Channel: GENETICS OF DISEASERESISTANCE AND PATHOGENICITY http://zwblxb.magtech.com.cn EN-US http://zwblxb.magtech.com.cn/EN/current.shtml http://zwblxb.magtech.com.cn 5 Melampsora larici-populina (Mlp), the casual agent of popular leaf rust, were analyzed. The results demonstrated that although Mlp urediniospores normally germinated on wheat leaves, only 3.7% recognized the stomata, and a very few of them were able to develop sub-stomatal vesicle-like (SSVL) structure and infection hypha. The immediately induction of H₂O₂ and callose at the infection site arrested the further infection of the rust fungi. In addition, no cell death was observed, suggested that the defense reaction of wheat against Mlp belongs to type I nonhost resistance. Two genes involved in jasmonic acid synthesis, LOX1 and AOS1, as well as PR1a, the downstream pathogenesis related gene of JA pathway, were all induced by Mlp infection, highlighted an important role of JA pathway in wheat nonhost resistance to Mlp. This study provided groundwork for further elucidation of the molecular mechanism of wheat nonhost resis-tance to poplar leaf rust.]]> B. sorokiniana, is an important foliar disease on barley, being widely prevalent in most barley-growing regions in the world. It is most destructive especially in the regions with warm and moist climates, consequently bringing about serious yield losses.Presently, spot blotch is the first important fungal epidemic disease in the spring barley-growing regions in northeastern China.The disease usually occurs in mid- and late-growth stages of barley. Growing resistant varietiesis, therefore,the most cost-effective measure for the disease control. In this study, two highly virulent dominant B.sorokiniana isolates Z12028 and Z15525 derived from northeastern China were selected to identify spot blotch resistance in barley germplasm accessions at the seedling and adult plant stages. Only one accession 2013F₆1903 was found to be highly resistant to Z12028 at the seedling stage, and no immune one accession to B. sorokiniana was detected. Nine accessions, such as ZDM00009,ZDM00013,ZDM00094,ZDM08888,ZDM01414,ND14049,ND B112,Newdale, and kenpimai 9 among the tested germplasm accessions, were found to be of allstage resistance to the both highly virulent isolates; fourteen accessions (4.3%)like ZDM00074,Bowman and Stander were resistant only at the seedling stage but susceptible at the adult plant stage, and another 72 accessions(28.3%) of adult plant resistance to spot blotch. Barley accessions of adult plant resistance accounted for 28.1% and 29.5% to Z12028 and Z15525, respectively. As a result, the percentage of adult plant resistant accessions to spot blotch was significantly higher than that of those with all stage resistance. The results of this study provided valuable resistant resources for exploiting new spot blotch resistance genes.]]>