The genetic similarities of eight closely related rye cultivars were estimated using two molecular marking techniques : restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) . Cultivars were evaluated for variation by 11 random cDNA and genomic clones used in combination with four restriction enzymes and 40 decamer primers . A total of 53 polymorphic RFLP fragments and 94polymorphic RAPD fragments were observed. Based on the presence/absence of fragments, two genetic similarity matrices were calculated which were then used in cluster analysis . Differences between pair of cultivars were observed in RFLP and RAPD dendrograms . RFLP analysis produced estimates of genetic relationships more in accordance with the partially known pedigree of the cultivars than did RAPD analysis . The use of bulk samples of DNA in these analyses affected the sensitivity of RAPD assays more strongly . Dendrograms which took into account all fragments produced, either by RFLP or RAPD, reflected better the relationships between cultivars than did dendrograms based on only one type of marker. This reflects the importance of the number of markers used in determining the genetic relationships between genotypes .
Fluorescent in situ hybridization (FISH) with multiple probes was used to analyze mitotic and meiotic chromosome spreads of Avena sativa cv 'Sun II' monosomic lines, and of A. byzantina cv 'Kanota' monosomic lines from spontaneous haploids. The probes used were A. strigosa pAs120a (a repetitive sequence abundant in A-genome chromatin), A. murphyi pAm1 (a repetitive sequence abundant in C-genome chromatin), A. strigosa pITS (internal transcribed spacer of rDNA) and the wheat rDNA probes pTa71 (nucleolus organizer region or NOR) and pTa794 (5S). Simultaneous and sequential FISH employing pairs of these probes allowed the identification and genome assignation of all chromosomes. FISH mapping using mitotic and meiotic metaphases facilitated the genomic and chromosomal identification of the monosome in each line. Of the 17 'Sun II' lines analyzed, 13 distinct monosomic lines were found, corresponding to four monosomes of the A-genome, five of the C-genome and four of the D-genome. In addition, 12 distinct monosomic lines were detected among the 20 'Kanota' lines examined, corresponding to six monosomes of the A-genome, three of the C-genome and three of the D-genome. The results show that 19 chromosomes out of 21 of the complement are represented by monosomes between the two genetic backgrounds. The identity of the remaining chromosomes can be deduced either from one intergenomic translocation detected on both 'Sun II' and 'Kanota' lines, or from the single reciprocal, intergenomic translocation detected among the 'Sun II' lines. These results permit a new system to be proposed for numbering the 21 chromosome pairs of the hexaploid oat complement. Accordingly, the A-genome contains chromosomes 8A, 11A, 13A, 15A, 16A, 17A and 19A; the C-genome contains chromosomes 1C, 2C, 3C, 4C, 5C, 6C and 7C; and the D-genome consists of chromosomes 9D, 10D, 12D, 14D, 18D, 20D and 21D. Moreover, the FISH patterns of 16 chromosomes in 'Sun II' and 15 in 'Kanota' suggest that these chromosomes could be involved in intergenomic translocations. By comparing the identities of individually translocated chromosomes in the two hexaploid species with those of other hexaploids, we detected different types of intergenomic translocations.
Fluorescence in situ hybridization (FISH) was used to determine the physical location of the (AC) microsatellite in metaphase chromosomes of six diploid species (AA or CC genomes), two tetraploid species (AACC genome), and five cultivars of two hexaploid species (AACCDD genome) of the genus Avena, a genus in which genomic relationships remain obscure. A preferential distribution of the (AC) microsatellite in the pericentromeric and interstitial regions was seen in both the A- and D-genome chromosomes, while in C-genome chromosomes the majority of signals were located in the pericentromeric heterochromatic regions. New large chromosome rearrangements were detected in two polyploid species: an intergenomic translocation involving chromosomes 17AL and 21DS in Avena sativa 'Araceli' and another involving chromosomes 4CL and 21DS in the analyzed cultivars of Avena byzantina. The latter 4CL-21DS intergenomic translocation differentiates clearly between A. sativa and A. byzantina. Searches for common hybridization patterns on the chromosomes of different species revealed chromosome 10A of Avena magna and 21D of hexaploid oats to be very similar in terms of the distribution of 45S and Am1 sequences. This suggests a common origin for these chromosomes and supports a CCDD rather than an AACC genomic designation for this species.
Satellite DNA specific to the oat C genome was sequenced and located on chromosomes of diploid, tetraploid, and hexaploid Avena ssp. using in situ hybridization. The sequence was present on all seven C genome chromosome pairs and hybridized to the entire length of each chromosome, with the exception of the terminal segments of some chromosome pairs. Three chromosome pairs belonging to the A genome showed hybridization signals near the telomeres of their long arms. The existence of intergenomic chromosome rearrangements and the deletions of the repeated units are deduced from these observations. The number of rDNA loci (18S-5.8S-26S rDNA) was determined for the tetraploid and hexaploid oat species. Simultaneous in situ hybridization with the satellite and rDNA probes was used to assign the SAT chromosomes of these species to their correct genomes.
A three-gene data set was generated to explore species diversity and delimitations within the stalked puffballs (Tulostoma, Agaricales) in Europe. Data on species from other parts of the world were included for comparison of species concepts and distribution ranges. Sequence data from 26 type specimens are included. The phylogenetic analyses support Tulostoma as monophyletic. Eleven major clades, 37 minor clades, and 20 single branches were recovered and found to correspond to 30 described species and 27 species without scientific names.Five species are here described as new to science: Tulostoma calcareum, T. calongei, T. eckbladii, T. grandisporum, and T. pannonicum. In total we report 26 described, and 19 undescribed, species from Europe. An epitype for T. fimbriatum with ITS sequence data is selected to fix the name.The recovered tree topology was not in congruence with the current infrageneric classification of Tulostoma, suggesting that many of the morphological characters used for segregation of taxa are plesiomorphic or homoplasious. Spore ornamentation and hyphal structure of the peridium are found to be reliable characters for delimitation of species. RESEARCH ARTICLEMikael Jeppson et al. / MycoKeys 21: 33-88 (2017) 34The majority of the species occur in the dry, arid areas of southern and east central Europe but a few are shown to be restricted to humid temperate regions in the North. The study confirms that species with smooth or sub-smooth spores are restricted to dry and arid habitats whereas species with more strongly ornamented spores occur in humid habitats.Areas with steppe vegetation in Hungary and Spain are here identified as hot spots for Tulostoma species diversity.
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