Modern Phytomorphology 9 (Suppl.): 87–88, 2016

Floral reward inRa nunculaceae

Bożena Denisow *, Monika Strzałkowska-Abramek, Anna Jeżak

Key words: , nectar production, pollen production, floral phases, insect visitors

Department of Botany, University of Life Sciences, 15 Akademicka Str., 20-950 Lublin, Poland; * [email protected]

Floral reward is important in ecological species differences are considerable, 49 anthers and evolutionary perspectives and essential are noted in Aquilegia vulgaris, 70 anthers in in pollination biology. For example, floral Ranunculus lanuginosus, 120 in Adonis vernalis. traits, nectar and pollen features are essential A significant intra-species differences’ in the for understanding the functional ecology, the number of anthers are also noted (e.g. 41 to dynamics of pollen transport, competition for 61 in Aquilegia vulgaris, 23-45 in Ranunculus pollinator services, and patterns of specialization cassubicus. Pollen production can be up to 62 kg and generalization in –pollinator per ha for Ranunculus acer on meadows. interactions. We believe to present a synthetic Nectaries are secretory structures that description in the field of floral reward in synthesize and release nectar, a multi-component Ranunculaceae family important in pollination carbohydrate-rich aqueous solution. The relative biology and indicating connections between location of nectaries within a flower is under ecological and evolutionary approaches. The pressure to maximize relations with pollinators, links between insect visitors’ behaviour and and hence to ensure the deposition of pollen on floral reward type and characteristics exist. the stigma by pollinators. Nectaries are common Ranunculaceae is a family of aboot in Ranunculaceae. Location, morphology and 1700 species (aboot 60 genera), distributed structure of the floral nectaries differ among worldwide, however the most abundant Ranunculaceae representatives. Nectaries are representatives are in temperate and cool tubular in Helleborus spp. or situated in nectary regions of the northern and southern spurs (, Aquilegia). Nectaries consist hemispheres. The flowers are usually radially of an external epidermis, a photosynthesizing symmetric (zygomorphic) and bisexual, but in parenchyma, large branches of vascular tissue, a Aconitum, Aquilegia are bilaterally symmetric nectar-producing parenchyma, and an internal (zygomorphic). Most Ranunculaceae flowers epidermis (Vesprini et al. 2008). offer no nectar, only pollen (e.g., Ranunculus, Nectar production is generally associated Adonis vernalis, Thalictrum), but numerous with mutualistic relations with animals that species create trophic niches for different wild rely on sugar secretions in their nutrition. Inter- pollinators (e.g. Osmia, Megachile, Bombus, species differences in the amount of nectar Andrena) (Denisow et al. 2008). produced and nectar chemistry are noted among Pollen is a source of protein, vitamins, Ranunculaceae species. Significant variations mineral salts, organic acids and hormones, but in nectar carbohydrate composition between the nutritional value varies greatly between male and female sexual phases occur both in different plant species. The pollen production the protandrous and protogynous flowers. In can differ significantly between Ranunculacea Aconitum carmichaelii, male-phase flowers species. The mass of pollen produced in produced 2.4-fold more nectar than female- anthers differ due to variations in the number phase flowers. Nectar sugar composition can of developed anthers. For example, inter- differ between species within genera. The nectar

© The Author(s), 2016 88 Modern Phytomorphology 9 Suppl. (2016) can be sucrose-dominant, e.g. in Aconitum indicate the patterns for generalized insect carmichaelii or sucrose-rich and lacking glucose visitors/pollinators (Apoidea bees, Coleoptera, in A. lycoctonum (Antoń & Denisow 2014). Diptera) in actinomorphic species, for Variability in nectar production and/or specialization towards bumblebees or show in- carbohydrate composition in an individual between form from entomophily to anemophily. plant may be considered to be evolutionarily significant. It can modify insect movements References between flowers and , impact on visitation rates, reduce geitonogamy and thus increase Antoń S., Denisow B., 2014. Nectar production and plant fitness by cross-pollination. The floral carbohydrate composition across floral sexual phases: morphology and the type of the floral attractant contrasting patterns in two protandrous Aconitum in Anemone sylvestris is an example of the in- species (Delphinieae, Ranunculaceae). Flora 209 (9): 464–470. Doi: 10.1016/j.flora.2014.07.001 between form from entomophily to anemophily Denisow B., Wrzesień M., Cwener A. 2008. The (lack of nectar, papillous stigma, dense hairs estimation of Adonis vernalis populations in chosen situated between single carpels, small pollen patches of Lublin Upland. Acta Agrobot. 61 (1): 3–11. grains – 10-25 µm, lack of balsam on the exine Vesprini J.L., Nepi M., Ciampolini F., Pacini E. surface, starch accumulation in pollen). 2008. Holocrine secretion and cytoplasmic content In conclusion, the flower morphology and of Helleborus foetidus L. (Ranunculaceae) nectar. Plant type of floral reward in Ranunculaceae species Biol. 10 (2): 268–271.