Detection of DNA sequence polymorphisms among wheat varieties

Abstract

A DNA marker detection strategy that allows the rapid, efficient resolution of high levels of polymorphism among closely related lines of common wheat (Triticum aestivum) has been developed to circumvent the apparent lack of restriction fragment length polymorphism in many important self-pollinated crop species. The technique of randomly amplified polymorphic DNA (RAPD) was combined with a denaturing gradient gel electrophoresis system (DGGE) to explore DNA sequence polymorphisms among different genotypes of wheat. Of the 65 primer combinations used for the polymerase chain reaction (PCR) amplifications, over 38% of them produced readily detectable and reproducible DNA polymorphisms between a spring wheat line, SO852, and a winter wheat variety, 'Clark'. A high level of polymorphism was observed among a number of commercial varieties and breeding lines of wheat. This procedure was also used to detect polymorphisms in a recombinant inbred population to test the feasibility of its application in genome mapping. This DNA polymorphism detection system provides an opportunity for pedigree analysis and fingerprinting of developed wheat lines as well as construction of a high density genetic map of wheat. Without the need for (32)P and sophisticated DNA extraction procedures, this approach should make it feasible to utilize marker-based selection in a plant breeding program.

Extreme homogeneity among Brazilian wheat genotypes determined by RAPD markers

“…This homogeneity of 73% is probably due to the fact that all the wheat genotypes used in Brazil have a common origin. Similar (though not as extreme) RAPD results were also obtained with British (Devos & Gale, 1992) or USA (He et al, 1992) varieties, but Sun et al (1998) also found extreme homogeneity (79% to 88%, using 32 arbitrary primers) among respectively Chinese winter and spring common wheat. He et al (1992) combined RAPD analysis with the DGGE (denaturing gradient gel electrophoresis) technique, and even with this potentially more discriminating combination obtained an overall similarity index of 62%.…”

“…Similar (though not as extreme) RAPD results were also obtained with British (Devos & Gale, 1992) or USA (He et al, 1992) varieties, but Sun et al (1998) also found extreme homogeneity (79% to 88%, using 32 arbitrary primers) among respectively Chinese winter and spring common wheat. He et al (1992) combined RAPD analysis with the DGGE (denaturing gradient gel electrophoresis) technique, and even with this potentially more discriminating combination obtained an overall similarity index of 62%. Quantitative estimates of genetic homogeneity based on RAPD markers were obtained by Lanza et al (1997) in maize (37%), Graham & McNicol (1995) in Rubus (61%), Williams & St. Clair (1993) in tomato (63%), and Colombo et al (1998) in Manihot (65%).…”

Identification of promising wheat genotypes for crossing

“…These discrepant results from other studies in the area can be explained by the study methodology (RAPD). RAPD has not proven effective for detecting variability in wheat due to the complex genome (allohexaploid) of this cereal, according to results of Devos and Gale (1992) in England and He et al (1992) and Riede et al (1994) in the United States. Besides, the genotypes studies were mostly specifically adapted to environments of cold and rainy climate and acidic soils.…”

Wheat biotechnology: A minireview

“…RAPD markers provide a useful alternative to RFLP analysis for screening markers linked to a single trait within near isogenic lines and bulked segregants. He et al (1992) reported the development of a DNA polymorphism detection method by combining RAPD with DGGE (denaturing gradient gel elecrophoresis) for pedegree analysis and fingerprinting of wheat cultivars. RAPD markers can be converted to more user-friendly Sequence Characterized Amplified Region (SCAR) markers, that display a less complex banding pattern.…”