Pollen morphology of nine species representing four genera: Cephalaria Schrad, Dipsacus L., Pterocephalus Vaill. and Scabiosa L. of the family Dipsacaceae in Iran has been investigated by means of scanning electron microscopy (SEM). The results showed that pollen grains were triporate and tricolpate. The pollen type of Scabiosa rotata Bieb. (tri-and tetraporate) is the first report in the world. The sizes of pollen grains fall into the classification group magna (pollen grain diameter 50-100 µm). Pollen shapes vary from preoblate to prolate and their polar views were triangulate and lobate. The exine ornamentation varies from gemmate in S. rotata to spinulate in the rest studied species. Species of Scabiosa have been dispersed in UPGMA tree that this confirmed the previous studies about taxonomic problems and species complexity in this genus. These results show the transfer of the some Scabisoa species to Lomelosia Raf. based on palynological characters. Pollen morphology of the family is helpful at the generic and specific level.
Besides Quercus, Acer L. genus is the largest tree genus in the Northern Hemisphere and consists of about 124-156 species. High morphological and molecular variability has led to infra-specific complexity within most species of this genus. In Iran, the Acer cappadocicum subsp. cappadocicum Gled. is distributed in eastern to western parts of the Hyrcanian forests. In this study, three leaf-morphotypes in A. cappadocicum Gled. were identified during sampling in a forest located in the Hyrcanian region, leading to obscuring taxonomic situations of this taxon. Against this backdrop, the present study was performed to clarify intraspecific situation of this valuable tree using both macro-/micromorphological and molecular approaches. Forty-five plant samples of A. cappadocicum were randomly selected within nine geographical regions of four provinces in Hyrcanian forests of Iran. Internal transcribed spacer (ITS) (for eight individuals) and inter-simple sequence repeat (ISSR) molecular markers (for 45 individuals) were used along with the epidermal scanning electron micrograph (SEM) of the leaf epidermis. Considering the obtained results, acceptance of the expected lower taxa in A. cappadocicum ssp. cappadocicum in north of Iran could not be supported by molecular evidence. Results of the study indicated no correlation between variations in leaf-morphology, ISSRs, and ITS. However, there are two main clusters in ITS tree without discrete morphological characters showing differentiation and variability in ITS region within this species. This subspecies was compared also with other subspecies.
One of the greatest challenges in ecology is to understand and predict the functional outcome of interaction networks. Size‐matching between plants and pollinators is one of the key functional traits expected to play a major role in structuring plant–pollinator interactions. However, the community‐wide patterns of size‐matching remain largely unexplored. We studied the association between the degree of size‐matching and foraging efficiency, pollination efficiency and the probability of pairwise interactions in a community of Lamiaceae. Our study revealed that foraging efficiency is maximal when bee proboscis length corresponds to the corolla tube depth of the flower visited. Pollination efficiency was maximal when the bee body height corresponds to the corolla width of the flower visited. While the degree of size‐matching did not influence the probability of interaction, it significantly influenced the strength of the interaction in terms of visitation frequency. We suggest a size‐matching index as a reliable metric to predict the frequency of interactions as well as the effectiveness of visits in terms of foraging efficiency and pollination efficiency.
The evolution of bilabiate flowers in Lamiaceae has several times led to a reduction in stamen number. It is generally assumed that stamen reduction goes along with decreasing pollen production. One should, therefore, expect that bistaminate flowers have either a more efficient pollen transfer mechanism or a higher selfíng rate than tetrastaminate species to adapt to the stamen reduction. We tested this hypothesis in a community of Lamiaceae including three bistaminate and three tetrastaminate species. The results of selfing experiments, extra-pollination, counting pollen number, and stigmatic pollen load analysis were used to calculate the autonomous selfing index, the pollen limitation index, and the pollination efficiency index. The results indicate a significantly lower pollen number in bistaminate flowers than in tetrastaminate flowers of similar anther size. Bistaminate species shared a higher selfing rate which was related to their structural adaptation to delayed selfing. In Ziziphora clinopodioides, the delayed selfing was accompanied by low pollination efficiency, and plants suffered from pollen limitation at the location studied. However, in Salvia sclarea and Salvia hypoleuca, which benefited from a relatively high pollination efficiency, no pollen limitation was observed. Our results reveal a close association between adaptive mechanisms such as increasing precision of pollen transfer and evolution of delayed selfing with stamen reduction in bistaminate Lamiaceae.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.