University of Arkansas, Fayetteville, AZ, USA.
Phytopathology. 2012 Jul;102(7):700-6. doi: 10.1094/PHYTO-02-12-0026-R.
The Pib gene in rice confers resistance to a wide range of races of the rice blast pathogen, Magnaporthe oryzae, including race IE1k that overcomes Pita, another broad-spectrum resistance gene. In this study, the presence of Pib was determined in 164 rice germplasm accessions from a core subset of the National Small Grains Collection utilizing DNA markers and pathogenicity assays. The presence of Pib was evaluated with two simple sequence repeat (SSR) markers and a dominant marker (Pib-dom) derived from the Pib gene sequence. Pathogenicity assays using two avirulent races (IE1k and IB1) and a virulent race (IB54) were performed to verify the resistance responses of accessions. Of the 164 accessions evaluated, 109 contained the Pib gene as determined using both SSR markers and pathogenicity assays, albeit different haplotypes were detected. The remaining 52 germplasm accessions were different in their responses to the blast races IB54, IE1k, and IB1, thus indicating the presence of R gene(s) other than Pib. The accessions characterized in this study could be used for marker-assisted breeding to improve blast resistance in indica and japonica cultivars worldwide.
水稻中的 Pib 基因赋予了对稻瘟病菌（Magnaporthe oryzae）广泛菌株的抗性，包括克服 Pita 的 IE1k 菌株，后者是另一个广谱抗性基因。在这项研究中，利用 DNA 标记和致病性测定，从国家小谷物核心收集品系中鉴定了 164 份水稻种质资源品系中 Pib 的存在。使用两个简单重复序列（SSR）标记和源自 Pib 基因序列的显性标记（Pib-dom）评估 Pib 的存在。使用两个无毒菌株（IE1k 和 IB1）和一个有毒菌株（IB54）进行致病性测定，以验证品系的抗性反应。在所评估的 164 个品系中，使用两种 SSR 标记和致病性测定均确定 109 个品系含有 Pib 基因，尽管检测到不同的单倍型。其余 52 个种质资源品系对 IB54、IE1k 和 IB1 三种菌株的反应不同，因此表明存在除 Pib 之外的 R 基因。本研究中鉴定的品系可用于标记辅助育种，以提高全球籼稻和粳稻品种的稻瘟病抗性。
