Developing Of Resistance Markers For Northern Corn Leaf Glight And Head Smut And Stalk Rot Of Maize And Screening Of Resistance Germplasms

Northern corn leaf blight (NCLB), head smut (HS) and stalk rot (SR) were three majordiseases of northern spring maize region in China. When the diseases occurred seriously, it wouldresult in no yield and cause greatly damage to maize production. It had important significance tobreak the narrow genetic basement of resistant germplasms and result in lack of multi-resistantgermplasms, which include resistant identification of germpalsm resources in field, screening ofeffective markers used in resistant identification and creation of multi-resistant germplasms bymulti-genes pyramiding.The resistance of69maize inbred lines to three main diseases was analyzed in field. Thegenetic diversity and population structure among69inbred lines were analysized by70pairs ofSSRs, which was evenly distributed over10chromosomes. The effective markers uesd in diseaseidentification were screened from42pairs of molecular markers, which were linkage with resistantgenes of NCLB, HS and SR of maize. Combined with the aboved effective markers andmulti-genes pyramiding, multi-resistant germplasms were created. The main results weresummarized as followed:(1)69inbred lines were evaluated the resistance to NCLB and HS and SR by artificialinoculation. Among them,13inbred lines were detected with high resistance to three main disease,37inbred lines with resistance,19inbred lines with susceptible, medium resistance and highsusceptible materials were less.(2) The population division based on UPGMA cluster and Structure software was similar andall inbred lines were divided into five groups (PA, PB, Lancaster, Lüda red cob and Tangsipingtou).(3) Three markers (umc1316, umc2212, umc1327) applied in the identification of NCLB andtwo markers (SSR148152and SSR58) respectively applied in the identification of HS and SR werescreened from42pairs of related markers. Based on the above five effective markers, the materialswere clearly distinguished, which had comprehensively resistant and susceptible performance tothree main diseases.(4) Based on the resistant identification for successional two years (2009-2010),8hybridization combinations of BC2F4lines were gained from12BC2F2populations. By detecting of5effective markers, the combination number of1,7and8probably had the resistance genes of NCLB and HS, the combination number of3probably had the resistance genes of NCLB and ST.