RESUMEN
We present the first characterization of 360 sequences in six species of the genus Secale of both cultivated and wild accessions. These include four distinct kinds of dispersed repetitive DNA sequences named pSc20H, pSc119.1, pSaO5(411), and pSaD15(940) belonging to the Revolver family. During the evolution of the genus Secale from wild to cultivated accessions, the pSaO5(411)-like sequences became shorter mainly because of the deletion of a trinucleotide tandem repeating unit, the pSc20H-like sequences displayed apparent homogenization in cultivated rye, and the second intron of Revolver became longer. In addition, the pSc20H-, pSc119.1-, and pSaO5(411)-like sequences cloned from wild rye and cultivated rye could be divided into two large clades. No single case of the four kinds of repetitive elements has been inherited by each Secale accession from a lone ancestor. It is reasonable to consider the vertical transmission of the four repetitive elements during the evolution of the genus Secale. The pSc20H- and pSaO5(411)-like sequences showed evolutionary elimination at specific chromosomal locations from wild species to cultivated species. These cases imply that different repetitive DNA sequences have played different roles in the chromosome development and genomic evolution of rye. The present study adds important information to the investigations dealing with characterization of dispersed repetitive elements in wild and cultivated rye.
Asunto(s)
Evolución Molecular , Variación Genética , Secuencias Repetitivas de Ácidos Nucleicos/genética , Secale/genética , Cromosomas de las Plantas/genética , Clonación Molecular , ADN de Plantas/química , ADN de Plantas/clasificación , ADN de Plantas/genética , Hibridación Fluorescente in Situ , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Secale/clasificación , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
To better understand the evolution of allopolyploids, 4 different combinations between wheat (Triticum aestivum L.) and rye (Secale cereale L.) including 12 F1 hybrids and 12 derived amphiploids were analyzed and compared with their direct parental plants by PCR analysis using 150 wheat SSR (single sequence repeat) markers and by FISH analysis using a rye-specific repetitive sequence (pSc200) as a probe. Nine SSR markers amplified rye-specific fragments whose sizes ranged from 471 bp to 1089 bp. These fragments contain regulatory elements and (or) promoters. Some of these fragments were amplified from all 24 progenies, while others were amplified from a subset of the progenies. The disappearance of rye-specific fragments from some progenies was caused by sequence elimination or DNA modification. Marker Xgwm320 amplified a new fragment (403 bp), a rye-specific tandem repeat, from some of the progenies. Twenty-eight SSR markers displayed microsatellite variation in progenies derived from 'Chinese Spring' x 'Jinzhou-heimai', but none of the 150 SSR markers displayed microsatellite variation in the progenies derived from the other three combinations. FISH signals of pSc200 were eliminated from one telomere/subtelomere of 4 chromosomes of 'Kustro' during allopolyploidization and expanded in amphiploids derived from 'Chinese Spring' x 'AR106BONE'. Thus, allopolyploidization in wheat-rye can be accompanied by rapid variation of tandem repeats, regulatory elements, and promoter regions. The alterations of repetitive sequence pSc200 indicate coordination between the constituent genomes of the newly formed amphiploids. Different genetic backgrounds of parents appear to affect genome changes during allopolyploidization.
Asunto(s)
Ploidias , Regiones Promotoras Genéticas/genética , Secuencias Reguladoras de Ácidos Nucleicos/genética , Secale/genética , Secuencias Repetidas en Tándem/genética , Triticum/genética , Cromosomas de las Plantas , ADN de Plantas/genética , Variación Genética , Hibridación Fluorescente in SituRESUMEN
Specific primers were designed according to the rye-specific repetitive sequence pSc119.1 and were used for polymerase chain reaction (PCR) analysis using the genomic DNA of two sets of sister T1RS.1BL translocations, CN12, CN17, CN18, 96 I 176-1 and 96 I 176-3 as templates. The results indicated that the target fragments were amplified from CN12, CN17, and CN18. A target and a non-target fragment were produced from 96 I 176-1. However, no products were obtained from 96 I 176-3. Southern blot analysis indicated that the elimination of pSc119.1 did not occur in line 96 I 176-3. Three target fragments were cloned from CN12, CN17, and CN18 respectively through recovering. For each target fragment, ten clones were selected randomly for sequencing. Variation of the sequence pSc119.1 was observed in all of the three wheat lines and line CN18 had the most obvious variation. Most of the 30 sequences had 94% or 95% similarity with the sequence pSc119.1 published and the variation of bases of these sequences. Most variations of most bases arose from transition, and a few of them were transversion. Furthermore, there was great coherence among these changed bases in type and site. The evolution process of progenies of wide hybrids may be continuous. For each set of sister 1RS.1BL translocation, difference of some traits was observed among the wheat lines or cultivars. The difference was probably related to the variation of the repetitive DNA. This research provides some useful information for studying on mechanism of epigenetics.
Asunto(s)
Cromosomas de las Plantas/genética , Secale/genética , Translocación Genética/genética , Southern Blotting , Cartilla de ADN/genética , ADN de Plantas/genética , Variación Genética , Reacción en Cadena de la Polimerasa , Secuencias Repetitivas de Ácidos Nucleicos/genéticaRESUMEN
The advanced progeny lines (BC1F5) from the monosomic addition lines between common wheat cultivar Mianyang 11, which is highly susceptible to powdery mildew, and an inbred rye line R12 were analyzed for selection of wheat-rye translocations. Based on a rye-specific repetitive sequence of pSc20H, which spread over all chromosomes of rye but did not existed in wheat, a set of PCR primer was designed and used to identify the rye chromosome segments in wheat. From 300 of the BC1F5 progeny lines 70 were found to contain chromosome composition of rye. An advanced line, 96II691-830-98, originated from 6R monosomic addition line was observed to be immune to powdery mildew, different from its wheat parent Mianyang 11. A small segment of rye chromosome at telomere in a pair of wheat chromosome in the line was found by means of GISH. The results indicated that a small segment of rye chromosome 6R carrying the gene(s) for resistance to powdery mildew has been transferred into common wheat. In the progeny of monosomic addition lines a high frequency of wheat-alien species translocation with various segments of chromosomes could be found by application of both PCR and GISH technique.
Asunto(s)
Cromosomas de las Plantas/genética , Técnicas de Transferencia de Gen , Inmunidad Innata/genética , Enfermedades de las Plantas/microbiología , Secale/genética , Secale/inmunología , Triticum/genética , Cromatina/metabolismo , Hibridación in Situ , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Reacción en Cadena de la Polimerasa , Secale/citología , Secale/microbiologíaRESUMEN
DNA samples of 19 wheat cultivars or lines were screened with the primer pair Xgwm410, a diagnostic marker of wheat stripe rust resistant gene YrCN19. The results showed that the wheat cultivars or lines CN19, XK5, AIM5 and AIM6 produced the amplicon Xgwm410/391, which co-segregated with the resistance of YrCN19, but other cultivars or lines did not produced it. Pedigree analysis and resistance test showed that CN19, XK5, AIM5 and AIM6 carried wheat stripe rust gene YrCN19. Genetic analysis proved that the resistance to wheat stripe rust of CN19, XK5, and AIM5 inherited in single dominant gene genetic law (3 resistant: 1 susceptible). The results also proved that the resistance descent in the cross combination Yanfu188/AIM6 complied with the single dominant gene genetic law (3 resistant: 1 susceptible), while the resistance inheritance in other cross combinations (CN18/AIM6, Lu955159/AIM6 and Shu3110/ AIM6) complied with two gene complementary genetic law (9 resistant: 7 susceptible). The results suggested that the resistance expression and separation of YrCN19 was distinct in the various genetic backgrounds or cross combinations. This study would expedite the exploitation and utilization of YrCN19 in wheat resistant breeding.
Asunto(s)
Basidiomycota/genética , Genoma de Planta/fisiología , Inmunidad Innata/genética , Enfermedades de las Plantas/genética , Hojas de la Planta/microbiología , Triticum/genética , Basidiomycota/patogenicidad , Genes de Plantas/fisiología , Genotipo , Control Biológico de VectoresRESUMEN
The wheat-rye translocation 1RS/1BL has spread to wheat breeding programs and commercial wheat cultivars throughout the world. But the 1RS arm in the translocation carries locus Sec-1, which encodes rye storage proteins (secalins) and affects bread- making quality. In this study an attempt was made to remedy the quality defect of the 1RS translocation in wheat by developing new 1RS/1BL lines. The chromosomal constitution of 200 advanced lines from 1R monosomic addition lines between the wheat cultivar Mianyang11 (MY11) and different rye lines R3, R12, and Baili-rye was studied by the improved C-banding and A-PAGE method. The result showed that 45 lines were identified as 1RS/1BL translocation lines congruously by the two methods. But a line (843-1-1), originated from an 1R addition line of wheat cultivar MY11 and rye line R12, was identified as 1RS/1BL translocation line by C-banding and genomic in situ hybridization(GISH), but the secalin block from chromosome arm 1RS of rye was absent in the A-PAGE pattern of its seed proteins. It is sure that the wheat line 843-1-1 carries a pairs of 1RS/1BL chromosomes with expression absence of the Sec-1 site. It is a rarely material for further study on the effect of 1RS/1BL translocation on wheat quality. The results indicated that wide genetic variability may exist in rye population, which can be exploited for wheat breeding.