Diploid Triticum Species Research Articles

Diploid Triticum species as a potential source of resistance to powdery mildew

Mączniak prawdziwy jest jedną z najważniejszych chorób grzybowych roślin zbożowych. Powoduje obniżenie plonu i jakości zbieranego ziarna. Jednym z najlepszych sposobówochrony roślin przed mączniakiem jest wprowadzenie do odmian uprawnych efektywnych genów odporności. W niniejszej pracy przeprowadzono screening diploidalnych gatunków z rodzaju Triticum pod kątem identyfikacji potencjalnych źródeł genetycznej odporności na mączniaka. Spośród analizowanych form zidentyfikowano 21 genotypów, które wykazywały pełną odporność na wszystkie 3 zastosowane izolaty mączniaka. Cztery z nich należą do gatunku T. urartu, 12 do T. monococcum i 4 do T. boeoticum. Badania przedstawione w niniejszej pracy wykazały, że każdy z badanych gatunków może być źródłem genów odporności na mączniaka prawdziwego. Ponadto najbardziej odporne genotypy zidentyfikowano wśród form z Libanu i Syrii. Najniższy poziom odporności wykazałygenotypy z Turcji, co wskazuje, że obszar ten nie jest regionem o dużej presji tego patogena.

Diploid genome differentiation conferred by RNA sequencing-based survey of genome-wide polymorphisms throughout homoeologous loci in Triticum and Aegilops

BackgroundTriticum and Aegilops diploid species have morphological and genetic diversity and are crucial genetic resources for wheat breeding. According to the chromosomal pairing-affinity of these species, their genome nomenclatures have been defined. However, evaluations of genome differentiation based on genome-wide nucleotide variations are still limited, especially in the three genomes of the genus Aegilops: Ae. caudata L. (CC genome), Ae. comosa Sibth. et Sm. (MM genome), and Ae. uniaristata Vis. (NN genome). To reveal the genome differentiation of these diploid species, we first performed RNA-seq-based polymorphic analyses for C, M, and N genomes, and then expanded the analysis to include the 12 diploid species of Triticum and Aegilops.ResultsGenetic divergence of the exon regions throughout the entire chromosomes in the M and N genomes was larger than that between A- and Am-genomes. Ae. caudata had the second highest genetic diversity following Ae. speltoides, the putative B genome donor of common wheat. In the phylogenetic trees derived from the nuclear and chloroplast genome-wide polymorphism data, the C, D, M, N, U, and S genome species were connected with short internal branches, suggesting that these diploid species emerged during a relatively short period in the evolutionary process. The highly consistent nuclear and chloroplast phylogenetic topologies indicated that nuclear and chloroplast genomes of the diploid Triticum and Aegilops species coevolved after their diversification into each genome, accounting for most of the genome differentiation among the diploid species.ConclusionsRNA-sequencing-based analyses successfully evaluated genome differentiation among the diploid Triticum and Aegilops species and supported the chromosome-pairing-based genome nomenclature system, except for the position of Ae. speltoides. Phylogenomic and epigenetic analyses of intergenic and centromeric regions could be essential for clarifying the mechanisms behind this inconsistency.

DNA barcoding of different Triticum species

BackgroundThe genus Triticum L. includes diploid, tetraploid, and hexaploid species. DNA barcoding is a new method to identify plant taxa by using short sequences of DNA and within a short time. In this investigation, we determined a phylogenetic analysis of 20 different Triticum species by partial chloroplast Maturase encoding gene (matK).Materials and methodsTwenty accessions of different Triticum species diploid, tetraploid, and hexaploid were obtained from different countries. Genomic DNA was isolated from young leaves of studied samples and then used as a template for PCR reaction. PCR products were checked by electrophoresis, purified, sequenced, and submitted in the GenBank nucleotide sequence database, the nucleotide sequence was translated into an amino acid sequence. The nucleotide and amino acid sequences were aligned with Clustal W multiple sequence alignment programs to obtain the phylogenetic tree depending on two statistical data analysis such as bootstrapping and pairwise distance from both nucleotide and amino acid sequences.ResultsThe phylogenetic tree obtained from both nucleotide and amino acid sequences divided the 20 Triticum species into two groups, A and B. Group A represented the diploid Triticum species. Group B was divided into two subgroup, I and II. Subgroup I represented the hexaploid Triticum species and subgroup II represented the tetraploid species.ConclusionThe matK gene sequence has a critical role in discriminating the closely related Triticum species. So these sequences could be used as a DNA barcode for detecting the evolutionary history of Triticum species.

Genetic relationship of diploid wheat (Triticum 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.

Identification and molecular characterization of novel LMW-m and -s glutenin genes, and a chimeric -m/-i glutenin gene in 1A chromosome of three diploid Triticum species

Low molecular weight glutenin subunits (LMWGs) are part of the gluten network that gives dough its viscoelastic properties. A-genome-containing diploid species related to modern polyploid wheat show great variability in these subunits. The current study characterized the variability of LMW-m and -s genes, being identified fifteen LMWGs genes in the three species evaluated, of which 14 were novel. Ten were pseudogenes, which are common in cereal prolamins. The rest of genes, with intact coding region, corresponded to the LMW-m genes and some single nucleotide polymorphisms and insertion/deletion events were detected, which could alter protein structure and affect dough quality. Two variants of the LMW-s genes were detected in cultivated einkorn and Triticum urartu, the former being novel. The LMW-m and -s genes were related to TuA3-391 and TuA3-400 genes, and to the Tu-460 gene, respectively, of T. urartu. Screening the sequences characterized for reactive epitopes of celiac disease revealed that LMW-m could be less toxic than other subunits for celiac patients. One novel chimeric gene with features from LMW-m and LMW-i genes was detected in T. urartu, and it produces a novel mature protein that may have a distinguishing effect on dough quality. Novel insights into the evolution of LMWGs genes are also reported. These species are a potential source of novel LMWGs variants.

Molecular diversity of α-gliadin expressed genes in genetically contrasted spelt (Triticum aestivum ssp. spelta) accessions and comparison with bread wheat (T. aestivum ssp. aestivum) and related diploid Triticum and Aegilops species.

The gluten proteins of cereals such as bread wheat (Triticum aestivum ssp. aestivum) and spelt (T. aestivum ssp. spelta) are responsible for celiac disease (CD). The α-gliadins constitute the most immunogenic class of gluten proteins as they include four main T-cell stimulatory epitopes that affect CD patients. Spelt has been less studied than bread wheat and could constitute a source of valuable diversity. The objective of this work was to study the genetic diversity of spelt α-gliadin transcripts and to compare it with those of bread wheat. Genotyping data from 85 spelt accessions obtained with 19 simple sequence repeat (SSR) markers were used to select 11 contrasted accessions, from which 446 full open reading frame α-gliadin genes were cloned and sequenced, which revealed a high allelic diversity. High variations among the accessions were highlighted, in terms of the proportion of α-gliadin sequences from each of the three genomes (A, B and D), and their composition in the four T-cell stimulatory epitopes. An accession from Tajikistan stood out, having a particularly high proportion of α-gliadins from the B genome and a low immunogenic content. Even if no clear separation between spelt and bread wheat sequences was shown, spelt α-gliadins displayed specific features concerning e.g. the frequencies of some amino acid substitutions. Given this observation and the variations in toxicity revealed in the spelt accessions in this study, the high genetic diversity held in spelt germplasm collections could be a valuable resource in the development of safer varieties for CD patients.Electronic supplementary materialThe online version of this article (doi:10.1007/s11032-016-0569-5) contains supplementary material, which is available to authorized users.

Characterization of the waxy gene in diploid Triticum L. and Aegilops L. species and its geographic distribution

Waxy gene plays a key role for amylose synthesis in wheat seeds. The study evaluated the Waxy gene variability in 59 accessions of six diploid Triticum and Aegilops species. The percentages of variable sites, singleton variable sites, and parsimony informative sites were 16.38, 5.59, and 10.79 %, respectively. A total of 22 amino acid changes in the transit peptide and the remaining in the mature protein were observed. Moreover, 17 amino acid changes between Triticum and Aegilops species were also detected. Specially, Gla 14 and Phe 153 was observed in diploid Triticum, compared with Thr 14 and Tyr 153 in diploid Aegilops. Two types of amino acids, Gla 5/Val 5 and Ile 140/Val 140, were identified in T. urartu, as well as Val 22/Phe 22, Thr 52/Lys 52, and Gln 54/delete in A. tauschii. The insertion/deletions (InDels) had high frequency in intron region, but very low in transit peptide and exon region. Neighbour-joining tree showed that 146 sequences from 23 species could be clustered into eight groups with the species characterizations. The Wx-B1 of polyploid Triticum were grouped with A. sharonensis, A. longissima, A. searsii, A. speltoides, while Wx-D1 of T. aestivum and T. spelta together with A. umbellulata, A. markgrafii, A. comosa, and A. tauschii. The Wx-A1 of polyploid Triticum were separated clearly with the diploid species. The Wx-B1 could be divided into two subgroups and maybe had two phylogenetic origins, but most of them were related to A. speltoides. Waxy gene of A. tauschii also had two subgroups, and the sequences from southern Caspian (Mazandaran, Iran) were more closed with Wx-D1. The variability of 5′ Un-Translation Region (UTR) of waxy was stronger than intron and exon region based on genetic distance. Phylogeography analysis showed that geography affected strongly the distribution of all accessions along the north–south axis based on the partial open reading fragment (ORF) of waxy gene, A. speltoides and A. longissima along the west–east axis and north–south axis based on exon, and A. tauschii along the west–east axis based on 5′ UTR, respectively. Our results suggest that diploid Triticum and Aegilops have new waxy gene resources; waxy gene could play a more important role in genetic exploitation, genetic relationship evaluation and phylogeography investigation.

Genetic diversity of diploid Triticum species in Iran assessed using inter-retroelement amplified polymorphisms (IRAP) markers

AbstractIran, as a part of Fertile Crescent, is within the center of diversity and origin of the Triticum L. from Poaceae Barnhart (Gramineae A. L. de Jussieu) family. This study concerns the genetic diversity and inter-relationships analyses of 89 accessions of diploid Triticum (2n = 2x = 14) species including T. monococcum, T. boeoticum subsp. boeoticum, T. boeoticum subsp. thaoudar and T. urartu belong to the einkorn wheat group collected all around Iran using 8 primer pairs of IRAP (Inter-Retrotransposon Amplified Polymorphism). Of 220 DNA fragments analysed from all of accessions, 217 (98.6%) were polymorphic. The genetic distances among taxa and accessions were estimated and dendrograms showing relationship among accessions were generated. The results of this study showed that four taxa of diploid wheat are very similar to each other genetically and there is a high affinity, gene flow and genetic relationships between diploid Triticum accessions, although T. monococcum can be distinct loosely from the two other species including T. boeoticum and T. urartu. The highest average Nei genetic distances were found between T. monococcum and T. urartu (0.14) and the lowest between T. boeoticum subsp. boeoticum and T. boeoticum subsp. thaoudar (0.03). Analyssi of molecular variance (AMOVA) was revealed that 84% of total variation attributed to within population’s variability and the remaining 16% variation was ascribed to the differences among species; also it demonstrated a geographical distinction among Triticum accessions. These data proved a center of high diversity in the West and the Northwest of Iran and clearly exposed patterns of two distinct geographic regions.

Molecular analysis of diversity of diploid Triticum species in Iran using ISSR markers

Genetic diversity of wild wheats germ- plasm especially those growing in center of origin is of critical value for breeding proposes. In this study 89 accessions belonging to the three species (T. mono- coccum, T. urartu, T. boeoticum), collected all around Iran, were analysed using nine inter-simple sequence repeat (ISSR) primers. Polymerase chain reactions amplified 170 DNA fragments, from which, 156 (91.2 %) were polymorphic. The highest and lowest genetic polymorphism were detected within T. boeot- icum (90 %) and T. monococcum (68.62) respectively. From geographic viewpoint, the western accessions showed the highest (86.44) and the southwestern accessions the lowest (74.7) ISSR polymorphism. According to the Neighbor Joining dendrogram and the principal coordinate analysis 2D plot, all acces- sions were divided into two clusters: accessions of T. urartu in one cluster and accessions of T. boeoticum and T. monococcum in another. Within these clusters, subgroupings related to the geographic distribution were evident. Analysis of molecular variance (AM- OVA) showed that 0.82 of genetic diversity resulted from the intra-specific variation. AMOVA results attributed 0.93 of T. boeoticum and 0.82 of T. urartu genetic diversity to the within regions variations. Based on the results of this study, it seems that Triticum represented in Iran by two diploid species. This study showed a high level of genetic diversity within the Iranian diploid Triticum species that can be of interest for crops improvement.

Genome‐wide analysis of short interspersed nuclear elements SINES revealed high sequence conservation, gene association and retrotranspositional activity in wheat

Short interspersed nuclear elements (SINEs) are non-autonomous non-LTR retroelements that are present in most eukaryotic species. While SINEs have been intensively investigated in humans and other animal systems, they are poorly studied in plants, especially in wheat (Triticum aestivum). We used quantitative PCR of various wheat species to determine the copy number of a wheat SINE family, termed Au SINE, combined with computer-assisted analyses of the publicly available 454 pyrosequencing database of T. aestivum. In addition, we utilized site-specific PCR on 57 Au SINE insertions, transposon methylation display and transposon display on newly formed wheat polyploids to assess retrotranspositional activity, epigenetic status and genetic rearrangements in Au SINE, respectively. We retrieved 3706 different insertions of Au SINE from the 454 pyrosequencing database of T. aestivum, and found that most of the elements are inserted in A/T-rich regions, while approximately 38% of the insertions are associated with transcribed regions, including known wheat genes. We observed typical retrotransposition of Au SINE in the second generation of a newly formed wheat allohexaploid, and massive hypermethylation in CCGG sites surrounding Au SINE in the third generation. Finally, we observed huge differences in the copy numbers in diploid Triticum and Aegilops species, and a significant increase in the copy numbers in natural wheat polyploids, but no significant increase in the copy number of Au SINE in the first four generations for two of three newly formed allopolyploid species used in this study. Our data indicate that SINEs may play a prominent role in the genomic evolution of wheat through stress-induced activation.

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.

Expression of α-amylase inhibitors in diploid Triticum species

The aim of the work was to characterize the expression of various α-amylase inhibitors (αAIs), well known anti-nutritional compounds, for the development of healthier diploid wheat-based functional foods.The salt-soluble protein fractions from the seeds of 53 accessions among Triticum monococcum subsp. monococcum (T.m.), T. monococcum subsp. boeoticum (T.b.) and Triticum urartu (T.u.) were analyzed by immunoblotting after SDS–PAGE and Urea–PAGE using polyclonal antibodies (PABs) raised against 0.19 and 0.28 αAIs expressed in bread-wheat. Reverse zymography with human saliva and Tenebrio molitor α-amylases was used to assay inhibition activity. A great variability of the expression of αAI-related proteins was observed among T.b. and T.u. PABs, and reverse zymography revealed different bands, often not correlating with those present in bread-wheat. Two-dimensional electrophoresis followed by immunoblotting and mass spectrometric analysis identified these proteins as αAIs. Interestingly, no signal was observed within T.m. accessions. This makes T.m. an important candidate for the production of novel functional foods.

Comparison of genomic and EST-derived SSR markers in phylogenetic analysis of wheat

Microsatellite markers (simple sequence repeats, SSRs) are used for a wide range of crop genetic and breeding applications, including genetic diversity assessment, phylogenetic analysis, genotypic profiling and marker-assisted selection. Genomic SSR (gSSR) have attracted more attention because of abundance in plant genome, reproducibility, high level of polymorphism and codominant inheritance. Recently, the availability of data for expressed sequence tags (EST), has given more emphasis to EST-derived SSRs, which belong to the transcribed regions of DNA, and are expected to be more conserved and have a higher transferability rate across species than gSSR markers. In the present study, several gSSR and EST-SSR markers were investigated for their transferability and level of DNA polymorphism in different ancestral tetraploid and diploid Triticum and Aegilops species. The same gSSR and EST-SSR markers were also evaluated for their applicability in the phylogenetic analysis of wheat. Both gSSR and EST-SSR markers showed differences for the average transferability rate and the number of alleles/locus. Phylogenetic trees based on gSSR and EST-SSR markers were in accordance with phylogenetic relations based on cytogenetic and molecular analyses.

Analysis of Triticum boeoticum and Triticum urartu seed defensins: To the problem of the origin of polyploid wheat genomes

The origin of polyploid wheat genomes has been the subject of numerous studies and is the key problem in wheat phylogeny. Different diploid species have been supposed to donate genomes to tetraploid and hexaploid wheat species. To shed light on phylogenetic relationships between the presumable A genome donors and hexaploid wheat species we have applied a new approach: the comparison of defensins from diploid Triticum species, Triticum boeoticum Boiss. and Triticum urartu Thum. ex Gandil., with previously characterized Triticum kiharae defensins [T.I. Odintsova et al., Biochimie 89 (2007) 605–612]. Defensins were isolated by acidic extraction of seeds followed by three-step chromatographic separation. Isolated defensins were identified by molecular masses using MALDI-TOF mass spectrometry and N-terminal sequencing. For the first time, we have shown that T. urartu defensins are more similar to those of the hexaploid wheat than T. boeoticum defensins, although variation among samples collected in different regions of the world was revealed. Our results clearly demonstrate that T. urartu of the Asian origin contributed the A genome to polyploid wheat species.

Variations in Seed Storage Protein-Triticin among Diploid Triticum and Aegilops Species

Variations in Seed Storage Protein-Triticin among Diploid Triticum and Aegilops Species

A chromosome-specific sequence common to the B genome of polyploid wheat and Aegilops searsii

A low-copy, non-coding chromosome-specific DNA sequence, isolated from common wheat, was physically mapped to the distal 19% region of the long arm of chromosome 3B (3BL) of common wheat. This sequence, designated WPG118, was then characterized by Southern hybridization, PCR amplification and sequence comparison using a large collection of polyploid wheats and diploid Triticum and Aegilops species. The data show that the sequence exists in all polyploid wheats containing the B genome and absent from those containing the G genome. At the diploid level, it exists only in Ae. searsii, a diploid species of section Sitopsis, and not in other diploids including Ae. speltoides, the closest extant relative to the donor of the B genome of polyploid wheat. This finding may support the hypothesis that the B-genome of polyploid wheat is of a polyphyletic origin, i.e. it is a recombined genome derived from two or more diploid Aegilops species.

Genetic diversity of wheat wild relatives in the Near East detected by AFLP

In order to reveal the molecular genetic diversity of wheat wild relatives, an AFLP analysis was conducted with 16 accessions of five Triticum andAegilops species originating from the Near East. Variation within population was studied with at least seven individuals per accession. Four primer combinations were used for selective amplification. Based on the scored bands, we estimated percentage of polymorphic bands, 1 – proportion of shared bands (1-psb) and nucleotide diversity (π). Of the five species used in this study, Ae. speltoides had the highest level of `within population' variation. This species had also the highest value of the variation among populations. As for Triticum species, the level of variation within population was low in diploid species (T. urartu and T. boeoticum),whereas two tetraploid species (T. dicoccoides and T. araraticum) had relatively high levels of variation within population. While the two diploid Triticum indicated a clear interspecific divergence, the two tetraploid wild wheats were not clearly divergent in this study. The variance portioning analysis indicated that the variation detected for diploid Triticum species was mainly composed of `between species' variation, on the other hand that for tetraploid Triticum was mostly composed of `within population' variation. In conclusion, AFLP analysis reveals molecular variation in all accessions used in this study, suggesting a potential genetic diversity of the wheat wild relatives in natural populations. These results have implications for the design of strategies to maintain genetic diversity within genebank collections.

RFLP-based analysis of three RbcS subfamilies in diploid and polyploid species of wheat

The RbcS multigene family of hexaploid (bread) wheat, Triticum aestivum (genome BBAADD), which encodes the small subunit of Rubisco, comprises at least 22 genes. Based on their 3' non-coding sequences, these genes have been classified into four subfamilies (SFs), of which three (SF-2, SF-3 and SF-4) are located on chromosomes of homoeologous group 2 and one (SF-1) on homoeologous group 5. In the present study we hybridized three RbcS subfamily-specific probes (for SF-1, SF-2 and SF-3) to total DNA digested with four restriction enzymes and analyzed the RFLP patterns of these subfamilies in eight diploid species of Aegilops and Triticum, and in two tetraploid and one hexaploid species of wheat (the diploid species are the putative progenitors of the polyploid wheats). The three subfamilies varied in their level of polymorphism, with SF-2 being the most polymorphic in all species. In the diploids, the order of polymorphism was SF-2 > SF-3 > SF-1, and in the polyploids SF-2 > SF-1 > SF-3. The RbcS genes of the conserved SF-1 were previously reported to have the highest expression levels in all the wheat tissues studied, indicating a negative correlation between polymorphism and gene expression. Among the diploids, the species with the D and the S genomes were the most polymorphic and the A-genome species were the least polymorphic. The polyploids were less polymorphic than the diploids. Within the polyploids, the A genome was somewhat more polymorphic than the B genome, while the D genome was the most conserved. Among the diploid species with the A genome, the RFLP pattern of T. urartu was closer to that of the A genome of the common wheat cultivar Chinese Spring (CS) than to that of T. monococcum. The pattern in Ae. tauschii was similar to that of the D genome of CS. Only partial resemblance was found between the RFLP patterns of the species with the S genome and the B genome of CS.

Occurrence of Fungal Endophytes in Species of Wild Triticum

Seedborne, nonpathogenic, fungal endophytes are commonly found in symbiotic relationships with many members of the cool‐season grass subfamily Pooideae The beneficial effects on plants possessing fungal endophytes, and the detrimental effects on consumers of fungal endophyte‐infected plants are widely known. The objective of our research was to determine if fungal endophytes exist in indigenous, wild Triticum (wheat) species from Turkey. From the Triticum species collected, we found two different fungal endophytes. Fungi identified morphologically as members of the genus Neotyphodium were found in the diploid Triticum species T. dichasians (Zhuk.) Bowden and T. tripsacoides (Jaub. & Spach) Bowden. The second endophyte, an Acremonium species, was found in T. columnare (Zhuk.) Morris & Sears, T. cylindricum Ces., T. monococcum L., T. neglecta Morris & Sears, T. recta Morris & Sears, T. triunciale (L.) Raspail, T. turgidum L., and T. umbellulatum (Zhuk.) Bowden. No fungal endophytes were found in T. kotschyi (Boiss.) Bowden, T. ovatum (L.) Raspail, T. peregrinum Morris & Sears, T. speltoides (Tausch) Gren. ex Richter, and T. tauschii (Coss.) Schmal., although the number of samples tested was small for some of these species. Both Acremonium endophyte‐infected and Acremonium endophyte‐free plants of T. triunciale were found to occur at different frequencies at four collection sites on the Anatolian Plateau. Through two selfed generations of the plants, it was found that the Neotyphodium endophyte was transmitted to 100% of the progeny of T. dichasians and T. tripsacoides However, the Acremonium endophytes were not transmitted in all plants that originally possessed them. We concluded that fungal endophytes of the genera Neotyphodium and Acremonium inhabit some wild wheat species grown indigenously in Turkey. These endophytes may influence the ecology and distribution of Triticum species, and may also serve as a source of biological control agents of pests or abiotic stress factors in wheat.

The origins of the genomes of Triticum biunciale, t. ovatum, t. neglectum, t. columnare, and t. rectum (poaceae) based on variation in repeated nucleotide sequences

The origins of the genomes of allotetraploid species Triticum biunciale, T. ovatum, T. neglectum, and T. columnare, and allohexaploid T. rectum were investigated by examining the presence of specific restriction fragments of repeated nucleotide sequences in DNAs of the polyploid species. The restriction fragments were detectable either in a single diploid Triticum species (unique characters) or a group of diploid species (unique shared characters). The analysis showed that Triticum biunciale and T. ovatum are closely related. In both species, one pair of genomes is closely related to the genome of T. umbellulatum and the other is a modified genome of T. comosum. The same genome formula, UUM°M°, is proposed for T. biunciale and T. ovatum. Potential reasons for the modification of the M° genome are discussed. Triticum neglectum and T. columnare are also closely related to each other and have the same genomes. They share the U genome with T. biunciale and T. ovatum, but their second pair of genomes is unrelated to the M° genome. No relationship was found of this genome to a genome of any extant diploid species of Triticum or any phylogenetic lineage leading to the extant diploid species. This unknown genome is designated X'.∗∗∗ The proposed genome formula for T. neglectum and T. columnare is UUX'X'∗∗∗. Hexaploid T. rectum originated from hybridization of one of the tetraploid species with the formula UUX'X', likely T. neglectum, with T. uniaristatum (genome N), and its genome formula is UUX'X'NN.