Studies of Neotropical Compositae—XIX. Sciadocephala gentryi (Eupatorieae), a New Species from Pasco, Peru

Gone with the wind: understanding evolutionary transitions between wind and animal pollination in the angiosperms

Premise of research. Evolutionary transitions from insect to wind pollination are thought to have occurred many times during the angiosperm radiation. On the basis of floral features, several such transitions have been postulated for Leucadendron (Proteaceae), a dioecious genus of 96 taxa confined almost entirely to the Cape Floristic Region. To confirm whether these transitions took place, we carried out experimental tests for wind pollination and sampled insect flower visitors in 15 Leucadendron species, representing six clades in the genus. Methodology. In three clades in which an insect-wind shift has been inferred, we sampled species with traits suggestive of either wind or insect pollination. Plants were bagged with fine-mesh exclusion bags that excluded insects but allowed the passage of airborne pollen. Insects visiting female inflorescences were collected for identification and analysis of their pollen loads. Pivotal results. We found that insect exclusion had little effect on seed set of five species conforming to the wind pollination syndrome (L. rubrum, L. salicifolium, L. dubium, L. coniferum, and L. teretifolium), while seed set was strongly reduced by insect exclusion in the remaining 10 species conforming to an insect pollination syndrome. The most common pollinator of the insect-pollinated species was the nitidulid beetle Pria cinerascens. Conclusions. This study provides experimental verification of contrasting insect and wind pollination systems in Leucadendron and will thus enable formal phylogenetic tests of adaptive changes in floral traits, such as color and scent, that may be associated with pollination system transitions in this diverse lineage.

The Andean swamp rat Neotomys ebriosus is a sigmodontine rodent restricted to the Central Andes of South America. A distribution map of the species in Peru have been previously drawn based on few of the localities where the species has been captured and collected. I update the distribution of the species in Peru based on new records from three different areas surveyed by the author, specimens at Museum collections in the United States and France from VertNet webpage, localities from the collection at the Natural History Museum of Universidad Nacional Mayor de San Marcos, and localities from the collection at the Natural History Museum of the Universidad Nacional San Agustín. The northern limit of the species distribution is increased based on new localities with collected individuals. Habitat used by N. ebriosus is mainly high Andean bogs; most individuals caught adjacent to the borders of Andean bogs and along streams near the bogs. Collected individuals leave unclear subspecies division and identity.

<p>Floral reward is important in ecological and evolutionary perspectives and essential in pollination biology. For example, floral traits, nectar and pollen features are essential for understanding the functional ecology, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant–pollinator interactions. We believe to present a synthetic description in the field of floral reward in Ranunculaceae family important in pollination biology and indicating connections between ecological and evolutionary approaches. The links between insect visitors’ behaviour and floral reward type and characteristics exist. Ranunculaceae is a family of aboot 1700 species (aboot 60 genera), distributed worldwide, however the most abundant representatives are in temperate and cool regions of the northern and southern hemispheres. The flowers are usually radially symmetric (zygomorphic) and bisexual, but in Aconitum, Aquilegia are bilaterally symmetric (zygomorphic). Most Ranunculaceae flowers offer no nectar, only pollen (e.g., Ranunculus, Adonis vernalis, Thalictrum), but numerous species create trophic niches for different wild pollinators (e.g. Osmia, Megachile, Bombus, Andrena) (Denisow et al. 2008). Pollen is a source of protein, vitamins, mineral salts, organic acids and hormones, but the nutritional value varies greatly between different plant species. The pollen production can differ significantly between Ranunculacea species. The mass of pollen produced in anthers differ due to variations in the number of developed anthers. For example, inter-species differences are considerable, 49 anthers are noted in Aquilegia vulgaris, 70 anthers in Ranunculus lanuginosus, 120 in Adonis vernalis. A significant intra-species differences’ in the number of anthers are also noted (e.g. 41 to 61 in Aquilegia vulgaris, 23-45 in Ranunculus cassubicus. Pollen production can be up to 62 kg per ha for Ranunculus acer on meadows. Nectaries are secretory structures that synthesize and release nectar, a multi-component carbohydrate-rich aqueous solution. The relative location of nectaries within a flower is under pressure to maximize relations with pollinators, and hence to ensure the deposition of pollen on the stigma by pollinators. Nectaries are common in Ranunculaceae. Location, morphology and structure of the floral nectaries differ among Ranunculaceae representatives. Nectaries are tubular in Helleborus spp. or situated in nectary spurs (Aconitum, Aquilegia). Nectaries consist of an external epidermis, a photosynthesizing parenchyma, large branches of vascular tissue, a nectar-producing parenchyma, and an internal epidermis (Vesprini et al. 2008). Nectar production is generally associated with mutualistic relations with animals that rely on sugar secretions in their nutrition. Inter-species differences in the amount of nectar produced and nectar chemistry are noted among Ranunculaceae species. Significant variations in nectar carbohydrate composition between male and female sexual phases occur both in the protandrous and protogynous flowers. In Aconitum carmichaelii, male-phase flowers produced 2.4-fold more nectar than female-phase flowers. Nectar sugar composition can differ between species within genera. The nectar can be sucrose-dominant, e.g. in Aconitum carmichaelii or sucrose-rich and lacking glucose in A. lycoctonum (Antoń & Denisow 2014). Variability in nectar production and/or carbohydrate composition in an individual plant may be considered to be evolutionarily significant. It can modify insect movements between flowers and plants, impact on visitation rates, reduce geitonogamy and thus increase plant fitness by cross-pollination. The floral morphology and the type of the floral attractant in Anemone sylvestris is an example of the in-between form from entomophily to anemophily (lack of nectar, papillous stigma, dense hairs situated between single carpels, small pollen grains – 10-25 µm, lack of balsam on the exine surface, starch accumulation in pollen). In conclusion, the flower morphology and type of floral reward in Ranunculaceae species indicate the patterns for generalized insect visitors/pollinators (Apoidea bees, Coleoptera, Diptera) in actinomorphic species, for specialization towards bumblebees or show in-between form from entomophily to anemophily.</p>

栽培イネは花器構造上自殖性が強いのでF1雑種の種子親として使われる雄性不稔個体上の結実率は低く，経済的採種は困難た現状にある.したがって，イネの受粉生態や花器形質を調査し，高い自然交雑率が確保できる種子規，花粉親の特性を明らかにするとともに，F1採種圃で自然交雑が高頻度で起こる条件を明らかにする必要がある.そこで本研究では，種子規・花粉親の花器形質と自然交雑率の関係を調査した.一方，F1採種時の種子親の自然交雑率にかかわる要因として空中花粉量と風速を取り上げ，自然交雑率との関係を調査した.その結果，種子親の花器形質として，柱頭露出しやすい性質は自然交雑率を高めることと密接に関係していることが明らかとなった.さらに，柱頭露出願花率，雌蕊または柱頭が大きいことならびに，各頴花の開頴時間が長く，かつ開頴角度が大きいことは相互に正の相関関係を持ち，しかも，これらは自然交雑による結実率向上とかかわることがわかった.また，花粉親の花器形質として，葯抽出時の葯内花粉残存数の多い品種が，多数の花粉を空中に放出する上で優れていることが明らかとなった.種子親の結実率と空中花粉量および風速との関係については，空中花粉量が多く風速が2～3m/secの場合には自然交雑による結実率が高いことがわかった、以上のことから，よく柱頭が露出する種子親と蒲抽出時の花粉残存数が多い花粉親を用い，2～3m/secの風速下で採種を行えば，効率の高いイネのF1採種が可能と考えられた.

Pollination efficacy in the dioecious Coprosma spathulata was investigated in eight 900-m2 study plots. Mean fruit set was generally high (>75% in six of eight populations), aided by male-biased populations, male floral abundance and extended female receptivity in unpollinated flowers. However, pollen receipt and fruit set were both susceptible to reduction by dense understory vegetation, low abundance of males at the plot scale and in isolated females. There was a steep reduction in fruit set when females were >7 m from the nearest male, suggesting Allee effects in isolated females and in low-density populations. Although C. spathulata lives in an unpromising habitat for wind pollination, floral characteristics and flowering behaviour ensure it is surprisingly successful.

Evolution of dioecy among plants is a distinct phenomenon, debated extensively among biologists. It has now been realized that besides the underlying gender determination mechanisms, it is equally important to understand the contextual framework of eco-evolutionary forces that are instrumental in shaping dioecy in general. The theoretical framework of evolution of dioecy is well-argued in literature. Several empirical studies have indicated ecological factors like habitat, floral features, wind pollination, and clonality to be advantageous for establishing dioecy. Further, resource partitioning among genders is known to modulate the sex ratios, which is crucial for its evolutionary maintenance. How these factors influence evolutionary pathways and evolution of dioecy, has not been sufficiently investigated. Available phylogenetic analyses indicate that the factors are interlinked, and that they serve as usual correlates of dioecy. Although, such associtations are not clearly elucidated in literature due to paucity of information about the prevailing sexual systems, further obscured by low species richness in existing dioecious clades. In this chapter, we present a conspectus of present understanding of ecological correlates of evolution and maintenance of dioecy, especially among the flowering plants. The information which has emerged so far indicates the involvement of multivariable eco-evolutionary suites. However, in order to appropriately characterize them, there is need to extend empirical studies on the complete range of sexual variation.

Thymelaea hirsuta is a circum-Mediterranean subdioecious shrub used to model the evolutionary pathway from heterodichogamy to dioecy. Since discordant data on the pollination mechanism of this plant have been reported, in this study we have tried to clarify the complex of features and events involved in the breeding system of this species at the Northern edge of its range (Tyrrhenian coast, Italy and France). Flower and pollen features related to pollination mechanism were analyzed, and the seasonal presence of insects visiting the plant was monitored. Despite the presence of small pollen grains, normally associated with wind pollination, the Crotonoid-pattern of exine, the large amount of pollenkitt and the presence of nectar are typical entomophilous adaptations. Among insects visiting the plant, thrips (Thysanoptera) might have a role in pollination owing to their large number and for the constant presence of T. hirsuta pollen on their body. In contrast, no evidence of anemophilous transport of pollen was obtained, clashing with reports of a wind pollination system for Egyptian populations. Based on our observations wind seems not to play a key role in the pollination process of this species in the Northern Mediterranean region, while insects might play a major role.

濒危植物丰都车前的繁育系统与传粉生物学研究

金沙江干热河谷滇榄仁开花物候与繁育系统

Sexual dimorphism and pollination mechanism of Zanthoxylum armatum, a vulnerable medicinally important dioecious tree

<p><strong>Background</strong>. Common bean (<em>Phaseolus vulgaris</em> L.) is a species of great importance in Peru due to its high nutritional value, wide diversity, and its significant contribution to the economic income of thousands of families involved in the production of this crop. <strong>Objective</strong>. To characterize the agromorphological diversity of 50 common bean accessions from Peru. <strong>Methodology</strong>. 21 qualitative and 17 quantitative traits were evaluated using descriptive analysis, multiple correspondence analysis, analysis of variance, Scott-Knott test, principal components analysis, Pearson correlation coefficient, and hierarchical clustering analysis using Euclidean distance and the Ward method. <strong>Results</strong>. The multiple correspondence analysis revealed greater diversity in the qualitative traits of the predominant color of the wings, the standard leaf blade, green pod color, as well as the predominant seed shape and primary seed color. In the quantitative traits, the following were observed: hypocotyl length, epicotyl length, pod width, pod apex length, days to flowering, 100-seed weight, and yield. The Pearson correlation coefficient showed positive correlations for pod length and width, seed length and width, and 100-seed weight. Principal components analysis indicated that the first two dimensions explained 47.6 % of the total variance, and five hierarchical groups were established. <strong>Implications</strong>. Describing the agromorphological diversity of common bean contributes to the knowledge of this species in Peru, which is essential for establishing mechanisms for its preservation. <strong>Conclusions</strong>. The diversity of common bean in Peru is notably explained by the variability of qualitative and quantitative traits, influenced mainly by its geographical origin, with accession PER013004 standing out for its productivity and early flowering.</p>

Se registra un nuevo espécimen de Langea euprosopides W. Horn, 1901 en la región Cusco (Perú). El género Langea W. Horn contiene tres especies. Debido a la falta de observaciones de miembros de este género en su ambiente natural, se desconocen sus hábitos, ciclo biológico y sus estadios de ciclo de vida. El género es aparentemente endémico del Perú. Se presentan algunos datos sobre el posible sustrato de captura y un mapa de distribución de la especie en el Perú.

Nearly forty years ago R. L. Berg proposed that plants with specialized pollination ecology evolve genetic and developmental systems that decouple floral morphology from phenotypic variation in vegetative traits. These species evolve separate floral and vegetative trait clusters, or as she termed them, "correlation pleiades." The predictions of this hypothesis have been generally supported, but only a small sample of temperate-zone herb and grass species has been tested. To further evaluate this hypothesis, especially its applicability to plants of other growth forms, we examined the patterns of phenotypic variation and covariation of floral and vegetative traits in nine species of Neotropical plants. We recognized seven specific predictions of Berg's hypothesis. Our results supported some predictions but not others. Species with specialized pollination systems usually had floral traits decoupled (weak correlation; Canna and Eichornia) or buffered (relationship with shallow proportional slope; Calathea and Canna) from variation in vegetative traits. However, the same trend was also observed in three species with unspecialized pollination systems (Echinodorus, Muntingia, and Wedelia). One species with unspecialized pollination (Croton) and one wind-pollinated species (Cyperus) showed no decoupling or buffering, as predicted. While species with specialized pollination usually showed lower coefficients of variation for floral traits than vegetative traits (as predicted), the same was also true of species with unspecialized or wind pollination (unlike our prediction). Species with specialized pollination showed less variation in floral traits than did species with unspecialized or wind pollination, as predicted. However, the same was true of the corresponding vegetative traits, which was unexpected. Also in contrast to our prediction, plants with specialized pollination systems did not exhibit tighter phenotypic integration of floral characters than did species with generalized pollination systems. We conclude that the patterns of morphological integration among floral traits and between floral and vegetative traits tend to be species specific, not easily predicted from pollination ecology, and generally more complicated than R. L. Berg envisaged.

Styrax buchananii, recorded as endemic to Myanmar, has been known only in flower and S. chrysocarpus, endemic to China, only in fruit. Here we report the rediscovery of S. buchananii and S. chrysocarpus after ca. 100 and 70 years, respectively, since their publication. Both species were found in Yunnan Province, China. We also update the morphological descriptions of the two species to include fruit and floral characters, respectively, and provide a table of morphological characters that distinguish them from each other. A distribution map, photographs of living plants, and conservation assessment of each species are also provided.