Plant remains from Asikli Höyük,a pre-pottery Neolithic site in central Anatolia

Cereal crop plants at Asikli Höyük included einkorn wheat (Triticum monococcum), emmer wheat (T. dicoccum), free-threshing wheat (T. cf. durum), hulled two-rowed barley (Hordeum distichum) and naked barley (H. vulgare var. nudum). As for pulses, bitter vetch (Vicia ervilia), lentil (Lens culinaris) and probably pea (Pisum sativum) were grown. Hackberry (Celtis tournefortii) fruits were gathered intensively. In addition, fruits of pistachio (Pistacia cf. atlantica) and almond (Amygdalus spec.) were collected from the wild.     

A Celtic, La Tène trade centre in Ramsautal in the Dürrnberg, Austria: Macrofossil data towards reconstruction of environment and food plants

Soil samples from a La Tène salt-mining settlement were examined for botanical macroremains. Mining, trade and metal-processing (bronze and iron) were major elements in this prehistoric economic centre situated in the high-altitude Ramsau valley (Ramsautal), near Hallein, province of Salzburg. Cultigens found are broomcorn millet (Panicum miliaceum), hulled barley (Hordeum vulgare), naked barley (Hordeum vulgare var.nudum), emmer (Triticum dicoccum), spelt (Triticum spelta) and peas (Pisum sativum). Most of the plant remains consisted of non-charred seeds and fruits that originated from the close vicinity of the settlement. The species may be assigned mainly to nitrophilous ruderal communities and moist to wet habitats. Conditions in the valley were probably unsuitable for the cultivation of cereals. It is suggested that the crop plants derive mainly from the fertile lower plains of the pre-Alpine lowlands.     

Trends in comparative genetics and their potential impacts on wheat and barley research

We review some general points about comparative mapping, the evolution of gene families and recent advances in the understanding of angiosperm phylogeny. These are considered in relation to studies of large-genome cereals, particularly barley (Hordeum vulgare) and wheat (Triticum aestivum), with reference to methods of gene isolation. The relative merits of direct map-based cloning in barley and wheat, utilization of the smaller genome of rice (Oryza sativa) and gene homology methods that utilize information from model species such as Arabidopsis thaliana are briefly discussed.     

Genetic mapping of QTL controlling tissue-culture response on chromosome 2B of wheat (Triticum aestivum L.) in relation to major genes and RFLP markers

 Three quantitative trait loci (QTL) for tissue- culture response (Tcr) were mapped on chromosome 2B of hexaploid wheat (Triticum aestivum L.) using single-chromosome recombinant lines. Tcr-B1 and Tcr-B2, affecting both green spots initiation and shoot regeneration, were mapped in relation to RFLP markers in the centromere region and on the short arm of chromosome 2B, linked to the photoperiod-response gene Ppd2. A third QTL (Tcr-B3), influencing regeneration only, was closely related to the disease resistance locus Yr7/Sr9g on the long arm of chromosome 2B. The homoeologous relationships to the tissue-culture response loci Qsr, Qcg and Shd of barley are discussed. A possible influence of the earliness per se genes of wheat and barley is suggested. Received: 30 August 1996 / Accepted: 15 November 1996     

High transferability of bread wheat EST-derived SSRs to other cereals

The increasing availability of expressed sequence tags (ESTs) in wheat (Triticum aestivum) and related cereals provides a valuable resource of non-anonymous DNA molecular markers. In this study, 300 primer pairs were designed from 265 wheat ESTs that contain microsatellites in order to develop new markers for wheat. Their level of transferability in eight related species [Triticum durum, T. monococcum, Aegilops speltoides, Ae. tauschii, rye (Secale cereale), barley (Hordeum vulgare), Agropyron elongatum and rice (Oryza sativa)] was assessed. In total, 240 primer pairs (80%) gave an amplification product on wheat, and 177 were assigned to wheat chromosomes using aneuploid lines. Transferability to closely related Triticeae species ranged from 76.7% for Ae. tauschii to 90.4% for T. durum and was lower for more distant relatives such as barley (50.4%) or rice (28.3%). No clear putative function could be assigned to the genes from which the simple sequence repeats (SSRs) were developed, even though most of them were located inside ORFs. blast analysis of the EST sequences against the 12 rice pseudo-molecules showed that the EST-SSRs are mainly located in the telomeric regions and that the wheat ESTs have the highest similarity to genes on rice chromosomes 2, 3 and 5. Interestingly, most of the SSRs giving an amplification product on barley or rice had a repeated motif similar to the one found in wheat, suggesting a common ancestral origin. Our results indicate that wheat EST-SSRs show a high level of transferability across distantly related species, thereby providing additional markers for comparative mapping and for following gene introgressions from wild species and carrying out evolutionary studies.     

Linkage mapping of mutant loci in rye (Secale cereale L.)

Eight mutant loci determining the traits waxy plant (w and wa1), brown culm (cb), multiple pistils (mp), weak plant with reduced plant height (np), monoculm growth habit (mc), compactum growth habit (ct3) and anthocyaninless (an) were mapped on rye chromosomes 4R (w, np), 6R (cb, mc) and 7R (mp, wa1, ct3, an). For five mutants (w, wa1, cb, mp, np) molecular and biochemical markers were applied, whereas for mc, ct3 and an a classical linkage analysis was performed. Furthermore, it could be demonstrated that homoeologous relationships exist between most of the mapped rye loci and comparable mutants in wheat and barley. It was confirmed not only that genes controlling fundamental aspects of plant biology are highly conserved across the Triticeae species but so also were many mutant loci. Received: 19 June 2000 / Accepted: 18 October 2000     

Crop water availability in early agriculture: evidence from carbon isotope discrimination of seeds from a tenth millennium BP site on the Euphrates

The analysis of carbon isotope discrimination (Δ) in crop plant remains from archaeological sites may help to assess water availability for early agriculture. This study presents the analysis of Δ in seeds of naked wheat (Triticum aestivum/durum), lentil (Lens orientalis/culinaris), and flax (Linum sp.) found at the archaeological site of Tell Halula in the valley of the Middle Euphrates (Syria). This Neolithic site is the oldest in this region of the Fertile Crescent where the cultivation of domesticated plants has been reported, with seed remains ranging from 9550 to 8465 BP. Most of the seeds analysed showed Δ values greater than 16 ‰, reaching 20 ‰ for some samples of flax. For wheat, Δ values were much higher than those reported in present-day (1996) durum wheat crops cultivated under rainfed conditions in north-west Syria under environments with somewhat higher rainfall than Tell Halula. Similarly, grains of present-day (1997) barley cultivated in the archaeological site also showed lower values than those found in archaeological kernels. An empirical relationship between Δ of mature kernels and total precipitation (plus irrigation where applicable) from heading to maturity (r² = 0.82, n = 11) was established for durum wheat, currently cultivated in different environments of the Mediterranean basin. The resulting relationship was applied to the data on Δ of wheat fossil kernels from Tell Halula to estimate the accumulated water inputs during the time (about 6 weeks) the kernels were produced. Calculated water inputs for wheat during early agriculture were (over 110 mm) at least 5 times higher than current-day rainfall accumulated in Tell Halula during the same phenological period. These results strongly suggest that early agriculture wheat was cultivated at Tell Halula under much wetter conditions than are currently to be found in the area. The presence of flax and its very high Δ values also support this conclusion. Whether such humid conditions during cultivation were due to moister conditions prevailing at this time, by planting in alluvial areas or by irrigation works is discussed.     

Mapping and sequence analysis of barley hordoindolines

Barley (Hordeum vulgare L.) cultivars vary in traits such as grain hardness and malt quality. However, little is known about the genetic basis of these grain quality traits in barley, while more is known about the basis of grain hardness in wheat (Triticum aestivum L.). Puroindolines are endosperm-specific proteins found in wheat and barley, as well as other members of the Triticeae. In wheat, variation of puroindoline sequence is associated with most of the variability in wheat grain texture. However, no information exists on sequence variation of the barley homologs of puroindolines, the hordoindolines. We have therefore chosen to isolate and characterize the hordoindoline (hin) sequences of eight North American barley cultivars. The barley sequences contain numerous non-conservative amino-acid substitutions relative to their wheat counterparts. However, no significant rearrangements were found in either hinA or hinB of barley. Three hinA and two hinB sequence types were found among the eight barley cultivars examined, indicating substantial allelic variation at this locus. The hinB sequence variability was used to map hinB to the short arm of chromosome 5H in a Steptoe/Morex mapping population, which is coincident with the previously mapped location of hinA and Gsp (grain-softness protein). This chromosomal location also coincides with a small barley malt-extract QTL, suggesting that hordoindoline sequence variation may play a small role in barley grain quality. Efforts to correlate barley seed textural differences and malting quality with hordoindoline sequence type are ongoing. Received: 25 May 2000 / Accepted: 21 September 2000     

Remote Assay for Chlorophyll Photosynthetic Potential of Crops on the Example of Wheat

An optical remote assay for biological production of crops in the field during the vegetation period is proposed. Our calculations demonstrate a good correlation between the S(t) value and crop yield (in the range from 0.85 to 0.90); the higher is S(t) for the vegetation period, the higher is the crop yield. S(t) value can be used to calculate the increase in dry and wet biomass for various crops during the whole vegetation period with an error of less than 10–12%. The absolute error of crop yield for 110 cultivars of wheat, oats, and barley during the experimental period was ±3–3.5 quintal/ha with the mean crop yield of 14–38 quintal/ha.     

Exploring the tertiary gene pool of bread wheat: sequence assembly and analysis of chromosome 5Mg of Aegilops geniculata

Next‐generation sequencing (NGS) provides a powerful tool for the discovery of important genes and alleles in crop plants and their wild relatives. Despite great advances in NGS technologies, whole‐genome shotgun sequencing is cost‐prohibitive for species with complex genomes. An attractive option is to reduce genome complexity to a single chromosome prior to sequencing. This work describes a strategy for studying the genomes of distant wild relatives of wheat by isolating single chromosomes from addition or substitution lines, followed by chromosome sorting using flow cytometry and sequencing of chromosomal DNA by NGS technology. We flow‐sorted chromosome 5M^g from a wheat/Aegilops geniculata disomic substitution line [DS5M^g (5D)] and sequenced it using an Illumina HiSeq 2000 system at approximately 50 × coverage. Paired‐end sequences were assembled and used for structural and functional annotation. A total of 4236 genes were annotated on 5M^g, in close agreement with the predicted number of genes on wheat chromosome 5D (4286). Single‐gene FISH indicated no major chromosomal rearrangements between chromosomes 5M^g and 5D. Comparing chromosome 5M^g with model grass genomes identified synteny blocks in Brachypodium distachyon, rice (Oryza sativa), sorghum (Sorghum bicolor) and barley (Hordeum vulgare). Chromosome 5M^g‐specific SNPs and cytogenetic probe‐based resources were developed and validated. Deletion bin‐mapped and ordered 5M^g SNP markers will be useful to track 5M‐specific introgressions and translocations. This study provides a detailed sequence‐based analysis of the composition of a chromosome from a distant wild relative of bread wheat, and opens up opportunities to develop genomic resources for wild germplasm to facilitate crop improvement.     

Stable Carbon Isotope Evidence for Neolithic and Bronze Age Crop Water Management in the Eastern Mediterranean and Southwest Asia

In a large study on early crop water management, stable carbon isotope discrimination was determined for 275 charred grain samples from nine archaeological sites, dating primarily to the Neolithic and Bronze Age, from the Eastern Mediterranean and Western Asia. This has revealed that wheat (Triticum spp.) was regularly grown in wetter conditions than barley (Hordeum sp.), indicating systematic preferential treatment of wheat that may reflect a cultural preference for wheat over barley. Isotopic analysis of pulse crops (Lens culinaris, Pisum sativum and Vicia ervilia) indicates cultivation in highly varied water conditions at some sites, possibly as a result of opportunistic watering practices. The results have also provided evidence for local land-use and changing agricultural practices.     

Alternative Hosts for Fusarium spp. Causing Crown and Root Rot of Asparagus in Spain

Asparagus crown and root rot caused by Fusarium oxysporum f.sp. asparagi (Foa), F. proliferatum (Fp) and F. solani (Fs) result in early decline and loss of crop production. The role of several crop species on the survival of the Fusarium spp. was investigated. The root symptoms and plant weight of seven crop species were evaluated after inoculation with each of the three Fusarium spp. The number of colony‐forming units of the Fusarium spp. from root tissues was also determined. Garlic was shown to be a symptomatic host for Foa, Fp and Fs; Fs was also pathogenic to onion. Root colonization of garlic, onion, maize, wheat, potato and sunflower suggested that they are reservoirs of Foa, Fp and Fs from asparagus and demonstrated the importance of crop rotation on the development of this asparagus disease.     

Crops and agriculture during the Iron Age and late antiquity in Cerdanyola del Vallès (Catalonia,Spain)

Various sites in the valley of the Sant Cugat stream in Cerdanyola del Vallès (Catalonia) were subject to systematic archaeobotanical sampling to obtain an overview of the crops and agriculture of the area during the Iron Age and late antiquity. In all cases, the most numerous taxa were crop plants. Among these, cereals were clearly predominant at all sites investigated, especially Hordeum vulgare var. vulgare (hulled barley) and Triticum aestivum/durum (bread or macaroni wheat), both in numbers and frequency. Other cereals, such as Triticum dicoccum (emmer) or Setaria italica (foxtail bristle-grass), were regularly present in considerably lower numbers but in fairly high frequencies. Pulses were much less numerous, although their presence increases in terms of frequency. Among them, clearly the best represented was Lens culinaris (lentil). The results show that the agriculture in the period considered was principally based on winter cereals, with a gradual substitution of hulled barley by bread/hard wheat, accompanied by other cereals of minor importance, led by Triticum dicoccum (emmer), and pulses. The appearance of Vitis (grapevine) in the Iberian period is one of the important characteristics of agriculture in the Iberian world. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Susceptibility to take‐all of cereal and grass species,and their effects on pathogen inoculum

Two field trials were conducted to investigate different herbage grasses and cereals for their susceptibility to the disease take‐all, for their impact on concentrations of the pathogen, Gaeumannomyces graminis var. tritici (Ggt), in soil and for their effect on development of take‐all in a subsequent wheat crop. In the herbage grass trial, Bromus willdenowii was highly susceptible to Ggt, produced the greatest post‐senescence Ggt concentrations in soil and highest incidence of take‐all in following wheat crop. Lolium perenne, Lolium multiflorum and Festuca arundinacea supported low Ggt soil concentrations and fallow the least. The relationship between susceptibility to Ggt and post‐senescence concentrations in soil differed between pasture grasses and cereals. In a trial in which Ggt was added to half the plots and where wheat, barley, triticale, rye or fallow were compared, the susceptibility of the cereals to take‐all was not clearly linked to post‐harvest soil Ggt concentrations. In particular, triticale and rye had low and negligible take‐all infection respectively, but greater post‐harvest soil Ggt concentrations than barley or wheat. This indicates that low Ggt concentrations on roots may build up during crop senescence on some cereals. Soil Ggt concentrations were greater following harvest in inoculated plots sown to cereals, but in the second year there was more take‐all in the previously non‐inoculated than inoculated plots. Thus, the grass and cereal species differed in susceptibility to take‐all, in their impact on Ggt multiplication and in associated take‐all severity in following wheat crop.     

The Lr34 adult plant rust resistance gene provides seedling resistance in durum wheat without senescence

The hexaploid wheat (Triticum aestivum) adult plant resistance gene, Lr34/Yr18/Sr57/Pm38/Ltn1, provides broad‐spectrum resistance to wheat leaf rust (Lr34), stripe rust (Yr18), stem rust (Sr57) and powdery mildew (Pm38) pathogens, and has remained effective in wheat crops for many decades. The partial resistance provided by this gene is only apparent in adult plants and not effective in field‐grown seedlings. Lr34 also causes leaf tip necrosis (Ltn1) in mature adult plant leaves when grown under field conditions. This D genome‐encoded bread wheat gene was transferred to tetraploid durum wheat (T. turgidum) cultivar Stewart by transformation. Transgenic durum lines were produced with elevated gene expression levels when compared with the endogenous hexaploid gene. Unlike nontransgenic hexaploid and durum control lines, these transgenic plants showed robust seedling resistance to pathogens causing wheat leaf rust, stripe rust and powdery mildew disease. The effectiveness of seedling resistance against each pathogen correlated with the level of transgene expression. No evidence of accelerated leaf necrosis or up‐regulation of senescence gene markers was apparent in these seedlings, suggesting senescence is not required for Lr34 resistance, although leaf tip necrosis occurred in mature plant flag leaves. Several abiotic stress‐response genes were up‐regulated in these seedlings in the absence of rust infection as previously observed in adult plant flag leaves of hexaploid wheat. Increasing day length significantly increased Lr34 seedling resistance. These data demonstrate that expression of a highly durable, broad‐spectrum adult plant resistance gene can be modified to provide seedling resistance in durum wheat.     

Phylogenetic position and revised classification of Acacia s.l. (Fabaceae: Mimosoideae) in Africa,including new combinations in Vachellia and Senegalia

Previous phylogenetic studies have indicated that Acacia Miller s.l. is polyphyletic and in need of reclassification. A proposal to conserve the name Acacia for the larger Australian contingent of the genus (formerly subgenus Phyllodineae) resulted in the retypification of the genus with the Australian A. penninervis. However, Acacia s.l. comprises at least four additional distinct clades or genera, some still requiring formal taxonomic transfer of species. These include Vachellia (formerly subgenus Acacia), Senegalia (formerly subgenus Aculeiferum), Acaciella (formerly subgenus Aculeiferum section Filicinae) and Mariosousa (formerly the A. coulteri group). In light of this fragmentation of Acacia s.l., there is a need to assess relationships of the non‐Australian taxa. A molecular phylogenetic study of Acacia s.l and close relatives occurring in Africa was conducted using sequence data from matK/trnK, trnL‐trnF and psbA‐trnH with the aim of determining the placement of the African species in the new generic system. The results reinforce the inevitability of recognizing segregate genera for Acacia s.l. and new combinations for the African species in Senegalia and Vachellia are formalized. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 500–523.     

Phytotoxicity of pathogenic fungi and their mycotoxins to cereal seedling viability

Aspergillus flavus, Alternaria alternata and Fusarium oxysporum were the pathogenic fungi most reduced cereal (barley, sorghum and wheat) seedlings. The pathogens have the ability to produce aflatoxin B₁ and G₁, diacetoxyscirpenol, kojic acid and tenuazonic acid that reduced seedling viability. The inhibition dose for 50% reduction (LD₅₀) was recorded by aflatoxins at 0.83 mg L^-1 for barley, 1.74 mg L^-1 for wheat and 2.75 mg L^-1 for sorghum. Diacetoxyscirpenol produced its inhibition at 1.26 mg L^-1 for barley, 3.98 mg L^-1 for wheat and 10 mg L^-1 for sorghum. Kojic acid induced 50% inhibition at 63 mg L^-1 for barley, 105 mg L^-1 for wheat and 251 mg L^-1 for sorghum. However, tenuazonic acid was less toxic where the toxicity ranged between 79–550 mg L^-1. The germination inhibition was more pronounced in barley followed by wheat and was negligible in sorghum for all tested mycotoxins. This inhibition was attributed to the reduction in the seedling amylase activity, where amylase was also reduced in the same trend: barley > wheat > sorghum. Grain treated with carboxin-captan and thiophanatemethyl-thiram at 1 g kg^-1 grain increased the seedlings vigour of wheat in sterilized soil by 45 and 22%, barley by 24 and 33% and sorghum by 15 and 30%, respectively. These fungicides also had a positive effect on cereal when the soil was inoculated with A. flavus, A. alternata and F. oxysporum, but the improvement was still below normal. This revised version was published online in June 2006 with corrections to the Cover Date.     

Oviposition behavior of orange wheat blossom midge on low- vs. high-ranked grass seed heads

The discovery of Sm1, a highly effective resistance (R) gene that targets the first instar of the orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), has created concerns about wheat midge adaptation. Strategies for delaying adaptation to Sm1 include the simultaneous deployment of a resistance trait targeting a different life stage, i.e., the ovipositing adult female. Previous studies have shown that adult females distinguish between wheat genotypes and seed head developmental stages and are attracted by volatiles from young wheat heads. We focused on what happens after the female lands on the seed head, comparing in three tests a seed head of the high‐ranked pre‐anthesis ‘Roblin’ wheat, Triticum aestivum L. (Poaceae), and a head of one of three lower‐ranked types: post‐anthesis ‘Roblin’, pre‐anthesis ‘Key’ wheat (T. aestivum), and pre‐anthesis ‘Robust’ barley (Hordeum vulgare L.). Within each test, high‐ and low‐ranked heads were presented in choice and no‐choice assays, with the behavior of wheat midge females scored every 5 min from 20:30 to 23:00 hours, under mid‐summer natural light conditions and sunset occurring between 20:50 and 21:20 hours. Head type influenced both proportions of females observed on the head and proportions of females probing with the ovipositor. Head*assay interactions occurred only in the test comparing wheat to barley, with barley reducing females observed on the wheat head and wheat increasing females probing on barley. Results indicate that the wheat midge female detects plant cues while examining the seed head and that this detection contributes to differences in egg counts.     

Overexpression of Wheat <i>TaELF3-1BL</i> Delays Flowering in Arabidopsis

EARLY FLOWERING 3 (ELF3), a light zeitnehmer (time-taker) gene, regulates circadian rhythm and photoperiodic flowering in Arabidopsis, rice, and barley. The three orthologs of ELF3 (TaELF3-1AL, TaELF3-1BL, and TaELF3-1DL) have been identified in wheat too, and one gene, TaELF3-1DL, has been associated with heading date. However, the basic characteristics of these three genes and the roles of the other two genes, TaELF3-1BL and, TaELF3-1AL, remain unknown. Therefore, the present study obtained the coding sequences of the three orthologs (TaELF3-1AL, TaELF3-1BL, and TaELF3-1DL) of ELF3 from bread wheat and characterized them and investigated the role of TaELF3-1BL in Arabidopsis. Protein sequence comparison revealed similarities among the three TaELF3 genes of wheat; however, they were different from the Arabidopsis ELF3. Real-time quantitative PCR revealed TaELF3 expression in all wheat tissues tested, with the highest expression in young spikes; the three genes showed rhythmic expression patterns also. Furthermore, the overexpression of the TaELF3-1BL gene in Arabidopsis delayed flowering, indicating their importance in flowering. Subsequent overexpression of TaELF3-1BL in the Arabidopsis ELF3 nonfunctional mutant (elf3 mutant) eliminated its early flowering phenotype, and slightly delayed flowering. The wild-type Arabidopsis overexpressing TaELF3-1BL demonstrated reduced expression levels of flowering-related genes, such as CONSTANS (AtCO), FLOWERING LOCUS T (AtFT), and GIGANTEA (AtGI). Thus, the study characterized the three TaELF3 genes and associated TaELF3-1BL with flowering in Arabidopsis, suggesting a role in regulating flowering in wheat too. These findings provide a basis for further research on TaELF3 functions in wheat.     

Interspecific variation in the resprouting responses of Acacia species following simulated herbivory in a semi‐arid southern African savannah

Plants have evolved a diverse suite of tolerance traits against herbivory, including compensatory growth, increased photosynthesis and activation of dormant meristems. We studied the responses of five Acacia species to simulated herbivory in a semi‐arid southern African savannah. We clipped terminal shoots of five juvenile Acacia species (Acacia rehmanniana, A. nilotica, A. karroo, A. arenaria and A. gerarrdii) to simulate herbivory. We then determined biomass change after 5 months and also counted the number of resprouts and measured their length and diameter. All clipped shoots produced resprouts, with all the Acacia species compensating for the lost biomass. We found considerable interspecific variation in the compensation for biomass lost to herbivory in the five Acacia species. Resprouts biomass ranged from two times in A. arenaria to four times that removed in A. karroo. Acacia karroo produced many resprouts, while A. arenaria produced very few resprouts (4 vs 15 resprouts). The relationship between the number of resprouts and their growth also varied among the different Acacia species. We conclude that the response of Acacias to herbivory ranges from prolific resprouters (such as A. karroo) to poor resprouters (e.g. A. arenaria).