甘肃豌豆地方资源的抗白粉病基因鉴定及er1等位基因挖掘

Pea powdery mildew caused by Erysiphe pisi DC. is one of the important diseases in Gansu. The cultivation and promotion of resistant varieties are the most economical, secure and effective measures during controlling continuously Erysiphe pisi prevailing. Therefore, it is of great significance for carrying out the research of discovering pea powdery mildew-resistant landraces. Up to date, only three powdery mildew resistance genes have been identified，two single recessive genes, er1 and er2 in pea，and one dominant gene Er3 in wild pea. It has been reported that resistance exhibited in the genotypes with gene er1 is complete and durable under field and controlled environments，whereas er2 provides leaf resistance only and is not durable under heavy infection. In this study，our aims are to detect and postulate the resistance genes via inoculating with the different powdery mildew isolates; Then SCAR markers closely linked to resistance gene er1 and er2 were used to do molecular identification for exploring pea powdery mildew resistance gene(s) in pea landraces. The full-length cDNA sequences of the er1 candidate gene，PsMLO1，from the resistant landraces were analyzed. To identify alleles and mining new alleles at er1 locus，the resulting sequences were compared with PsMLO1 cDNA sequences from the controls and wild-type pea cultivar Sprinter. The ultimate objectives of this study are to identify durable pea powdery mildew-resistant landraces，and lay the foundation for pea powdery mildew resistance breeding work of our province in the future.

白粉病是豌豆发生的重要病害之一，培育和推广抗病品种是持续控制豌豆白粉病流行危害最经济、安全、有效的措施。因此，开展豌豆抗病地方种质资源挖掘具有重要意义。已报道的豌豆白粉病抗性基因为隐性基因er1、er2和显性基因Er3。其中，er1抗性最为稳定，且受外界环境影响小，而er2则仅表现叶片抗性，且在发病严重时表现不耐病。本研究拟以7份甘肃豌豆地方品种资源为试材，通过不同豌豆白粉菌分离物接种进行抗白粉病表型鉴定，推导可能携带的抗病基因，并利用与抗白粉病基因紧密连锁SCAR标记进行抗病基因分子鉴定，探究抗病基因携带情况。同时对携带er1抗病基因的资源进行候选基因PsMLO1cDNA序列测定，与野生型序列比对，进行er1等位基因鉴定和新等位基因的挖掘，最终鉴定出具有持久抗性的地方抗病资源，为今后甘肃省豌豆抗白粉病育种工作奠定基础。

豌豆白粉病是由白粉菌（Erysiphe pisi DC.）引起的一种重要病害。控制豌豆白粉病最经济有效且环保的方法是抗病品种的应用。对 20个甘肃地方豌豆品种(系) 进行抗白粉病表型和标记基因型鉴定，结果显示，20个品种中，7个表现高抗（HR），9个品种表现抗病(R)，4个品种表现中抗(MR)；5个与豌豆抗白粉病基因 er1 连锁的 SCAR标记将20个豌豆品种(系) 区分为 4 个标记基因型。迄今， 2 个隐性抗白粉病基因 er1、er2 和一个显性抗白粉病基因 Er3 已在豌豆中被鉴定，其中 er1 基因在世界上被广泛应用于抗病品种培育。er1 基因隶属 MLO 基因家族，其抗性由豌豆 PsMLO1 基因座位功能丧失产生。每个er1等位基因都对应着不同的PsMLO1 同源基因突变位点和模式。PsMLO1 基因序列分析发现， 7个高抗豌豆品种含有3个已知的er1等位基因（er1-2，er1-6，er1-7）。这些研究结果为下一步提高对甘肃地方抗病资源的认识和豌豆分子辅助育种提供工具都具有重要作用。