(Editorial comment)
Dr. H. Miura summarized the meeting report of "The Fifth Triticeae Meeting of Japan, 2010" held on November 24 and 25 in Obihiro, Japan. We circulate the abstracts of lectures and oral presentations as edited by Drs. K. Kato and K. Ohnishi.
The Fifth Triticeae Meeting of Japan, 2010
Hideho Miura
Department of Crop Science, Obihiro University of Agriculture and Veterinary Medicine, Inadacho, Obihiro 080-8555, Japan
Corresponding author: Hideho Miura
E-mail: miurahm@obihiro.ac.jp
The Fifth Triticeae Meeting of Japan was held at Doshin Hall of Hokkaido Shimbun Press, Obihiro on November 24-25, 2010. This meeting was jointed with the fifteenth annual meeting on Pre-Harvest Sprouting in Cereals. More than seventeen researchers and students from universities and institutes participated in the meetings (Fig. 1). In the Triticeae Meeting, we had one keynote lecture, one invited lecture and seven oral presentations. The abstracts of the lectures and presentations are listed below. Young researchers and students as well as elder researchers had a good opportunity to know a wide field of Triticeae research and wheat breeding in Hokkaido, and all participants enjoyed local foods and beautiful late autumn in Obihiro. Next meeting will be held in Yokohama area next year. I thank all participants for joining the meeting.
Keynote Lecture
Wheat breeding in Hokkaido
L01. Wheat production and breeding in Hokkaido
Tadashi Tabiki
National Agriculture and Food Research Organization National Agricultural Research Center for Hokkaido Region
In 1970’s, paddy fields were converted into upland crop fields due to the overproduction of rice and beginning in 1973,wheat was promoted through incentives. In addition, improved varieties and cultivation techniques greatly raised the yield per hectare in Hokkaido. As a result, planted acreage expanded rapidly to 129,700 ha in 1989, after which it declined again. Since 1998, due to the reinforcement of the rice diversion program, the planted acreage increased again. As of 2009 it was 110,000 ha. The main variety of wheat is “Kitahonami” that is suitable for Japanese noodles. And for bread, “Haruyokoi” is popular at present.
The objectives of wheat breeding in Hokkaido are below.
Winter wheat: Improvement in Japanese noodle-quality, Improvement in bread-making quality, High-yield, Resistance to scab, yellow mosaic virus, powdery mildew, leaf rust, snow mold, and pre-harvest sprouting.
Spring wheat: Improvement in bread-making quality, High-yield, Resistance to scab, powdery mildew, leaf rust, , and pre-harvest sprouting.
L02. Breeding of hard red winter wheat in Hokkaido and a new winter wheat variety ‘Yumechikara’
Zenta Nishio
National Agricultural Research Center for Hokkaido Region (Memuro)
‘Yumechikara’ a hard red winter wheat variety developed by National Agricultural Research Center for Hokkaido Region, was released in January 2009. ‘Yumechikara’ was released because of its resistance to Wheat Yellow Mosaic Virus (WYMV) and decent bread-making quality. ‘Yumechikara’ was registered as ‘Wheat Norin No.172’ by the Ministry of Agriculture, Forestry and Fisheries in 2009. The pedigree of ‘Yumechikara’ is ‘Satsukei 159/KS 831957 (F1)’ and ‘Tsukikei 9509 (Kitanokaori)’. ‘Satsukei 159’ was a donor of winter hardiness and early maturity traits. ‘KS 831957’ was introduced from Kansas State University, USA, and a donor of WYMV resistance, high protein content and extra strong dough quality traits. ‘Tsukikei 9509 (Kitanokaori)’ was a donor of short culm, lodging tolerance, powdery mildew and leaf rust resistance.
‘Yumechikara’ has fairly good resistance to WYMV, Fusarium head blight and leaf rust, good bread-making quality, and high lodging resistance compared to ‘Hokushin.’ In the test field of National Agricultural Research Center for Hokkaido Region (Memuro) from 2006 to 2008 (harvest year), the average yield of ‘Yumechikara’ (8.34 t/ha) was 8% higher than that of ‘Hokushin’ (7.72 t/ha). The bread-making quality score of ‘Yumechikara’ (76.5) was similar to that of ‘Haruyokoi’ (Hard Red Spring) (75.5) in Hokkaido Flour Millers Association tests (2006-2007). In addition, the bread-making quality score by blending with soft flour (Hokushin) resulted in superior loaf volume by Japan Institute of Baking’s tests. ‘Yumechikara’ will be very useful for the WYMV infested areas and increasing self-sufficiency in food of Japan by enlarging domestic wheat market for bread.
L03. Wheat breeding for good noodle quality and development of new winter wheat variety "Kitahonami"
Satoshi Kobayashi
Kitami Agricultural Experiment Station
A new winter wheat variety“Kiatahonami” was released by Kitami Agricultural Experiment Station at Kunneppu, Hokkaido in 2006.It was developed from the cross “Kitami 72” and “Kitakei 1660”. “Kitahonami” is high yield and good resistance to pre-harvest sprouting , good disease resistance and good noodle-making quality with bright color and suitable amylose content. In September 2010, “Kitahonami” is sown about 100,000 ha instead of “Hokushin”, previous leading variety in Hokkaido.
It is expected that this new variety will contribute to improvement of noodle quality and agricultural production in Hokkaido.
Invited Lecture
Genetic mechanisms of parasitic specialization of Magnaporthe oryzae on gramineous plants with special reference to wheat and barley
Yukio Tosa
Graduate School of Agricultural Sciences, Kobe University
Magnaporthe oryzae, a causal agent of blast diseases of gramineous plants, is composed of several plant genus-specific subgroups such as Oryza isolates pathogenic on rice, Setaria isolates pathogenic on foxtail millet, Eleusine isolates pathogenic on finger millet, etc. In 1985, blast disease occurred on common wheat (Triticum aestivum) in Brazil. The wheat blast has then rapidly spread to other wheat growing regions in Brazil and to other countries in South America. Isolates from blast lesions on wheat (Triticum isolates) were proved to be a new subgroup specific to the genus Triticum. Genetic analyses with Triticum isolates revealed that the subgroup - genus specificity is governed by interactions between avirulence genes and resistance genes. PWT1, a gene conditioning the avirulence of Setaria and Oryza isolates on wheat, was recognized not only by wheat but also by barley, oat, and Italian ryegrass, suggesting that its corresponding resistance gene (tentatively designated as Rwt1) is widely distributed in Pooideae. Identification of Rwt1 in common wheat was unsuccessful because all common wheat cultivars recognized PWT1. However, we found a barley cultivar (cv. Nigrate) that did not recognize PWT1. Using Nigrate as a susceptible cultivar, we succesfully identified a locus conditioning the resistance of barley to various subgroups of M. oryzae, and designated it as Rmo2. Rmo2 was considered to be a barley homolog of Rwt1. Interestingly, I found resistance genes (Rmg2 and Rmg3) against the wheat blast fungus in common wheat cultivar ‘Thatcher’ which had been bred before the appearance of the wheat pathogen. The original role of these genes will be discussed.
Oral Presentation
O01. Triticeae resources in the future
Kazuhiro Sato1, Shuhei Nasuda2
1Institute of Plant Science and Resources, Okayama University
2Laboratory of Plant Genetics, Graduate School of Agriculture, Kyoto University
The research community of Triticeae (wheat and barley) will be the biggest in plants in the world. The trends of research moving from model species to industrial crops may raise the numbers of users on Triticeae in the near future.
Cultivated barley is a true diploid and has been extensively studied genetically. Barley shares the same set of genome with hexaploid wheat and its related species and thus becoming a diploid model of cultivated species in Triticeae. By the schedule of International Barley Sequencing Consortium draft genome sequence will be available until 2011 and nearly complete sequence will be available by 2015. The uses of barley genome sequence will greatly accelerate the isolation and functional analysis of genes in barley and wheat. The main important role of barley resource in the near future is to provide germplasm with information of genetic variation in target traits, genomic information on the germplasm (mainly DNA markers and polymorphisms) and genetic materials for gene isolation. Some of these materials are already developed and can be provided in the near future.
NBRP-WHEAT has more than 12,000 germplasm accessions including wild species and landraces, which are the valuable sources of genetic diversity. We will maintain all the present genetic stocks, collect new seed stocks on demand and continue to distribute them to the world. NBRP-WHEAT will continue genotyping analysis of the collected genetic stocks to make them more user-friendly. Thanks to the recent rapid progress in the “genomics” technologies, in the near future we will obtain some tools for genotyping multiple markers throughout the genome simultaneously. In that event, forward genetics, i.e. from phenotypes of interest to their responsible genes, will easily be realized in bread wheat, and then the importance of the genetic stocks of NBRP-WHEAT will appreciate in value.
O02. Toward comprehensive use of the natural variation in Aegilops tauschii for wheat breeding
Nobuyuki Mizuno, Shigeo Takumi
Graduate School of Agricultural Science, Kobe University
Aegilops tauschii Coss., the D-genome progenitor of hexaploid wheat, has a wide natural species range in central Eurasia, spreading from Turkey to western China. Synthetic hexaploids can be produced through hybridization between tetraploid wheat and Ae. tauschii accessions. The wheat synthetics are useful for transfer of agriculturally important genes from Ae. tauschii to common wheat. However, abnormal growth phenotypes such as hybrid necrosis were frequently observed in the triploid hybrids between tetraploid wheat and Ae. tauschii. Based on the phenotypic characteristics, the hybrid necrosis is classified into two types, types II and III necrosis. In the triploid hybrids showing type III necrosis, cell death occurred gradually starting from older tissues. On the other hand, the hybrid plants showing type II necrosis clearly exhibited a necrotic phenotype and incomplete leaf sheath emergence at the tillering stage only under low temperature conditions. The abnormal growth phenotypes act as reproductive barriers to transfer the genes from Ae. tauschii to common wheat. To elucidate the mechanisms to express the hybrid necrosis, microarray analyses and mapping of the causal genes were performed. Together with the results, it is strongly suggested that autoimmune-response like cell death is associated with both types II and III necrosis, and that mitotic cell division is significantly repressed in shoot apical meristem of the type II necrosis-showing synthetics. The causal genes of type III and type II necrosis on the D-genome are respectively located on 7DS and 2DS, indicating that hybrid necrosis observed in the ABD triploids is different from the Ne1/Ne2-induced type I necrosis in common wheat. Development of the molecular markers tightly linked to the causal genes should be required for the efficient transfer of agriculturally important genes from Ae. tauschii to common wheat.
O03. Utilization of wild plants to improve wheat flour quality - especially in synthetic wheat -
Hiroyuki Tanaka
Laboratory of Plant Genetics and Breeding Science, Faculty of Agriculture, Tottori University
Aegilops tauschii (DD) is a rich source of genetic variability for Triticum aestivum (AABBDD) improvement through utilizing synthetic hexaploid wheat lines (AABBDD), which contain genomes from Ae. tauschii and tetraploid wheat (AABB). Allelic variations and expression profiles of seed storage proteins in wheat are responsible for the ability of dough strength affecting the end-use quality. In this study, we investigated expression profiles of seed storage proteins, which contain high-molecular-weight glutenin subunits (HMW-GSs), low-molecular-weight glutenin subunits (LMW-GSs) and gliadins in 18 accessions of Ae. tauschii. HMW-GSs and gliadins were classified into 5 and 16 types based on the protein profiles by one-dimensional gel electrophoresis, respectively. Of 11 accessions had one dominant type of HMW-GSs. Two-dimensional gel electrophoresis has resolved a total of 42 protein spots from LMW-GS genes. We also found changes of the density of some LMW-GSs’ spots from durum wheat cultivar ‘Langdon’ (AABB) hybridized with Ae. tauschii. The synthetic hexaploid wheat lines from each accession of Ae. tauschii showed various effects on the dough strength. The values were 0.7 to 1.4 times stronger than that of ‘Langdon’, although the protein profiles of HMW-GSs were same among the lines. These variations were caused by the different expression levels of the LMW-GSs. This shows that the dough strength can be affected not only by the presence or absence of the LMW-GSs, but also by the expression level.
O04. Evolution of the barley six-rowed spike gene by duplication
Shun Sakuma1, 2, Takao Komatsuda1
1National Institute of Agrobiological Sciences (NIAS), Plant Genome Research Unit, 2-1-2 Kan-non-dai, Tsukuba, Ibaraki 305-8602, Japan
2Graduate school of Horticulture, Chiba University, 648 Matsudo, Matsudo, Chiba 271-8510, Japan
DNA duplication is a major player in genome evolution. In some cases, a duplicated gene acquires a new function while the ancestral copies retains its original function; but in other cases, one or other duplicate is lost over evolutionary time. The vrs1 gene which is responsible for the six-rowed spike in barley has been isolated by positional cloning, and its functional allele (HvHox1) been shown to encode a homoeodomain leucine zipper (HD-Zip) type I transcription factor. Here we show that the Vrs1 gene evolved in the grasses via duplication, with a second copy of the gene, HvHox2. Micro-collinearity was well conserved between HvHox2 and its grass orthologues, but Vrs1 is unique to the barley tribe. Vrs1 and HvHox2 both consist of three exons and two introns, and their gene products share many residues; but their expression profiles are very distinct. Vrs1 expression is strictly limited to the lateral spikelets of the immature spike, whereas HvHox2 expression is ubiquitous. The VRS1 and HvHOX2 sequences differ in their homoeodomain, and in addition, the former has lost the C terminal motif.
O05. Using related species for improving the P efficiency and grain Zn/Fe concentration in wheat
Shiwen Wang, Lina Yin, Hiroyuki Tanaka, Kiyoshi Tanaka, Hisashi Tsujimoto
Faculty of Agriculture, Tottori University
Wheat related species have richer genetic variation than cultivated species. These were used for wheat breeding mainly for the source of disease resistance. We here report the ability of the wheat lines with alien chromosomes to P, Zn and Fe-deficient soils. Some addition lines conferred high ability of P uptake, efficiency and utilization. These addition lines with high P efficiency could be used for breeding wheat with high P efficiency. On the other hand, the grains of some other addition lines included three times more Fe or Zn than cultivated wheat. The alien chromosome for these characters belong to U or modified S genotype and homologous in group 1, 2 or 7. We will discuss significance of these characters in the world wheat cultivation facing to sever environmental conditions.
O06. Zebularine induces chromosomal breakage in the root apical meristem of wheat
Hitoshi Ito, Shuhei Nasuda
Laboratory of Plant Genetics, Graduate School of Agriculture, Kyoto University
Expression of genetic character is a result of translation from genetic information in DNA to RNA and finally to protein. Therefore, genetic variations reflect differences in base sequence. However, there are mechanisms of changes in gene expression patterns that are not explained by DNA sequence changes. The study of changes in gene expression caused by these mechanisms is termed epigenetics. One of the epigenetic mechanisms is the modification of cytosine in genomic DNA to 5-methylcytosine. Cytidine analogues, 5-azacytidine and 5-aza-2’-deoxycytidine, have been frequently used as DNA methylation inhibitors, but their instability in an aqueous solution and high toxicity were problematic in use of long culture periods. Therefore, in this study, we used Zebularine, a more stable and less toxic DNA methylation inhibitor, to investigate the effect of DNA demethylation on wheat. Wheat plants showed inhibition of root growth by Zebularine treatment. Moreover, chromosomal breakage and bridge were observed at anaphase and telophase stages of cell division in the root tips. Together with the result of Southern blot analysis which confirmed hypomethylation in genomic DNA of root tips following Zebularine treatment, chromosomal breakage may be associated with DNA hypomethylation. Observed phenotypic variations in the Zebularine-treated plants carrying five dominant marker genes indicated that Zebularine-induced chromosome breakage may be applied to produce mutants. However, the mechanism of chromosomal breakage by Zebularine has not been revealed. Aiming the tracing the changes in gene expression profiles under Zebularine treatment, we started cDNA sequencing by the next-generation sequencer.
O07. Multiple translocation of the AVR-Pita avirulence gene among chromosomes of the rice blast fungus Magnaporthe oryzae and related species
Izumi Chuma1, Chihiro Isobe1, Yuma Hotta1, Natsuru Futamata1, Kana Ibaragi1, Motoaki Kusaba2, Kentaro Yoshida3, Ryohei Terauchi3, Yoshikatsu Fujita4, Hitoshi Nakayashiki1, Yukio Tosa1
1Graduate School of Agricultural Sciences, Kobe University, Kobe 657-8501, Japan
2Faculty of Agriculture, Saga University, Saga 840-8502, Japan
3Iwate Biotechnology Research Center, Kitakami, Iwate 024-0003, Japan
4National Agricultural Research Center, 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
The genus Pyricularia (teleomorph, Magnaporthe) includes fungal populations causing the rice blast and wheat blast diseases as well as diseases of many other monocot species. Here, we show that AVR-Pita homologs differed significantly in their genomic locations (different chromosomes or chromosomal locations) during speciation or parasitic specialization of Pyricularia species. Chromosomes carrying homologs were different among species of Pyricularia and host-specific subgroups of P. oryzae. Among diverse fungal isolates of the P. oryzae rice-specific subgroup, AVR-Pita homolog was found to be on chromosomes 1, 3, 4, 5, and 7, as well as on supernumerary chromosomes, and virulence on Pita has mainly evolved via loss of AVR-Pita. When they are expressed in virulent isolate of rice-specific subgroup, most of the AVR-Pita homologs from non-rice Pyricularia isolates could elicit Pita-mediated resistance. In contrast, family member AVR-Pita3, which lacks avirulence activity, was on chromosome 7 in vast majority of the isolates examined. Comparative analysis of flanking regions of the AVR-Pita homologs suggested that some of the homologs were located on subtelomere, and insertion of a retrotransposon, Inago1, into flanks of ancestral AVR-Pita homolog(s) was a key event associated with its mobility. Overall, this suggests that diversification in sequence and genome location of AVR-Pita was a consequence of recognition by Pita in the rice-specific subgroup of this pathogen. Given that AVR-Pita is often deleted in virulent isolates, “recovery” of this gene most likely occurs through parasexual or horizontal transfer processes in asexual populations.