RESUMO
A new species, Alliumsunhangiisp. nov., of the Middle Asiatic section Brevidentia F.O.Khass. & Iengal., (subgenusAllium, tribe Allioideae, Amaryllidaceae) is described. The species is a small plant from the Babatag Ridge in the Surkhandarya province of Uzbekistan. It is morphologically close to Alliumbrevidens Vved. in having initially dark violet filaments and three-cuspidate inner filaments, but differs by its small size and visibly unequal tepals as well as in the phylogenetic analysis based on ITS data.
RESUMO
BACKGROUND AND AIMS: Macro- and micromorphology of seeds are diagnostic characteristics of importance in delimiting taxa in Allium (Amaryllidaceae). However, there is no consensus on the phylogenetic significance of testa cell characteristics and whether they reflect the different evolutionary levels recognized in Allium. METHODS: Seeds of 95 species (98 samples) representing 14 subgenera and 58 sections of Allium were examined using scanning electron microscopy (SEM) for such traits as periclinal wall surface area of ten testa cells, distance between testa cells (macromorphology), testa cell shapes, and arrangement and structure of anticlinal and periclinal walls (micromorphology). The data matrix was subjected to cladistic analysis. The produced phylogenetic tree was examined against the molecular tree obtained from publically available ITS sequences. KEY RESULTS: The periclinal wall surface area of ten testa cells and the distance between them, examined for the first time, were found useful for delimitation of species in Allium. Based on seed macro- and micromorphology, we present a taxonomic key and a hypothetical reconstruction of the migration routes during the early stages of evolution of Allium. CONCLUSIONS: The ancestors of Allium originated in an area bounded by the Caucasus, Central Asia and Iran. The seed testa morphology-based evolutionary state of a species is determined by two parameters: the shape of the periclinal walls and curvature of the anticlinal walls.
Assuntos
Allium , Amaryllidaceae , Allium/genética , Microscopia Eletrônica de Varredura , Filogenia , Sementes/anatomia & histologiaRESUMO
Allium sect. Cepa (Amaryllidaceae) comprises economically important plants, yet resolving the phylogenetic relationships within the section has been difficult as nuclear and chloroplast-based phylogenetic trees have been incongruent. Until now, phylogenetic studies of the section have been based on a few genes. In this study, we sequenced the complete chloroplast genome (plastomes) of four central Asian species of sect. Cepa: Allium oschaninii, A. praemixtum, A. pskemense and A. galanthum. Their chloroplast (cp) genomes included 114 unique genes of which 80 coded proteins. Seven protein-coding genes were highly variable and therefore promising for future phylogenetic and phylogeographic studies. Our plastome-based phylogenetic tree of Allium sect. Cepa revealed two separate clades: one comprising the central Asian species A. oschaninii, A. praemixtum, and A. pskemense, and another comprising A. galanthum, A. altaicum, and two cultivated species, A. cepa and A. fistulosum. These findings contradict previously reported phylogenies that relied on ITS and morphology. Possible explanations for this discrepancy are related to interspecific hybridization of species ancestral to A. galanthum and A. cepa followed by chloroplast capture; however, this is impossible to prove without additional data. Our results suggest that the central Asian Allium species did not play a role in the domestication of the common onion. Among the chloroplast genes, rpoC2 was identified as a gene of choice in further phylogeographical studies of the genus Allium.
RESUMO
BACKGROUND: Hitherto available sources from literature mentioned several wild growing Allium species as "edible" or "medicinally used" but without any further specification. METHODS: New data were gained during recent research missions: Allium plants were collected and shown to the local population which was asked for names and usage of these plants. RESULTS: Information was collected about current medical applications of sixteen wild species, nine of which belong to different sections of Allium subgenus Melanocrommyum. These plants are used against headache, cold, and stomach problems, and are mostly applied fresh or after boiling. CONCLUSION: Close taxonomic relatives of the common onion were used similar to cultivated onion species, but medical use like garlic was mostly reported for species taxonomically not related to garlic.