Remarks on the subfam. Betoideae (Chenopodiaceae/Amaranthaceae sensu APGIV)

Subfam. Betoideae (Amaranthaceae Juss./Chenopodiaceae Vent. sensu APGIV) is a monophyletic group which comprises five genera (Aphanisma, Beta, Hablitzia, Oreoblitum, and Patellifolia) and an undefined number of species (11‒16 according to the available literature). While the taxonomic position of the various groups in Betoideae is quite well studied and clarified, nomenclature is still poorly investigated and several names remain to be untypified. The present research has the aim to present a comprehensive view of all taxa (at all ranks) beloning to Betoideae by a list of their accepted names, main synonyms, and types. Taxonomic considerations were also made. The names Aphanisma blitoides, Beta patula, Beta lomatogona, Beta macrorhiza, Beta nana, Beta macrocarpa, Beta bourgaei (= Beta macrocarpa), Oreobliton thesioides, and Beta procumbens are typified on specimens deposited respectively at K (lecto-), BM (lecto-), LE (lecto-), H (lecto-), K (neo-, isoneotypes a FI, GOET, K, WAG), PAL (neo-), G (lecto-, isolectoypes a G, K), P, and C (neo-). The typification of the name Hablitzia tamnoides by Menitsky was discussed and accepted. A new nomenclature change [Beta sect. Corollinae subsect. Nanae (Ulbr.) Iamonico, comb. et stat. nov.] and two new taxa (Beta sect. Beta subsect. Patulae Iamonico, subsect. nov., and Beta sect. Macrocarpae Iamonico, sect. nov.) were proposed. A new classification of Subfam. Betoideae was proposed, including 2 tribes (Beteae, and Hablitzieae), 5 genera (Aphanisma, Beta, Hablitzia, Oreoblitum, and Patellifolia), and for the genus Beta 3 sections and 4 subsections (sect. Beta subsect. Beta, Beta sect. Beta subsect. Patulae Iamonico subsect. nov., sect. Corollinae subsect. Corollinae, sect. Corollinae subsect. nanae (Ulbr.) Iamonico comb. et stat. nov., Beta sect. Macrocarpae Iamonico sect. nov.).

Construction and characterization of a BAC library for the molecular dissection of a single wild beet centromere and sugar beet (Beta vulgaris) genome analysis

We have constructed a sugar beet bacterial artificial chromosome (BAC) library of the chromosome mutant PRO1. This Beta vulgaris mutant carries a single chromosome fragment of 6-9 Mbp that is derived from the wild beet Beta procumbens and is transmitted efficiently in meiosis and mitosis. The library consists of 50 304 clones, with an average insert size of 125 kb. Filter hybridizations revealed that approximately 3.1% of the clones contain mitochondrial or chloroplast DNA. Based on a haploid genome size of 758 Mbp, the library represents eight genome equivalents. Thus, there is a greater than 99.96% probability that any sequence of the PRO1 genome can be found in the library. Approximately 0.2% of the clones hybridized with centromeric sequences of the PRO1 minichromosome. Using the identified BAC clones in fluorescence in situ hybridization experiments with PRO1 and B. procumbens chromosome spreads, their wild-beet origin and centromeric localization were demonstrated. Comparative Southern hybridization of pulsed-field separated PRO1 DNA and BAC inserts indicate that the centromeric region of the minichromosome is represented by overlapping clones in the library. Therefore, the PRO1 BAC library provides a useful tool for the characterization of a single plant centromere and is a valuable resource for sugar beet genome analysis.Key words: Beta vulgaris, BAC library, Beta procumbens minichromosome, centromere, FISH.