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Introducing Agropyron cristatum chromosome 1P into common wheat can significantly reduce the plant height and leaf size, which can improve the plant architecture of common wheat. A new direction in crop breeding is the improvement of plant architecture for dense plantings to obtain higher yields. Wild relatives carry an abundant genetic variation that can increase the diversity of genes for crop genetic improvement. In this study, the A. cristatum 1P addition line, 1PS and 1PL telosomic addition lines were obtained by backcrossing the addition/substitution line II-3-1 (2n = 20'' W + 1P" + 2P") with the commercial recurrent parent cv. Jimai 22. Four continuous years of agronomic trait investigation in the genetic populations suggested that the introduction of A. cristatum chromosome 1P into wheat can significantly improve wheat plant architecture by reducing the plant height, leaf length and leaf width. A. cristatum chromosome arm 1PS reduced the plant height and leaf length of wheat, whereas introducing A. cristatum chromosome arm 1PL reduced the plant height, leaf length and leaf width. Altogether, our results demonstrated that A. cristatum chromosome 1P carries the dominant genes for small leaves and a dwarf habit for the enhancement of plant architecture in wheat. This study highlights wild relative donors as new gene resources for improving wheat plant architecture for dense planting.

This study demonstrated that the aberrant transcription of DvGW2 contributed to the increased grain width and thousand-grain weight in wheat-Dasypyrum villosum T6VS·6DL translocation lines. Due to the high immunity to powdery mildew, Dasypyrum villosum 6VS has been one of the most successful applications of the wild relatives in modern wheat breeding. Along with the desired traits, side-effects could be brought when large alien chromosome fragments are introduced into wheat, but little is known about effects of 6VS on agronomic traits. Here, we found that T6VS·6DL translocation had significantly positive effects on grain weight, plant heightand spike length, and small negative effects on total spikelet number and spikelet compactness using recipient and wheat-D. villosum T6VS·6DL allohexaploid wheats, Wan7107 and Pm97033. Further analysis showed that the 6VS segment might exert direct genetic effect on grain width, then driving the increase of thousand-grain weight. Furthermore, comparative transcriptome analysis identified 2549 and 1282 differentially expressed genes (DEGs) and 2220 and 1496 specifically expressed genes (SEGs) at 6 days after pollination (DAP) grains and 15 DAP endosperms, respectively. Enrichment analysis indicated that the process of cell proliferation category was over-represented in the DEGs. Notably, two homologous genes, TaGW2-D1 and DvGW2, were identified as putative candidate genes associated with grain weight and yield. The expression analysis showed that DvGW2 had an aberrant expression in Pm97033, resulting in significantly lower total expression level of GW2 than Wan7107, which drives the increase of grain weight and width in Pm97033. Collectively, our data indicated that the compromised expression of DvGW2 is critical for increased grain width and weight in T6VS·6DL translocation lines.

Agropyron cristatum (L.) Gaertn. (2n=4x=28, PPPP), which is a wild relative of common wheat and has a P genome, has many excellent characteristics (for example, it is disease resistant, is stress resistant and is high yielding) and has important utilization value for the genetic improvement of wheat. In this study, the wheat– A. cristatum 3P addition line I-27 and 3P(3B) substitution line I-15 were identified for the first time via in situ hybridization (ISH) and specific molecular marker (EST-STS) from wheat– A. cristatum -derived lines, which laid an representing important material for the utilization of excellent genes from A. cristatum chromosome 3P for wheat genetic improvement. In terms of agronomic traits, that the tiller number and spike length of 3P addition line I-27 were significantly higher than those of Fukuhokomugi. The spike length and spikelet number per spike of 3P substitution line I-15 were significantly greater than those of Fukuho. Additionally, wheat– A. cristatum 3P substitution line I-15 was resistant to wheat leaf rust. The generation of the 3P addition line I-27 and 3P substitution line I-15 was essential for the transfer of the excellent genes of the A. cristatum 3P chromosome into common wheat and resulted in the wheat– A. cristatum addition line containing a complete set of genetic research materials, laying a foundation for comparative studies of the P genome and subsequent fine mapping.

Wheat leaf rust (caused by

Agropyron cristatum (L.) Gaertn. (2n = 28, PPPP), a relative of wheat, carries desirable genes associated with high yield, disease resistance, and stress resistance, which is an important resource for wheat genetic improvement. The long arm of A. cristatum chromosome 2P carries favorable genes conferring powdery mildew and leaf rust resistance, and two wheat–A. cristatum 2P translocation lines, 2PT3 and 2PT5, with a large segment of 2P chromatin were obtained. In this study, 2PT3 and 2PT5 translocation lines with powdery mildew and leaf rust resistance genes were used to induce translocations of different chromosomal sizes via ionizing radiation. According to cytological characterization, 10 of those plants were new wheat–A. cristatum 2P small-chromosome segment translocation lines with reduced 2P chromatin, and 6 plants represented introgression lines without visible 2P chromosomal fragments. Moreover, four lines were resistant to both powdery mildew and leaf rust, while two lines were resistant only to leaf rust.

Wild relatives of wheat are essential gene pools for broadening the genetic basis of wheat. Chromosome rearrangements and genomic variation in alien chromosomes are widespread. Knowledge of the genetic variation between alien homologous chromosomes is valuable for discovering and utilizing alien genes. In this study, we found that 5113 and II-30-5, two wheat–A. cristatum 6P addition lines, exhibited considerable differences in heading date, grain number per spike, and grain weight. Genome resequencing and transcriptome analysis revealed significant differences in the 6P chromosomes of the two addition lines, including 143,511 single-nucleotide polymorphisms, 62,103 insertion/deletion polymorphisms, and 757 differentially expressed genes. Intriguingly, genomic variations were mainly distributed in the middle of the chromosome arms and the proximal centromere region. GO and KEGG analyses of the variant genes and differentially expressed genes showed the enrichment of genes involved in the circadian rhythm, carbon metabolism, carbon fixation, and lipid metabolism, suggesting that the differential genes on the 6P chromosome are closely related to the phenotypic differences. For example, the photosynthesis-related genes PsbA, PsbT, and YCF48 were upregulated in II-30-5 compared with 5113. ACS and FabG are related to carbon fixation and fatty acid biosynthesis, respectively, and both carried modification variations and were upregulated in 5113 relative to II-30-5. Therefore, this study provides important guidance for cloning desirable genes from alien homologous chromosomes and for their effective utilization in wheat improvement.

The powdery mildew resistance locus was mapped to A. cristatum chromosome 6PL bin (0.27-0.51) and agronomic traits evaluation indicated that this locus has potential breeding application value. Agropyron cristatum (2n = 4x = 28, PPPP) is a wild relative of wheat with an abundance of biotic and abiotic stress resistance genes and is considered one of the best exogenous donor relatives for wheat breeding. A number of wheat-A. cristatum derived lines have been generated, including addition lines, translocation lines and deletion lines. In this study, the 6P disomic addition line 4844-12 (2n = 2x = 44) was confirmed to have genetic effects on powdery mildew resistance. Four 6P deletion lines (del16a, del19b, del21 and del27) and two translocation lines (WAT638a and WAT638b), derived from radiation treatment of 4844-12, were used to further assess the 6P powdery mildew resistance locus by powdery mildew resistance assessment, genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH) and 6P specific sequence-tagged-site (STS) markers. Collectively, the locus harboring the powdery mildew resistance gene was genetically mapped to a 6PL bin (0.27-0.51). The genetic effects of this chromosome segment on resistance to powdery mildew were further confirmed by del16a and del27 BC

As an important wheat wild relative, the P genome of

Tiller number (TN) is an important agronomic trait affecting gramineous crop yield. To understand the static and dynamic information of quantitative trait locus (QTLs) controlling TN of

Agropyron cristatum (2n = 4x = 28, PPPP) is an important wild relative of common wheat (Triticum aestivum L., 2n = 6x = 42). A previous report showed that the wheat-A. cristatum 6P translocation line WAT655 carrying A. cristatum 6PS (0.81–1.00) exhibited high resistance to prevalent physiological races of stripe rust (CYR32 and CYR33). In this study, three disease resistance-related transcripts, which were mapped to A. cristatum 6PS (0.81–1.00) through the analysis of specific molecular markers, were acquired from among A. cristatum full-length transcripts. The BC5F2 and BC5F2:3 genetic populations of the translocation line WAT655 were analyzed by using three disease resistance-related gene markers, A. cristatum P genome-specific markers, and fluorescence in situ hybridization (FISH). The results revealed that the introgression between A. cristatum P genome and wheat genome was observed in progenies of the genetic populations of the translocation line WAT655 and the physical positions of the three genes were considerably adjacent on A. cristatum 6PS (0.81–1.00) according to the FISH results. Additionally, kompetitive allele-specific PCR (KASP) markers of the three genes were developed to detect and acquire 24 breeding lines selected from the progenies of the distant hybridization of wheat and A. cristatum, which showed resistance to physiological races of stripe rust (CYR32 and CYR33) and other desirable agronomic traits according to the field investigation. In conclusion, this study not only provides new insights into the introgression between A. cristatum P genome and wheat genome but also provides the desirable germplasms for breeding practice.

Agropyron cristatum (2n = 4x = 28, PPPP) is an important wild relative of common wheat (Triticum aestivum L., 2n = 6x = 42). A previous report showed that the wheat-A. cristatum 6P translocation line WAT655 carrying A. cristatum 6PS (0.81–1.00) exhibited high resistance to prevalent physiological races of stripe rust (CYR32 and CYR33). In this study, three disease resistance-related transcripts, which were mapped to A. cristatum 6PS (0.81–1.00) through the analysis of specific molecular markers, were acquired from among A. cristatum full-length transcripts. The BC5F2 and BC5F2:3 genetic populations of the translocation line WAT655 were analyzed by using three disease resistance-related gene markers, A. cristatum P genome-specific markers, and fluorescence in situ hybridization (FISH). The results revealed that the introgression between A. cristatum P genome and wheat genome was observed in progenies of the genetic populations of the translocation line WAT655 and the physical positions of the three genes were considerably adjacent on A. cristatum 6PS (0.81–1.00) according to the FISH results. Additionally, kompetitive allele-specific PCR (KASP) markers of the three genes were developed to detect and acquire 24 breeding lines selected from the progenies of the distant hybridization of wheat and A. cristatum, which showed resistance to physiological races of stripe rust (CYR32 and CYR33) and other desirable agronomic traits according to the field investigation. In conclusion, this study not only provides new insights into the introgression between A. cristatum P genome and wheat genome but also provides the desirable germplasms for breeding practice.

Agropyron cristatum (L.) Gaertn. (2n = 4x = 28, PPPP), one of the most important wild relatives of wheat, harbors many desirable genes for wheat genetic improvement. Development of wheat-A. cristatum translocation lines with superior agronomic traits facilitates wheat genetic improvement. In this study, 5106-DS was identified to be a wheat-A. cristatum 6P (6D) disomic substitution line using cytogenetic identification and molecular markers analysis, which displayed higher thousand-grain weight than its wheat parent Triticum aestivum cv. Fukuhokomugi (2n = 6x = 42, AABBDD). Analysis of its backcross populations indicated that there might be genes conferring increased grain weight and width on the chromosome 6P of 5106-DS. In the backcross population, we found three plants as Robertsonian translocation lines, created by chromosome centric breakage-fusion. Among them, there are one T6DS·6PL and two T6PS·6DL Robertsonian translocation lines. Additionally, the centromeres of these three translocation lines were determined to be fused centromeres of 6D and 6P using the probes pAcCR1 and pCCS1. The development of Robertsonian translocation lines would promote the utilization of A. cristatum chromosome 6P in wheat improvement. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11032-021-01251-y.

Background miR-539 functions as a tumor suppressor in many types of cancer. However, the role of miR-539 in gastric cancer remains unclear. The aim of this study is to investigate the clinical significance and functional role of miR-539 in gastric cancer. Methods Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression levels of miR-539 in gastric cancer patients tissues and cells. We analyzed the association between miR-539 expression levels and clinicopathological features, as well as overall survival information with Kaplan-Meier survival curves and Cox regression analysis. The functional role of miR-935 on the proliferation, migration, and invasion was also investigated by using miR-539 mimic or miR-539 inhibitor through CCK-8 assay, Transwell migration and invasion assays. The relationship between miR-539 and RUNX2 was verified by a dual luciferase assay. Results The expression of miR-539 was decreased in gastric cancer tissues and cell lines. Downregulation of miR-539 was closely associated with differentiation, lymph node metastasis, TNM stage, and poor survival outcome of gastric cancer patients. Furthermore, overexpression of miR-539 inhibited cell proliferation, migration, and invasion of gastric cancer cells. In addition, RUNX2 was a direct target of miR-539. Conclusion Taken together, miR-539 may serve as a tumor suppressor for inhibiting cell proliferation, migration, and invasion by targeting RUNX2. Reduced expression of miR-539 is an independent prognostic factor in gastric cancer and may be a potential prognostic biomarker and miR-539/RUNX2 axis may serve as a potential therapeutic target for the treatment of gastric cancer.

Agropyron cristatum (L.) Gaertn. (P genome) is cultivated as pasture fodder and can provide many desirable genes for wheat improvement. With the development of genomics and fluorescence in situ hybridization (FISH) technology, probes for identifying plant chromosomes were also developed. However, there are few reports on A. cristatum chromosomes. Here, FISH with the repeated sequences pAcTRT1 and pAcpCR2 enabled the identification of all diploid A. cristatum chromosomes. An integrated idiogram of A. cristatum chromosomes was constructed based on the FISH patterns of five diploid A. cristatum individuals. Structural polymorphisms of homologous chromosomes were observed not only among different individuals but also within individuals. Moreover, seventeen wheat-A. cristatum introgression lines containing different P genome chromosomes were identified with pAcTRT1 and pAcpCR2 probes. The arrangement of chromosomes in diploid A. cristatum was determined by identifying correspondence between the P chromosomes in these genetically identified introgression lines and diploid A. cristatum chromosomes. The two probes were also effective for discriminating all chromosomes of tetraploid A. cristatum, and the differences between two tetraploid A. cristatum accessions were similar to the polymorphisms among individuals of diploid A. cristatum. Collectively, the results provide an effective means for chromosome identification and phylogenetic studies of P genome chromosomes.

Agropyron cristatum (2n = 4x = 28, PPPP) is an important wild relative of common wheat and confers desirable agronomic traits to common wheat. A previous report showed that the wheat-A. cristatum 6P translocation line WAT655 carrying A. cristatum 6PS (0.81–1.00) exhibited high resistance to prevalent physiological races (CYR32 and CYR33). In this study, three disease resistance-related transcriptomes, which were mapped to A. cristatum 6PS (0.81–1.00) through the analysis of specific molecular markers, were searched from among A. cristatum full-length transcriptomes. Then, three disease resistance-related gene markers, A. cristatum P genome-specific markers, and fluorescence in situ hybridization (FISH)/genomic in situ hybridization (GISH) probes made from the DNA of three bacterial artificial chromosome (BAC) clones, three genes, and A. cristatum “Z559” were used to analyze the BC5F2 and BC5F2:3 genetic populations of the translocation line WAT655. The results revealed the introgression can spontaneously occur between A. cristatum P genome and wheat genome, and indicated the three genes could constitute a gene cluster according to the positions of their FISH signals. Additionally, kompetitive allele-specific PCR (KASP) markers of the three genes were developed to detect and acquire 24 wheat-A. cristatum breeding materials, which showed resistance to physiological races (CYR32 and CYR33) and other desirable agronomic traits according to the field investigation. In conclusion, our study not only provides new insights into the introgression between A. cristatum P genome and wheat genome, but also provides the desirable breeding materials for breeding practice.

An enhanced grain weight locus from Agropyron cristatum chromosome 7P was verified in two wheat backgrounds, localized to the 7PS1-2 region. Novel translocation lines with this locus were evaluated. Agropyron cristatum is a wild relative of wheat that harbours elite genes for wheat improvement. The wheat-A. cristatum 7P disomic addition line II-5-1 exhibits high grain weight. Here, to dissect the genetic basis of grain weight contributed by A. cristatum chromosome 7P in wheat backgrounds, four segregated populations of the addition line were developed and evaluated in two wheat backgrounds. The results showed that A. cristatum chromosome 7P can stably and significantly increase the grain weight by approximately 2 g, mainly by increasing grain length at different grain weight levels of the wheat background. The locus for increased grain weight from chromosome 7P shows dominant inheritance independent of the wheat background. Moreover, two deletion lines and 23 translocation lines were identified by cytological methods and molecular markers, and an enlarged chromosome 7P bin map was constructed with 158 STS markers and 40 bin intervals. With the genetic populations of these deletion and translocation lines, the genetic locus of increased grain weight was narrowed down to bin 7PS1-2. Two translocation lines (7PT-A18 and 7PT-B4) with smaller 7P chromosomal segments exhibited an increase in grain weight, grain length and grain width simultaneously. These translocation lines carrying the 7PS1-2 chromosomal fragment will be valuable genetic resources for wheat grain weight improvement. Collectively, this study uncovers the grain weight locus from chromosome 7P and provides novel pre-breeding lines with enhanced grain weight.

Common wheat is an allohexaploid (BBAADD) that originated from the hybridization and polyploidization of the diploid Aegilops tauschii (DD) with the allotetraploid Triticum turgidum (BBAA). Phenotypic changes often arise with the formation and evolution of allopolyploid wheat, but little is known about the evolution of root traits in different wheat species with varying ploidy levels. Here, we reported that the lateral root number on the primary root (LRNPR) of synthetic and natural allohexaploid wheats (BBAADD) is significantly higher than that of their allotetraploid (BBAA) and diploid (AA and SS) progenitors, but is much lower than that of their diploid (DD) progenitors. The expression of the wheat gene TaLBD16, an ortholog of the Arabidopsis LATERAL ORGAN BOUNDARIES-DOMAIN16/ASYMMETRIC LEAVES2-LIKE18 (LBD16), which is involved in lateral root development in Arabidopsis, was positively correlated with the LRNPR in diploid and allopolyploid wheats. In natural and synthetic allohexaploid wheats, the transcript of the TaLBD16 from the D genome (TaLBD16-D) was relatively more abundant compared with TaLBD16-A and TaLBD16-B. Consistent with the observed variation in LRNPR, the divergence in the expression of TaLBD16 homoeologous genes occurred before the formation of polyploidy wheat. Collectively, our observations indicate that the D genome played a crucial role in the increased lateral root number of allohexaploid wheats compared with their allotetraploid progenitors, and that TaLBD16-D was one of the key genes involved in the formation of lateral root number during wheat evolution.

Different types of P genome sequences and markers were developed, which could be used to analyze the evolution of P genome in Triticeae and identify precisely wheat- A. cristatum introgression lines. P genome of Agropyron Gaertn. plays an important role in Triticeae and could provide many desirable genes conferring high yield, disease resistance, and stress tolerance for wheat genetic improvement. Therefore, it is significant to develop specific sequences and functional markers of P genome. In this study, 126 sequences were isolated from the degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR) products of microdissected chromosome 6PS. Forty-eight sequences were identified as P genome-specific sequences by dot-blot hybridization and DNA sequences analysis. Among these sequences, 22 displayed the characteristics of retrotransposons, nine and one displayed the characteristics of DNA transposons and tandem repetitive sequence, respectively. Fourteen of 48 sequences were determined to distribute on different regions of P genome chromosomes by fluorescence in situ hybridization, and the distributing regions were as following: all over P genome chromosomes, centromeres, pericentromeric regions, distal regions, and terminal regions. We compared the P genome sequences with other genome sequences of Triticeae and found that the similar sequences of the P genome sequences were widespread in Triticeae, but differentiation occurred to various extents. Additionally, thirty-four molecular markers were developed from the P genome sequences, which could be used for analyzing the evolutionary relationship among 16 genomes of 18 species in Triticeae and identifying P genome chromatin in wheat-A. cristatum introgression lines. These results will not only facilitate the study of structure and evolution of P genome chromosomes, but also provide a rapid detecting tool for effective utilization of desirable genes of P genome in wheat improvement.

Additional file 11: Figure S1. PCR amplification patterns of polymorphic markers. The red arrows show A. cristatum-specific DNA fragments. M is a DNA marker; Lane 1 is A. cristatum Z559; Lane 2 is Pubing 3035; Lane 3 is Fukuho.

An enhanced-grain number per spike locus from Agropyron cristatum 6PL was mapped onto 6PL (0.27–0.51) via deletion mapping, and its effect was further verified by evaluating a newly created translocation line. Agropyron cristatum (2n = 4x = 28, PPPP) is an important wild relative of common wheat and carries many desirable yield-related traits. The wheat-A. cristatum 6P disomic addition line 4844-12 exhibited high grain number per spike (GNS), high spikelet number per spike (SNS), and high kernel number per spikelet (KNS). In this study, five A. cristatum 6P deletion lines, five wheat-A. cristatum 6P translocation lines, and genetic populations of these lines were used to map the enhanced-GNS locus from A. cristatum chromosome 6P, which were genotyped via genomic in situ hybridization, fluorescence in situ hybridization, or molecular markers. According to the evaluation of the agronomic traits in four growing seasons (2014–2015, 2015–2016, 2016–2017, and 2017–2018), we found that the deletion lines and the translocation lines carrying the long arm of A. cristatum chromosome 6P (6PL) exhibited high GNS, SNS, and KNS, and the enhanced-GNS locus was ultimately mapped onto 6PL (0.27–0.51). To verify the localization results, we created a new translocation line WAT650a (T5BL•5BS-6PL) that carried 6PL (0.35–0.42); this line exhibited higher GNS and SNS than the recipient parent Fukuhokomugi (Fukuho). Collectively, the enhanced-GNS locus of A. cristatum 6PL can be important for improving yield traits in common wheat; the translocation lines with the enhanced-GNS locus can serve as novel and valuable germplasm resources for wheat breeding.

The wild relative of wheat, Agropyron cristatum (L.) Gaertn. (genome PPPP), acts as an important genetic resource for providing valuable genes for wheat improvement and increasing the diversity of cultivated wheat. In the present study, cytogenetic and molecular tools were used to characterize wheat-A. cristatum 6P derivatives. The novel translocation line Pubing260 exhibiting wider flag leaves and superior spike traits was further characterized and analysed. Cytological studies demonstrated that Pubing260 (2n = 42) contained a T3BL·3BS-6PL terminal translocation. We compared molecular markers on chromosomes 6P and 3B and confirmed that the translocated wheat chromosome was 3BS and that the chromosome breakage occurred in bin 3BS9-0.57-0.75. Compared with its recurrent parent Fukuhokomugi, Pubing260 had a wider flag leaf, more spikelets and more grains per spike in two growing seasons. Genetic analysis conducted using BC1F2 and BC2F1 populations suggested that the A. cristatum chromosomal fragment from bin 6PL-0.72-1.00 conferred these potentially valuable agronomic traits. On average, the flag leaf width (FLW), and numbers of grain per spike (GNS), spikelets per spike (SNS) and kernels per spikelet of plants with the translocation were 2 mm wider and 5.1, 0.8 and 0.3 higher, respectively, than those of plants lacking the translocation in segregating populations. Significant and positive correlations were observed among GNS, SNS and FLW. In summary, this study not only reports a novel germplasm that is potentially valuable for wheat improvement but also enriches the genetic resources of wheat.

This study explored the genetic constitutions of several wheat- A. cristatum translocation lines and determined the effects of A. cristatum 6P chromosome segments on fertile tiller number in wheat. Progress in wheat breeding is hampered by a relatively narrow range of genetic variation. To overcome this hurdle, wild relatives of common wheat with superior agronomic traits are often used as donors of desirable genes in wheat-breeding programs. One of the successfully utilized wheat wild relatives is Agropyron cristatum (L.) Gaertn (2n = 4x = 28; genomes PPPP). We previously reported that WAT31-13 was a wheat-A. cristatum 5A-6P reciprocal translocation line with higher fertile tiller number and grain number per spike compared to common wheat. However, WAT31-13 was genetically unstable. In this study, we analyzed the 43 genetically stable progenies from WAT31-13 using genomic in situ hybridization, dual-color fluorescence in situ hybridization, and molecular markers. We classified them into three translocation types (TrS, TrL and TrA) and seven subtypes, and also pinpointed the translocation breakpoint. The genotypic data, combined with the phenotypes of each translocation type, enabled us to physically map agronomic traits to specific A. cristatum 6P chromosome arms or segments. Our results indicated that A. cristatum chromosome 6P played an important role in regulating fertile tiller number, and that positive and negative regulators of fertile tiller number existed on the A. cristatum chromosome arm 6PS and 6PL, respectively. By exploring the relationship between fertile tiller number and A. cristatum chromosome segment, this study presented a number of feasible approaches for creation, analysis, and utilization of wheat-alien chromosome translocation lines in genetic improvement of wheat.

Wheat leaf rust is one of the most common wheat diseases worldwide and can cause up to 40% wheat yield loss. To combat the growth and spread of leaf rust disease, continual exploration and identification of new and effective resistance genes are needed. Here, we report for the first time a locus conferring leaf rust resistance located on the long arm of Agropyron cristatum chromosome 2P in Triticum aestivum–A. cristatum 2P translocation lines. This study used 50 leaf rust races, including two Chinese major dominant leaf rust races, named by THT and PHT, and other 48 different leaf rust races collected from 11 provinces, 1autonomous region and 1 municipality of China to test the resistance to T. aestivum–A. cristatum 2P chromosome translocation lines and their backcross populations, the results indicated that the novel leaf rust resistance locus was immune or nearly immune to all tested leaf rust races. Four long arm translocation lines with different breakpoints of A. cristatum chromosome 2PL and their backcross populations were tested with leaf rust race THT at the seedling and adult stages and genotyped with 2P-specific STS markers. The results showed that the novel leaf rust resistance locus of the T. aestivum–A. cristatum 2P translocation lines was located in the chromosomal bin FL 0.66–0.86 of 2PL. Therefore, T. aestivum–A. cristatum 2P chromosome translocation lines conferring leaf rust resistance locus could provide a novel disease-resistance resource for future wheat breeding programs.

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive diseases of wheat (Triticum aestivum L.) worldwide. Agropyron cristatum (L.) Gaertn. (2n = 28, PPPP), one of the wild relatives of wheat, exhibits resistance to stripe rust. In this study, wheat-A. cristatum 6P disomic addition line 4844-12 also exhibited resistance to stripe rust. To identify the stripe rust resistance locus from A. cristatum 6P, ten translocation lines, five deletion lines and the BC₂F₂ and BC₃F₂ populations of two wheat-A. cristatum 6P whole-arm translocation lines were tested with a mixture of two races of Pst in two sites during 2015-2016 and 2016-2017, being genotyped with genomic in situ hybridization (GISH) and molecular markers. The result indicated that the locus conferring stripe rust resistance was located on the terminal 20% of 6P short arm's length. Twenty-nine 6P-specific sequence-tagged-site (STS) markers mapped on the resistance locus have been acquired, which will be helpful for the fine mapping of the stripe rust resistance locus. The stripe rust-resistant translocation lines were found to carry some favorable agronomic traits, which could facilitate their use in wheat improvement. Collectively, the stripe rust resistance locus from A. cristatum 6P could be a novel resistance source and the screened stripe rust-resistant materials will be valuable for wheat disease breeding.

Identification and mapping new powdery mildew resistance (Pm) genes is important for resistance breeding in wheat. Common wheat (Triticum aestivum L.) line X3986-2 was tested against 27 isolates of Blumeria graminis f. sp. tritici. To identify the Pm gene(s) in X3986-2, an F2 population and its derived F2:3 lines were developed from a cross between X3986-2 and susceptible line Mingxian169. Segregation ratios indicated the presence of a single dominant Pm locus, tentatively designated PmX3986-2. Bulked segregant analysis was applied to screen for molecular markers linked to PmX3986-2. Two sequence characterized amplified region (SCAR) markers SCAR112 and SCAR203, and five simple sequence repeat markers CFD40, CFD78, CFD81, GWM293 and WMC443 on chromosome 5D were linked to PmX3986-2, with CFD81 and SCAR112 flanking PmX3986-2 at 0.6 and 1.5 cM, respectively. This suggests that PmX3986-2 may be a novel allele of loci Pm2, Pm46 and PmLX66 on chromosome arm 5DS. PmX3986-2 with its tightly linked DNA markers should be useful for broadening the genetic basis of Pm and rapidly transferring the resistance gene to susceptible cultivars or for us in gene pyramiding for resistance breeding.

This study is to investigate the effects of brucea javanica oil emulsion (BJOE) combined with transcatheter hepatic arterial chemoembolization (TACE) on primary liver cancer (PLC) and the related mechanisms. Totally 64 PLC patients were divided into the TACE monotherapy and BJOE/TACE combination therapy groups. The short- and long-term efficacies, and the toxicity and tolerability profiles, of these treatments were evaluated. The serum levels of soluble Fas (sFas) and soluble Fas ligand (sFasL) were detected with ELISA. For the short-term efficacy, the response rate (RR) in the TACE monotherapy and BJOE/TACE combination therapy groups were 50% (16/32) and 78.12% (25/32), respectively. Survival analysis showed that, the combination therapy significantly elevated the 1-, 2-, and 3-year survival rates of PLC patients, compared with the monotherapy. No significant differences were observed in the toxicity and tolerability profiles between these therapies. ELISA showed that, the serum sFas/sFasL levels were significantly increased in PLC patients. At 1 m after the combination therapy, the serum sFas/sFasL levels were significantly higher than before treatment. At 3 m and 6 m after treatment, the serum sFas/sFasL levels were gradually declined. The short- and long-term efficacies of the BJOE/TACE combination therapy for PLC are superior to the TACE monotherapy. The combination therapy could promote liver cancer cell apoptosis by regulating the expression of sFas/sFasL. Serum sFas/sFasL levels might be used as the predictive marker for the disease pathogenesis and prognosis, and the treatment efficacy.

This study explored the genetic constitutions of wheat-Agropyron cristatum 6P chromosomal translocation and determined the effects of 6P intercalary chromosome segment on thousand-grain weight and spike length in wheat. Crop wild relatives provide rich genetic resources for wheat improvement. Introduction of alien genes from Agropyron cristatum into common wheat can broaden its genetic diversity. In this study, radiation-induced wheat-A. cristatum translocation line Pubing3035 derived from the offspring of wheat-A. cristatum 6P chromosomes addition line was identified and analyzed using genomic in situ hybridization (GISH), dual-color fluorescence in situ hybridization (FISH), and molecular markers. GISH analysis revealed that Pubing3035 was a Ti1AS-6PL-1AS·1AL intercalary translocation. The breakpoint was pinpointed to locate near the centromeric region on the short arm of wheat chromosome 1A based on a constructed F2 linkage map and it was flanked by markers SSR12 and SSR263. The genotypic data, combined with the phenotypes, indicated that A. cristatum 6P chromosomal segment played an important role in regulating the thousand-grain weight and spike length. On average, the thousand-grain weight and spike length in translocation individuals were approximately 2.5 g higher and 0.7 cm longer than those in non-translocation individuals in F2 and BC1F1 populations. The clusters of quantitative trait loci for thousand-grain weight, spike length, and spikelet density contributed by 6P chromosome segment were mapped between A. cristatum unique marker Agc7155 and wheat marker SSR263, which, respectively, explained phenotypic variance of 24.96, 12.38 and 17.20 % with an LOD of 10.63, 4.89 and 5.59. Overall, the translocation Pubing3035 had a positive effect on the yield of wheat, which laid the foundation for the localization of A. cristatum excellent genes and made itself a promising and valuable germplasm for wheat improvement.

Agropyron cristatum (L.) Gaertn. (2n = 4x = 28, PPPP) not only is cultivated as pasture fodder but also could provide many desirable genes for wheat improvement. It is critical to obtain common wheat–A. cristatum alien disomic addition lines to locate the desired genes on the P genome chromosomes. Comparative analysis of the homoeologous relationships between the P genome chromosome and wheat genome chromosomes is a key step in transferring different desirable genes into common wheat and producing the desired alien translocation line while compensating for the loss of wheat chromatin. In this study, six common wheat–A. cristatum disomic addition lines were produced and analyzed by phenotypic examination, genomic in situ hybridization (GISH), SSR markers from the ABD genomes and STS markers from the P genome. Comparative maps, six in total, were generated and demonstrated that all six addition lines belonged to homoeologous group 6. However, chromosome 6P had undergone obvious rearrangements in different addition lines compared with the wheat chromosome, indicating that to obtain a genetic compensating alien translocation line, one should recombine alien chromosomal regions with homoeologous wheat chromosomes. Indeed, these addition lines were classified into four types based on the comparative mapping: 6PI, 6PII, 6PIII, and 6PIV. The different types of chromosome 6P possessed different desirable genes. For example, the 6PI type, containing three addition lines, carried genes conferring high numbers of kernels per spike and resistance to powdery mildew, important traits for wheat improvement. These results may prove valuable for promoting the development of conventional chromosome engineering techniques toward molecular chromosome engineering.

The narrow genetic background restricts wheat yield and quality improvement. The wild relatives of wheat are the huge gene pools for wheat improvement and can broaden its genetic basis. Production of wheat-alien translocation lines can transfer alien genes to wheat. So it is important to develop an efficient method to induce wheat-alien chromosome translocation. Agropyron cristatum (P genome) carries many potential genes beneficial to disease resistance, stress tolerance and high yield. Chromosome 6P possesses the desirable genes exhibiting good agronomic traits, such as high grain number per spike, powdery mildew resistance and stress tolerance. In this study, the wheat- A . cristatum disomic addition was used as bridge material to produce wheat- A . cristatum translocation lines induced by 60Co-γirradiation. The results of genomic in situ hybridization showed that 216 plants contained alien chromosome translocation among 571 self-pollinated progenies. The frequency of translocation was 37.83%, much higher than previous reports. Moreover, various alien translocation types were identified. The analysis of M2 showed that 62.5% of intergeneric translocation lines grew normally without losing the translocated chromosomes. The paper reported a high efficient technical method for inducing alien translocation between wheat and Agropyron cristatum . Additionally, these translocation lines will be valuable for not only basic research on genetic balance, interaction and expression of different chromosome segments of wheat and alien species, but also wheat breeding programs to utilize superior agronomic traits and good compensation effect from alien chromosomes.