The Variety Identification And Purity Detection Of The Hybrid Rice Gang-You 527 Using SSR Marker

Rice blast disease is one of the three most important diseases on rice, and causesgreat lost in yield every year. Hybrid rice cultivar Gangyou 527 was bred by theSichuan Agricultral University in 1995, it is not only good at yield, but also excellentat resistance. The authenticity and purity of seeds are two factors that effect the resistance andyield of Gangyou 527, so the identification and purity detection of Gangyou 527 seedsare necessary measures to secure the stability of resistance and yield in field. The abundance and scattered distribution of simple sequence repeats (SSRs)promoted the explore of it as a promising marker in a lot of molecular-biologyresearch, such as genetic diversity analysis, genome addition and varietyidentification. 51 SSR markers distributing on 12 rice chromosomes were tested on 24 hybridrice vatieties. After PCR reaction and 2.0% agarose gel electrophoresis, one markerRM341 was found to have the ability distinguishing Gangyou 527 from other 23hybrid rice varieties. 4 conventional varieties were also amplified using primer-pairRM341, only one fragment amplified from each, at the same time, Gangyou 527, asall the other hybrid varieties, has two. The reliability of RM341 as a identify markerof Gangyou 527 was also verified by experiment. We employed fluorescence-labelled primer and ABI PRISM 310 Analyzer toamplify the SSR locus RM341. After the amplified fragments were separated bycapillary electrophoresis , some corresponding softwares employed in the SSRanalysis. This is a method with high sensibility , high flux and can be handledsemi-automatically. But, compared with the datum derived from cloning and sequenceanalysis, we found it not so accurate, there was some discrepansy of 2~4bp in length.Although the discrepansy is too small to influence our estimation in the identificationof Gang-you 527, we cann't set this method as a model system that could be used inpractice. Furthermore, we do some analysis on the SSRs sequences to decide thefeasibility of introducing real-time PCR into the identification and purity detection ofhybrid rice. The result shows that some special sequences may be found at either endof SSR region, based on which we can design fluorescence-labelled probes. In somecircumstances, the length polymorphism, too, could be looked as a kind of lengthpolymorphism in probe designing. However, in view of the structural particularity ofSSRs, we couldn't guarantee the efficiency of the probes of this kind. This research has founded the basis for the further study of the relationshipbetween the seeds' purity and the yield of Gangyou-527.