几类异质1BL／1RS小麦雄性不育系诱导孤雌生殖性的研究

系统调查了4种异质（即偏凸,粘果,易变和二角山羊草细胞质）1BL/1RS小麦雄性不育系与其一系列异质同核系,同质异核系,异质异核系杂交,回交世代诱导孤雌生殖性的遗传变异规律,染色体分裂行为和对外表现特点,结果表明：1、异源细胞质与小麦1BL/1RS核型专一互作,有着消弱同源染色体配对,提高中期单价体细胞率的作用;2、特定细胞质背景下,专一核型内细胞单价体频率高低与诱导孤雌生殖性的频率直接相关;3、1BL/1RS易位染色体中易位片所存在系列差异以及1BL/1RS易位染色体外基因型背景不同,诱导孤雌生殖性的频率明显不同;4、提高或抑制不同杂交,回交世代间孤雌生殖频率,不育系母本或不同基因型父本有着同等重要的作用。选择最佳父母本组合杂交可明显提高或降低后代群体中的孤雌生殖性频率。     

黑麦碱基因（Sec–1）表达缺失的1RS／1BL易位系的鉴定

用改良的Giemsa C－带技术、DNA原位杂交和酸性聚丙烯酰胺凝胶电泳（A-PAGE）对来源于小麦品种绵阳11与不同黑麦自交系远缘杂交获得的高代株系（BC1F7）的染色体结构和醇溶蛋白进行了研究。结果发现,在鉴定的200个株系中,有45个株系经C-带和A-PAGE检测均一致地发现它们含有一对1RS /1BL易位染色体,而一个株系843-1-1,C-带鉴定、原位杂交结果均证明它含有一对1RS/1BL易位染色体,但A-PAGE醇溶蛋白图谱却不具有黑麦1RS染色体臂的黑麦碱特征带,而表达出既不同于黑麦碱又不同于亲本绵阳11的醇溶蛋白带型。这一结果表明,利用不同的黑麦亲本资源,可以获得黑麦碱基因Sec-1表达缺失的新的1RS/1BL易位系。这种新的1RS/1BL易位系缺失了影响小麦品质的黑麦碱蛋白,因此是进一步研究1RS/1BL 易位对小麦品质影响的珍贵材料。研究指出,在利用外源基因的植物育种中,外源种供体材料的遗传多样性是值得重视的基因资源。     

1BL/1RS translocation in durum wheat and its effect on end use quality traits

The gluten proteins document the genotypic identity of a wheat variety, in addition to providing valuable clues about its ancestry and technological properties. In this study, an Indian durum wheat genotype B662 was identified to carry 1BL/1RS translocation and characterized further for its effect on end use quality traits. Comparison of the end use quality traits of B662 with five other durum cultivars without 1BL/1RS, showed decreased gluten content, lower swelling index of glutenins and low MSDS-SV indicating that, B662 with 1BL/1RS is not good for pasta making. In F_2:3 seeds from a durum wheat cross between the 1BL/1RS cultivar B662 and HI8498 without the translocation, the secalin Sec-1 loci segregated in theoretically expected 3:1 proportion and were inherited as a block of the rye chromosome arm. The analysis of F_2:3 harvests for the two most important durum wheat quality tests showed that the presence of 1BL/1RS translocation did not alter the grain protein content values, but was associated with significant reduction of micro SDS-sedimentation volume indicating inferior quality, thus limiting the commercial exploitation of durum wheat genotypes with 1BL/1RS translocation. The cautious use of rye translocation in Indian durum wheat breeding is suggested.     

Transfer of the 1BL/1RS wheat-rye-translocation from hexaploid bread wheat to tetraploid durum wheat

Summary The present study describes a cytological stable alien chromosome translocation in tetraploid durum wheat. By crossing the hexaploid 1BL/1RS wheat-rye translocation line Veery to the tetraploid durum wheat cultivar Cando it was possible to select a 28 chromosomic strain homozygous for the 1BL/1RS translocation. The disease resistance potential of the short arm of rye chromosome 1R, which has been widely introduced in many hexaploid bread wheat cultivars could be now also used for the improvement of durum wheat.     

Production of a new wheat line possessing the 1BL.1RS wheat-rye translocation derived from Korean rye cultivar Paldanghomil

The 1BL.1RS translocations between wheat (Triticum aestivum L.) and rye (Secale cereale L.) are widely used in bread wheat breeding programs, but all modern wheat cultivars with the 1BL.1RS have shown genetic vulnerability due to one rye source – a German cultivar, Petkus. We have developed, a new 1BL.1RS wheat-rye translocation line from the backcross of the F₁ hybrid of wheat cv. Olmil and rye cv. Paldanghomil, both cultivars from Korea. The GISH technique was applied to identify the presence of rye chromatin in 467 BC₁F₆ lines selected from 77 BC₁F₅ lines. Only one line, Yw62–11, showed wheat-rye translocated chromosomes, with a somatic chromosome number of 2n=42. C-banding patterns revealed that the translocated chromosome was 1BL.1RS, showing prominent bands in the terminal and sub-terminal regions of the short arm as well as in the centromeric region and terminal region of the long arm. This new 1BL.1RS translocation line formed 21 bivalents like common wheat at meiotic metaphase I, thereby showing complete homology. Received: 28 February 2001 / Accepted: 17 April 2001     

Conjugation of the 1BL/1RS translocation with qualitative and quantitative traits in the common wheat T.aestivum

The review considers the effect of the rye 1BL/1RS translocation in the common wheat genome on qualitative and quantitative traits: grain quality, resistance to diseases, productivity and adaptivity, parthenogenesis, regeneration in anther culture, frequency of chromosome aberrations and frequency of cross-pollination. Data on special features of transmission of the 1BL/1RS translocation through male and female gametes are presented.     

A Mutant with Expression Deletion of Gene Sec-1 in a 1RS.1BL Line and Its Effect on Production Quality of Wheat

The chromosome arm 1RS of rye (Secale cereal L.) has been used worldwide as a source of genes for agronomic and resistant improvement. However, the 1RS arm in wheat has end-use quality defects that are partially attributable to the presence of ω-secalins, which are encoded by genes at the Sec-1 locus. Various attempts in removing the Sec-1 genes from the 1RS.1BL translocation chromosome have been made. In the present study, two new primary 1RS.1BL translocation lines, T917-26 and T917-15, were developed from a cross between wheat variety “{"type":"entrez-nucleotide","attrs":{"text":"A42912","term_id":"2298361"}}A42912” and Chinese local rye “Weining.” The lines T917-15 and T917-26 carried a pair of intact and homogeneous 1RS.1BL chromosomes. The line T917-26 also harbored an expression deletion of some genes at the Sec-1 locus, which originated from a mutation that occurred simultaneously with wheat-rye chromosome translocations. These results suggest that the accompanying mutations of the evolutionarily significant translocations are remarkable resources for plant improvement. Comparison of translocation lines with its wheat parent showed improvements in the end-use quality parameters, which included protein content (PC), water absorption (WA), sodium dodecyl sulfate sedimentation (SDSS), wet gluten (WG), dry gluten (DG) and dough stickiness (DS), whereas significant reduction in gluten index (GI) and stability time (ST) were observed. These findings indicate that 1RS in wheat has produced a higher amount of protein, although these comprised worse compositions. However, in the T917-26 line that harbored an expression deletion mutation in the Sec-1 genes, the quality parameters were markedly improved relative to its sister line, T917-15, especially for GI and DS (P < 0.05). These results indicated that expression deletion of Sec-1 genes significantly improves the end-use quality of wheat cultivars harboring the 1RS.1BL translocation. Strategies to remove the Sec-1 genes from the 1RS.1BL translocation in wheat improvement are discussed.     

Reconstruction in wheat of complete chromosomes 1B and 1R from the 1RS.1BL translocation of 'Kavkaz' origin.

Translocation 1RS.1BL originally from the 'Aurora' and 'Kavkaz' wheats has spread to bread wheats all over the world. It offers several resistance genes and appears to significantly increase yields. For future study of the arm location of the yield-increasing factors, complete chromosomes 1B and 1R were reconstructed from the 1RS.1BL translocation. This was accomplished by centric misdivision and fusion in double monosomies 20 II + 1RS.1BL I + 1BS.1RL I. The frequency of misdivision and misdivision-fusion of the two unpaired chromosomes was 23.1%, which was much higher than expected but comparable with that observed in other stocks grown under similar conditions. Transmission of the reconstructed chromosomes to progeny was normal. In addition to all possible misdivision and misdivision-fusion products, two chromosomes of ambiguous origin were recovered: chromosome 1B with a proximal insert of about 40% of 1RS and chromosome 1R with a proximal insert of about 30% of 1BS. The study demonstrates that centric translocations can misdivide and fuse again to produce stable chromosomes with new arm combinations.     

Development of a wheat genotype combining the recessive crossability alleles kr1kr1kr2kr2 and the 1BL.1RS translocation, for the rapid enrichment of 1RS with new allelic variation

The main objective of the present work was to develop a wheat genotype containing both the recessive crossability alleles (kr1kr1kr2kr2), allowing high crossability between 6x wheat and diploid rye, and the 1BL.1RS wheat/rye translocation chromosome. This wheat genotype could be used as a recipient partner in wheat–rye crosses for the efficient introduction of new allelic variation into 1RS in translocation wheats. After crossing the wheat cultivars ‘Mv Magdaléna’ and ‘Mv Béres’, which carry the 1BL.1RS translocation involving the 1RS chromosome arm from ‘Petkus’, with the line ‘Mv9 kr1’, 117 F₂ plants were analysed for crossability, ten of which had higher than 50% seed set with rye and thus presumably carried the kr1kr1kr2kr2 alleles. Four of the ten plants contained the 1BL.1RS translocation in the disomic condition as detected by genomic in situ hybridization (GISH). The wheat × rye F₁ hybrids produced between these lines and the rye cultivar ‘Kriszta’ were analysed in meiosis using GISH. 1BL.1RS/1R chromosome pairing was detected in 62.4% of the pollen mother cells. The use of fluorescent in situ hybridization (FISH) with the repetitive DNA probes pSc119.2, Afa family and pTa71 allowed the 1R and 1BL.1RS chromosomes to be identified. The presence of the 1RS arm from ‘Kriszta’ besides that of ‘Petkus’ was demonstrated in the F₁ hybrids using the rye SSR markers RMS13 and SCM9. In four of the 22 BC₁ progenies analysed, only ‘Kriszta’-specific bands were observed with these markers, though the presence of the 1BL.1RS translocation was detected using GISH. It can be concluded that recombination occurred between the ‘Petkus’ and ‘Kriszta’ 1RS chromosome arms in the translocated chromosome in these plants.     

Effect of the 1BL.1RS translocation on the wheat endosperm, as revealed by proteomic analysis

The introduction of the 1RS chromosome of rye into wheat made wheat more resistant to several pathogens. Today, this resistance has been overcome but the 1BL.1RS translocation remains interesting because of the improved yield and despite the lower rheological properties it produces. Nothing has been reported yet on the impact of rye chromatin introgression on the grain proteome of wheat. The comparison of the 2-DE profiles of 16 doubled haploid lines, with or without the 1BL.1RS translocation, revealed quantitative and qualitative proteic variations in prolamins and other endosperm proteins. Eight spots were found specifically in lines having the 1BL.1RS translocation; 16 other spots disappeared from the same lines. Twelve spots, present in both genotypes, met the criteria for up- or down-regulated spots. In translocated genotypes, a highly overexpressed spot, identified as a gamma-gliadin with nine cysteine residues, suggests that the lack of LMW-GS induced by 1BL.1RS is counterbalanced by an overexpression of a relatively similar prolamin. Moreover, a spot that was absent from 1BL.1RS genotypes was identified as a dimeric alpha-amylase inhibitor. It was considered to be a valuable candidate to explain the sticky dough associated with translocated cultivars.     

青海省小麦品种中Yr10和Yr15基因及其1BL/1RS易位的分子检测

利用抗条锈病基因Yr10和Yr15的SCAR和Barc8标记以及1BL/1RS易位的复合标记,对青海省育成和引进的137份小麦品种进行检测,以明确Yr10和Yr15基因以及1BL/1RS易位在青海小麦品种资源中的分布.结果显示:在137份材料中,有4份检测到Yr10基因,19份检测到Yr15基因,分别占参试材料的2.9%和13.9%,没有检测到同时携带Yr10和Yr15基因的材料;有22份材料为1BL/1RS易位,占参试材料的16.1%.研究表明,青海省大部分小麦抗锈品种及1BL/1RS易位品种为外引种品种.     

Seedling lethality in wheat: a novel phenotype associated with a 2RS/2BL translocation chromosome

Summary When grown at normal temperatures, wheat plants disomic for a 2RS/2BL translocation chromosome substituting for chromosome 2B show seedling lethality. Morphological and physiological studies could not determine the cause of death. However, the seedling lethality can be partly to completely inactivated at higher temperatures and in stressed environments. The lethality can also be completely suppressed if the translocated chromosome is introduced into different wheat cultivars. These wheats must contain genes which suppress the lethal phenotype caused by disomy of 2RS/2BL.Whilst the temperature effect indicates that the seedling lethality is related to the grass clump dwarf phenotype of wheat, our results show that the genes involved in seedling lethality, its suppression and inactivation, are not related to the D genes which cause grass clump dwarfing in wheat.     

Cytogenetic characteristics of wheat lines with modified 1RS.1BL rye-wheat translocation

The higher frequency (almost 90%) of inheritance through pollen of heterozygous hybrids has been shown for the modified 1RS.1BL translocation compared with the 1BL telocentric, and, as a result, the segregations at the Gli-B1 and Glu-B1 loci strongly deviated from the expected values. The distance between the Glu-B1 locus and the centromere was 15.7–24.4 cM. Products of the 1RS_m.1BL translocation “misdivision” were observed at a frequency of 0.05%. Both the Pavon MA1 lines and the winter wheat line with the 1RS_m.1BL _al translocation have shown a significant decrease in the level of homologous chromosome pairing, causing aneuploidy. These lines did not contain any reciprocal translocations with respect to the Kuyal’nik cultivar. A “hybrid desynapsis” has been observed in F₁ hybrids (Kuyal’nik × Pavon MA1) in contrast to analogous hybrids from a winter line by the 1RS_m.1BL _al type. No single case of the 21_Closed ^II formation has been observed among the studied 693 pollen mother cells (PMCs), which would have indicated the presence of pairing between the short arms of the 1RS_m.1BL translocations and the intact chromosome 1B.     

Nuclear gametophytic genes from chromosome arm 1RS improve regeneration of wheat microspore-derived embryos.

The effect of the 1RS chromosome arm from rye on plant regeneration from microspore-derived embryos was studied using anther culture technology with genotypes carrying the 1BL-1RS translocated chromosomes, the normal wheat chromosome 1BL-1BS, and ditelosomic lines DT 1BS and DT 1BL. A significant difference was observed in microspore-derived green plants between chromosome structure concerned with 1RS and 1BS arms. An analysis of the inheritance of the 1B-1R translocation was performed on the basis of the frequency of male gametes 1BL-1RS in the microspore-derived green plants and that of the 1B-1R translocation inherited through the pollen or the egg cell from structurally heterozygous hybrids 1BL-1BS/1BL-1RS. Both the normal 1B and the translocated 1BL-1RS chromosomes were sexually transmitted through the pollen grains with the same frequency. The 1BL-1RS chromosome is only transmitted through 45% of the egg cells. On the contrary, two-thirds of the microspore-derived green plants regenerated from the anther culture experiments possess the translocated chromosome. The involvement of the rye chromosome arm 1RS from 'Aurora' on regeneration capacity of the microspore-derived embryos has been proposed through the effect of a "gametophytic gene."     

Haploid production in durum wheat by the interaction of Aegilops kotschyi cytoplasm and 1BL/1RS chromosomal interchange

The present study describes the development of an alloplasmic haploid-inducer in durum wheat cv Cando. This cultivar possesses the homozygous wheat-rye translocation 1BL/1RS from the 6x-wheat cv Veery. The nucleus of 4x-Cando-Veery 1BL/1RS was introduced into Aegilops kotschyi cytoplasm by initially using (kotschyi)-Salmon as the maternal parent. In the cross of this alloplasmic durum line with Cando-Veery 1BL/1RS, which was used as the recurrent pollen parent, haploids (n=14) were produced. The frequency of haploids increased from 5.7% in the F₁ generation to 14% in the BC₁ generation. The presence of rye chromosome arm 1RS and the concomitant loss of 1BS in (kotschyi)-Cando-Veery 1BL/1RS are necessary for haploid induction. Proposals are made which may enable the use of haploids produced by nucleo-cytoplasmic interactions in future wheat breeding programs.     

Effect of the 1BL.1RS wheat-rye translocation on the androgenic response in spring bread wheat

The study was conducted to investigate the effect of the 1BL.1RS wheat-rye-translocation on the androgenic response in spring bread wheat. Therefore, four bread wheat cultivars carrying the translocation, four Greek and three Canadian bread wheat cultivars without the translocation were used. An equal number of anthers from each cultivar, containing microspores in the mid (MU) to late uninucleate (LU) microspore developmental stage, were cultured after cold pre-treatment for seven days at 4°C. W14, 190-2 and the basic MS were used as induction, regeneration, and rooting media respectively. The best androgenic response was recorded in two cultivars carrying the translocation. Only two cultivars lacking the translocation responded to anther culture. It is concluded that the positive effect of the 1BL.1RS translocation on anther culture response of bread wheat cultivars cannot be attributed entirely to its presence because the genetic background of the cultivars carrying the translocation could be also important.     

Distribution of 1AL.1RS and 1BL.1RS wheat-rye translocations in Triticum aestivum using specific PCR

Chromosome arm 1RS of rye (Secale cereale) is a valuable resource for wheat (Triticum aestivum) improvement. 1AL.1RS and 1BL.1RS translocations play an important role in wheat breeding, since wheat carrying these chromosomal translocations has higher tolerance to biotic and abiotic stress. In this study, the presence of 1RS and the distribution of 1AL.1RS and 1BL.1RS wheat-rye translocations were examined in 66 Iranian cultivars and 70 regional foreign accessions of bread wheat, using three rye-specific primers (“RYER3/F3”, “O-SEC5′-A/O-SEC3′-R”, “PAWS5/S6”). Based on “RyeR3/F3”, the presence of 1RS was verified in 15 (23%) Iranian cultivars and in two (3%) foreign accessions. Further, “O-SEC5′-A/O-SEC3′-R” and “PAWS5/S6” were used to distinguish 1AL.1RS and 1BL.1RS translocations. According to results from these primers, 1BL.1RS was identified in 14 (21%) Iranian cultivars and two (3%) foreign accessions. The results confirm that “Sholeh” is the only cultivar (1.5%), among all cultivars and accessions, that carries 1AL.1RS. This study provides a useful tool in marker-assisted selection of materials containing 1RS, and in the creation of new Iranian common wheat cultivars with a larger genetic diversity in wheat breeding programs.     

Novel source of 1RS from Baili rye conferred high resistance to diseases and enhanced yield traits to common wheat

Rye is one of the most important related species used for wheat genetic improvement and breeding programs. In the present study, five novel 1BL.1RS translocations were developed and characterized from crossing of the common wheat line A42912 and a Chinese rye “Baili”. Codominant PCR and MC-FISH determined that these five translocation lines harbored a pair of 1BL.1RS chromosomes. The MC-FISH results indicated that several accompanying mutations on the wheat chromosomes occurred during the chromosome translocation process. These five new 1BL.1RS translocation lines also exhibited high resistance to stripe rust and powdery mildew and showed significantly better yield traits in the field. The present study indicates that Baili rye may carry yet untapped and potentially important sources of resistance, which may be used for wheat genetic improvement. These five novel primary 1BL.1RS translocations are likely to find application in wheat genetic improvement programs.     

普通小麦99-2439中的白粉病抗性遗传

普通冬小麦品系99-2439在郑州连续4年对田间白粉菌(Blumeria graminis sp.tritici)表现高抗,但其抗性基因来源不清.通过染色体C-分带和IRS染色体特异性SCAR标记鉴定,表明它是一个小麦-黑麦(Triticum aestivum-Secale cereale)lBL/1RS异易位系.通过对中国春×99-2439杂交F2代分离群体抗性鉴定和1RS染色体臂检测结果分析,证明该抗病基因不在1RS染色体臂上.用单孢小麦白粉菌分离株对其抗性遗传进行研究,结果表明,99-2439的白粉病抗性由一对小种专化、隐性抗病基因控制.由于携带Pm5a的Hope/8Cc对中国的21个小麦白粉菌分离菌株均高度感病,而99-2439高抗混和白粉菌和5个单孢分离菌株,所以,99-2439所携带的抗白粉病基因不同于Pm5a.