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1.
In Brassica oleracea, production of F1 hybrid seeds mainly makes use of the improved Ogura cytoplasmic male sterile (CMS) line. However, reliance on one particular line is a risk, and it would be advantageous to develop other CMS lines. In this study, we transferred Diplotaxis erucoides cytoplasm to B. oleracea cultivars using an alloplasmic B. rapaCMS line as a bridge plant to avoid incompatibility between donor and recipient plants. The new B. oleraceaCMS lines, which were derived by four generations of backcrossing, had small rudimentary anthers with no pollen grain and showed complete male sterility. There was no functional defect in other floral organs, and the ability to receive normal pollen did not appear to be impaired. Moreover, the B. oleraceaCMS lines carrying D. erucoides cytoplasm had larger leaf areas and a normal plastochron. As a consequence, the B. oleraceaCMS lines carrying D. erucoides cytoplasm have the potential to be valuable alternatives for use in commercial B. oleracea hybrid seed production.  相似文献   

2.
Wheat × Imperata cylindrica‐mediated approach of doubled haploidy breeding requires hand emasculation followed by pollination with I. cylindrica pollen. The pace of this endeavour can be enhanced by utilizing asynchronous flowering of wheat spikes by direct pollination without emasculation followed by morphological marker–assisted screening of selfed and crossed seeds. The emasculated and un‐emasculated spikes of 13 spring and six winter wheat genotypes and two triticale × wheat derivatives were pollinated with I. cylindrica pollen. The response of different genotypes for production of crossed and selfed seeds with direct pollination varied significantly within and between groups for spring and winter wheats, whereas triticale × wheat derivatives responded similarly to each other but significantly different from spring and winter wheats. Although, the proportion of pseudoseed formation was lower in case of direct pollination, yet in some genotypes, it was comparable to that of pollination after emasculation. Moreover, the response for haploid embryo induction frequency was similar in both the cases. The method of direct pollination can be utilized for easy and economical induction of haploids.  相似文献   

3.
We developed a new disomic addition line M11028‐1‐1‐5 (2n = 44 = 21” + 1”) from a cross between wheat cv. ‘7182’ and octoploid Tritileymus M47 (2n = 8x = 56, AABBDDN sNs ). Cytological observations demonstrated that M11028‐1‐1‐5 contained 44 chromosomes and formed 22 bivalents during meiotic metaphase I. The genomic in situ hybridization (GISH) investigations showed this line contained 42 wheat chromosomes and a pair of L. mollis chromosomes. SSR, EST and PCR‐based landmark unique gene (PLUG) markers were screened to determine the homoeologous relationships of the introduced L. mollis chromosomes in wheat background. Nine markers, i.e. Xwmc256, Xgpw312, Swes123, CD452568, BF483643, BQ169205, TNAC1748, TNAC1751 and TNAC1752, all of which were located on the homoeologous group 6 chromosomes of common wheat, amplified bands unique to L. mollis in M11028‐1‐1‐5. Gliadin analysis also confirmed that the added chromosomes in M11028‐1‐1‐5 were correlated with the sixth group chromosome. This indicated that M11028‐1‐1‐5 contained a pair of introduced L. mollis chromosome belonging to homoeologous group 6, which we designated it as Lm#6 Ns disomic addition line. This is the first report of a common wheat–L. mollis disomic addition line.  相似文献   

4.
Yellow mosaic disease (YMD) caused by mungbean yellow mosaic virus (MYMV) is the most important disease of mungbean, causing great yield loss. The present investigation was carried out to study the inheritance and identify molecular markers linked with MYMV resistance gene by using F1, F2 and 167 F2 : 8 recombinant inbred lines (RILs) developed from the cross ‘TM‐99‐37’ (resistant) × Mulmarada (susceptible). The F1 was susceptible, F2 segregated in 3S:1R phenotypic ratio and RILs segregated in 1S:1R ratio in the field screening indicating that the MYMV resistance gene is governed by a single recessive gene. Of the 140 RAPD primers, 45 primers showing polymorphism in parents were screened using bulked segregant analysis. Three primers amplified specific polymorphic fragments viz. OPB‐07600, OPC‐061750 and OPB‐12820. The marker OPB‐07600 was more closely linked (6.8 cM) with a MYMV resistance gene as compared to OPC‐061750 (22.8 cM) and OPB‐12820 (25.2 cM). The resistance‐specific fragment OPB‐07600 was cloned, sequenced and converted into a sequence‐characterized amplified region (SCAR) marker and validated in twenty genotypes with different genetic backgrounds.  相似文献   

5.
Intergeneric hybridization in seven diverse durum wheat genotypes was carried out using two composite varieties of Himalayan maize, viz., Bajaura Makka and Early Composite, and a wild grass, Imperata cylindrica, as pollen sources. Observations related to various haploid induction parameters put forth I. cylindrica as significantly better pollen source for haploid induction in durum wheat over maize in terms of pseudoseed formation (46.93%), embryo formation (38.06%), haploid regeneration (40.42%) and haploid formation efficiency (7.44%). The line x tester analysis revealed that both male and female genotypes had significant effects on all haploid induction parameters except haploid formation frequency in later. Among the pollen sources, I. cylindrica emerged as best combiner based on GCA values when compared with the two Himalayan maize composites. Durum wheat genotype, A‐9‐30‐1 was recognized as the best general combiner followed by PDW 314. The present investigation proposed durum wheat × I. cylindrica as a superior technique over maize‐mediated system, and its large‐scale use can open a new horizon in the sphere of durum wheat doubled haploidy breeding programme.  相似文献   

6.
Semi‐dwarf wheat is an important prerequisite for releasing a successful commercial cultivar in high‐yielding environments. In Northern Europe, this aim is achieved by using one of the dwarfing genes Rht‐B1 (formerly known as Rht‐1) or Rht‐D1 (Rht‐2). Both genes, however, result in a higher susceptibility to Fusarium head blight (FHB). We analysed the possibility to use the two non‐adapted FHB resistance quantitative trait loci Fhb1 and Fhb5 (syn. QFhs.ifa‐5A) to counterbalance the negative effect of the dwarfing allele Rht‐D1b in a winter wheat population of 585 doubled‐haploid (DH) lines segregating for the three loci. All lines were inoculated with Fusarium culmorum at four locations and analysed for FHB severity, plant height, and heading date. The DH population showed a significant (p < 0.001) genotypic variation for FHB severity ranging from 3.6% to 65.9% with a very high entry‐mean heritability of 0.95. The dwarfing allele Rht‐D1b reduced plant height by 24 cm, but nearly doubled the FHB susceptibility (24.74% vs. 12.74%). The resistance alleles of Fhb1 and Fhb5 reduced FHB susceptibility by 6.5 and 11.3 percentage points, respectively. Taken all three loci together, Fhb5 alone was already able to reduce FHB susceptibility to the same extent as Rht‐D1b increased it. This opens new avenues for selecting semi‐dwarf wheat by marker‐assisted introgression of Fhb5 without the enhancement of FHB susceptibility.  相似文献   

7.
Development of wheat–alien translocation lines has facilitated practical utilization of alien species in wheat improvement. The production of a compensating Triticum aestivum–Thinopyrum bessarabicum whole‐arm Robertsonian translocation (RobT) involving chromosomes 6D of wheat and 6Eb of Th. bessarabicum (2n = 2x = 14, EbEb) through the mechanism of centric breakage–fusion is reported here. An F2 population was derived from plants double‐monosomic for chromosome 6D and 6Eb from crosses between a DS6Eb(6D) substitution line and bread wheat cultivar ‘Roushan’ (2n = 6x = 42, AABBDD) as female parent. Eighty F2 genotypes (L1–L80) were screened for chromosome composition. Three PCR‐based Landmark Unique Gene (PLUG) markers specific to chromosomes 6D and 6Eb were used for screening the F2 plants. One plant with a T6EbS.6DL centric fusion (RobT) was identified. A homozygous translocation line with full fertility was recovered among F3 families and verified with genomic in situ hybridization (GISH). Grain micronutrient analysis showed that the DS6Eb(6D) substitution line and T6EbS.6DL stock have higher Fe and Zn contents than the recipient wheat cultivar ‘Roushan’.  相似文献   

8.
Microsatellite or simple sequence repeat (SSR) markers are valuable tools for many purposes, such as phylogenetic, fingerprinting and molecular breeding studies. However, such marker resources are unavailable in Assam tea (Camellia assamica ssp. assamica; Masters). With an objective to enrich the repertoire of microsatellite markers in traditional tea, 185 novel microsatellite (150 genomic and 35 genic) markers were identified from (GA)n‐enriched genomic libraries and public expressed sequence data in Assam tea. High‐quality 0.412‐Mb non‐redundant (NR) genomic data set derived from nucleotide sequencing of 1297 (GA)n‐enriched genomic positive clones and 2723 unigenes (1.33 Mb) predicted from 10 803 random public expressed sequence tags (ESTs) in C. assamica ssp. assamica were utilized for identification of genomic and genic microsatellite markers, respectively. The average number of alleles and polymorphic information content (PIC) recorded for the newly developed SSR markers were 6.17 and 0.398, respectively. The average observed (Ho) and expected (He) heterozygosity varied from 0.626 to 0.697, respectively. These markers were found to be highly transferable (74.5–100%) to cultivated (C. sinensis, C. assamica ssp. lasiocalyx) and five wild Camellia species. Genetic diversity coefficient detected a high level of divergence in 24 cultivated tea accessions (69.3%). Phylogenetic analysis revealed that major groupings were broadly in accordance with taxonomic classification of tea, and all the wild Camellia species remained as an out‐group. The high polymorphic content coupled with high rate of cross‐transferability demonstrates wider applicability of novel microsatellite markers in genotyping, genetic diversity, genome mapping and evolutionary studies in various Camellia species.  相似文献   

9.
Wheat grain protein content (GPC) is important for human nutrition and has a strong influence on the quality of pasta and bread. The objective of this study was to analyse the introduction of the Gpc‐B1 allele into two Argentinean bread wheat cultivars. Near‐isogenic lines were developed in ‘ProINTA Oasis’ and ‘ProINTA Granar’ using marker‐assisted selection. Gpc‐B1 lines showed a significant (P = 0.01) increase in GPC and a significant (P = 0.001) decrease in grain weight in comparison with control lines without Gpc‐B1. Differences in yield were not significant (P = 0.49) between lines. Gpc‐B1 lines significantly reduced (P = 0.02) straw nitrogen concentration at maturity and significantly increased (P = 0.02) the nitrogen harvest index. When data were analysed by genotype and environment, differences in some analysed parameters were found, indicating that Gpc‐B1 expression may be affected by different genetic backgrounds and environmental conditions. These results suggest that the introgression of the Gpc‐B1 allele into Argentinean wheat germplasm could be a valuable resource for improving GPC with no detrimental effect on grain yield.  相似文献   

10.
Cadmium (Cd) is a toxic heavy metal that occurs naturally in soils. Durum wheat is known to accumulate generally more Cd than other cereal crops. The uptake of Cd in durum wheat is governed by the gene Cdu1, which co‐segregates with several DNA markers, such as the co‐dominant marker usw47 and the dominant marker ScOPC20. A panel of 314 durum wheat cultivars or lines originating from 16 countries or regions were assessed with usw47. The plant material was mainly comprised of cultivars and modern breeding lines. From this set, 165 durum wheat lines were classified as low‐Cd accumulators, 144 high‐Cd accumulators and five were heterogeneous. A smaller subset of 16 cultivars had previously been evaluated for Cd accumulation in replicated field trials. Lines with the high‐Cd allele showed a 2.4‐fold higher Cd content in the seeds than lines with the low‐Cd allele. We also compared the utility of markers usw47 and ScOPC20 as selection tools. Marker‐assisted selection appears as a robust and practicable tool for breeding durum cultivars with low‐Cd content.  相似文献   

11.
Wheat blast disease, caused by Magnaporthe oryzae (anamorph Pyricularia oryzae), produces severe damage to wheat production in South America. It was observed that many resistant cultivars contain the 2NS/2AS translocation from Triticum ventricosum. In this study, we evaluate the presence of the 2NS/2AS translocation in 57 advanced breeding lines and one variety ‘Caninde 1’ from Paraguayan wheat germplasm, using VENTRIUP‐LN2 primers. The germplasm ‘Caninde 1 and 22’ of the breeding lines, found positive for the presence of 2NS/2AS translocation, were inoculated with a single aggressive Magnaporthe pathotype P14‐039, to assess their response to wheat blast infection under controlled conditions. Based on the disease infection score, ten of the breeding lines, ‘Caninde 1’ and ‘Milan’ (positive control), were classified as resistant. Three of the remaining breeding lines were classified as moderately resistant, five as moderately susceptible and other four as susceptible. Our results show that the expression of 2NS/2AS‐based blast resistance is more dependent on genetic background of the inserted germplasm than previously envisioned.  相似文献   

12.
Pyramiding Asian soybean rust (ASR) resistance (Rpp) genes in a single genotype has been shown to increase ASR resistance in soybean. However, it remains unclear which combinations of Rpp genes are superior. Therefore, here, we developed six new Rpp‐pyramided lines carrying different combinations of Rpp genes and evaluated their resistance against 13 Bangladeshi rust (Phakopsora pachyrhizi) isolates (BdRPs) alongside seven previously developed Rpp‐pyramided lines. We found that lines carrying one, two and three Rpp genes had high ASR resistance without sporulation in 13.8%, 35.2% and 73.1% of the assays, respectively. Among the new lines that were developed, those with Rpp3 + Rpp4 and Rpp3 + Rpp4 + Rpp5 had high levels of ASR resistance, while the line containing Rpp2 + Rpp4 + Rpp5 showed immunity phenotype at two weeks after inoculation by the BdRP‐22 infection. Thus, pyramiding larger numbers of Rpp genes confers soybean with a higher level of resistance to ASR pathogens and can produce an immunity phenotype at two weeks after inoculation.  相似文献   

13.
Two‐line hybrid rice as a novel hybrid breeding method has huge potential for yield increasing and utilization of intersubspecific heterosis, and it is of major significance for the food security of rice‐consuming populations. Zhu1S is a thermosensitive genic male‐sterile line of rice with low critical temperature and excellent combining ability, which has been widely exploited as a female parent in Chinese two‐line hybrid rice breeding. Here, genetic mapping in F2 populations was used to show that its male sterility is inherited as a single recessive gene and that responsible gene (termed tms9) lies on the short arm of chromosome 2. A high‐resolution linkage analysis which was based on the Zhu1S/R173 F2 population found that the thermosensitive genic male‐sterile gene tms9 of Zhu1S was fine mapped between insertion–deletion (Indel) markers Indel 37 and Indel 57, and the genetic distance from the tms9 to the two markers was 0.12 and 0.31 cM, respectively. The physical distance between the two markers was about 107.2 kb. Sequence annotation databases showed that the two Indel markers (Indel 37 and Indel 57) were located on two BAC clones (B1307A11 and P0027A02). There are sixteen open reading frames (ORF) present in this region. The results of this study are of great significance for further cloning tms9 and molecular marker–assisted selection.  相似文献   

14.
Cultivation of the same varieties of mungbean and blackgram across different seasons and locations is constrained by their photo‐ and thermo‐sensitive behaviour. Developing insensitive genotypes, which can fit well across all seasons, requires robust donors which would provide genes imparting this trait. This study was undertaken to identify such donors in the Vigna species. Forty‐eight accessions belonging to 13 Vigna species and eight released cultivars were evaluated under natural field conditions. Among these, two accessions, viz. V. umbellata (IC251442) and V. glabrescens (IC251372) were found photo‐ and thermo‐insensitive as these were able to flower and set pods at temperatures as high as 43.9°C and as low as 2.7°C. Pollen viability studies indicated viable pollen (>75% at 2.7°C and >85% at 41.9°C) and normal pollen tube growth at both the extremes of temperature. The identified V. glabrescens accession has long, constricted pods and dark green, mottled seeds while V. umbellata has smooth, curved pods and shining, oval, large seeds. Both these accessions can be utilized in developing photo–thermo insensitive genotypes in cultivated Vigna species.  相似文献   

15.
Development of effective molecular markers linked to Pm21 deriving from Haynaldia villosa is critical for wheat breeding of powdery mildew resistance. In this study, we designed 12 pairs of conserved‐intron scanning primers (CISPs), using intron‐containing conserved genes located on the short arm of Brachypodium distachyon chromosome 3 (3BdS) aligned with cDNA or expressed sequence tags (ESTs) of Triticeae crops. Of 12 CISP primer pairs, 11 amplified DNA both in H. villosa and in wheat, and four displayed H. villosa chromosome 6VS‐specific polymorphisms. Six non‐polymorphic DNAs were further sequenced for designing internal primers, and five additional 6VS‐specific markers were obtained. Of the total nine 6VS‐specific co‐dominant markers, six could effectively trace Pm21 in F2 population derived from the hybrid between the T6AL.6VS line and ‘Yangmai 158’. This study demonstrated that Brachypodium genomic information could be powerfully utilized to develop molecular markers in H. villosa or other Triticeae species.  相似文献   

16.
Adoption of pigeonpea hybrids in central and southern India is showing high impact with on‐farm yield advantages of >30%. The hybrid pigeonpea technology, the first in any legume crop, is based on a cytoplasmic‐nuclear male‐sterility (CMS) system. For a long‐term sustainability of hybrid programme, it is imperative that both nuclear diversity and cytoplasmic diversity are maintained among hybrid parents. In this context, a continuous search for new CMS‐inducing cytoplasms is necessary. This paper reports detection of maternal inheritance of male sterility in the progeny derived from a natural hybrid between a wild relative [Cajanus lineatus (W. & A.) Maesen comb. nov.] of pigeonpea and an unknown pigeonpea [Cajanus cajan (L.) Millsp.] genotype. In the present study, the male sterility was maintained up to BC7F1 generation by an advanced breeding pigeonpea line ICPL 99044. This male sterility inducing cytoplasm of C. lineatus was tagged as A6. In future, this CMS genetic stock can be used to develop a range of new pigeonpea hybrids with high yield and adaptation.  相似文献   

17.
In CMS (cytoplasmic male sterility)‐based hybrid rye (Secale cereale L.) breeding, effective pollen‐fertility restoration is an essential prerequisite for achieving maximum grain yield on the one hand and for minimizing ergot (Claviceps purpurea) infestation on the other. Restorer genes for the CMS‐inducing ‘Pampa’ cytoplasm derived from landraces collected in Iran and Argentina are used by breeders for achieving this goal. Here, restorer genes from four germplasm sources (‘Altevogt 14160’, ‘IRAN III’, ‘Trenelense’ and ‘Pico Gentario’) were analysed by producing three‐way cross hybrids between an elite CMS single cross and pollinators with and without a given restorer gene. Materials were evaluated on large drilled plots for restorer index (RI), grain yield, plant height and other traits in six environments. In experiment 1, a restorer gene from ‘Altevogt 14160’ was used. Seven pairs of marker‐selected carrier and non‐carrier backcross lines served as pollinators. In experiment 2, the pollinators were 17 backcross line pairs from the other three germplasm sources. These lines were grouped as high (RI > 67%) and low restorers (RI < 30%), respectively, using testcrosses with a highly diagnostic CMS tester. Hybrids carrying an exotic restorer gene suffered from a significant grain yield reduction by 4.4% and 9.4% and were 9.3 and 4.8 cm taller in experiments 1 and 2, respectively. Thousand‐kernel weight was reduced, whereas quality traits were only slightly affected. For all traits, significant genetic variance existed among the testcrosses to the presence vs. absence of a given exotic restorer gene. This offers a chance for the breeder to reduce or ultimately overcome the presently observed performance reductions brought about by exotic restorer genes.  相似文献   

18.
Fusarium wilt is one of the most widespread diseases of pea. Resistance to Fusarium wilt race 1 was reported as a single gene, Fw, located on linkage group III. The previously reported AFLP and RAPD markers linked to Fw have limited usage in marker‐assisted selection due to their map distance and linkage phase. Using 80 F8 recombinant inbred lines (RILs) derived from the cross of Green Arrow × PI 179449, we amplified 72 polymorphic markers between resistant and susceptible lines with the target region amplified polymorphism (TRAP) technique. Marker–trait association analysis revealed a significant association. Five candidate markers were identified and three were converted into user‐friendly dominant SCAR markers. Forty‐eight pea cultivars with known resistant or susceptible phenotypes to Fusarium wilt race 1 verified the marker–trait association. These three markers, Fw_Trap_480, Fw_Trap_340 and Fw_Trap_220, are tightly linked to and only 1.2 cM away from the Fw locus and are therefore ideal for marker‐assisted selection. These newly identified markers are useful to assist in the isolation of the Fusarium wilt race 1 resistance gene in pea.  相似文献   

19.
Twenty‐two wild, 16 intermediate and 20 cultivated soybean varieties were used to analyse relationships among the species of subgenus Soja, genus Glycine using 11 morphological traits and simple sequence repeat (SSR) markers. These genotypes using eleven agronomic characteristics were divided into three clusters: cluster I included 20 G. max, cluster II included 12 intermediate, and cluster III included 22 G. soja and four intermediate lines. Genetic relationships among the species of subgenus Soja showed three distinct clusters. Cluster I consisted of 20 G. max cultivars and two intermediate type lines, and cluster II consisted of 13 intermediate type and two G. soja lines; however, cluster III consisted of 20 G. soja and one intermediate type lines. These phenotypic and genetic data suggest that the intermediate type lines could be distinguished between G. max and G. soja lines. However, the intermediate type could not be classified as a new species.  相似文献   

20.
Plant regeneration through callus initiation from mature embryo of Triticum   总被引：3，自引：0，他引：3  
R. M. Bi    M. Kou    L. G. Chen    S. R. Mao    H. G. Wang 《Plant Breeding》2007,126(1):9-12
The behaviour of diverse Triticum genotypes in the tissue culture response of mature embryo callus was compared, and factors affecting tissue culture response were studied in this paper. Significant differences were detected in callus induction, embryogenic callus differentiation, plantlet regeneration and culture efficiency when mature embryos of 31 plants of different Triticum species were compared. These were the main wheat cultivars of the Chinese northern winter‐type wheat region and breeding lines (Triticum aestivum L.), durum wheat (Triticum durum Desf.), cultivable emmer wheat (Triticumdicoccum Schuble) and the common wheat progenitors Triticum dicoccoides and Triticum aegilopides. The genotype dependency was particularly high in tissue culture of mature embryos of these Triticum genotypes. The efficiency of induction, differentiation and regeneration of mature embryos callus was high in genotypes selected out. Mature embryo‐derived callus of HB341, TS021, SN2618, T. dicoccum, HB188, and T9817 showed better tissue culture response than the other genotypes. Plantlets can be regenerated from mature embryo‐derived callus of 31 genotypes, saving on growth facility resources and time required for the collection of other explants, and providing a solid basis for the genetic transformation and molecular plant breeding of Triticum plants.  相似文献   

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