Population Division Of Puccinia Helianthi Schw. And Scar Markers

This research is first time to study on the physiological race identification of Puccinia helianthi Schw. of the main producing areas of sunflower in China. Based on44samples which were collected in north China, Heilongjiang. Inner Mongolia, Hebei, Ningxia, Shannxi, Xinjiang province in July to September in2010. Through the single urediospores isolation and purification, we have got44strains.6races were identified According to the reaction of9international differential hosts which were named300、735、310、500、737、724by coded triplet system. The frequency of occurrence were59%、16%、14%、7%2%、2%respectively. The results show that300is the main race. Then the race300was inoculated to the representative of sunflower varieties which come from the main producing areas.12varieties are susceptible and31varieties are resistant.15%of the oil sunflower varieties are susceptibale,39%of confectionery sunflower are susceptible,31.6%of hybrid varieties and80%conventional varieties of are susceptible.The genetic diversity of44isolates was analyzed through RAPD molecular ma rker technique. The results showed that115fragments were amplified from44isola tes with13primers, among them the number of polymorphic loci was91,which ac counted for79.1%in the total amplified fragments and the average amplified fragm ents was8.8each primer. The analysis of dendrograms and genetic similarity coeffi cient showed that genetic similarity coefficient of44isolates was0.63～1.00, the av erage was0.815. At the level of0.74,44isolates could be obviously divided into three RAPD groups, the relations between RAPD group partition and distribution of isolates was not obvious. Specific RAPD band was picked out from100primers PCR amplifying products, and one primer (S8:ACGGATCCTG) is correlated to Ra ce300. Specific band was recycled, re-amplified, purified and then cloned by PGE M-T vector.1pair of primer was designed according to the sequences with softwar e DNAMAN (Forward primer:5-CCTGAGGAAGACGGTATT-3, Reverse primer:5-CCTGCATGCCATTGGTGTT-3), which then was used for PCR amplifying different strains. This SCAR markers of Race300can specifically detect Race300of diffe rent origin.