Allelic variation and distribution of HMW glutenin subunit 1Ay in Triticum species

The allelic variation and distribution of high-molecular-weight (HMW) glutenin subunit 1Ay in 814 Triticum lines were investigated by sodium dodecyl sulfate polyacrylamide-gel electrophoresis (SDS–PAGE). 1Ay subunit existed in 13 out of analyzed 21 species. The four species T. turgidum L., T. polonicum L., T. turanicum Jakubz. and T. zhukovskyi Men. et Er. were firstly discovered with expressed 1Ay subunit. The distribution frequencies for diploid, tetraploid and hexaploid wheats were at 87.89, 20.31 and 1.79%, respectively. Among the observed eight 1Ay alleles, three with the electrophoretic mobilities similar to 1Bx6, 1By8, and between 1By8 and 1Dy10 were firstly observed. Five had the mobilities similar to 1Bx6, 1Bx7, 1By8, 1Dy10, and 1Dy12 in Glu-1B and Glu-1D loci of hexaploid wheat. It is very difficult to distinguish these 1Ay alleles in Glu-1Ay from those in hexaploid wheat. The predominant 1Ay alleles were those with the mobilities similar to 1Bx7, 1By8, 1Dy10 and 1Dy12, and faster than 1Dy12. Comparison results of 1Ay alleles in different species indicated that multiple diploid lines were involved in the evolution process of tetraploid wheat. The 1Ay allelic variations and genetic resources might be useful in the quality improvement of common wheat.     

Genetic diversity of HMW glutenin subunits in diploid,tetraploid and hexaploid <Emphasis Type="Italic">Triticum</Emphasis> species

The genetic variations of high-molecular-weight (HMW) glutenin subunits in 1051 accessions of 13 Triticum subspecies were investigated using sodium dodecyl sulfate polyacrylamide-gel electrophoresis. A total of 37 alleles were detected, resulting in 117 different allele combinations, among which 20, 68 and 29 combinations were observed in diploid, tetraploid and hexaploid wheats, respectively. Abundance and frequency of allele and combinations in tetraploid wheats were higher than these in hexaploid wheats. Allele Glu-A1c was the most frequent subunit at Glu-A1 locus in tetraploid and hexaploid wheats. Consequently, the results also suggested that the higher variations occurred at Glu-B1 locus compared to Glu-A1 and Glu-D1. Therefore, carthlicum wheat possessing the allele 1Ay could be presumed a special evolutional approach distinguished from other tetraploid species. Furthermore, this provides a convenient approach of induction of the 1Ay to common wheat through direct cross with carthlicum wheat. Alleles Glu-B1c and Glu-B1i generally absent in tetraploid wheats were also found in tetraploid wheats. Our results implied that tetraploid and hexaploid wheats were distinguished in dendrogram, whereas carthlicum and spelta wheats and however displayed the unique performance. In addition, founder effect, no-randomness of diploidization, mutation and artificial selection could cause allele distribution of HMW-GS in Triticum. All alleles of HMW-GS in Triticum could be further utilized through hybrid in the quality improvement of common wheat.     

Polymorphism of high M r glutenin subunits in wild emmer Triticum turgidum subsp. dicoccoides: chromatographic,electrophoretic separations and PCR analysis of their encoding genes

Triticum turgidum subsp. dicoccoides (Körn. ex Asch. et Graebn.) Thell. (AABB), the immediate progenitor of tetraploid and hexaploid wheats, is a species characterised by a wide range of protein polymorphism and by high protein content. Surveys on polymorphism and genetic control of the high molecular weight glutenin subunits (HMW-GS) present in this species, in two forms x- and y-type at the Glu-A1 and Glu-B1 loci, are still considered useful, both to improve technological properties of breeding varieties and to study the genome evolutionary process in wheats. Comparative Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoretic and Reversed Phase High Performance Liquid Chromatographic analyses (SDS-PAGE, RP-HPLC) of the HMW-GS present in several accessions of T. turgidum subsp. dicoccoides allowed the detection of new alleles of Glu-A1 and Glu-B1 loci, with x- and y-type glutenin subunits, apparently similar to those present in cultivated wheats in molecular weight, but different in surface hydrophobicity. In addition, changes in the number of x- and y-type subunits at the glutenin loci were also ascertained. The y-type subunits at the Glu-A1 locus, which are never expressed in cultivated bread and durum wheats, and single y-type expressed glutenin subunits at the Glu-B1 locus were also identified in several accessions. DNA extracted from samples, differing in number or type of HMW-GS and corresponding to x- and y-type genes at Glu-1 loci, were amplified using specific primers, two of which were constructed within the transposon-like sequence of Chinese Spring DNA and analysed by polymerase chain reaction. The results showed this insertion in some accessions of T. turgidum subsp. dicoccoides and also the presence of silent Ax, Bx and By type genes. The usefulness for breeding of these comparative analyses carried out on different HMW-GS alleles detected in Triticum turgidum subsp. dicoccoides, is discussed.     

Characterization of a world collection of <Emphasis Type="Italic">Agropyron cristatum</Emphasis> accessions

The genetic diversity was studied of 115 Agropyron cristatum accessions from 17 countries. Tetraploids were the most common (74.8%), followed by diploid (16.3%) and hexaploid (6.9%). We observed a relation between geographic distribution and ploidy level. The tetraploids, the most widespread, were found from Europe through Russia to East Asia. The diploids appeared over the same general range, except in Turkey, Iran and Georgia where no diploid accessions were found. Hexaploid accessions mainly came from a region comprising the east of Turkey, the north of Iran and Georgia. A selection of 71 accessions, including all three ploidy levels, were analyzed by capillary electrophoresis using six wheat simple sequence repeat (SSR) markers. All markers presented high levels of polymorphism, generating 166 different alleles ranging in size between 84 and 256 bp. Based on polymorphic information content values obtained (0.579–0.968), all the SSRs were classified as informative markers (values?>?0.5). According to the dendrogram generated, all the A. cristatum accessions were distinctly classified. Diploid, tetraploid and hexaploid accessions are not clearly differentiated from each other on the basis of SSR markers. A field experiment was conducted to morphologically characterize 18 accessions including the three ploidy levels. Significant differences were found between the accessions in spike length, spike width and number of spikelets per spike. All the cytological, molecular, and morphological data demonstrate the high genetic diversity present in A. cristatum, making it a valuable resource for future breeding programs.     

Towards allelic diversity in the storage proteins of old and currently growing tetraploid and hexaploid wheats in Portugal

Using sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE), the different alleles encoded at the 6 glutenin loci and 3 ω-gliadin loci were identified from a set of 134 hexaploid and 128 tetraploid wheat accessions mainly grown in Portugal. In the hexaploid wheats (T. aestivum L.), a total of 56, 42 and 36 patterns were observed for high molecular weight-glutenin subunits (HMW-GS), low molecular weight-glutenin subunits (LMW-GS) and ω-gliadins respectively. For HMW-GS encoded at Glu-A1, Glu-B1 and Glu-D1 loci, 4, 10 and 6 alleles were observed, respectively. LMW-GS displayed similar polymorphism, as Glu-A3, Glu-B3 and Glu-D3 loci, which comprises 5, 9 and 3 alleles. Twenty-four alleles were observed for ω-gliadins found at Gli-A1, Gli-B1 and Gli-D1 loci with, 5, 16 and 3 alleles respectively. For tetraploid collection fifty different alleles were identified for the seven loci studied Glu-A1 (3), Glu-B1 (13), Glu-A3 (6), Glu-B3 (7), Glu-B2 (2), Gli-A1 (5) and Gli-B1 (14). The genetic distances within hexaploid and tetraploid wheats were presented using cluster representation. The mean value of genetic variation indices (H) for wheat storage protein loci was slightly lower in current commercially available varieties (0.592) and highest for old varieties (0.574).     

Size homoplasy and mutational behavior of chloroplast simple sequence repeats (cpSSRs) inferred from intra- and interspecific variations in four chloroplast regions of diploid and polyploid <Emphasis Type="Italic">Triticum</Emphasis> and <Emphasis Type="Italic">Aegilops</Emphasis> species

Chloroplast simple sequence repeats (cpSSRs) are widely distributed in the chloroplast genomes of all plant species, and are frequently employed for genotypic and phylogenetic analysis. However, information on intra- and interspecies variation in cpSSRs is lacking. In this study, we sequenced four intergenic (non-coding) chloroplast DNA regions in 57 accessions of 12 tetraploid, and 16 accessions of 4 hexaploid species of Triticum and Aegilops. These sequence data added to our previous data for diploid species in the same chloroplast regions. Intra- and interspecific genetic variation was analyzed for a total of 189 accessions of 13 diploid, 12 tetraploid, and 4 hexaploid species of Triticum and Aegilops, such that all species were represented by multiple accessions. The data were used to infer phylogenetic relationships within and among Triticum and Aegilops species. Based on this robust phylogenetic tree, seven of eight cpSSR loci clearly exhibited “size homoplasy,” referring to the fact that cpSSRs of identical size and DNA sequence can arise even if the alleles are not descended from a common ancestor. These data indicate that cpSSRs should be used with caution in phylogenetic analyzes. Interestingly, as observed from several previous studies, our data also suggest that observed mutation rates may increase significantly when mononucleotide (homopolymer) repeat numbers reach or exceed 9 bp. In the present report, using this sequence data set involving cpSSRs, 81 unique haplotypes among 189 accessions were detected, and five tetraploid Triticum and Aegilops species were successfully identified and genotyped. Our results indicate that combinations of nucleotide substitutions, indels and SSRs of chloroplast nucleotide sequences are available for genotyping at the species accession level.     

Allelic diversity of HMW and LMW glutenin subunits and omega-gliadins in French bread wheat (Triticum aestivum L.)

Wheat endosperm storage proteins, namely gliadins and glutenins, are the major components of gluten. They play an important role in dough properties and in bread making quality in various wheat varieties. In the present study, the different alleles encoded at the 6 glutenin loci and at 3 -gliadin loci were identified from a set of 200 hexaploid wheat cultivars grown primarily in France using SDS PAGE. At Glu-A1, Glu-B1 and Glu-D1, encoding high molecular weight glutenin subunits (HMW-GS), 3, 8 and 5 alleles were observed respectively. Low molecular weight glutenin subunits (LMW-GS) displayed similar polymorphism, as 5 and 11 alleles were identified at loci Glu-A3 and Glu-B3 respectively. Four alleles were observed at Glu-D3 loci. Omega-gliadin diversity was also very high, as 7, 13 and 9 alleles were found at Gli-A1, Gli-B1 and Gli-D1, respectively. A total of 147 (or 149) patterns resulted from the genetic combination of the alleles encoding at the six glutenin loci (or Glu-1 and Gli-1 loci). Although Glu-1 and Glu-3 loci were located on different chromosome arms and were theoretically independent, some associations were revealed due to pedigree relatedness between some French wheat cultivars. The usefulness of allelic identification of LMW-GS together with HMW-GS and gliadins for future genetic and technological wheat improvement is discussed.     

Genetic relationship of diploid wheat (<Emphasis Type="Italic">Triticum</Emphasis> spp.) species assessed by SSR markers

Genetic diversity of 139 accessions of diploid Triticum species including Triticum urartu, Triticum boeoticum and Triticum monococcum was studied using 11 SSR (simple sequence repeats) markers. A total of 111 alleles with an average of 10 alleles per locus were detected. The polymorphism information content (PIC) of each SSR marker ranged from 0.30 to 0.90 with an average value of 0.62. Among the three Triticum species T. urartu had the highest number of total alleles (Na?=?81), private alleles (Npa?=?15) and showed higher genetic diversity (Hex?=?0.58; PIC?=?0.54). The genotypes from Turkey exhibited the highest genetic diversity (PIC?=?0.6), while the least diversity was observed among 4 Georgian accessions (PIC?=?0.11). Cluster analysis was able to distinguish 139 wheat accessions at the species level. The highest genetic similarity (GS) was noted between T. boeticum and T. monococcum (GS?=?0.84), and the lowest between T. urartu and T. monococcum (GS?=?0.46). The grouping pattern of the PCoA analysis corresponded with cluster analysis. No significant differences were found in clustering of T. urartu and T. monococcum accessions with respect to their geographic regions, while within T. boeoticum species, accessions from Iran were somewhat associated with their geographical origin and clustered as a close and separate group. The results from our study demonstrated that SSR markers were good enough for further genetic diversity analysis in einkorn wheat species.     

Phylogenetic relationships among Triticum L. and Aegilops L. species as genome progenitors of bread wheat based on sequence diversity in trnT-F region of chloroplast DNA

Cultivated wheat, (Triticum aestivum L.), is one of the most important food crops in the world. The Aegilops L. genus is frequently utilized by plant breeders for improving the current wheat cultivars due to their close relationships. Therefore, understanding the phylogenetic relationships among the species of these genera is not only valuable for plant taxonomy, but also for plant breeding efforts. The presented phylogenetic analysis was based on the sequences of trnT-F chloroplast DNA containing three non-coding sub-regions. Twelve genotypes belonging to four species of Triticum L. genus and twenty-four genotypes belonging to eight species of Aegilops genus were used in the current study. The results postulated a close genetic relationship between diploid Aegilops species containing the BB genome and polyploid Triticum species. With the exception of Aegilops cylindrica Host (CCDD), all other Aegilops species having the CC genome were alienated from Aegilops speltoides Tausch (BB) and clustered together. These two clusters joined by a third cluster including the AA genome containing diploid Triticum species.     

The genome biogeography of Hibiscus L. section Furcaria DC

Summary Hibiscus L. section Furcaria DC. (Malvaceae) is a natural group of more than 100 known species, many of which are handsome ornamentals with large, showy, delicate flowers. This group includes the fiber, food, and medicinal plants kenaf, H. cannabinus L., and roselle, H. sabdariffa L. The basic chromosome number is x = 18. In nature are found diploid, tetraploid, hexaploid, octoploid, and decaploid taxa. This group displays a remarkable amount of genome diversity, as shown by cytological analysis of 140 hybrid combinations from over 60,000 crosses. At least 13 genomes are present: A, B, C, D, E, G, H, J, P, R, V, X, and Y. Subsaharan Africa is the center of genome diversity; nine of the 13 genomes are represented in African taxa, and nine of the 10 confirmed diploid species occur in Africa. Five (possibly six) genomes reside in extant diploids. The G genome (or a modified G genome) is widely distributed. Found in only one diploid species in Africa, it is found also in African tetraploid and African and Indian octoploid species, in New World tetraploid and decaploid species, and in Australian hexaploid species. The G-genome apparently was widely dispersed and differentiated, followed by hybridization, subsequent chromosome doubling, and radiation. The A, B, X, and Y genomes, on the other hand, are confined mainly to Africa, with a few taxa in Asia, and apparently are the products of a later round of hybridization and allopolyploidy.     

Diversity of <Emphasis Type="Italic">Trifolium ambiguum</Emphasis>—nodulating rhizobia from the lower Caucasus

Kura clover (Trifolium ambiguum M.B.) is a perennial rhizomatous forage legume whose use is currently limited by difficulties in its establishment in part attributable to nodulation problems and very specific rhizobial requirements. A limited number of Kura clover-nodulating rhizobial strains are currently available and many have a limited effectiveness. In this study, 128 rhizobia were isolated from four sites in the center of origin of Kura clover (i.e., two in Azerbaijan, one in Armenia, and one in Northwest Iran) using the three ploidy levels of Kura clover (diploid, tetraploid, and hexaploid), red clover (Trifolium pratense L.), and white clover (Trifolium repens L.) plants as trap hosts. Rhizobia were fingerprinted using repetitive extragenic palindromic polymerase chain reaction (BOXA1R primer) and their genetic diversity was measured using the Shannon-Weaver diversity index. The nodulation specificity and phenotypic diversity of a subset of 13 isolates was determined. Genetic diversity among the 128 isolates was large and similar for rhizobia grouped according to their geographic origin or original host plant. Phenotypic diversity was significant; percentage of similarity among 13 isolates ranging between 38 and 92%. Nodulation specificity of the Kura clover-nodulating rhizobial isolates studied was less complex and not as clearly delineated as previously reported. Some strains originally isolated from Kura clover could effectively nodulate more than one ploidy level of Kura clover and even one or both of two other Trifolium species (i.e., red clover and white clover). Three strains formed effective nodules on both Kura clover and white clover; however, none promoted plant growth of both species to levels currently obtained with commercial inoculants when evaluated in a growth chamber. Rhizobial isolates that are highly effective with both species have yet to be identified.     

Single-copy nuclear PolA1 gene sheds light on the origin of S genome with relationships to B and G genomes of polyploid wheat species

PolA1, a single-copy nuclear gene encoding the largest subunit of RNA polymerase I, comprises highly polymorphic intron 19 and nucleotide tag (Ntag) sequences. We analyzed these sequences in 42 accessions, which differed in ploidy, of Triticum–Aegilops and Hordeum species. The lengths of the intron 19 sequences were ca. 110?bp long in Triticum–Aegilops species, except in four Sitopsis species, Ae. longissima, Ae. searsii, Ae. sharonensis, Ae. speltoides, which had introns similar in length to those of Hordeum species, i.e., ca. 240?bp long. Phylogenetic analyses of the Ntag sequences showed that the four Sitopsis and remaining Triticum–Aegilops species were classified into two discrete Hordeum and Triticum clades, respectively. The A and D genome-specific Ntag sequences of polyploid wheats were highly homologous with those of T. urartu and Ae. tauschii, respectively. In Ae. bicornis, another Sitopsis species, two accessions had the short intron 19 and Triticum–type Ntag sequence, which were highly homologous with those of the B genome in polyploid wheats, whereas one accession contained the long intron 19 and Hordeum–type Ntag sequences. In contrast, partial sequence analyses revealed that the three accessions of Ae. bicornis shared highly homology to single-copy DMC1 and EF-G genes. The discrepancy between these results indicates that the Sitopsis species were probably established by hybrid speciation including ancient introgressive hybridization between progenitors of Triticum–Aegilops and Hordeum. Although many researchers have proposed Ae. speltoides as a candidate for the B genome donor, our data suggest the existence of diploid B genome species in the past that were responsible for the origin of both polyploid wheats and Sitopsis species, including Ae. speltoides.     

Allopatric distributions of tetraploid and hexaploid forms of Aegilops neglecta Req. ex Bertol.

The genus Aegilops L. comprises 22 annual wild species that are closely related to wheat (Hammer in Kulturpflanze 28: 33–180, 1980). Aegilops neglecta Req. ex Bertol. is a member of the Aegilops section of this genus and is distributed from Morocco and Spain in the west to Transcaucasia and western Iran in the east. This species includes tetraploid (2n = 28, genome UUMM) and hexaploid forms (2n = 42, UUMMNN). However, the geographical distributions of the two cytological forms remain unclear. Clarifying the distribution of the two cytological forms is essential for a better understanding of the diffusion of Ae. neglecta and its tetraploid and hexaploid forms. In the present study, chromosome numbers were determined for accessions of Ae. neglecta from a total of 137 populations, located in the western area of the species distribution from the Aegean Islands to Morocco. Taken together with previous studies, the present data reveal a difference in the geographical distribution of tetraploid and hexaploid forms: tetraploid form is distributed in the eastern part of the species area and hexaploid form predominantly occurs in the western part with their border on the western margin of the Aegean Sea. Near the border, tetraploid and mixed populations are sporadically found among hexaploid populations in the Balkan and Peloponnesus Peninsulas, while a few hexaploid and mixed populations are found among tetraploid populations in the East Aegean Islands and West Anatolia.     

Eco-geographical assessment of <Emphasis Type="Italic">Avena</Emphasis> L. wild species at the VIR herbarium and genebank collection

On the bases of analysis of the collecting sites of 1160 herbarium specimens and 1640 genebank accessions of wild Avena L. species from the world collection of the Vavilov Institute of Plant Genetic Resources maps of areas of the species were produced data base. A comparison of the climate conditions of the Mediterranean, Southwestern Asiatic and Abyssinian centers of diversity with those of the oat species distribution areas shows that all oat species mostly prefer the moderately hot, semi-arid and dry climate. An analysis of the range of soils in the areas of wild oat species distribution has shown that the collected accessions, preferred different types of soil. When considering the soil diversity within the areas of natural distribution of wild oat species, it could be established that the majority of diploid and tetraploid taxa prefer to grow on mountain or plain cinnamon soils; the hexaploid taxa favorites were the mountain forest brown or red-brown soils, as well as subtropical desert soils. An analysis of the database of geographic distribution on wild oat species showed a full picture of oat species diversity, and a basis to make plans concerning further collecting activities or a basis for selecting potential sources of novel genes that can improve some valuable traits and characters to use them for practical purposes.     

Allelic diversity of high molecular weight glutenin subunits (HMW-GS) in Iranian Aegilops tauschii Coss. accessions by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE)

Variation of high molecular weight glutenin subunits (HMW-GS) in 28 Iranian Aegilops tauschii (2n = 2x = 14, DD) accessions studied by sodium dodecyl sulphate electrophoresis method (SDS-PAGE). The results showed high variation of HMW-GS in the accessions. The range of frequency in 14 HMW-GS combinations was 3.57–25 % in the accessions. AMOVA showed the molecular variance between the geographic areas was lower than within the geographic areas. According to Nei’s genetic diversity, the highest diversity levels were in Semnan, Golestan and Azarbayjan, on the other hand the lowest levels of diversity were found in Khorasan, Gilan and Mazandaran accessions. Hence, the Caspian Sea South East accessions also Azerbayjan in Iran have more diversity. AMOVA did not show variance between strangulata and tauschii but there was more genetic diversity in ssp. tauschii subspecies in comparison of ssp. strangulata according to Nei’s gene diversity and Shannon information index. It showed Iranian Ae. tauschii have a good potential for bread making quality improvement in bread wheat.     

Genetic diversity in tolerance of wild <Emphasis Type="Italic">Avena</Emphasis> species to aluminium (Al)

An evaluation of diversity of aluminium (Al) tolerance of 180 genebank accessions of diploid, tetraploid and hexaploid of wild Avena species from the world collection of the N.I. Vavilov Institute of Plant Genetic Resources (VIR) showed that the accessions with a high degree of aluminium tolerance belonged to the diploids A. canariensis, A. longiglumis and A. wiestii, the tetraploids A. barbata, A. vaviloviana, and hexaploids A. ludoviciana and A. sterilis. A comparison of the data on Al tolerance with the soil conditions demonstrated that most highly tolerance accessions tend to be collected on different type of soils. According to the results of the principal component analysis, preliminary screening for Al tolerance can be carried out among hexaploid species with higher degree of plant resistance to pathogens.     

Six new botanical varieties of <Emphasis Type="Italic">Triticum</Emphasis> from Oman

Due to its geographic position on the northeastern tip of the Arabian Peninsula and its sea trade relationships with Asia, East Africa and the Middle East, Oman has for millennia been at the cross-roads of inter-regional exchange of cultivated plants. This is reflected in recent findings of new cultivars of banana (Musa spp.) and wheat (Triticum spp.) in remote oases of the Hajar Mountains in northern Oman. Material collected in 2003 and 2004 contained six new botanical varieties of wheat which are described here. One of them belongs to the tetraploid T. aethiopicum, the others are hexaploid.     

Molecular diversity of restriction enzyme sites, Indels and upstream open reading frames (uORFs) of 5′ untransalted regions (UTRs) of Waxy genes in Triticum L. and Aegilops L. species

5′ Untransalted regions (UTR) sequences of Waxy genes were amplified from all 81 Triticum L. and Aegilops L. species by PCR with specific primers. It was found that the sequence length at 7D loci was longer than that 7B and 7A. These sequences contained 170 singleton variable sites and 484 polymorphic sites and that the average length of Indels was 8.5?bp. There were abundant regions of restriction enzyme sites and two regions of simple sequence repeat, “GAA” and “CTGA”, in all sequences. A total of 65 uORFs were detected and classed into 37 types, with the variation in uORFs mainly due to single nucleotide polymorphisms (SNPs), and also to the presence of Indels. All sequences in tetraploids and hexaploids could be grouped into Types A, B, I, II, GI and GII based on sequence variation. Restriction enzyme sites, Indel polymorphisms and the classes of uORFs present together indicated that Type I was more similar to Ae. tauschii whereas Type II was more similar to Type B, and both more similar to Ae. longissima; Type A was more similar to Ae. speltoides. Population analysis was performed and Neighbour-joining trees derived from different species, types and accessions further confirmed that the ancestors of T. urartu, Ae. speltoides, Ae. longissima and Ae. tauschii were involved to the evolution of common wheat, and also implied that Ae. longissima might have participated later than Ae. speltoides. 5′ UTRs of Waxy genes in tetraploid and hexaploid species conserved characters from their respective progenitors when compared with diploid. For the first time, we are able to conclude there is abundant variation in SNPs, Indels and uORFs between 5′ UTRs of Waxy genes from different species related to common wheat, and suggest that further research could help to understand Waxy gene function more deeply and hence improve wheat breeding. Our results also show that three hexaploid species in China have unique diversity in the 5′ UTR of their Waxy gene.     

Cytological characterisation of the underutilized forage crop Onobrychis viciifolia Scop. and other members of the Onobrychis genus

Sainfoin (Onobrychis viciifolia Scop.) is a perennial forage legume that possesses beneficial properties in the context of sustainable agriculture. A germplasm collection of O. viciifolia was assembled from many geographic regions, as well as a collection of Onobrychis species that might be crossed with O. viciifolia to improve its biological and agronomic properties. The objective of the present study was to obtain cytological information for a broad range of O. viciifolia varieties and related species, in order to confirm and extend previous findings. The study set was 143 accessions of O. viciifolia as well as 34 accessions of 17 other species from the Onobrychis genus. Three of the O. viciifolia accessions were diploid (2n = 2x = 14) and the remainder tetraploid (2n = 4x = 28). Chromosomes were <5 μm in length. Among the other Onobrychis species, roughly half were found to be diploid and the other half tetraploid, with two species, O. arenaria (Kit.) DC. and O. alba subsp. laconica (Orph. ex Boiss.) Hayek, including a mixture of diploid and tetraploid accessions. The basic number of chromosomes was seven, except for O. aequidentata (Sm.) d’Urv. and O. crista-galli Lam., where it was eight. The 2C value for O. viciifolia was estimated at 2.5 pg. These cytological data will be valuable as part of a pre-breeding programme aimed at the eventual production of improved O. viciifolia varieties for use in sustainable agriculture.     

Ploidy levels of Dioscorea alata L. germplasm determined by flow cytometry

Dioscorea alata L. is a highly important crop, widely distributed in the humid and semi-humid tropics. Flow cytometry was used to determine the ploidy levels of 74 D. alata genotypes collected mainly from West African countries. Sixty three of the genotypes were found to be tetraploid, one was hexaploid and ten were octoploid. The high percentage of tetraploids together with the small percentage of hexaploid individuals and the absence of diploid individuals gives us some more clues on the possible origin of these species. No association between ploidy level and place of cultivation was found for the tested material. The obtained results represent important knowledge for enhancing the breeding methodologies and optimize germplasm management of this species. It also offers further insights to the phylogeny and evolution of Dioscorea species.