22,028 research outputs found
Proceedings of the COST SUSVAR/ECO-PB Workshop on organic plant breeding strategies and the use of molecular markers
In many countries,national projects are in progress to investigate the sustainable low-input approach.In the present COST network,these projects are coordinated by means of exchange of materials,establishing common methods for assessment and statistical analyses and by combining national experimental results.The common framework is cereal production in low-input sustainable systems with emphasis on crop diversity.The network is organised into six Working Groups,five focusing on specific research areas and one focusing on the practical application of the research results for variety testing:1)plant genetics and plant breeding,2)biostatistics,3)plant nutrition and soil microbiology,4)weed biology and plant competition,5)plant pathology and plant disease resistance biology and 6)variety testing and certification.It is essential that scientists from many disciplines work together to investigate the complex interactions between the crop and its environment,in order to be able to exploit the natural regulatory mechanisms of different agricultural systems for stabilising and increasing yield and quality.The results of this cooperation will contribute to commercial plant breeding as well as official variety testing,when participants from these areas disperse the knowledge achieved through the EU COST Action
Use of DNA-based genetic markers in plant breeding
Genetic markers have been used since the beginnings of plant breeding, but the concept of linkage and recently the availability of molecular markers have offered new and powerful tools that can help to perform the traditional tasks of selection or that can change the traditional breeding process. Markers can either be used in a descriptive manner to identify varieties, to study the ‘micro-evolution’ of composite crosses or variety mixtures or to analyse the breeding progress retrospectively in order to learn from the past. The operative use of markers in plant breeding is connected to the selection of parental lines and progeny lines. The possible implementation of these processes stretches from the introgression of specific chromosome fragments to ‘marker-based idiotype breeding’
Cereal variety and population selection
This research review notes that cereal variety breeding in the last 50 years has been based on pedigree line bred varieties as part of the development of a production system dependent on oil-based inputs. The characteristics desirable for an organic system are frequently at odds with those designed for non-organic systems. Despite this, varietal choice for organic farmers remains largely from the pool of varieties developed for non-organic production. The challenges to address are on what basis can farmers and advisers select varieties, and how to develop varieties suitable for organic production. Plant characteristics are discussed and main desirable features outlined under the headings of:
• Nutrient use efficiency
• Disease resistance
• Weed competitive ability
• Quality
Breeding selection parameters are then considered. The wide variation that occurs in organic systems and the aim to improve the consistency of performance (yield stability) means that the adaptability of a single variety is not sufficient to buffer these variables. The place for variety mixes is considered, and then the case for composite cross populations. The development of these alternative approaches is hindered by market acceptability and for composite populations by the legislative framework. The conclusions note there are many and different combinations of characteristics that may be of advantage. The suitability of a variety can be affected by the management of the whole organic system, not just one crop in isolation. The situation is complex and selection of genotypes is best undertaken under organic management. Low input line breeding programmes have achieved some success, but the review argues that better environmental adaptation is achieved by genotype diversity, either as variety mixes or as composite populations. For the future there is potential in the (relatively) short term for line breeding under organic conditions. For the longer term there is opportunity in mixtures, and especially of populations. For these to be successfully developed there is a need to address cultural attitudes, inertia in the market and production infrastructure and legislative framework
International Symposium on Evolutionary Breeding in Cereals
Evolutionary plant breeding has a long history, but has so far not become part of mainstream breeding research, nor has it been implemented in practice to any substantial degree.
However, over the last decade, research in evolutionary plant breeding has markedly intensified. For example, there are currently major research projects on-going in this area, including the EU funded project SOLIBAM, the Wheat Breeding LINK project in the UK, and the Danish Biobreed project. Also, a new 3-year international research project called COBRA on this topic is due to start in March 2013. Funded by the CORE Organic 2 Eranet the project brings together over 40 partner organizations from 18 European countries.
In addition, interest in evolutionary plant breeding is growing among farmers, breeders and policy makers. In fact, there are currently encouraging developments in the imminent revision of seed legislation in Europe that could lead to more room for evolutionary plant breeding approaches in the future.
This renewed interest in evolutionary plant breeding is partly due to the recognition that mainstream plant breeding is limited in terms of its engagement with end users, i.e. farmers and growers. More urgently however, effects of climate change on agricultural production have become more noticeable and there is also a growing awareness of increasing resource constraints; together, these will create more stressful growing conditions for agricultural crops. With this background, it is now being recognized that crops need to be able to cope with more variable, contrasting, fluctuating, and generally more unpredictable growing conditions.
To be able to deal with this large and increasing environmental variability, plant breeding needs to become more decentralized and diversified. Evolutionary plant breeding offers great potential in this respect. The contributions collated from this symposium explore this potential as well as the limitations of evolutionary plant breeding. While they only show a part of the on-going research activities in Europe, we hope that these proceedings provide inspiration both for further research and for implementation in practice
Increased yield and yield stability in variety mixtures of spring barley
In the DARCOF II BAR-OF project, six variety mixtures are studied in organic as well as conventional growing systems in the period 2002 to 2005. The focus has been on competitive ability of the component varieties in addition to their disease resistance. This study is included in a European Network on sustainable low-input cereal production focusing on varietal characteristics and crop diversity (SUSVAR - COST 860), initiated in 2004. The following is based on papers presented at two SUSVAR workshops
Selection for high spike fertility index increases genetic progress in grain yield and stability in bread wheat
Spike fertility index (SF) has been proposed as a promising trait to be used as a selection criterion in wheat breeding programs aimed at increasing grain yield, but no actual evidence of its successful application has been reported. In this study, 146 recombinant inbred lines derived from a cross between ‘Baguette 10’ and ‘Klein Chajá’, Argentinean spring bread wheat cultivars with contrasting SF, were evaluated during three crop seasons (2013, 2014 and 2015) at Balcarce, Argentina. Grain yield, grain number/m2, grain weight, and SF were measured at maturity. Changes in grain yield (i.e., responses to selection) after application of different selection strategies, including different selection criteria and selection intensities, were determined. Significant correlations were observed between grain number and grain yield, SF and grain yield, and SF and grain weight. Analysis of SF variance components showed a significant genotype × environment interaction, but it represented only 9% of the total variation, whereas 51% of the variation was genetic, resulting in a high narrow-sense heritability (0.84). The use of SF as a selection criterion, either solely or in combination with selection for high yield, increased yield, resulting in higher and more stable yields than if selecting for high yield alone. Our findings support the use of spike fertility index as a selection criterion for increasing genetic progress and stability of yield in bread wheat breeding programs.Fil: Alonso, María Pía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Agronomía; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Mirabella, Nadia Estefania. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Agronomía; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Panelo, Juan Sebastián. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Agronomía; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Cendoya, Marcelo Gustavo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Agronomía; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Pontaroli, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Agronomía; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentin
European perspectives of organic plant breeding and seed production in a genomics era.
For further optimisation of organic agricultural systems, more focus is required on
organically produced seeds and the development of better adapted varieties.
Organic plant breeding and seed production need to comply with the concept of
naturalness as applied in organic agriculture, which not only includes the nonchemical
and agro-ecological approaches, but also the integrity of life approach.
As organic environments are less controllable and are more variable, breeding
should aim at improved yield stability and product quality by being adapted to
organic soil fertility as well as sustainable weed, pest and disease management.
Also the ability to produce economicacceptable seed yield avoiding seed-borne
diseases should be included. On the short term, organic plant production can gain
better yield stability by increasing within-crop diversity by the use of mixtures of
conventionally bred varieties or crop populations. Because of expected genotype
by environment interaction more research is needed to define the best selection
environment for selecting organic varieties. To arrive at better adapted varieties for
organic farming systems the role of practical participatory plant breeding may be
crucial.
Although organic farming is clear on excluding the use of genetically modified
organisms and their derivates, the use of molecular markers is still under debate.
Questions arise with respect to their efficiency in selecting the most important
organic traits, such as yield stability, and on the compounds and substances to
produce and apply them. A major concern for a GM-free organic agriculture is an
increasing contamination with genetically modified organisms in organic
production and products, i.e., the problems related to co-existence of GM and non-
GM agriculture. This paper discusses some important factors with regard to
possible impact of co-existence on organic farming. Perspectives to a global scale
of organic plant breeding and seed production are given from a European point of
view
Populations of doubled haploids for genetic mapping in hexaploid winter triticale.
To create a framework for genetic dissection of hexaploid triticale, six populations of doubled haploid (DH) lines were developed from pairwise hybrids of high-yielding winter triticale cultivars. The six populations comprise between 97 and 231 genotyped DH lines each, totaling 957 DH lines. A consensus genetic map spans 4593.9 cM is composed of 1576 unique DArT markers. The maps reveal several structural rearrangements in triticale genomes. In preliminary tests of the populations and maps, markers specific to wheat segments of the engineered rye chromosome 1R (RM1B) were identified. Example QTL mapping of days to heading in cv. Krakowiak revealed loci on chromosomes 2BL and 2R responsible for extended vernalization requirement, and candidate genes were identified. The material is available to all parties interested in triticale genetics
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