148,717 research outputs found

    Future breeding for organic and low-input agriculture: integrating values and modern breeding tools for improving robustness

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    Organic production and also the attention for plant breeding for organic agriculture is still increasing in Europe. The question often raised is how much does plant breeding for the organic sector differ from modern plant breeding and does a ban on GMO also include refraining from molecular marker assisted selection (MAS)? In this paper I will first elaborate on the values in organic agriculture and it related systems approach as a central focus in organic agriculture and will then discuss in which way molecular marker assisted selection can be of use for plant breeding for organic and low-input agriculture

    Molecular breeding for resilience in maize - A review

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    Abiotic and biotic constraints have widespread yield reducing effects on maize and should receive high priority for maize breeding research. Molecular Breeding offers opportunities for plant breeders to develop cultivars with resilience to such diseases with precision and in less time duration. The term molecular breeding is used to describe several modern breeding strategies, including marker-assisted selection, marker-assisted backcrossing, marker-assisted recurrent selection and genomic selection. Recent advances in maize breeding research have made it possible to identify and map precisely many genes associated with DNA markers which include genes governing resistance to biotic stresses and genes responsible for tolerance to abiotic stresses. Marker assisted selection (MAS) allows monitoring the presence, absence of these genes in breeding populations whereas marker assisted backcross breeding effectively integrates major genes or quantitative trait loci (QTL) with large effect into widely grown adapted varieties. For complex traits where multiple QTLs control the expression, marker assisted recurrent selection (MARS) and genomic selection (GS) are employed to increase precision and to reduce cost of phenotyping and time duration. The biparental mapping populations used in QTL studies in MAS do not readily translate to breeding applications and the statistical methods used to identify target loci and implement MAS have been inadequate for improving polygenic traits controlled by many loci of small effect. Application of GS to breeding populations using high marker densities is emerging as a solution to both of these deficiencies. Hence, molecular breeding approaches offers ample opportunities for developing stress resilient and high-yielding maize cultivars

    Economic Analysis of Marker-Assisted Selection in Canola

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    Replaced with revised version of poster 07/19/11.Production Economics, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies,

    Marker Assisted Selection in Rice

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    A rising global population requires increased crop production and some research suggests that the rate of increase in crop yields is currently declining and traits related to yield, stability and sustainability should be a major focus of plant breeding efforts. These traits include durable disease resistance, abiotic stress tolerance and nutrient and water use efficiency. The use of DNA markers in plant breeding is called marker assisted selection (MAS). So far, about 40 major blast genes have been identified, about 30 genes have been mapped on different rice chromosomes, and tightly linked DNA markers have been developed. Eight blast resistance genes have been cloned and the genes have been used for their selective introgression into susceptible rice cultivars.  Recently Genetic and physical mapping of blast resistance gene Pi-42(t) located on the short arm of rice chromosome 12 in a resistant genotype ‘DHR9’ has been achieved. The PCR-based allele specific and in Del marker sets are available for nine blast resistance genes and they provide an efficient marker system for MAS for blast resistance breeding. Recently a novel resistance gene Pi40 derived from wild Oryza species (O. australiensis), have been located on chromosomes 6 and it shows promise for broad spectrum resistance. Tetep, the likely donor of Pi5(t) confers broad-spectrum resistance to Magnaporthe grisea. Additionally, several blast resistance genes could be combined using MAS in a single genetic background to develop rice cultivars with broad-spectrum durable resistance to blast. In future combination of conventional and marker assisted selection approach will provide opportunities for breeders to develop high yielding, stress tolerant and better quality rice cultivars. No doubt the cost of using DNA markers is expensive but it is worth the investment.Key words: Rice, Molecular markers, Polymorphism, Foreground and background selection Sabina Akhtar et al. Marker Assisted Selection in Rice. J Phytol 2/10 (2010) 66-8

    Molecular Marker-Assisted Selection of Rice Grain Quality on Rice (Oryza Sativa L.) Lines Tolerant to Fe Toxicity Stress

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    The elite rice has been produced, including iron (Fe) tolerant varieties. To get the appropriate rice lines which superior not only Fe tolerant but also have good grain quality needs to be developed selection system, especially in the use of molecular markers. This study was aimed to develop molecular markers for selection the rice grain quality characters of selected rice lines Fe tolerant. A total of 30 selected Fe tolerant rice lines and 5 parents as control lines were used in this research. Characterization of grain quality were quantitatively using the standard. While for genotyping analysis used 19 molecular markers of STS, SSR, Indel and SNP. This study showed that 14 of 19 markers result polymorphic DNA band (DNA markers). Association analysis of genotype and phenotype showed that 10 of 14 markers were significantly (p < 0.05) related to high quality of rice grain. Among four types of markers used in this study, STS was the most widely associated significantly with four characters of rice quality. The phenotyping analysis showed that the physical grain and palatability quality which obtained from the total mean of 30 rice lines tested tend to nearly with the parent\u27s value as controls lines. The most of these lines were included in the group IV of National Rice Grain Quality Standard (SNI). The amylose content (AC) showed that the texture was varied from firm and dry (high AC) to soft and sticky (low AC). The association results showed that there were significant (p ≤ 0.05) markers related with the biosynthesis starch genes, i.e: SBE1, SS1, SSIIa, GPA, PUL and S3cl which contributed on the character of rice palatability. These selected significant markers could be useful for screening of other population with Fe tolerant and/ or other desired morpho-agronomical traits in support of rice breeding program in Indonesia

    Precision of genetic parameters and breeding values estimated in marker assisted BLUP genetic evaluation

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    In practical implementations of marker-assisted selection economic and logistic restrictions frequently lead to incomplete genotypic data for the animals of interest. This may result in bias and larger standard errors of the estimated parameters and, as a consequence, reduce the benefits of applying marker-assisted selection. Our study examines the impact of the following factors: phenotypic information, depth of pedigree, and missing genotypes in the application of marker-assisted selection. Stochastic simulations were conducted to generate a typical dairy cattle population. Genetic parameters and breeding values were estimated using a two-step approach. First, pre-corrected phenotypes (daughter yield deviations (DYD) for bulls, yield deviations (YD) for cows) were calculated in polygenic animal models for the entire population. These estimated phenotypes were then used in marker assisted BLUP (MA-BLUP) evaluations where only the genotyped animals and their close relatives were included

    Modern approaches for breeding high quality apples with durable resistance to scab, powdery mildew and fire blight

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    New methods to allow for more precise selection of tree and fruit characters in breeding programmes were developed in recent years. Marker-assisted selection (MAS) is common practice in the ACW apple breeding programme at Wädenswil. Genetic markers can reduce the number of plants and the time required for evaluation, thus new varieties become commercially available sooner. How can this molecular selection method reasonably be applied in an apple breeding programme? Application of phenotypic and molecular selection techniques in the ACW apple breeding programme and results are presented

    Science and Society in Dialogue About Marker Assisted Selection

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    Analysis of a European Union funded biotechnology project on plant genomics and marker assisted selection in Solanaceous crops shows that the organization of a dialogue between science and society to accompany technological innovations in plant breeding faces practical challenges. Semi-structured interviews with project participants and a survey among representatives of consumer and other non-governmental organizations show that the professed commitment to dialogue on science and biotechnology is rather shallow and has had limited application for all involved. Ultimately, other priorities tend to prevail because of high workload. The paper recommends including results from previous debates and input from societal groups in the research design phase (prior to communication), to use appropriate media to disseminate information and to make explicit how societal feedback is used in research, in order to facilitate true dialogue between science and society on biotechnology

    Molecular Breeding for Abiotic Stresses in Maize (Zea mays L.)

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    Abiotic constraints resulting from climate changes have widespread yield reducing effects on all field crops and therefore should receive high priority for crop breeding research. Conventional breeding has progressed a lot in building tolerant genotypes but abiotic stress tolerance breeding is limited by the complex nature of abiotic stress intensity, frequency, duration and timing, linkage drag of undesirable traits/genes with desirable traits; and transfer of favorable genes/alleles from diverse plant genetic resources limited by gene pool barriers giving molecular breeding a good option for breeding plant genotypes that can thrive in stress environments. Molecular breeding (MB) approaches viz., marker-assisted selection (MAS), marker-assisted backcrossing breeding (MABB), marker assisted recurrent selection (MARS) and genomic selection (GS) or genome wide selection (GWS) offer opportunities for plant breeders to develop high yielding maize cultivars with resilience to diseases in less time duration precisely. For complex traits (mainly abiotic stresses) where multiple QTLs control the expression, new strategies like marker assisted recurrent selection (MARS) and genomic selection (GS) are employed to increase precision and to reduce cost of phenotyping and time duration with disease resilience. This review discusses recent developments in molecular breeding for developing and improving abiotic stress resilience in field crops

    Marker assisted selection in plant breeding

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    Marker assisted selection (MAS) is ‘smart breeding’ or fast track plant breeding technology. It is one tool utilized in breeding companies and research institutes for fast development of improved varieties, giving possibility to select desirable traits more directly using DNA markers. In this review, we discussed the use of MAS in biotic, abiotic, quality and other agronomic traits. Besides, we emphasized the importance of MAS at ICARDA and underlined the successful application of MAS in the last 10 years. The use of molecular markers makes the process of selecting parental lines more efficient based on genetic diversity analysis. It can aid the conventional breeding, especially for certain biotic and abiotic traits laborious to manage. Still, MAS contributed very little to the release of improved cultivars with greater tolerance to abiotic stresses, with only a few exceptions. MAS was extensively used to improve rice varieties, mainly resistant to bacterial blight and blast disease and was applied in drought tolerance along with GPC (Grain protein content) in quality traits. MAS at ICARDA is used to characterize new parental materials for disease resistance genes as well as in screening advanced lines with a focus on association mapping and identification of new QTLs. The application of MAS increased in the last decade. It is more and more used in different crops. However, rice is still the dominant crop in terms of number of publications using MAS. Keywords: marker assisted selection, plant, biotic stress, abiotic stress, quality, ICARD
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