剖析存在于黑山春小麦品系 PI 362698 中的多基因小麦秆锈病抗性。

Dissection of the multigenic wheat stem rust resistance present in the Montenegrin spring wheat accession PI 362698.

机构信息

Department of Plant Pathology, North Dakota State University, Fargo, ND, USA.

USDA-ARS, National Clonal Germplasm Repository, Corvallis, OR, USA.

出版信息

BMC Genomics. 2018 Jan 22;19(1):67. doi: 10.1186/s12864-018-4438-y.

DOI:10.1186/s12864-018-4438-y

PMID:29357813

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5776780/

Abstract

BACKGROUND

Research to identify and characterize stem rust resistance genes in common wheat, Triticum aestivum, has been stimulated by the emergence of Ug99-lineage races of the wheat stem rust pathogen, Puccinia graminis f. sp. tritici (Pgt), in Eastern Africa. The Montenegrin spring wheat landrace PI 362698 was identified as a source of Pgt resistance. This accession exhibits resistance to multiple Ug99-lineage and North American Pgt races at seedling and adult-plant stages. A recombinant inbred population was developed by crossing the susceptible line LMPG-6 with a single plant selection of PI 362698. A genetic map was constructed using the Illumina iSelect 90 K wheat assay and the markers csLv34, NB-LRR3, and wMAS000003 and quantitative trait locus (QTL) analysis was performed.

RESULTS

QTL analysis identified five significant QTLs (α = 0.05) on chromosomes 2B, 3B, 6A, 6D, and 7A associated with wheat stem rust resistance. The QTL on chromosome 3B was identified using both field data from Kenya (Pgt Ug99-lineage races) and seedling data from Pgt race MCCF. This QTL potentially corresponds to Sr12 or a new allele of Sr12. The multi-pathogen resistance gene Sr57 located on chromosome 7D is present in PI 362698 according to the diagnostic markers csLv34 and wMAS000003, however a significant QTL was not detected at this locus. The QTLs on chromosomes 2B, 6A, and 6D were identified during seedling trials and are thought to correspond to Sr16, Sr8a, and Sr5, respectively. The QTL identified on chromosome 7A was detected using MCCF seedling data and may be Sr15 or a potentially novel allele of recently detected Ug99 resistance QTLs.

CONCLUSIONS

The combination of resistance QTLs found in PI 362698 is like the resistance gene combination present in the broadly resistant cultivar Thatcher. As such, PI 362698 may not be a landrace as previously thought. PI 362698 has been crossed with North Dakota wheat germplasm for future breeding efforts. Additional work is needed to fully understand why the combination of genes present in PI 362698 and 'Thatcher' provide such durable resistance.

摘要

背景

由于乌加利-99 谱系的小麦秆锈病菌（Puccinia graminis f. sp. tritici，Pgt）在东非的出现，刺激了对普通小麦（Triticum aestivum）中鉴定和描述秆锈病抗性基因的研究。蒙蒂内格罗春小麦地方品种 PI 362698 被鉴定为 Pgt 抗性的来源。该品种在幼苗和成株期对多个乌加利-99 谱系和北美 Pgt 菌株表现出抗性。通过将易感系 LMPG-6 与 PI 362698 的单个植株选择杂交，开发了一个重组自交系群体。使用 Illumina iSelect 90K 小麦测定和标记 csLv34、NB-LRR3 和 wMAS000003 构建了遗传图谱，并进行了数量性状位点（QTL）分析。

结果

QTL 分析鉴定了与小麦秆锈病抗性相关的五个显著 QTL（α=0.05），位于染色体 2B、3B、6A、6D 和 7A 上。在肯尼亚（乌加利-99 谱系 Pgt 菌株）的田间数据和 Pgt 菌株 MCCF 的幼苗数据中都鉴定到了 3B 染色体上的 QTL。该 QTL 可能对应于 Sr12 或 Sr12 的新等位基因。7D 染色体上的 Sr57 是多病原体抗性基因，根据 csLv34 和 wMAS000003 这两个诊断标记，PI 362698 中存在该基因，但在该基因座上未检测到显著的 QTL。2B、6A 和 6D 染色体上的 QTL 是在幼苗试验中鉴定到的，分别被认为对应于 Sr16、Sr8a 和 Sr5。在 MCCF 幼苗数据中检测到的 7A 染色体上的 QTL 可能是 Sr15 或最近检测到的乌加利-99 抗性 QTL 的潜在新等位基因。

结论

PI 362698 中发现的抗性 QTL 组合与广泛抗性品种 Thatcher 中的抗性基因组合相似。因此，PI 362698 可能不像以前认为的那样是一个地方品种。PI 362698 已经与北达科他州的小麦种质杂交，用于未来的育种工作。需要进一步研究以充分了解为什么 PI 362698 和 'Thatcher' 中存在的基因组合提供如此持久的抗性。