1RS-7DS.7DL小麦-黑麦小片段易位系的鉴定

黑麦(Secale cereale L., RR)是改良普通小麦(Triticum aestivum L., AABBDD)的重要基因资源,将黑麦优异基因转移到普通小麦中,是小麦品种改良的有效途经之一。文章将四川地方品种蓬安白麦子(T. aestivum L., AABBDD) 与秦岭黑麦(S. cereale cv. Qinling, RR)杂交,染色体自动加倍获得八倍体小黑麦CD-13(AABBDDRR);通过顺序FISH和GISH分析,发现该八倍体小黑麦1RS端部与7DS的端部发生相互易位,是一个携带1RS-7DS.7DL小麦-黑麦小片段易位染色体的八倍体小黑麦。利用八倍体小黑麦CD-13与四川推广小麦品种川麦42杂交、连续自交,获得包含60个株系的F₅群体;对F₅群体的58个株系进行GISH和FISH分析发现,其中13个株系含有1RS-7DS.7DL小片段易位染色体。在这13个株系中,株系811染色体数目为2n=6x=42,是稳定的1RS-7DS.7DL小片段易位系;并且1RS特异分子标记和醇溶蛋白分析表明,1RS-7DS.7DL易位染色体1RS小片段的断裂点位于分子标记IB267-IAG95之间,不包含编码黑麦碱蛋白的Sec-1位点;同时1RS-7DS.7DL小片段易位系的千粒重与川麦42相当,远远高于八倍体小黑麦CD-13,对千粒重无负作用。因此,1RS-7DS.7DL小麦-黑麦小片段易位系可作为进一步深入研究1RS小片段上的优异基因及其遗传效应的重要材料。     

Production of wheat-rye substitution lines and identification of chromosome composition of karyotypes using C-banding, GISH, and SSR markers

Based on the cross (Triticum aestivum L. x Secale cereale L.) x T. aestivum L., wheat-rye substitution lines (2n = 42) were produced with karyotypes containing, instead of a pair of homologous wheat chromosomes, a homeologous pair of rye chromosomes. The chromosome composition of these lines was described by GISH and C-banding methods, and SSR analysis. The results of genomic in situ hybridization demonstrated that karyotype of these lines included one pair of rye chromosomes each and lacked wheat--rye translocations. C-banding and SSR markers were used to identify rye chromosomes and determine the wheat chromosomes at which the substitution occurred. The lines were designated 1R(1D), 2R(2D)2, 2R(2D)3, 3R(3B), 6R(6A)2. The chromosome composition of lines IR(1A), 2R(W)1, 5R(W), 5R(5A), and 6R(W)1, which were earlier obtained according to the same scheme for crossing, was characterized using methods of telocentric analysis, GISH, C-banding, and SSR analysis. These lines were identified as 1R(1A), 2R(2D)1, 5R(5D), 5R(5A), and 6R(6A)1, C-banding of chromosomes belonging to line 1R(1A) revealed the presence of two translocated chromosomes (3DS.3DL-del. and 4AL.W) during simultaneous amplification of SSR markers located on 3DL and 4AS arms. The "combined" long arm of the newly derived chromosome 4A is assumed to be formed from the long arm of chromosome 4AS itself and a deleted segment 3DL. All examined lines are cytologically stable, except for 3R(3B), which does not affect the stability of rye 3R chromosome transfer. Chromosome identification and classification of the lines will permit them to be models for genetic studies that can be used thereafter as promising "secondary gene pools" for the purpose of plant breeding.     

High levels of genetic diversity throughout the range of the Portuguese wheat landrace 'Barbela'

BACKGROUND AND AIMS: Landrace populations represent an important intra-crop reservoir of biodiversity and source of novel gene alleles for use in breeding programmes. Here the aim was to measure the diversity of a wheat landrace, 'Barbela', from the north of Portugal. METHODS: DNA was extracted from 59 accessions of Barbela collected across its geographical range. Diversity was measured by microsatellite length polymorphisms using 27 primer pairs amplifying 34 polymorphic microsatellite loci. KEY RESULTS: High levels of polymorphism were found, with an average polymorphism information content of 0.52; an average of 4.77 alleles (range 2-11) were present at each locus, and half of these loci showed an additional allele in the reference variety 'Chinese Spring'. CONCLUSIONS: 'Barbela' is maintained from seeds collected by farmers, but it maintains high allelic variation, and no groupings of accessions were detected when analysed by geographical region, farm or climate, indicating that the wheat landrace is a homogeneous entity. The diversity within the farmer-maintained landrace demonstrates the importance of characterization and maintenance of landrace collections before valuable genetic combinations are lost as uniform commercial crops are introduced.     

New wheat-rye 5DS-4RS·4RL and 4RS-5DS·5DL translocation lines with powdery mildew resistance

Powdery mildew is one of the serious diseases of wheat (Triticum aestivum L., 2n = 6 × = 42, genomes AABBDD). Rye (Secale cereale L., 2n = 2 × = 14, genome RR) offers a rich reservoir of powdery mildew resistant genes for wheat breeding program. However, extensive use of these resistant genes may render them susceptible to new pathogen races because of co-evolution of host and pathogen. Therefore, the continuous exploration of new powdery mildew resistant genes is important to wheat breeding program. In the present study, we identified several wheat-rye addition lines from the progeny of T. aestivum L. Mianyang11 × S. cereale L. Kustro, i.e., monosomic addition lines of the rye chromosomes 4R and 6R; a disomic addition line of 6R; and monotelosomic or ditelosomic addition lines of the long arms of rye chromosomes 4R (4RL) and 6R (6RL). All these lines displayed immunity to powdery mildew. Thus, we concluded that both the 4RL and 6RL arms of Kustro contain powdery mildew resistant genes. It is the first time to discover that 4RL arm carries powdery mildew resistant gene. Additionally, wheat lines containing new wheat-rye translocation chromosomes were also obtained: these lines retained a short arm of wheat chromosome 5D (5DS) on which rye chromosome 4R was fused through the short arm 4RS (designated 5DS-4RS·4RL; 4RL stands for the long arm of rye chromosome 4R); or they had an extra short arm of rye chromosome 4R (4RS) that was attached to the short arm of wheat chromosome 5D (5DS) (designated 4RS-5DS·5DL; 5DL stands for the long arm of wheat chromosome 5D). These two translocation chromosomes could be transmitted to next generation stably, and the wheat lines containing 5DS-4RS·4RL chromosome also displayed immunity to powdery mildew. The materials obtained in this study can be used for wheat powdery mildew resistant breeding program.     

phKL基因和Ph2基因缺失重组体的创制及其与小麦外源物种杂种的染色体减数分裂观察

以小麦(Triticum aestivum L.)双端体3DL为细胞学标记,用具有phKL基因的小麦地方品种"开县罗汉麦"为受体连续回交,将促进小麦外源部分同源染色体配对的phKL基因和Ph2基因缺失重组在一起获得了重组体phKL+Ph2.这种重组体有正常的育性.与只有phKL基因的小麦材料相比,重组体与外源物种AegilopsvariabilisEig.或黑麦(Secale cereale L.)杂种的部分同源染色体配对水平显著增加,表明Ph2基因的缺失体与phKL基因可能存在加性效应.部分同源染色体配对水平的增加表现在棒状二价体、环状二价体和三价体的数量变多而单价体数量减少.单价体的减少主要是由于棒状二价体的增加所造成的.在小麦外源遗传转移中,运用重组体pHKL +Ph2可能比单纯应用Ph2缺失或phKL基因材料更理想.当与具有ph1b基因的材料比较时发现,重组体phKL+Ph2与 Ae.variabilis(或黑麦)杂种的部分同源染色体配对水平显著降低,这主要是由环状二价体和多价体的减少造成的,但是棒状二价体数量表现增加(与Ae.variabilis杂种)或达到类似水平(与黑麦杂种),这一有趣的发现从表现型上证明了Ph1基因与Ph2或phKL基因在诱导部分同源染色体配对时的遗传作用机制存在差异.     

Production of wheat-rye substitution lines based on winter rye cultivars with karyotype identification by means of C-banding, GISH, and SSR markers

The study presents a continuation of the research aimed at producing of wheat-rye substitution lines based on the cross (Triticum aestivum L. x Secale sereale L.) x Triticum aestivum L., and using winter rye cultivars Vyatka and Vietnamskaya Mestnaya. In BC1F5 two lines were identified, having karyotypes in which a pair of homologous wheat chromosomes was substituted by a homeologous pair of rye chromosomes. The chromosome composition of these lines was analyzed using C-banding, GISH, and SSR markers. It was demonstrated that karyotype of each line included a single pair of rye chromosomes and lacked wheat-rye translocations. The rye chromosomes were identified, and the chromosomes of wheat, at which the substitutions occurred, were determined. The lines generated by crosses with rye of Vyatka and Vietnamskaya Mestnaya cultivars were designated 1Rv(1A) and 5Rviet(5A), respectively. Chromosome identification and classification of the lines makes it possible to use them in breeding programs and genetic studies.     

Identification of Bilby, a diverged centromeric Ty1-copia retrotransposon family from cereal rye (Secale cereale L.).

A diminutive rye chromosome (midget) in wheat was used as a model system to isolate a highly reiterated centromeric sequence from a rye chromosome. Fluorescence in situ hybridization (FISH) shows this sequence localized within all rye centromeres and no signal was detected on wheat chromosomes. DNA sequencing of the repetitive element has revealed the presence of some catalytic domains and signature motifs typical of retrotransposon genes and has been called the Bilby family, representing a diverged family of retrotransposon-like elements. Extensive DNA database searching revealed some sequence similarity to centromeric retrotransposons from wheat, barley, and centromeric repetitive sequences from rice. Very low levels of signal were observed when Bilby was used as a probe against barley, and no signal was detected with rice DNA during Southern hybridization. The abundance of Bilby in rye indicates that this family may have diverged from other distantly related centromeric retrotransposons or incorporated in the centromere but rapidly evolved in rye during speciation. The isolation of a rye retrotransposon also allowed the analysis of centromeric breakpoints in wheat-rye translocation lines. A quantitative analysis shows that the breakpoint in IDS.1RL and 1DL.1RS and recombinant lines containing proximal rye chromatin have a portion of the rye centromere that may contribute to the normal function of the centromeric region.     

Identification and development of diagnostic markers for a powdery mildew resistance gene on chromosome 2R of Chinese rye cultivar Jingzhouheimai

Chinese rye cultivar Jingzhouheimai (Secale cereale L.) shows a high level of resistance to powdery mildew. Identification, location, and mapping of the resistance gene would be helpful for developing a highly resistant germplasm or cultivar in wheat. Using sequential C-banding, GISH, and marker analysis, an addition chromosome with powdery mildew resistance was identified in a line derived from a cross between Chinese wheat landrace Huixianhong and rye cultivar Jingzhouheimai. The line, designated H-J DA2RDS1R(1D), had 44 chromosomes including two pairs of rye chromosomes, 1R and 2R, and lacked a pair of wheat chromosomes 1D, that is, it is a double disomic addition disomic substitution line. According to its reaction to different isolates of the powdery mildew pathogen, the resistance gene in H-J DA2RDS1R(1D) differed from the Pm8 and Pm7 genes located earlier on rye chromosomes 1R and 2R, respectively. In order to determine the location of the resistance gene, line H-J DA2RDS1R(1D) was crossed with wheat landrace Huixianhong and the F2 population and corresponding F2:3 families were tested for disease reaction and assessed with molecular markers. The results showed that a resistance gene, designated PmJZHM2RL, is located in rye chromosome arm 2RL.     

Chromosome markers in the tetraploid wheat Aegilops ventricosa analysed by in situ hybridization

 Three lines of the tetraploid wheat Aegilops ventricosa Tausch (2n=4x=28), which contains good resistance to eyespot, were analysed using fluorescent in situ hybridization. Probes used included rDNA, cloned repeated sequences from wheat and rye, simple-sequence repeats (SSRs) and total genomic DNA. The banding patterns produced could be used to distinguish most chromosome arms and will aid in the identification of Ae. ventricosa chromosomes or chromosome segments in breeding programmes. All lines had a single major 18S-25S rDNA site, the nucleolar organizing region (NOR) in chromosome 5N and several minor sites of 18S-25S rDNA and 5S rDNA. A 1NL.3DL, 1NS.3DS translocation was identified, and other minor differences were found between the lines. Received: 11 August 1998 / Accepted: 28 November 1998     

Production of wheat-rye substitution lines and identification of chromosome composition of karyotypes using C-banding, GISH, and SSR markers

Based on the cross (Triticum aestivum L. × Secale cereale L.) × T. aestivum L., wheat-rye substitution lines (2n = 42) were produced with karyotypes containing, instead of a pair of homologous wheat chromosomes, a homeologous pair of rye chromosomes. The chromosome composition of these lines was described by GISH and C-banding methods, and SSR analysis. The results of genomic in situ hybridization demonstrated that karyotype of these lines included one pair of rye chromosomes each and lacked wheat-rye translocations. C-banding and SSR markers were used to identify rye chromosomes and determine the wheat chromosomes at which the substitution occurred. The lines were designated 1R(1D), 2R(2D)₂, 2R(2D)₃, 3R(3B), 6R(6A)₂. The chromosome composition of lines 1R(1A), 2R(W)₁, 5R(W), 5R(5A), and 6R(W)₁, which were earlier obtained according to the same scheme for crossing, was characterized using methods of telocentric analysis, GISH, C-banding, and SSR analysis. These lines were identified as 1R(1A), 2R(2D)₁, 5R(5D), 5R(5A), and 6R(6A)₁, C-banding of chromosomes belonging to line 1R(1A) revealed the presence of two translocated chromosomes (3DS.3DL-del. and 4AL.W) during simultaneous amplification of SSR markers located on 3DL and 4AS arms. The “combined” long arm of the newly derived chromosome 4A is assumed to be formed from the long arm of chromosome 4AS itself and a deleted segment 3DL. All examined lines are cytologically stable, except for 3R(3B), which does not affect the stability of rye 3R chromosome transfer. Chromosome identification and classification of the lines will permit them to be models for genetic studies that can be used thereafter as promising “secondary gene pools” for the purpose of plant breeding.     

Production of wheat-rye substitution lines based on winter rye cultivars with karyotype identification by means of C-banding,GISH, and SSR markers

The study presents a continuation of the research aimed at producing of wheat-rye substitution lines (2n = 42) based on the cross (Triticum aestivum L. × Secale sereale L.) × Triticum aestivum L., and using winter rye cultivars Vyatka and Vietnamskaya Mestnaya. In BC 1 F 5 two lines were identified, having karyotypes in which a pair of homologous wheat chromosomes was substituted by a homeologous pair of rye chromosomes. The chromosome composition of these lines was analyzed using C-banding, GISH, and SSR markers. It was demonstrated that karyotype of each line included a single pair of rye chromosomes and lacked wheat-rye translocations. The rye chromosomes were identified, and the chromosomes of wheat, at which the substitutions occurred, were determined. The lines generated by crosses with rye of Vyatka and Vietnamskaya Mestnaya cultivars were designated 1Rv(1A) and 5Rviet(5A), respectively. Chromosome identification and classification of the lines makes it possible to use them in breeding programs and genetic studies.     

利用杀配子染色体2C诱导中国春-黑麦二体附加系染色体畸变的研究

将中国春-黑麦(1R-7R)二体附加系与中国春-2C(Aegilops cylindrica)二体附加系杂交,获得F1,对F1体细胞染色体进行C分带鉴定和花粉母细胞减数分裂行为的观察与分析,发现减数分裂行为异常。对自交获得的430株F2进行单株染色体C分带和荧光原位分子杂交鉴定,检测到易位、缺失、等臂染色体、双着丝点染色体等染色体畸变类型。此外还检测到2C与小麦2A、2B、2D染色体的二体或单体自发代换系。杂交F。染色体畸变的规律与频率如下：研究共得到含黑麦染色体的变异22株,变异频率为5,1％。其中含黑麦染色体的易位系为10株,占2,3％;缺失12株,占2．79％;黑麦的等臂染色体3株,占O．7％。易位染色体既有含小麦着丝点的(大部分),也含有黑麦着丝点的(仅1例)。黑麦的染色体畸变中,发生于不同同祖群的频率不同,1R为5个,2R为3个;3R为1个;4R为3个;5R为6个;6R为4个。易位多为端部易位。共鉴定出小麦的缺失系54株,其中A基因组有27个,占6.27％;B基因组有20个,占4,65％;D基因组有7个,占1.66％。对杀配子染色体对小麦及黑麦不同同祖群染色体作用的差异性及作用特点进行了探讨。     

Comparison of homoeologous chromosome pairing between hybrids of wheat genotypes Chinese Spring ph1b and Kaixian-luohanmai with rye

The ph-like genes in the Chinese common wheat landrace Kaixian-luohanmai (KL) induce homoeologous pairing in hybrids with alien species. In the present study, meiotic phenotypic differences on homoeologous chromosome pairing at metaphase I between hybrids of wheat genotypes Chinese Spring ph1b (CSph1b) and KL with rye were studied by genomic in situ hybridization (GISH). The frequency of wheat-wheat associations was higher in CSph1b×rye than in KL×rye. However, frequencies of wheat-rye and rye-rye associations were higher in KL×rye than in CSph1b×rye. These differences may be the result of different mechanisms of control between the ph-like gene(s) controlling homoeologous chromosome pairing in KL and CSph1b. Wheat-wheat associations were much more frequent than wheat-rye pairing in both hybriods. This may be caused by lower overall affinity, or homoeology, between wheat and rye chromosomes than between wheat chromosomes.     

Characterisation of mildew resistant wheat-rye substitution lines and identification of an inverted chromosome by fluorescent in situ hybridisation

Seven different mildew resistant wheat lines derived from crosses between triticale and bread wheat were examined by molecular cytogenetics and chromosome C-banding in order to determine their chromosomal composition. Genomic in situ hybridisation (GISH) showed the presence of rye germplasm in all the lines and identified three substitution lines, three double substitution lines and one addition-substitution line. C-banding identified rye chromosomes 1R and 4R in the addition-substitution line, rye chromosomes 1R and 6R in two substitution lines and 1R and 2R in the third line, and rye chromosome 1R in the three substitution lines. Two of the latter lines (7-102 and 7-169) contained a modified form of the chromosome; fluorescent in situ hybridisation (FISH) using five different repetitive DNA-probes showed a pericentric inversion of 1R in both lines. The breakpoints of the 1R inversion were between (1) the 5S rDNA site and the NOR-region on the satellite of the short arm, and (2) between two AAC(5) sites close to the centromere on the long arm. The role of the rye chromosomes in the mildew resistance, the utilisation of the inverted 1R and the significance of the lines in wheat breeding are discussed.     

Use of RFLPs to determine the chromosome composition of tetraploid triticale (A/B)(A/B)RR.

Tetraploid triticale, (A/B)(A/B)RR (2n = 28), is a botanical novelty, an amphiploid composed of a diploid rye and a 14 chromosome wheat genome made up of chromosomes of the A and B genomes of tetraploid wheat. Restriction fragment length polymorphism (RFLP) markers were used to elucidate the chromosome composition of the mixed wheat genome of 35 different tetraploid triticale lines. Of 128 possible A/B chromosome pair combinations, only 6 were found among these lines, with a prevalence of the 1A, 2A, 3B, 4B, 5B, 6B, and 7B karyotype. In most triticale lines stable wheat genomes made up of only homologous A or B genome chromosome pairs were identified, however, in some lines homoeologous chromosome pairs were found. In this paper we demonstrate that RFLPs can be used successfully as an alternative to C-banding for the identification of the chromosome composition of tetraploid triticale and discuss the possible selective advantage of specific chromosome composition.     

Comparative Effects of Rye Chromosomes 1R and 5R on Androgenesis in Cultured Anthers of Wheat–Rye Substitution Lines as Dependent on the Line Origin

The effects of rye chromosomes 1R and 5R on androgenesis in cultured anthers of wheat–rye substitution lines was studied as dependent on the cultivar origin of the rye chromosomes and on the wheat genome (A or D) subjected to substitution. Chromosome 1R stimulated embryogenesis in anther cultures, while chromosome 5R suppressed it regardless of whether the corresponding wheat chromosomes were substituted in the A or D genome. The effect of chromosome 1R on embryogenesis proved to depend on its cultivar origin. Along with rye chromosome 1R, wheat chromosome 1A was shown to substantially affect total seedling regeneration. Regeneration of green seedlings was dramatically affected both by rye chromosome 1R and by wheat chromosome 1D. The results supported the published data that individual androgenesis parameters (embryogenesis, total plant regeneration, green plant regeneration) are controlled by different genetic mechanisms.     

Development and application of EST-based markers specific for chromosome arms of rye (Secale cereale L.)

To develop a set of molecular markers specific for the chromosome arms of rye, a total of 1,098 and 93 primer pairs derived from the expressed sequence tag (EST) sequences distributed on all 21 wheat chromosomes and 7 rye chromosomes, respectively, were initially screened on common wheat 'Chinese Spring' and rye cultivar 'Imperial'. Four hundred and fourteen EST-based markers were specific for the rye genome. Seven disomic chromosome addition lines, 10 telosomic addition lines and 1 translocation line of 'Chinese Spring-Imperial' were confirmed by genomic in situ hybridization and fluorescencein situ hybridization, and used to screen the rye-specific markers. Thirty-one of the 414 markers produced stable specific amplicons in 'Imperial', as well as individual addition lines and were assigned to 13 chromosome arms of rye except for 6RS. Six rye cultivars, wheat cultivar 'Xiaoyan 6' and accessions of 4 wheat relatives were then used to test the specificity of the 31 EST-based markers. To confirm the specificity, 4 wheat-rye derivatives of 'Xiaoyan 6 × German White', with chromosomes 1RS, 2R and 4R, were amplified by some of the EST-based markers. The results indicated that they can effectively be used to detect corresponding rye chromosomes or chromosome arms introgressed into a wheat background, and hence to accelerate the utilization of rye genes in wheat breeding.     

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。     

Leaf-rust resistance in rye (<Emphasis Type="Italic">Secale cereale</Emphasis> L.). 1. Genetic analysis and mapping of resistance genes <Emphasis Type="Italic">Pr1</Emphasis> and <Emphasis Type="Italic">Pr2</Emphasis>

Genetic analysis of resistance to leaf rust in rye (Puccinia recondita f. sp. secalis) led to the identification of two dominant resistance genes, Pr1 and Pr2. Both genes proved to be effective against a local leaf-rust population as well as a subset of single-pustule isolates (SPIs) the latter of which comprised SPIs with very high virulence complexity. Resistance conferred by Pr1 and Pr2 was expressed in detached-leaf tests of seedlings as well as in field tests of adult plants. Molecular marker analysis allowed us to map Pr1 in the proximal part of rye chromosome 6RL, whereas Pr2 was assigned to the distal part of chromosome 7RL. These results are discussed in view of homoeology relationships among Triticeae. A proposal is submitted for the designation of resistance genes to rye leaf rust which would avoid interference with existing gene-symboling in respect to wheat leaf-rust resistances introgressed from rye into wheat or triticale.     

含有抗白粉病基因的黑麦染色体小片段向小麦的转移

利用感白粉病的小麦品种绵阳11的纯系和黑麦自交系R12杂交, 在其单体附加系自交后代的BC₁F₅株系中选择小麦－黑麦异源易位系。根据已报道的黑麦特异重复序列pSc20H设计了一对特异引物, 用PCR方法鉴定了300个单体附加系的自交BC₁F₅株系,发现其中70个株系含有黑麦染色体成分。一个来源于6R单体附加系的小麦株系96Ⅱ691-830-98表现了对白粉病的高度抗性, PCR方法鉴定证明其含有黑麦染色体成分。对该株系作进一步的基因组原位杂交(GISH)鉴定, 证明它的一对染色体的端部含有黑麦染色体的小片段。这一结果指出, 含有抗白粉病基因的黑麦染色体6R小片段被引入了小麦。研究表明利用单体附加诱导染色体小片段易位是一种有效的方法。利用PCR和GISH原位杂交相结合的方法可提高检测外源染色体小片段的准确性和选择效率。