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Teodoro Cardi 《Plant Breeding》2016,135(2):139-147
Plant genetic resources (PGR) represent valuable sources of genetic variability for crop breeding. The development of novel biotechnologies is necessary for increasing the efficiency of their use in pre‐breeding and breeding work. The genome sequencing of hundreds of genotypes and the mining of allele diversity in major crops and populations of landraces and wild relatives allow the isolation of genes underlying characters of interest and their precise modification or transfer into targeted varieties. The technological developments and applications of new plant breeding techniques (NPBT) that maximize the similarity with gene transfer by crossing (cisgenesis/intragenesis) or the accuracy of biotechnological approaches (genome editing) are reviewed. Their potentialities and current limitations as well as the possible advantages of using them separately or combined for the exploitation of PGR in crop breeding are also discussed. Above‐mentioned NPBT tackle some objections to the application of biotechnologies in agriculture and are under review worldwide to assess the possible exclusion from the current regulation systems for genetically modified plants.  相似文献   

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The stem solidness trait in wheat has been the most effective mechanism for management of the wheat stem sawfly (WSS) for six decades. However, recent results have shown that in certain genotypes, the degree of stem solidness is not a useful indicator of WSS resistance. A morphological characterization of solidness expression indicated that in the genotype ‘Conan’, very solid pith undergoes rapid retraction during stem maturation, resulting in significantly less solidness at maturity. In other solid‐stemmed genotypes, including the standard WSS‐resistant cultivar ‘Choteau’, dense pith in the stem remains nearly unchanged throughout plant development. In cage trials, ‘Conan’ plants were less preferred for oviposition by the WSS when paired with ‘Choteau’ plants. Field bioassays using near‐isogenic lines differing for alleles at Qss.msub‐3BL showed that the Conan allele provides higher levels of early stem solidness and rapid pith retraction during stem maturation. These results suggest that the traditional approach for increasing WSS resistance by selecting for increasing stem solidness needs to be modified to consider temporal variations in pith expression associated with alleles at Qss.msub‐3BL.  相似文献   

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Verticillium wilt (VW) is a soil‐borne disease of cotton that is destructive worldwide. Transferring desired traits from Gossypium barbadense is challenging through traditional interspecific introgression. We previously demonstrated that a molecular marker, BNL3255‐208, is associated with VW resistance in G. barbadense. This breakthrough opens the way for marker‐assisted selection (MAS) breeding. Here, the highly resistant G. barbadense cv. ‘Pima90‐53’ and the severe diseased Gossypium hirsutum cv. ‘CCRI8’ were used as donor parent and recipient parent, respectively. Our goal was to transfer the disease resistance from donor to recipient via MAS. Among 71 MAS obtained lines, as many as 19 lines had enhanced resistance. Among those lines, 11 lines showed high resistance and four lines displayed resistance to VW. Moreover, seven lines displayed improved fibre quality. After combining the markedly improved resistance and fibre properties, we identified two elite innovated introgression lines – ZY2 and ZY31 – that did not seem to differ in other agronomic traits from the recipient parent. This study first successfully transferred of G. barbadense resistance into G. hirsutum by MAS.  相似文献   

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A widely grown but rust susceptible Indian wheat variety HD2932 was improved for multiple rust resistance by marker‐assisted transfer of genes Lr19, Sr26 and Yr10. Foreground and background selection processes were practised to transfer targeted genes with the recovery of the genome of HD2932. The near‐isogenic lines (NILs) of HD2932 carrying Lr19, Sr26 and Yr10 were individually produced from two backcrosses with recurrent parent HD2932. Marker‐assisted background selection of NILs with 94.38–98.46% of the HD2932 genome facilitated rapid recovery of NILs carrying Lr19, Sr26 and Yr10. In the BC2F2 generation, NILs were intercrossed and two gene combinations of Lr19+Yr10, Sr26 + Yr10 and Lr19+Sr26 were produced. A total of 16 progeny of two gene combinations of homozygous NILs of HD2932 have been produced, which are under seed increase for facilitating the replacement of the susceptible HD2932 with three of the sixteen improved backcross lines with resistance to multiple rusts.  相似文献   

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This study describes the identification of a quantitative trait locus (QTL) in the recombinant inbred line population of ILL2024 × ILL6788 and subsequent validation of associated molecular markers. A high‐quality genetic linkage map was constructed with 758 markers that cover 1,057 cM, with an average intermarker distance of 2 cM. QTL analysis revealed a single genomic region on Lc2 to be associated with B tolerance and accounted for up to 76% of phenotypic variation (Vp). The best markers for B tolerance were assessed for their utility in routine breeding applications using validation panels of diverse lentil germplasm and breeding material derived from ILL2024. A marker generated from the dense genetic map of this study was found to be the most accurate of all markers available for B tolerance in lentil, with a success rate of 93% within a large breeding pool derived from ILL2024. However, given the number of the unrelated lines for which the marker–trait association was not conserved, B tolerance screening is still required at later stages to confirm predicted phenotypes.  相似文献   

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Durum wheat is the most important tetraploid wheat mainly used for semolina and pasta production, but is notorious for its high susceptibility to Fusarium head blight (FHB). Our objectives were to identify and characterize quantitative trait loci (QTL) in winter durum and to evaluate the potential of genomic approaches for the improvement of FHB resistance. Here, we employed an international panel of 170 winter and 14 spring durum lines, phenotyped for Fusarium culmorum resistance at five environments. Heading date, plant height and mean FHB severity showed significant genotypic variation with high heritabilities and FHB resistance was negatively correlated with both heading date and plant height. The dwarfing gene Rht‐B1 significantly affected FHB resistance and the genome‐wide association scan identified eight additional QTL affecting FHB resistance, explaining between 1% and 14% of the genotypic variation. A genome‐wide prediction approach yielded only a slightly improved predictive ability compared to marker‐assisted selection based on the four strongest QTL. In conclusion, FHB resistance in durum wheat is a highly quantitative trait and in breeding programmes may best be tackled by classical high‐throughput recurrent phenotypic selection that can be assisted by genomic prediction if marker profiles are available.  相似文献   

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Soybean (Glycine max (L.) Merr.) seed contains small amounts of tocopherol, a non‐enzymatic antioxidant known as lipid‐soluble vitamin E (VE). Dietary VE contributes to a decreased risk of chronic diseases in humans and has several beneficial effects on resistance to stress in plants, and increasing VE content is an important breeding goal for increasing the nutritional value of soybean. In this study, quantitative trait loci (QTLs) underlying VE content with main, epistatic and QTL × environment effects were identified in a population of F5 : 6 recombinant inbred lines from a cross between ‘Hefeng 25’ (a low‐VE cultivar) and ‘OAC Bayfield’ (a high‐VE cultivar). A total of 18 QTLs were detected that showed additive main effects (a) and/or additive × environment interaction effects (ae) in different environments. Moreover, 19 epistatic pairs of QTLs were found to be associated with α‐tocopherol (α‐Toc), γ‐tocopherol (γ‐Toc), δ‐tocopherol (δ‐Toc) and total VE (TE) contents. The QTLs identified in multienvironments could provide more information about QTL by environment interactions and could be useful for the marker‐assistant selection of soybean cultivars with high seed VE contents.  相似文献   

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The identification of quantitative trait loci (QTL) across different environments is a prerequisite for marker‐assisted selection (MAS) in crop improvement programmes. CottonSNP63k Illumina infinium array was used for genotyping 178 inter‐specific recombinant inbred lines and the parents, and identified 1,667 homozygous polymorphic markers between the parents. Of these, 1,430 markers were used for the construction of linkage map after removing 237 redundant markers. The genetic map spans a total genetic length of 3,149.8 cM with an average marker interval size of 2.2 cM. The phenotypic data from five environments were analysed separately using inclusive composite interval mapping which identified a total of 56 QTL explaining phenotypic variances (PVE) in the range of 8.18%–28.91%. There were 11 and 24 major QTL found for fibre quality and yield components, respectively. A total of 64 QTL were identified through Multi‐Environment Trials analysis, of which 34 recorded QTL × Environment interactions.  相似文献   

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Sweet cherry (Prunus avium L.) has stylar gametophytic self‐incompatibility, which is controlled by the multi‐allelic S‐locus and encompasses the highly polymorphic genes for the S‐ribonuclease (S‐RNase) and S‐haplotype‐specific F‐box (SFB), which are female and male determinants, respectively. The self‐compatible mutant SFB4′ corresponds to an allele variant of SFB4 and presents a frameshift mutation. Even though male‐determinant molecular markers can discriminate between SFB4 and SFB4′ alleles, the methods required are laborious, time‐consuming and expensive, and not suitable for massive analysis and integration into breeding programmes. Our aim was to develop molecular markers for the evaluation of self‐compatibility alleles in sweet cherry, that could be used as a high‐throughput screening strategy to identify SFB4 and SFB4′ alleles, based on a marker for male determinacy. Our results were consistent using primers flanking the mutation responsible for the SFB4′ allele. We designed a specific molecular marker and confirmed it in sweet cherry commercial varieties. This new molecular marker is feasible for self‐compatibility alleles in the male determinant in sweet cherry‐assisted breeding programs.  相似文献   

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CRISPR是细菌或古生菌对入侵到体内的病毒,通过核酸特异性识别、Cas9蛋白酶切割产生的一种天然免疫系统.基于CRISPR/Cas9系统的基因组编辑技术,通过sgRNA介导和Cas9蛋白切割实现对靶基因的定点编辑.因其操作简便、编辑效率高、适用范围广的特点,迅速成为研究植物、动物、微生物基因功能的重要手段.同时,随着...  相似文献   

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TMV 2 is a very popular peanut variety among the Indian farmers, but it is highly susceptible to fungal foliar diseases like late leaf spot (LLS) and rust. Marker‐assisted backcrossing (MABC) in TMV 2 using foliar disease‐resistant donor, GPBD 4 and the disease resistance‐linked markers (GM2009, GM2079, GM2301, GM1839 and IPAHM103) resulted in a large number of backcross populations and also straight cross populations. Foreground selection followed by field evaluation under disease epiphytotic conditions could identify a few superior genotypes. Two homozygous backcross lines TMG‐29 and TMG‐46 showed enhanced resistance to LLS and rust diseases (score of 3.00 for both) along with 71.0% and 62.7% increase in the pod yield per plot, respectively, over the check, TMV 2. These foliar disease‐resistant and productive lines can be released as commercial varieties or can be used as genetic resources in the peanut improvement.  相似文献   

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Summary Gene pyramiding in Phaseolus vulgaris is being utilized to develop more effective resistance to the temperature-insensitive-necrosis-inducing (TINI) strains of Bean Common Mosaic Virus (BCMV) present in the USA. Our data indicate that contrary to previous work, the bc-3 gene is effective against these strains in the absence of the strain unspecific bc-u gene in genotypes possessing the I gene. The epistatic bc-3 gene interferes with traditional efforts to pyramid the other recessive resistance genes by masking their activity. Indirect selection based on markers linked to the other recessive resistance genes would likewise be ineffective without the ability to also select for the bc-u gene which is required for expression of the bc-2 2 gene in germplasm carrying the I gene. Because the most resistant genotype (I, bc-u, bc-I 2, bc-22, bc-3) can only be introduced into a wide range of germplasm through the use of molecular markers linked to the different resistance genes, the search for a marker linked to the strain unspecific bc-u gene should also be given priority.  相似文献   

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