 genera and 104 families. It constitutes a relatively higher (29%) proportion of the total flora of the region. Families with largest number of alien representatives are Poaceae (60 species), Asteraceae (54 species), and Brassicaceae (30 species). However, families such as Amaranthaceae (83%) and Chenopodiacae (71%) show higher percentage of aliens relative to their total number of plant species in the region. Most of the alien plant species (38%) trace their origin to Europe, followed by Asia (27%) and Africa (15%). Present study also reports, for the first time, occurrence of seven plant species in this region. Each alien plant species is provided with information on the origin, habit, mode/purpose of introduction, current invasion status, altitudinal range and the primary published source.  相似文献   

6.
Previous work at the National Vegetable Research Station indicated that cross-pollination of Brussels sprouts by honeybees could be improved when parent lines with similar flowering characteristics were used. During 1973-5 inbred lines were tested at three sites for matching ability based on flowering times, plant height and flower colour. One pair of inbreds satisfied all criteria at all sites, and a further twelve gave satisfactory results. Two pairs visually matched in 1973 were grown in larger plots in 1973-4 to assess the effect of matching on honeybee behaviour. Results showed that matching improved cross-pollination by honeybees between the parent lines.  相似文献   

7.
Bees get a head start on honey production   总被引:1,自引:0,他引:1  
Nectar concentration is assumed to remain constant during transport by honeybees between flowers and hive. We sampled crop contents of nectar foragers on Aloe greatheadii var. davyana, a major winter bee plant in South Africa. The nectar is dilute (approx. 20% w/w), but the crop contents of bees captured on flowers are significantly more concentrated. In returning foragers, the concentration increases further to 38–40%, accompanied by a volume decrease. The doubling of sugar concentration suggests that nectar is regurgitated onto the tongue and evaporated during foraging and on the return flight. Processing of the dilute nectar into honey thus begins early, aided by low ambient humidities. This has implications for honeybee thermoregulation, water balance and energetics during foraging, and for the communication of nectar quality to recruits.  相似文献   

8.
Forests with different flora and vegetation types harbor different assemblages of flower visitors, and plant-pollinator interactions vary among forests. In monsoon-dominated East and Southeast Asia, there is a characteristic gradient in climate along latitude, creating a broad spectrum of forest types with potentially diverse pollinator communities. To detect a geographical pattern of plant-pollinator interactions, we investigated flowering phenology and pollinator assemblages in the least-studied forest type, i.e., tropical monsoon forest, in the Vientiane plain in Laos. Throughout the 5-year study, we observed 171 plant species blooming and detected flower visitors on 145 species. Flowering occurred throughout the year, although the number of flowering plant species peaked at the end of dry season. The dominant canopy trees, including Dipterocarpaceae, bloomed annually, in contrast to the supra-annual general flowering that occurs in Southeast Asian tropical rain forests. Among the 134 native plant species, 68 were pollinated by hymenopterans and others by lepidopterans, beetles, flies, or diverse insects. Among the observed bees, Xylocopa, megachilids, and honeybees mainly contributed to the pollination of canopy trees, whereas long-tongued Amegilla bees pollinated diverse perennials with long corolla tubes. This is the first community-level study of plant-pollinator interactions in an Asian tropical monsoon forest ecosystem.  相似文献   

9.
  1. Korla fragrant pear (Pyrus sinkiangensis Yü) depends on cross-pollination by honeybees (Apis mellifera) but may suffer from low honeybee visitation.
  2. We assessed whether honeybee abundance and visitation frequency are enhanced by using synthetic Nasonov gland pheromone (NGP), which is naturally produced by worker bees to stimulate the aggregation of bees to food resources or nesting sites.
  3. The response of honeybees to synthetic NGP was firstly assessed using Y-tube olfactometer tests in the laboratory, and subsequently in the field, by placing NGP lures on Korla fragrant pear trees in orchards with and without beehives. Honeybee abundance was assessed using coloured pan traps while honeybee visits were assessed by visual observations on pear flowers.
  4. Y-tube olfactometer tests showed a significant preference of honeybees for NGP. In pear orchards with beehives, honeybee abundance was 2.5-fold higher on trees with NGP lures than on trees without NGP, and 2.2-fold higher in orchards in which all trees contained NGP lures than in orchards without NGP lures. Such positive effects were not observed in orchards without beehives.
  5. Flower visitation by honeybees was significantly higher in trees with NGP lures than without NGP lures, irrespective of the presence (5.7-fold higher) or absence of beehives (27.6-fold higher).
  6. In mixed pear-apricot orchards, honeybee abundance was higher in pear trees with NGP lures than without lures.
  7. Our results show that NGP lures attract honeybees to flowering pear trees in monoculture pear and mixed pear-apricot orchards, and that this effect is greatest in orchards with beehives.
  相似文献   

10.
In eastern North America, the field milkweed, Asclepias syriaca L. (Asclepiadaceae), is used in planting schemes to promote biodiversity conservation for numerous insects including the endangered monarch butterfly, Danaus plexippus (Linnaeus) (Nymphalidae). Less is known about its pollinators, and especially in urban habitats where it is planted often despite being under increasing pressure from invasive plant species, such as the related milkweed, the dog‐strangling vine (DSV), Vincetoxicum rossicum (Kleopow) Barbar. (Asclepiadaceae). During the A. syriaca flowering period in July 2016, we surveyed bees in open habitats along a DSV invasion gradient and inspected 433 individuals of 25 bee species in 12 genera for pollinia: these were affixed to bees that visited A. syriaca for nectar and contain pollen packets that are vectored (e.g., transferred) between flowers. Of all bees sampled, pollinia were found only on the nonindigenous honeybee, Apis mellifera (43% of all bees identified), as well as one individual bumblebee, Bombus impatiens Cresson. Pollinia were recorded from 45.2% of all honeybees collected. We found no relationship between biomass of DSV and biomass of A. syriaca per site. There was a significant positive correlation between A. syriaca biomass and the number of pollinia, and the proportion vectored. No relationship with DSV biomass was detected for the number of pollinia collected by bees but the proportion of vectored pollinia declined with increasing DSV biomass. Although we find no evidence of DSV flowers attracting potential pollinators away from A. syriaca and other flowering plants, the impacts on native plant–pollinator mutualisms relate to its ability to outcompete native plants. As wild bees do not appear to visit DSV flowers, it could be altering the landscape to one which honeybees are more tolerant than native wild bees.  相似文献   

11.
Guozhen Du  Wei Qi 《Plant Ecology》2010,206(2):321-333
Flowering timing is of fundamental biological importance for its tight association with pre-flower growth states and subsequent reproduction success. Here, we selected plant height and seed size to represent plant growth and reproduction states, respectively, and analyzed their associations with flowering time in 11 communities together representing a QingHai-Tibetan flora. Trait associations were examined using Pearson correlation analyses (TIPs) and phylogenetically independent contrasts (PICs) within individual communities and meta-analyses across all communities. The results of TIPs-based and PICs-based analyses were generally congruent, although fewer contrasts were significant with PICs, probably because of low statistical power. Overall, flowering time was negatively correlated with seed size and plant height (i.e., plants with larger seeds and stature started flowering earlier) in various woody communities, but correlations were neutral or positive in herbaceous communities. The seed size–flowering time relationship was negative for woody and herbaceous perennials but not for annual herbs in most communities. The relationship between plant height and flowering time was negative for woody but positive for herbaceous plants. Moreover, the lack of difference in time–size relationships between anemophilous and entomophilous plants suggests that pollination type may only be a secondary force in controlling flowering phenology. Our studies demonstrate that environmental conditions, community structure, and plant life history strategies may affect community flowering time singly or in combination.  相似文献   

12.
Summary Flowering time, plant height and flower size in Petunia hybrida Hort. (multiflora type) have been genetically analysed by means of a 5 × 5 diallel cross. The results indicated that: (1) the three characters are controlled by additive-dominance polygenic systems. The contribution of the additive gene actions to the genetic variance of flowering time was relatively higher than that of dominance. The reverse situation was found for plant height and flower size. (2) Dominance is ambi-directional for the three characters. Ratios of average dominance were in the range of partial for flowering-time, complete for plant height and overdominance for flower size. (3) Number of genes (or gene groups) controlling the characters are about 3, 3 and 5 for flowering time, plant height and flower size: respectively, (4) Heritability estimates are 0.84, 0.88 and 0.89 in the broad-sense and 0.40, 0.49 and 0.37 in the narrow-sense, for flowering time, plant height and flower size; respectively. (5) Heterosis as percent increase of the mean F1-hybrid above the higher parent, or decrease below the lower parent, was observed for flowering time (+ 9.7% to +13.3%), for plant height (–13.6% to –20.3%) and for flower size (+2.5% to +16.0%).  相似文献   

13.
Aim Grasslands and savannas, which make up > 75% of Madagascar’s land area, have long been viewed as anthropogenically derived after people settled on the island c. 2 ka. We investigated this hypothesis and an alternative – that the grasslands are an insular example of the post‐Miocene spread of C4 grassy biomes world‐wide. Location Madagascar, southern Africa, East Africa. Methods We compared the number of C4 grass genera in Madagascar with that in southern and south‐central African floras. If the grasslands are recent we would expect to find fewer species and genera in Madagascar relative to Africa and for these species and genera to have very wide distribution ranges in Madagascar. Secondly, we searched Madagascan floras for the presence of endemic plant species or genera restricted to grasslands. We also searched for evidence of a grassland specialist fauna with species endemic to Madagascar. Plant and animal species endemic to C4 grassy biomes would not be expected if these are of recent origin. Results Madagascar has c. 88 C4 grass genera, including six endemic genera. Excluding African genera with only one or two species, Madagascar has 86.6% of southern Africa’s and 89.4% of south‐central Africa’s grass genera. C4 grass species make up c. 4% of the flora of both Madagascar and southern Africa and species : genus ratios are similar (4.3 and 5.1, respectively). Turnover of grasses along geographical gradients follows similar patterns to those in South Africa, with Andropogoneae dominating in mesic biomes and Chlorideae in semi‐arid grassy biomes. At least 16 monocot genera have grassland members, many of which are endemic to Madagascar. Woody species in frequently burnt savannas include both Madagascan endemics and African species. A different woody flora, mostly endemic, occurs in less frequently burnt grasslands in the central highlands, filling a similar successional niche to montane C4 grasslands in Africa. Diverse vertebrate and invertebrate lineages have grassland specialists, including many endemic to Madagascar (e.g. termites, ants, lizards, snakes, birds and mammals). Grassland use of the extinct fauna is poorly known but carbon isotope analysis indicates that a hippo, two giant tortoises and one extinct lemur ate C4 or CAM (crassulacean acid metabolism) plants. Main conclusions The diversity of C4 grass lineages in Madagascar relative to that in Africa, and the presence of plant and animal species endemic to Madagascan grassy biomes, does not fit the view that these grasslands are anthropogenically derived. We suggest that grasslands invaded Madagascar after the late Miocene, part of the world‐wide expansion of C4 grassy biomes. Madagascar provides an interesting test case for biogeographical analysis of how these novel biomes assembled, and the sources of the flora and fauna that now occupy them. A necessary part of such an analysis would be to establish the pre‐settlement extent of the C4 grassy biomes. Carbon isotope analysis of soil organic matter would be a feasible method for doing this.  相似文献   

14.
Outside their natural range, honeybees (Apis mellifera) are known to have detrimental effects on indigenous pollinators through exploitative or interference competition, but little is known about the effect of honeybee farming in areas where honeybees occur naturally. In the Cape Floristic Region of South Africa, where honeybees are indigenous, managed hives potentially elevate the abundance of honeybees far above natural levels, but impacts on other floral resource-dependent species have not been studied. Here we use experimental manipulation of honeybee density to test whether honeybee farming affects nectar-feeding birds. We selected the common sugarbush (Protea repens), utilized by both birds and bees, and analysed the time (before/after) by treatment (control/experiment) interaction to explore changes in bee abundance, nectar availability and bird abundance at three sites. Hive addition increased honeybee abundance in inflorescences of P. repens above expected levels. Despite experimental increase in honeybee numbers, there is no reduction in nectar sugar availability relative to the control areas. Where honeybee density was highest, sugarbird (Promerops cafer) numbers declined relative to expected, but sunbirds (Nectarinidae) were not affected at any of the sites. We conclude that stocking rates of more than one honey bee per P. repens inflorescence have detrimental effects on bird abundance due to interference, rather than resource competition.  相似文献   

15.
Field-grown large leaf Rhododendron and Kalmia latifolia were treated with one of three concentrations of paclobutrazol or uniconazol in April, June, or August in the second year from propagation. The elongation of stems was measured as was the number of flower buds initiated. Spray applications in April or June increased flowering at the lowest concentrations tested; 4 mg · L–1 paclobutrazol and 1.5 mg · L–1 uniconazol. Flowering was induced in cultivars that normally did not flower, and the number of flower buds per plant was increased in cultivars that normally flowered. All treatments that induced flowering also reduced stem elongation. Spray application in August failed to enhance flowering. At the concentrations tested, uniconazol was more effective than paclobutrazol in increasing the number of flower buds and reducing stem elongation of Rhododendron. For Kalmia, there was less response to the concentration of growth retardant, and the two chemicals enhanced flowering equally.  相似文献   

16.
在云南,人们有食用蜜蜂幼虫和蛹的习俗。市场上销售的蜜蜂幼虫和蛹多经热水烫过或煮过,因而缺少成虫形态,俗名易混用,食用种类长期未予明确。本文在市场调查的基础上,收集其中部分样品,通过形态学和mtDNA的COI基因部分序列初步鉴定其分类地位,以明确食用种类。结果表明,云南蜜蜂的食用集中在横断山脉南部地区,接受人群广泛,食用方式多样;云南食用本地分布的全部5种野生蜜蜂,包括东方蜜蜂(Apis cerana)、小蜜蜂(A.florea)、大蜜蜂(A.dorsata)、黑大蜜蜂(A.laboriosa)和黑小蜜蜂(A.andreniformis);基于COI序列构建的邻接法(NJ)和最大简约法(MP)系统发育树支持现有的蜜蜂属系统发育关系;现有的食用蜜蜂大多采集自野外,亟待开展遗传资源保护。本研究为食用蜜蜂的鉴定提供了数据支持,也为蜜蜂自然资源的利用和保护提供参考。  相似文献   

17.
Aim The plant diversity of one location on the Guiana Shield, Kaieteur National Park in Guyana, is used to examine the various hypothesized origins of the flora and to evaluate which may best explain the current plant distributions. Location Kaieteur National Park is located on eastern edge of the Potaro Plateau in central Guyana, South America. The species examined have distributions that vary from local to global. Methods The distribution patterns of the families, genera and species known from Kaieteur are examined using generalized distribution patterns. Results Data on distribution patterns, elevation and habitat were gathered from 131 flowering plant families, 517 genera and 1227 species. These plants represent all taxa that are currently known to occur in the area of the original Kaieteur National Park. Families tend to have cosmopolitan or pantropical distribution, genera are mostly neotropical and at the species level, most species are restricted to the Guiana Shield (c. 40%), northern South America (69%) or neotropical (96%) in distribution, each level inclusive of the previous. Conclusions The flora at the study site in Kaieteur National Park has its strongest affinity with the Guiana Shield; 42.1% of the species have a distribution that corresponds with the Shield or is more restricted within the Shield. There is a distinct flora on the Guiana Shield and its affinities lie with the flora of northern South American and beyond that, the neotropics. The flora is not closely affiliated with the floras of the Brazilian Shield, the Amazon, the Andes, the eastern coastal forests of Brazil, southern South America, or Africa as has been previous suggested.  相似文献   

18.
The paper analyses an unintentional experiment conducted 40 years ago with species termed wool aliens which were observed in employee garden allotments of a wool-processing factory in Brno, Czech Republic. The waste from processing was used as a garden fertilizer, and alien species were recorded by Dvořák and Kühn (1966) Zavlečené rostliny na pozemcích přádelny vlny ‘Mosilana’ n.p. v Brně. Preslia 38: 327–332. The survival of these species was assessed by their occurrence in the current alien flora of the Czech Republic. Of the 56 species introduced in the 1960s and classified as wool aliens, 18 are still present in the Czech alien flora. The remaining 38 species are considered extinct, i.e. alien plants not capable of long-term survival in the country. The resulting survival rate of wool aliens is 22.1%. Three species on the list (5.4%) were clearly capable of naturalization. Compared to the other alien flora of the Czech Republic, wool aliens were disproportionally introduced from Australia, Africa and South and Central America. Species from Europe and Africa tended to survive the best. Grasses were most strongly represented, contributing 62.5% to wool alien species but only 7.9% to the total Czech neophyte flora. All surviving species were annuals, whereas none of the perennials survived; the survival rate in annuals was 37.5%. Survival of species introduced with wool was significantly comparable to their performance in the UK and in Central Europe, indicating that survival is not determined by mere chance and that the same species tend to be successful elsewhere in Europe. Maximum height and the month of first flowering were not significantly related to the species survival. The role of specific events in the enrichment of alien floras is discussed.  相似文献   

19.
The honeybee, Apis mellifera, is the world's most important pollinator and is ubiquitous in most agricultural ecosystems. Four major evolutionary lineages and at least 24 subspecies are recognized. Commercial populations are mainly derived from subspecies originating in Europe (75–95%). The Africanized honeybee is a New World hybrid of A. m. scutellata from Africa and European subspecies, with the African component making up 50–90% of the genome. Africanized honeybees are considered undesirable for bee‐keeping in most countries, due to their extreme defensiveness and poor honey production. The international trade in honeybees is restricted, due in part to bans on the importation of queens (and semen) from countries where Africanized honeybees are extant. Some desirable strains from the United States of America that have been bred for traits such as resistance to the mite Varroa destructor are unfortunately excluded from export to countries such as Australia due to the presence of Africanized honeybees in the USA. This study shows that a panel of 95 single nucleotide polymorphisms, chosen to differentiate between the African, Eastern European and Western European lineages, can detect Africanized honeybees with a high degree of confidence via ancestry assignment. Our panel therefore offers a valuable tool to mitigate the risks of spreading Africanized honeybees across the globe and may enable the resumption of queen and bee semen imports from the Americas.  相似文献   

20.
Introduced honeybees have had a large impact on native ecosystems by disrupting native plant–pollinator interactions. However, little is known of the effect of honeybees on reproduction of bumblebee-pollinated plants. Seasonal displacement of native bumblebees by introduced honeybees (Apis mellifera and A. cerana) was observed in Pedicularis densispica, endemic to Hengduan Mountains, China, providing an opportunity for honeybee presence/absence comparisons. Five-year field surveys were conducted in one frequently disturbed population at Yila Pasture (YP). We compared pollination effectiveness (combinations of visitation rate, efficiency in pollen transfer, and potential geitonogamy) between native and introduced managed bees. The total visitation rate of native bees and subsequent reproductive output decreased progressively, but honeybee introduction resulted in at least twofold increase in visitation and 70 % increase in seed set. In general, native bumblebees, which have larger bodies and longer proboscises and spent more time probing single flowers, were more efficient than honeybees in terms of pollen removal and pollen deposition during first visits to virgin flowers. Compared with bumblebees, honeybees visited markedly fewer flowers in sequence within individual plants, potentially reducing geitonogamous pollination. Our data highlight that introduced honeybees can provide pollination service in terms of both quantity and quality for P. densispica. We suggest honeybee introduction as an effective way to augment pollination of P. densispica at disturbed and isolated sites.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号