Flower Diversity Research Articles

Floral traits are associated with the quality but not quantity of heterospecific stigmatic pollen loads

BackgroundIn flowering communities, plant species commonly share pollinators and therefore plant individuals receive heterospecific pollen (HP). However, the patterns of HP transfers can deviate from patterns of plant-pollinator visitations. Although flower-visitor interactions are known to be mediated by floral traits, e.g. floral size or nectar tube depth, the explanatory power of these traits for HP transfer patterns remains elusive. Here, we have explored pollen transfer patterns at three sites in Southern Germany on three dates (early, mid and late summer). At the plant level, we tested whether flower abundance and floral traits are correlated with HP reception and donation. At the community level, we determined whether flower and bee diversity are correlated with network modularity and whether floral traits explain the module affiliation of plant species. We collected the stigmas of flowering plant species, analysed HP and conspecific pollen (CP) loads and measured floral traits, flower and bee diversity.ResultsOur results show that the degree and intensity of HP reception or donation at the plant level do not correlate with floral traits, whereas at the community level, the module affiliation of who is sharing pollen with whom is well-explained by floral traits. Additionally, variation in network modularity between communities is better explained by plant diversity and abundance than by bee diversity and abundance.ConclusionsOverall, our results indicate that floral traits that are known to mediate flower-visitor interactions can improve our understanding of qualitative HP transfer but only provide limited information about the quantity of HP transfer, which more probably depends on other floral traits, flower-visitor identity or community properties.

Phylogenomics of the aquatic plant genus Ottelia (Hydrocharitaceae): Implications for historical biogeography

Ottelia Pers. is the second largest genus of the family Hydrocharitaceae, including approximately 23 extant species. The genus exhibits a diversity of both bisexual and unisexual flowers, and complex reproductive system comprising cross-pollinated to cleistogamous flowers. Ottelia has been regarded as a pivotal group to study the evolution of Hydrocharitaceae, but the phylogenic relationships and evolutionary history of the genus remain unresolved. Here, we reconstructed a robust phylogenetic framework for Ottelia using 40 newly assembled complete plastomes. Our results resolved Ottelia as a monophyletic genus consisting of two major clades, which correspond to the main two centers of diversity in Asia and Africa. According to the divergence time estimation analysis, the crown group Ottelia began to diversify around 13.09 Ma during the middle Miocene. The biogeographical analysis indicated the existence of the most recent common ancestor somewhere in Africa/Australasia/Asia. Basing on further insights from the morphological evolution of Ottelia, we hypothesized that the ancestral center of origin was in Africa, from where the range expanded by transoceanic dispersal to South America and Australasia, and further from Australasia to Asia. We suggested that the climatic change and global cooling since the mid-Miocene, such as the development of East Asian monsoon climate and tectonic movement of the Yunnan-Guizhou Plateau (YGP), might have played a crucial role in the evolution of Ottelia in China.

Contrasting effects of exotic plant invasions and managed honeybees on plant–flower visitor interactions

AbstractAimTo explore how a highly invasive plant species (Buddleja davidii Franch.), managed honeybees and flower diversity affected plant–flower visitor interactions over the whole elevational range distribution of the exotic plant.LocationItalian Alps.MethodsWe selected nine pairs of sites (one invaded and one non‐invaded by B. davidii) across gradients in honeybee abundance and diversity of flower resources. We observed plant–flower visitor interactions every three weeks, for a total of five surveys covering the full flowering season of B. davidii (June–August). We tested how B. davidii, honeybee abundance and flowering plant diversity affected network robustness, overlap in flower resource use of wild flower visitors with honeybees and flower visitor specialization. We also tested for an interaction between B. davidii presence and honeybee abundance, and tested whether the effects of the two variables changed among insect orders.ResultsBuddleja davidii and honeybees had contrasting effects on network robustness and on several species‐level metrics. Network robustness increased with increasing honeybee abundance and flower diversity. Increasing honeybee abundance generally increased specialization of lepidopterans and dipterans that tended to switch to less visited plant species, possibly in order to avoid competition. Specialization of flower visitors declined in sites invaded by B. davidii, indicating that the invasive plant attracted pollinators, which in turn also visited co‐occurring species in the neighbourhood.Main conclusionsAlthough increasing honeybee abundance was associated with higher network stability, it also modified plant–flower visitor interactions by forcing species to shift their diet irrespective of floral diversity. The effect was particularly strong for non‐bee flower visitors. The consequences of these changes in plant–flower visitor interactions for the reproductive success of flowering plants are still largely unknown.

Changes in plant community structure and decrease in floral resource availability lead to a high temporal β-diversity of plant–bee interactions

Biological communities are subject to spatiotemporal variations in community structure, i.e., species composition, richness, and abundance. Plant–pollinator interactions are affected by species composition and abundance, so that rapid changes in plant community structure can lead to critical impacts on plant–pollinator interactions at the community level. The extent of these impacts depends on how plants respond to different kinds of stressors, such as the disturbance caused by invading species. In this research, we conducted a before-and-after study to evaluate the potential effects of an invasive fast-growing alien grass species on the structure of a plant–pollinator interaction network. We described the changes in community structure and plant–pollinator interactions over two sampling periods, through the temporal β-diversity of plant and bee species, plant–bee interactions, and plant functional traits. Our results showed that changes in plant community composition (especially the plants in the network core) and decrease in plant species richness, as well as in floral resources availability impacted plant–pollinator interactions of a grassland community after the growth of a fast-growing alien grass species. These changes were accompanied by a decrease in plant–bee interaction diversity, and a high β-diversity of species interactions mainly due to interaction rewiring. However, we found no effect on the functional diversity of flowers. In conclusion, our study showed that a short-term change in plant species composition and floral resource abundance impacted plant–bee interactions, which markedly changed network structure and dynamics.

Outstanding questions in flower metabolism.

The great diversity of flowers, their color, odor, taste, and shape, is mostly a result of the metabolic processes that occur in this reproductive organ when the flower and its tissues develop, grow, and finally die. Some of these metabolites serve to advertise flowers to animal pollinators, other confer protection towards abiotic stresses, and a large proportion of the molecules of the central metabolic pathways have bioenergetic and signaling functions that support growth and the transition to fruits and seeds. Although recent studies have advanced our general understanding of flower metabolism, several questions still await an answer. Here, we have compiled a list of open questions on flower metabolism encompassing molecular aspects, as well as topics of relevance for agriculture and the ecosystem. These questions include the study of flower metabolism through development, the biochemistry of nectar and its relevance to promoting plant-pollinator interaction, recycling of metabolic resources after flowers whiter and die, as well as the manipulation of flower metabolism by pathogens. We hope with this review to stimulate discussion on the topic of flower metabolism and set a reference point to return to in the future when assessing progress in the field.

A "plan bee" for cities: Pollinator diversity and plant-pollinator interactions in urban green spaces.

Green infrastructure in cities is considered to serve as a refuge for insect pollinators, especially in the light of an ongoing global decline of insects in agricultural landscapes. The design and maintenance of urban green spaces as key components of green infrastructure play a crucial role in case of nesting opportunities and for foraging insects. However, only few research has explored the impact of urban green space design on flower visitor communities, plant-pollinator interaction and the provision of the ecosystem service of pollination in cities. We investigated the abundance and diversity of pollinator communities in different urban park types in designed, standardized vegetation units, linked the visitation rates to the structural composition of the park types and derived indices for implemented pollination performances. The study was performed in two different structural park elements, flower beds and insect-pollinating trees. To gain a comprehensive understanding of the interaction between plants and pollinators, we calculated a plant-pollinator network of the recorded community in the investigation area. Visitation rates at different park types clearly showed, that the urban community gardens in comparison to other urban park types had a significantly higher abundance of pollinator groups, comparable to results found on a rural reference site. Tilia trees contributed significantly to the ecosystem service of pollination in investigated green spaces with a high supply of nectar and pollen during their flowering period. Calculations of pollination performances showed that recreational parks had comparably low visitation rates of pollinators and a high potential to improve conditions for the ecosystem service of pollination. The results indicated the strong potential of cities to provide a habitat for different groups of pollinators. In order to access this refuge, it is necessary to rely on near-natural concepts in design and maintenance, to create a wide range of flower diversity and to use even small green patches. Based on the findings, we encourage an integrated management of urban free spaces to consider parks as key habitats for pollinators in anthropogenic dominated, urban environments.

Allele combinations of maturity genes E1-E4 affect adaptation of soybean to diverse geographic regions and farming systems in China

Appropriate flowering and maturity time are important for soybean production. Four maturity genes E1, E2, E3 and E4 have been molecularly identified and found to play major roles in the control of flowering and maturity of soybean. Here, to further investigate the effect of different allele combinations of E1-E4, we performed Kompetitive Allele Specific PCR (KASP) assays based on single nucleotide polymorphisms (SNPs) at these four E loci, and genotyped E1-E4 genes across 308 Chinese cultivars with a wide range of maturity groups. In total, twenty-one allele combinations for E1-E4 genes were identified across these Chinese cultivars. Various combinations of mutations at four E loci gave rise to the diversity of flowering and maturity time, which were associated with the adaptation of soybean cultivars to diverse geographic regions and farming systems. In particular, the cultivars with mutations at all four E loci reached flowering and maturity very early, and adapted to high-latitude cold regions. The allele combinations e1-as/e2-ns/e3-tr/E4, E1/e2-ns/E3/E4 and E1/E2/E3/E4 played important roles in the Northeast China, Huang-Huai-Hai (HHH) Rivers Valley and South China regions, respectively. Notably, E1 and E2, especially E2, affected flowering and maturity time of soybean significantly. Our study will be beneficial for germplasm evaluation, cultivar improvement and regionalization of cultivation in soybean production.

Optimizing yield and flower resources for pollinators in intensively managed multi-species grasslands

Intensively managed grasslands, typically containing a few high-yielding species, play a key role in providing biomass feedstock for animal feed and bioenergy production. However, these grasslands often contain few resources for flower-visiting insects, which provide pollination services for crops. In this study, we investigate if both high yield and floral resources for pollinators can be achieved in intensively managed grasslands by varying species diversity and composition, and cutting frequency. Four perennial grassland mixtures containing 3, 5, 11 and 13 species of grasses and/or forbs were established at three sites varying in surrounding landscape, and plots were managed with three cutting strategies (four cuts per year, two cuts per year and no cut). Biomass production was measured as annual herbage yield. Every 2–4 weeks throughout the flowering season, flower abundance, richness, temporal stability and flower-visiting insects were monitored. The 11- and 13-species mixtures, designed to enhance pollinators, produced similar or higher herbage yield than the 3-species mixture under a two-cut strategy or the 5-species mixture under a four-cut strategy. The 3- and 5- species mixtures had a high accumulated flower abundance due to excessive flowering of lucerne under the two-cut strategy and white clover under the four-cut strategy. Interestingly, flower abundance was not significantly reduced under the two-cut strategy compared to no cut. As expected, the 11- and 13- species mixtures presented a higher diversity of flowers during the flowering season. Flower temporal stability was generally higher in 11- and 13-species mixtures under the two-cut strategy, while it was highest in the 5-species mixture under the four-cut strategy. Pollinator profiles (visits by different functional groups of insects) were plant-species specific, and varied very little among sites. Legume species mainly attracted large bees (honey bees and bumblebees), while the most abundant forbs attracted other insect groups, in particular syrphids and other flies. Our results suggest that multi-species grasslands can be designed to support a high diversity of pollinators without compromising herbage yield. In particular, adding forbs to the grass-legume seed mixtures and managing grasslands with a two-cut strategy may increase flower resources available for a larger range of wild pollinators.

Pollinator-dependent evolution of floral trait combinations in an orchid herb

Abstract Aims As one of the most important agents driving floral evolution, pollinators shape the diversity of flowers in angiosperms. However, most previous studies have only quantified pollinators driving the evolution of a single floral trait, and experimental estimates of the potential role of pollinators in shaping the evolution of floral trait associations are relatively rare. Methods We experimentally identified and estimated the pollinator-mediated directional and correlational selection on single floral traits and trait combinations across 2 years in an orchid species, Spiranthes sinensis. Important Findings Pollinators mediated directional selection for an earlier flowering start date and larger corolla size. Pollinators mediated positive correlational selection on the combinations of floral display traits and negative correlational selection on the combinations of flowering phenology and floral display traits. In addition, the strength of selection differed over time. Our results highlight the potential role of pollinators in driving the evolution of floral trait combinations and suggest that it is necessary to consider floral character functional associations when seeking to understand and predict the evolutionary trajectory of flowers in angiosperms.

Management of forest fire buffer zones: Implications for flowering plants and bees

Pollination, especially by bees, has high importance for man and nature. Ongoing global declines in bee populations make their present and future conservation crucial. We investigated how management of natural areas affects plants and pollinators, in the context of fire prevention measures in Mediterranean forests. The standard forestry practice to reduce fire hazard includes construction of vegetation-thinned buffer zones near roads and human settlements. Such buffer zones are commonly maintained by livestock grazing or mechanical trimming to prevent forest regrowth. We conducted a controlled and replicated field experiment to assess the effects of these maintenance practices on flowering plants and bees. Vegetation was thinned in 32 experimental plots at the Mt. Carmel Nature Reserve, Israel, to simulate construction of fire buffer zones. Sixteen plots were either grazed by sheep or trimmed during the following year, while the remaining plots received no maintenance treatment. We surveyed the flowers (identified to species) and bees (identified to genus) in the plots over three years: before, during and after the maintenance interventions. Maintenance management (regardless whether by grazing or by trimming) affected the floral community composition, as did monitoring date and the plots' fire history (burnt either four or >20 years earlier). However, the abundance and diversity of flowers and bees, and the bees' community composition, did not differ between plots that received maintenance treatments and their paired non-maintenance controls. We conclude that many aspects of flower and bee assemblages in the reserve are little affected, in the short term, by the maintenance practices of fire buffer zones. As our experiment was limited to a one-year grazing/trimming intervention, future studies should assess the longer-term effects of these management activities on pollination interactions.

Male Visitors May Decrease Modularity in Flower–Visitor Networks

An ecological community network generally has a clustering structure formed by evolutionary and ecological processes. Because females and males of a single visitor species often differ in their evolutionary and ecological relationship with flowering plants, visitor sex should affect the clustering structure of flower-visitor networks. Two related metrics are used to evaluate clustering structures: compartmentation and modularity. Compartmentation refers to the number of clearly separate subgroups, whereas modularity describes subgroups according to their number of aggregating links. Thus, compartmentation is a measure of network fragmentation and modularity is a measure of network heterogeneity. Because male visitors tend to give priority to search for mates, we hypothesized that male visitors increased compartmentation and decreased modularity compared with female visitors. By using museum specimens of flower-visitor insects together with the plant species that they were visiting, recorded at the time of collection, we constructed 11 networks for each research site and collection year, separated each into male and female subnetworks, and then compared the two metrics between them. Results showed that compartmentation was not different between them, while male subnetworks had lower modularity than female subnetworks, and strengthened modularity of species networks together with female subnetworks. These structural characteristics of male subnetworks likely reflect less choosy and less mutualistic visits of males compared with females. This might imply that the role of male visitors in maintaining flower diversity has been overlooked.

Diversity of Floral Visitors in Apple Orchards: Influence on Fruit Characteristics Depends on Apple Cultivar.

Most cultivars of apple trees are highly dependent on insects for successful pollination and fruit production. In this study, we evaluated the insect diversity in apple orchards of southern Brazil and verified whether or not there is a relationship between the diversity of insect visitors and the characteristics (weight, seed number, and symmetry) of the fruits of 'Fuji' and 'Gala' apples produced by the orchards. We also evaluated the diversity of insects on flowering weeds within apple orchards and compared it with the apple flowers. Diversity of anthophilous insects was low, in general, and differed between the regions. Furthermore, regarding insect diversity, orchards were grouped by management system: organic orchards were more similar to each other than to conventional orchards. The insect diversity of weed flowers was higher than apple flowers, but insect abundance was greater on apple flowers, suggesting that weeds may increase insect diversity within apple orchards and may sustain pollinators. We found a positive effect of insect diversity on the number of seeds of 'Fuji' apples and of honeybee abundance on their weight, suggesting that honeybee management is important in the studied areas. In contrast, we found no significant effect of insect diversity and abundance on 'Gala' apple characteristics. Despite this, the analyses of the seeds of 'Gala' apples indicate that the orchards may suffer a pollination deficit, which could be overcome by improving insect pollination. These results reinforce previous findings that insect diversity is important for apple yield, but its influence varies with cultivar.

Comparative floral development reveals novel aspects of structure and diversity of flowers in Cannabaceae

AbstractSpecies of Cannabaceae are wind pollinated, have inconspicuous and reduced flowers that are pistillate, staminate and apparently perfect on the same individual or on different individuals, with a single-whorled perianth and a pseudomonomerous gynoecium. Our objective is to understand the developmental processes that lead to such a reduced flower morphology and polygamy in Cannabis sativa, Celtis iguanaea and Trema micrantha. Floral buds and flowers were processed for surface, histological examinations and 3D reconstructions of vasculature. The single-whorled perianth is interpreted as a calyx because the organs are robust, have a broad base, an acute apex and quincuncial aestivation and are opposite the stamens. Petals are absent from inception. The dicliny is established at different development stages: stamens or carpels are absent from inception (Cannabis sativa), initiated and aborted during early (Trema micrantha, before sporo/gametogenesis) or late (Celtis iguanaea, after sporo/gametogenesis) development. Furthermore, in all species studied the carpels are congenitally united and the pseudomonomerous nature of the gynoecium is confirmed. Glandular trichomes are distributed on the bracts, sepals, anther connective and receptacle. Special floral features shared by species of Cannabaceae include precocious ovule development and sepals that are each vascularized by one bundle. The reduced flowers of Cannabaceae are the result of the absence from inception and/or abortion of organs and even of a whole whorl at different developmental stages, which were probably selected in response to pressures exerted by the similar pollination mechanism.

Limiting resources on the reproductive success of a cavity-nesting bee species in a grassland agroecosystem

Intensive agricultural land use can impact pollinators mainly through habitat loss and/or modification. Native bees are negatively affected by agricultural intensification, isolation from natural habitats, decreases in plant diversity, and reduction in the availability of nesting sites. Despite this, in the Pampean region, there are scarce studies about the effect of agricultural activities on native bees. We studied the nesting ecology of the native leafcutter bee Megachile gomphrenoides (Megachilidae) in eight sites immersed in an agricultural matrix, where land use is a mosaic of agricultural land and some semi-natural areas. The sampling was developed using paired trap-nests in fragments without agricultural management and in soybean crops. We aimed to analyse the effects of floral and nesting resources on the abundance, the reproductive success and the parasitism rate of a population of M. gomphrenoides in a Pampean agroecosystem. Floral diversity was significantly correlated with abundance of nests and brood cells, and both parasitism rate and reproductive success of M. gomphrenoides were higher in nests built in fragments without agricultural management when compared to crop areas. Additionally, a negative correlation was found between reproductive success and flower diversity in crop areas. These results suggest that floral diversity is limiting the abundance of M. gomphrenoides nests, its reproductive success as well as its parasitism rate.

Phenological diversity of flowering and fruiting in cassava germplasm

Genetic and environmental factors can influence the flowering and fruit setting performance of cassava varieties. The objective of this work was to assess the genetic variability of cassava germplasm for flowering and fruiting traits, as well as to cluster the genotypes based on based on its flowering performance. A total of 1032 accessions were evaluated monthly from 3 to 12 months after planting – MAP for flower and fruit production using a grade scale ranging from 0 absence or poor flowering to 3 full flowering, and the accumulated degree-days ADD was recorded for each period. The following traits were analyzed: a the mean flowering score MFS from 3 to 12 MAP and b a weighted average of the flowering scores that emphasizes early flowering WAS. The cassava accessions were clustered based on principal component analysis PCA. Seven clusters were identified via PCA, with very contrasting traits including a early flowering 8.5 % of the accessions, Group 4); b) consistent flowering after 2036 ADD (0.6 % of the accessions, Group 2); and c) accessions that do not flower (54 % of the accessions, Group 7). For most of the cassava germplasm, flowering occurred during the longest photoperiod (5–6 MAP). This study demonstrated that accessions belonging to Group 2 are very interesting for breeding programs and genomic studies due to their high flowering throughout the year. This is the first report of phenological diversity of flowering and fruiting performance in cassava germplasm.

KERAGAMAN SERANGGA PENGUNJUNG BUNGA KELAPA SAWIT (Elaeis guineensis Jacq) DI PERKEBUNAN SWASTA SINGINGI HILIR, RIAU

Kelapa sawit (Elaeis quineensis Jacq) merupakan salah satu tanaman komoditas andalan sumber devisa non migas bagi Indonesia. Bunga kelapa sawit mengeluarkan senyawa volatil yang dapat mengundang datang nya serangga. Jenis serangga yang mengunjungi bunga kelapa sawit beragam, tidak semua yang mengunjungi bunga mampu berperan sebagai penyerbuk. Penelitian ini bertujuan untuk mempelajari keragaman serangga bunga kelapa sawit sehingga informasi yang diperoleh dapat bermanfaat untuk kegiatan konservasi berikutnya. Identifikasi dilakukan sampai tingkat morfospesies. Metode purposive sampling digunakan untuk menentukan tanaman sampel yang digunakan untuk diamati keragaman serangga pengunjungnya. Berdasarkan hasil pengamatan keragaman pada bunga kelapa sawit diperoleh 16 morfospesies yaitu dengan urutan banyaknya populasi yaitu E. kamerunicus, Gelechiidae sp. 01, Chelisoches sp. Rhabdoscelus sp, Forficula sp, Velinus nigrigenu, Salticidae sp. 1, Formicinae sp.1, Tirathaba sp, Rhinocoris fuscipes, Thrips hawaiiensis, Formicinae sp.2, Metisa sp, Tetragnathide sp. 1, Thomisidae sp. 1, Euchantecona sp. dengan indeks dominasi 0,89, indeks keragaman 0,33 dan indeks kemerataan 0,12 yang tergolong rendah.

Development of Microsatellite Markers for a Dioecious Herpetospermum pedunculosum (Cucurbitaceae).

Understanding the evolution of flower diversity is a central topic in plant evolutionary ecology, and natural selection on floral traits via male fitness could be estimated quantitatively using microsatellites. Here, based on RNA sequencing, we developed simple sequence repeat primers and verified polymorphisms in 2 wild populations of Herpetospermum pedunculosum (Cucurbitaceae), a dioecious annual plants native to the Himalaya Mountains. A total of 131 paired primers were designed; 15 paired primers were found to be polymorphic, with the expected heterozygosity varying between 0.280 and 0.767. We also identified 58 genotypes in 20 plants from the 2 populations. Conclusively, these primers could be effective in examining male fitness and population genetic structure of H pedunculosum in future studies.

Grassland management for meadow birds in the Netherlands is unfavourable to pollinators

Agricultural intensification and loss of semi-natural grassland have contributed to biodiversity decline, including pollinator species, in pastures around the world. To reverse the decline, agri-environmental schemes have been implemented, varying widely in effectiveness. In addition, many countries, including the Netherlands, have established nature reserves in which semi-natural grasslands are restored and are often managed for specific groups of species, e.g. meadow birds or plants. The effects of such measures on insect biodiversity are not well known but recent reports on the dramatic decline of insect biomass in nature reserves have put even more attention to the impact of land use and management on biodiversity. This study compares pollinator abundance and species richness in three common semi-natural grassland management types in the Netherlands: (1) hay meadows, (2) herb-rich grasslands and (3) meadow bird grasslands. Pollinator abundance and species richness were assessed in eleven study areas, each with all three management types present. Standardized transects, insect sampling within a standard 20min time frame and plot-based flower surveys were used in spring and summer to assess the relationships between management regime, floral abundance and diversity and pollinator communities. The results show that meadow bird grasslands have lower pollinator abundance and diversity and a less unique pollinator assemblage than both other types. Moreover, flower abundance has a positive effect on pollinator abundance and flower diversity has a positive effect on pollinator species richness. These results indicate that meadow-bird grasslands are a comparatively unfavourable habitat for bees, hoverflies and butterflies, which may be explained by a lack of flowers as well as unsuitable mowing practices. Measures benefitting both insectivorous birds and flower-visiting insects, such as rotational mowing, could remediate this imbalance.

Variables de influencia para la producción de miel utilizando abejas Apis mellifera en la región de Misantla


 Diversas notas de portales electrónicos, documentales y en menor grado artículos de corte científico, han reportado el interés por mejorar el rendimiento de producción de miel por colmena. Entre estos trabajos pueden encontrarse reportados, en su forma dimensional, factores climáticos, sociales y tecnológicos, en donde expertos y especialistas reconocen que contribuyen a mejorar la producción de miel. Apoyado de expertos apícolas, del método Delphi y el análisis estructural MICMAC, en este artículo se reporta la influencia y dependencia de 22 variables y su relación directa e indirecta con la producción de miel en la región intermunicipal de Misantla del distrito apícola núm. 52. Las variables con base en MICMAC se clasifican en clave, reguladoras, palanca y autónomas. En el plano estratégico, la ‘ubicación del apiario’ relacionado con la ‘diversidad de floración melífera’ y el ‘tiempo que transcurre entre la colocación del apiario y la cosecha de miel’, representan las variables clave con mayor valor estratégico de 75/79, 61/79 y 63/79, respectivamente. Si bien, la ‘floración de especies melíferas’ es una variable clave para producción de miel, el resultado también indica que esta variable no es una determinante para que el apicultor decida la ‘ubicación de apiarios’. Estos resultados aportan conocimiento en cuatro categorías de variables influyentes en la producción de miel para que el apicultor reflexione sobre sus practica apícolas y pueda diseñar estrategias y tomar decisiones, para mejorar el rendimiento de producción miel.

Developmental mechanisms involved in the diversification of flowers.

We all appreciate the fantastic diversity of flowers. How flowers diversified, however, remains largely enigmatic. The mechanisms underlying the diversification of flowers are complex because the overall appearance of a flower is determined by many factors, such as the shape and size of its receptacle, and the arrangement, number, type, shape and colour of floral organs. Modifications of the developmental trajectories of a flower and its components, therefore, can lead to the generation of new floral types. In this Review, by summarizing the recent progress in studying the initiation, identity determination, morphogenesis and maturation of floral organs, we present our current understanding of the mechanisms underlying the diversification of flowers.