BG-101
Progress in the development of nutrient-rich nematode resistant carrots
Philipp W. Simon, USDA-ARS, Vegetable Crops Unit, Dept. of Horticulture, University of Wisconsin-Madison,1575 Linden Drive, Madison, WI 53706
Philip A. Roberts, Nematology and Nematologist in the Agricultural Experiment Station, University of California, Riverside, CA 92521
Joe Nunez, Vegetable/Plant Pathology Advisor, UC Cooperative Extension, 1031 South Mount Vernon Avenue, Bakersfield, CA 93307
Carrots are an important source of nutrients for the U.S. diet and economic value to agriculture, but root-knot nematode threatens approximately 3/4 of U.S. carrot crop. We have identified resistance to M. javanica (MJ) and recent germplasm evaluations indicate additional genetic resistance for M. incognita (MI) in the MJ resistant selections. Furthermore, we have identified additional MI resistance in four unrelated germplasm sources. Now we are in a position to incorporate resistance from these several sources.While nematode resistance is of paramount importance for carrot growers, and for the environment, consumers make eating choices, including carrots, based upon appearance and flavor, and they expect carrots to be nutritious. Breeders have been successful in genetically improving carrot flavor and nutritional content (primarily provitamin A carotenoids), and the new nematode resistant germplasm varies widely in nutritional content and flavor. Using a combination of detailed screening for nematode resistance along with marker-assisted genetic selection and field evaluation of crop performance, we propose strategies for incorporating improved nematode resistance along with improved nutritional value for the U.S. carrot production industry.
BG-102
Genetic influences on the seed yielding ability of carrot hybrids
Robert Kane and Philipp W. Simon, USDA-ARS, Vegetable Crops Unit, Dept. of Horticulture, University of Wisconsin-Madison,1575 Linden Drive, Madison, WI 53706, USA
Carrot seed production characteristics of four different threeway carrot hybrids were evaluated over three years during seed production from transplanted roots in Madison, Wisconsin. Components of seed yielding ability and plant architecture were measured. Both the male sterile seed parent and inbred pollen parent significantly influenced variables that are considered major factors for yield. Significant differences were detected between male sterile hybrid seed parents and between inbred pollen parents for their influence on seed yield. Significant differences in some aspects of yield were influenced by the male sterile hybrid seed parent. Basic plant stature, as measured by plant height and post harvest dry weight, has a positive effect on yield of carrot seed. Phenotypic variation in the umbel characteristics also contributed to differences in yield. More specifically, the superior male sterile hybrid seed producer had a greater number of umbels that measure from 4-7 cm in diameter. Pre-transplant weight of the root grown in El Centro, California did not appear to play a major role in the quantity of seed produced. Expected seed size, and the number of seeds per umbel can be estimated by the position of the source umbel on the plant. Inbreds used as pollenizers are more successful if there is pollen available in the cage during fertilization of the smaller sized umbel classes. It may be possible for plant breeders to design hybrid combinations possessing the desired horticultural characteristics to take advantage of this model of superior seed yielding phenotypes.
BG-103
Development of 304 new microsatellite markers for carrot. Analysis of their potential for linkage mapping, assessment of genetic diversity and cross-taxa utilization.
Pablo F. Cavagnaro1, Sang-Min Chung2, Aamir Ali3, Mehtap Yildiz4, Maria S. Alesandro5, Robin Schroll6, Philipp W. Simon7,*
1 Dept. of Horticulture, University of Wisconsin-Madison,1575 Linden Drive, Madison, WI 53706, USA; and CONICET, Argentina
2 Dept. of Life Science, Dongguk University, 3-26 Pil-dong, Chung-gu, Seoul 100-715, South Korea
3 Department of Biological Sciences, University of Sargodha, Sargodha, Pakistan
4 Dept. of Horticulture, Faculty of Agriculture, Yuzuncu Yil University, 65080, Van, Turkey
5 Estación Experimental Agropecuaria La Consulta, Instituto Nacional de Tecnología Agropecuaria, Ex Ruta 40, km 96, La Consulta, Mendoza, Argentina, PC. 5567, CC 8
6 Dept. of Horticulture, University of Wisconsin-Madison, 1575 Linden Drive, Madison, WI 53706, USA.
7 USDA-ARS, Vegetable Crops Unit, Dept. of Horticulture, University of Wisconsin-Madison,1575 Linden Drive, Madison, WI 53706, USA
* Corresponding author: Philipp W. Simon. E-mail: psimon@wisc.edu
Two different approaches were used to isolate carrot SSRs: 1) Construction and analysis of a genomic DNA library enriched for SSR loci (GSSRs) and 2) Bioinformatic mining for SSR motifs in a 1.7 Mb BAC-end sequence database (BSSR). The SSR-enriched library yielded microsatellites with more repeats but shorter motifs than the BAC-end sequence derived SSRs. The most abundant motifs found were di- (47%) and tetranucleotides (40%) for GSSRs, and tri- (43%) and tetranucleotides (25%) for BSSRs. A total of 304 SSRs (158 GSSRs and 146 BSSRs) were successfully characterized in a subset (16 plants/population) of 5 F2 carrot mapping populations, and in 16 different Apiaceae. The percentage of potentially mapable markers (codominant or dominant) in the F2 families, as resolved by high-resolution agarose electrophoresis, ranged from 34-45 % for GSSRs, and 25-34 % for BSSRs. More than 80 % of the SSR markers amplified DNA in Daucus species other than carrot, whereas in the more distantly related non-Daucus species the SSRs performance varied greatly depending on the species and the SSR. To assess genetic relatedness among 90 cultivated and wild Daucus accessions 24 selected SSRs were used and resolved by 6% polyacrilamide gel electrophoresis, and 1 marker (GSSR4) was sequence-analyzed. Sequence analysis of GSSR4 revealed novel size and sequence polymorphisms (e.g., indels and SNPs) beyond the microsatellite region, thus increasing its discriminatory power. The addition of codominant SSR to the carrot maps will allow their integration and therefore improve their potential for map-based cloning.
BG-104
Understanding the molecular mechanism of carotenoid accumulation in carrot (Daucus carota) using real time quantitative PCR
Megan J. Bowman1, D. Kyle Willis1,2,4 and P.W Simon1,3,4
1 Plant Breeding and Plant Genetics Program, University of Wisconsin-Madison, 1575 Linden Drive, Madison, WI 53706
2 Department of Plant Pathology, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706
3 Department of Horticulture, University of Wisconsin-Madison, 1575 Linden Drive, Madison, WI 53706
4 USDA-ARS, Vegetable Crops Research Unit, 1575 Linden Drive, Madison, WI 53706
Carrot (Daucus carota) is an important source of pro-vitamin A in the human diet, as well as other important antioxidant compounds. While essential to human health, very little is currently understood about the accumulation of carotenoids, the vitamin A precursors within the storage root that give carrot its orange, red and yellow pigmentation. In understanding the molecular mechanism for carotenoid accumulation in carrot, it may be possible to enhance the biosynthesis and therefore increase the amount of total carotenoids within the carrot storage root. As an initial approach to this work, expression of genes within the carotenoid biosynthesis were analyzed, using real time quantitative PCR. No significant difference in gene expression was found in most of the nine genes evaluated within the pathway, but two fold higher expression was observed in dark orange pigmented carrot in comparison to white, in some cases. This study has identified a region of interest in the biosynthetic pathway for further investigation of carotenoid accumulation in carrot.
BG-105
Evaluation of Daucus genetic resources as a source of health promoting compounds
T. Nothnagel1, R. Baranski4, R. Carle3, D. Grzebelus4, D.R. Kammerer3, M. Kramer3, M. Leja, A. Maksylewicz-Kaul4, H. Schulz2, J. Schulz-Witte2, D. Ulrich2
1Institute for Breeding Research on Horticultural and Fruit Crops, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Erwin-Baur-Str. 27, 06484 Quedlinburg, Germany
2Institute for Ecological Chemistry, Plant Analysis and Stored Product, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Erwin-Baur-Str. 27, 06484 Quedlinburg, Germany
3Institute of Food Science and Biotechnology, Section Plant Foodstuff Technology, Hohenheim University, August-von-Hartmann Str. 3, 70599 Stuttgart, Germany
4Department of Genetics, Plant Breeding and Seed Science, University of Agriculture in Krakow, Al. 29 Listopada 54, 31425 Krakow, Poland
A new binational cooperation project between the Agricultural University of Krakow (Poland), Hohenheim University, Stuttgart (Germany) and the Julius Kühn-Institute, Federal Research Centre for Cultivated Plants, Quedlinburg (Germany) comprising both fundamental and applied research in the areas of carrot genetics, molecular biology, plant physiology, analytical chemistry and food technology will be presented.
The aim of this joint project is to evaluate the genetic variability of carrots with respect to their profile of valuable compounds and their health-beneficial potential and to promote these properties in field experiments. For this purpose, carrot genotypes adapted to cultivation conditions in Europe with various root colours and high amounts of health-beneficial compounds (alpha- and beta-carotene, lutein, lycopene, anthocyanins, volatile compounds) will be selected for food consumption by the project partners in Krakow and Quedlinburg.
On the other hand, genotypes (especially wild Daucus species), expressing bitter polyacetylenes to a higher extent, will be assessed in terms of their potential as a raw material for the production of phytopharmaceuticals, since the latter components may be particularly helpful in the prevention of cancer.
In this context, the carotenoid, polyacetylene and anthocyanin profiles in the carrots are analysed by HPLC-MS as well as micro Raman spectroscopy.
In frame of the project, methods for the adsorptive recovery of these pharmacologically active compounds will be developed using lipophilic styrene-divinylbenzene copolymers or acrylic resins. These processes may also be applied for the debittering of carrot-derived products, such as juice and purée, by adsorptive binding of the bitter principles, thus minimising economic losses for the carrot processors.
First annual results of the running studies will be presented.
BG-106
Carrot AOX–a source for potential functional marker candidates to assist breeding on multi-stress tolerance
Birgit Arnholdt-Schmitt*, Hélia G. Cardoso, Maria Doroteia Campos, Ana Rita Costa, Catharina Campos, Alexandre O. Ferreira, Elisete Santos Macedo, Augusto Peixe, António Miguel Frederico, Alejándro Hernández
1EU Marie Curie Chair, ICAM, University of Évora, Apartado 94, 7002-554 Évora, Portugal
Correspondence to: eu_chair@uevora.pt
Plant reactions upon diverse forms of stress are typically linked to the generation of reactive oxygen species (ROS) and highly adaptive, morpho-physiological responses. Mitochondria seem to play a crucial role in stress perception and signal transformation in the ‘decision’ of plant cell’s for survival or death. Alternative oxidase (AOX) is increasingly recognized as being of central importance to relieve stress and to regulate mitochondrial signalling. Additionally, AOX is known to be related to growth and development. Thus, this enzyme is highly suspect of being an important source for the development of functional markers for multi-stress tolerance (www.aox2008.uevora.pt). As a prerequisite for the identification of AOX - deduced molecular markers, polymorphic AOX gene sequences must be available that can discriminate individual plants. Here we report about research approaches to develop AOX functional markers from diverse species and about the identification of polymorphic carrot AOX gene sequences as a natural source for genetic variability.
This work was supported by the European Commission through providing a ‘Marie Curie Chair’ to Birgit Arnholdt-Schmitt at the University of Évora, Portugal. We thank the Foundation for Science and Technology, FCT, Portugal, for scholarships to Hélia G. Cardoso, M. Doroteia Campos, Alexandre O. Ferreira, Elisete S. Macedo and António Miguel Frederico.