The RAPD Optimization System And SCAR Marker Of CY32 Of Strip Rust Race

Stripe rust , caused by Puccinia striiform is f. sp. Tritici(PST) is one of the most important epidemic diseases of wheat in the world. New races continue to evolve, leading to partial or complete loss of resistance in current cultivars. As an obligate fungus, the race identification and the virulence analysis of PST were complicated and time consuming. The identification results were affected by the environmental condition. Because of the limited differential number, it is very difficult to find the low-frequency race and to understand population genetic structure of this pathogen in nature.In recent years, the molecular biology provides us new way to monitor the constitution and change of PST races as its development.The PST is an obligate fungus, the sexual time is not been foud.In order to establish a practical molecular identification system of PST, specific molecular markers of the prevailing races in China were searched on a large scale.The results were obtained as follows:For design RAPD system of PST, the RAPD system of PST was developed. The many experiments indicated that the system is more steady and its Repeatability is good.Of the 99 random primers analyzed in this paper, 51 primers can show us steady amplification bands. The results obtained from 12 races in China indicate that: the genetic variations between races were abundance as a whole. The RAPD bands of different single-spore isolations in each race were identical, so the inheritance background of single race was coherent.The special DNA fragments of race CY32 was founded in this research. The DNA fragments of race CY32 was cloned and sequenced. Based on the sequencing result, two pairs of specific PCR primers were designed and the SCAR markers for race CY32 was obtained successfully.Rapid identification of the races of Puccinia striiformis f. sp. tritici by molecular technique was very important to monitor and control of wheat stripe rust in China. The results here indicates that a molecular identification system for the PST races could be established by means of cosmically searching special RAPD fragments of different races. Using such system, the identification time of PST would be cut to a few days. This would be essential for developing more effective strategies in management of wheat stripe rust in China.