EVALUATION, IMPROVEMENT, AND DEVELOPMENT OF NEW/ALTERNATIVE INDUSTRIAL CROPS
Location: Plant Physiology and Genetics Research
Title: CROSS-SPECIES AMPLIFICATION OF SIMPLE SEQUENCE REPEATS (SSRS) BETWEEN ARABIDOPSIS THALIANA L., BRASSICA SPECIES, AND LESQUERELLA AND PHYSARIA (BRASSICACEAE)
Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: February 18, 2003
Publication Date: October 12, 2003
Citation: Salywon, A.M., Krishna, G., Dierig, D.A., Puppala, N. 2003. Cross-species amplification of simple sequence repeats (ssrs) between arabidopsis thaliana l., brassica species, and lesquerella and physaria (brassicaceae). Association for the Advancement of Industrial Crops Conference. p. 40.
Lesquerella and Physaria species (Brassicaceae) are sources for three types of hydroxy fatty acids (HFA), auricolic, densipolic, and lesquerolic, with potential for industrial applications including lubricants, novel plastics, protective coatings, cosmetics, surfactants, drying agents, and pharmaceuticals. Although identified as possible new crops in the 1950s, a breeding and selection program has been developed for them only within the last 15 years. While much progress has been made within this time using traditional selection methods for increased seed size, yield, oil content, oil composition, and improved agronomic characteristics, DNA-based markers should accelerate the selection time frame and should be useful in precisely identifying trait loci.
Many DNA-based markers are used for crop improvement. However, simple-sequence repeat (SSR) loci, or microsatellites, are becoming the molecular marker of choice in marker-assisted plant breeding and marker-based genetic analysis because they are easy to use, abundant, dispersed throughout the genome, usually co-dominant, and generally more polymorphic than other genetic markers. However, developing these markers de novo is costly and time-consuming. Several studies have shown the ability of SSRs developed for one species to be amplified in related species or genera, thus saving time and money. Hundreds of SSR primers have been developed for related species in Brassicaceae, particularly from Arabidopsis thaliana L. and Brassica crop species, so that a great potential exists to use these SSR primers in our breeding program with Lesquerella and Physaria.
The goal of this study was to test 24 SSR primer pairs developed for A. Thaliana, Brassica napa L., and Rapa L. for their transferability to loci in Lesquerella and Physaria, with the long term aim of using these SSR loci to construct a genetic linkage map for the several species of Lesquerella and Physaria.
Sixteen primer pairs developed for A. Thaliana that cross amplified with Brassica spp. These were shown to contain micro satellite repeat regions. Eight additional primer pairs for Brassica napa and B. Rapa (4 from each species) were chosen for this study. Preliminary results indicate that a majority of the primer pairs amplify fragments in both Lesquerella and Physaria. DNA sequencing and probe hybridization assays are underway to determine whether the loci contain SSR.s
These SSR markers are the first DNA markers to be developed in our breeding program and the first step toward developing genetic maps for Lesquerella and Physaria. Once constructed, the genetic map will allow us to investigate genes influencing important traits and their location along the chromosomes. Also, it will help us implement marker-assisted selection for improvement of specific pheneotypes.