Distribution and Nucleotide Diversity of Yr15 in Wild Emmer Populations and Chinese Wheat Germplasm
Distribution and Nucleotide Diversity of Yr15 in Wild Emmer Populations and Chinese Wheat Germplasm
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野生二粒小麦群体和中国小麦种质中Yr15的分布和核苷酸多样性
DOI：
10.3390/pathogens9030212
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发表时间：
2020-03-01
期刊：
影响因子：
3.7
通讯作者：
Fahima，Tzion
中科院分区：
文献类型：
--
作者：
He，Yu;Feng，Lihua;Fahima，Tzion
条锈病是由小麦条锈菌（Puccinia striiformis f.）小麦赤霉病（Pst）是小麦的一种毁灭性真菌病害。野生型emmer基因Yr15（Wtk1）是由激酶和假激酶结构域组成的，对Pst菌株具有广谱抗性。对361份野生二粒小麦种质资源的分析表明，Wtk 1主要沿沿着一条窄轴分布。从卡梅尔到以色列北方的赫尔蒙地区，那里的环境条件有利于条锈病的发生。对49份野生二粒小麦种质的Wtk1全长DNA序列进行分析，发现了3种单倍型和极低的核苷酸多样性（π = 0.00002）。Wtk1的序列多样性比广谱部分抗性基因Yr 36的低9.5倍（π = 0.00019），并且两者与先前报道的小种特异性抗性基因的高水平核苷酸多样性（例如，Lr 10和Pm 3）。然而，无功能的wtk1序列具有高水平的核苷酸多样性（π = 0.07）。这些结果可能反映了形成这些抗性基因的不同抗性机制和不同的进化过程。Yr15在189份中国小麦地方品种中缺失，在583份现代小麦品种中仅1.02%存在。这些结果证实了我们以前的结果，即在全球收集的513个小麦品种中，94%的品种中没有Yr 15，因此表明Yr 15在中国和地球仪的小麦抗条锈育种计划中的重要性。
Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating fungal disease of wheat. The wild emmer gene, Yr15 (Wtk1), which confers a strong broad-spectrum resistance to Pst isolates, is composed of kinase and pseudokinase domains. The analysis of 361 wild emmer accessions from a wide range of natural habitats confirms that functional Wtk1 is distributed mainly along a narrow axis from Mt. Carmel to Mt. Hermon regions, in the northern part of Israel, where environmental conditions are favorable to the onset of stripe rust. An analysis of full-length Wtk1 DNA sequences from 49 wild emmer accessions identified three haplotypes and extremely low nucleotide diversity (π = 0.00002). The sequence diversity of Wtk1 is 9.5 times lower than that of broad-spectrum partial resistance gene Yr36 (π = 0.00019), and both are in sharp contrast to the high level of nucleotide diversity previously reported for race-specific resistance genes (e.g., Lr10 and Pm3). However, the nonfunctional wtk1 sequences possess high level of nucleotide diversity (π = 0.07). These results may reflect the different resistance mechanisms and the different evolutionary processes that shaped these resistance genes. Yr15 was absent in 189 Chinese wheat landraces and was present in only 1.02% of the 583 tested modern Chinese wheat cultivars. These results corroborate our previous results showing that Yr15 was absent in 94% of a worldwide collection of 513 wheat cultivars, therefore indicating the importance of Yr15 in wheat stripe rust resistance breeding programs in China and elsewhere around the globe.