Analysis Of Genetic Struture Of Drechslera Graminea Populations And Identification Of Resistance Barley Germplasm To Barley Stripe

The barley stripe is one of the major diseases of barley, it is more serious in Northern Europe and the Mediterranean region and it occurs widespreadly in the winter barley regions, hulless barley area on the Qinghai-Tibet Plateau and the spring barley regions in China. In recent years, because of changing of farming system, delaying of sowing time and frequent exchanging of barly cultivars, barley stripe are getting increasingly severe, and it can lead to up to30%loss of yield. It is essential to control barley stripe effectively in order to ensure the safety of barley production. In this study, we identified leaf stipe desease resistance of115landraces, and investigate their agronomic traits by a successive two years field trial; genetic diversity of579D. graminea isolates based on SNP (single nucleotide polymorphism) of ITS in rDNA was analyzed, and the isolates were collected from26barley varieties in11provices by sequencing; a preliminary study on pathogenic differentiation of D. graminea isolates was by inoculating "Hua30" with13different. D. graminea isolates selected from different haplotypes from different lacations. The main findings obtained are as follows:1.The results for resistance identification showed:31varieties of all were resistant to barley strpe,24varieties moderately resistant,53varieties moderately susceptibility and7varieties highly susceptible among115tested matierials; the average deseased plant rate of two-row varieties (4%) higher than the six-rowed varieties (3.02%); of the proportion of resistant varieties in the two-rowed varieties (11.1%) is lower than of six-rowed varieties (26.8%)..Rich variation of agronomic traits of barley germplasm resources investigated provide good resistance material used in breeding progamm for resistance to barley stripe.2. We fonud the that13variable loci and15modification patterns containing nucleotide substitution, insertion and deletion in the ITS sequences of rDNA of579D. graminea isolates fromll provinces. Based SNP of their ITS sequences detected, all isolates are divided into3major groups,52small subdivisions, and the first has28haplotypes, the second has11haplotypes, and the third has13haplotypes.3. The D. graminea isolates from Zhejiang, Jiangsu, Anhui, Qinghai and Tibet were mostly included in the first group, most of the ones from Henan and Baoshan of Yunnan in the second category, most of the ones from Gansu, Inner Mongolia, Xinjiang in the third category.2-4special D. graminea isolate haplotypes in each province were observed. Allelic variation types found in the provinces located in middle and east China wer more than the ones in west and northwestern, and variable haplotypes for ITS sequence detected in different subpopulations of D. graminea isolates from different varieties were more different in the provinces located in middle and east China than the ones in west and northwestern4. Higher pathogenic differentiation were found among13differnt D. graminea isolates inoculated to host. The disease had significient influence on plant height and heading, but had obvious influence on tillering. The isolates belonged to the same variation type from the same areas had possibly different pathogenicity.