我国甘蔗锈病病原菌及甘蔗品系抗褐锈病基因Bru1的分子检测

Molecular Detection of Causal Pathogens Causing Rust Disease and Bru1 Resistance-gene in Elite Sugarcane Clones

为了解我国甘蔗锈病病原菌发生以及优良甘蔗新品种(系)抗褐锈病基因Bru1的分布频率情况,以来自我国5省(区)81份疑似甘蔗锈病叶片样品为材料,分别用Pm1-F/Pm1-R和Pk1-F/Pk1-R引物对进行褐锈病菌(Puccinia melanocephala)与黄锈病菌(Puccinia kuehnii)分子鉴定。结果表明,锈病病原菌检出率为40.7%,除了福建省福州市叶片样品仅检测到P.melanocephala外,其他省(区)的叶片样品均检测到2种锈病病原菌,且存在混合侵染现象。对24份黄锈病菌阳性PCR产物(527 bp)克隆并测序,结果发现P.kuehnii间隔区1(ITS1)第183个核苷酸存在单核苷酸多态性(SNP),其中,A碱基(183A)、G碱基(183G)位点的病菌分离物分别占29.2%和25.0%,2种碱基(183A/G)位点的混合病菌分离物有45.8%。通过R12H16与9020-F4/Rsa I两种分子标记对40份甘蔗新品种(系)抗褐锈病基因Bru1进行分子检测,结果表明,42.5%参试新品种(系)含抗褐锈病基因Bru1,这些材料可作为甘蔗抗褐锈病新品种加以推广应用。

The aim of this study was to investigate the incidence of causal pathogens causing sugarcane rust and frequency of Brul gene in new elite sugarcane clones. Two sets of primers of Pml-F/Pml-R and Pkl-F/Pkl-R were used for the identification of Puccinia melanocephala and Puccinia kuehnii respectively, causing the sugarcane rust in 81 leaf samples collected from five provinces in China. PCR assay revealed 40.7% of samples were verified to infect with P. melanocephala or/and P. kuehnii. Co-infection with two causal fungi was observed in leaf samples from most of provinces except for Fuzhou, Fujian. Subsequently, PCR products from 24 leaf samples infected with P. kuehnii were cloned and then sequenced to analyze the SNP （Single Nucleotide Polymorphism） in P. kuehnii ITS1 183A/G locus. Results showed that allele 183A and 183G were observed in 29.2% and 25.0% causal isolates, respectively, whereas 183A/G was detected in 45.8% causal isolates. Two marker-assisted R12H16 and 9020-F4/RsaI were used for screening of Brul resistance gene for brown rust in 40 new elite sugarcane clones. Brul frequency was 42.5% in the tested clones, of which would be applied in the effective and durable resistance in sugarcane against the P. kuehnii.