Identification and molecular mapping of PmHNK54: a novel powdery mildew resistance gene in common wheat

Abstract

Powdery mildew of wheat is caused by Blumeria graminis (DC.) Speer f. sp. tritici (Bgt). Wheat line Zheng 9754 is resistant in Henan Province. In seedling tests with seven Bgt isolates, Zheng 9754 had a different reaction pattern from those of lines Khapli with Pm4a, Armada with Pm4b, 81-7241 with Pm4c and Lankao 906 with PmLK906. F 1 hybrids, 516 F 2 plants and 327 F 2:3 lines derived from Zheng 9754/Chinese Spring (CS) were used for resistance gene tagging and linkage analysis. Simple sequence repeat (SSR) markers were used to test the two parents and resistant and susceptible bulks. Subsequently, three polymorphic markers were used for genotyping the F 2 and F 2:3 populations. Powdery mildew resistance in Zheng 9754 was conferred by a single dominant gene, tentatively designated PmHNK54, flanked by SSR markers Xgwm312, Xgwm372 and Xbarc5 on chromosome 2AL. The resistance gene was closely linked to Xbarc5 and Xgwm312, with genetic distances of 5.0 and 6.0 cM, respectively, and located on the chromosome bin 2AL-1-0.85 in the test with a set of deletion lines. The results suggested that PmHNK54 in Zheng 9754 is a new powdery mildew resistance gene in common wheat.

Identification, High-Density Mapping, and Characterization of New Major Powdery Mildew Resistance Loci From the Emmer Wheat Landrace GZ1

“…To date, eight powdery mildew resistance genes have been identified on chromosome 2AL. These include formally named multi-allelic Pm4 (Briggle, 1966), and tentatively designated genes for powdery mildew such as PmLK906 (Niu et al, 2008), PmHNK54 (Xu et al, 2011), PmPS5A (Zhu et al, 2005, PmYm66 (Hu, 2008), Pm50 (Mohler et al, 2013), PmHo (Komáromi et al, 2016), and pmX (Fu et al, 2013). Pm4 consists of four resistance alleles Pm4a, Pm4b, Pm4c, and Pm4d (The et al, 1979;Hao et al, 2008;Schmolke et al, 2011).…”

“…The direct comparison revealed that only PmHNK54, which was located together with QPm.GZ1-2A between the Xbarc5 and Xgwm312 markers maps to the same region (Figure 4). However, this gene was found to be dominant (Xu et al, 2011), whereas GZ1 resistance was so far characterized as recessive. Therefore, QPm.GZ1-2A is distinguishable from PmHNK54.…”

“…Since genes from the signaling pathways are mostly dominant R-genes (e.g., Peart et al, 2005;Sánchez-Martín et al, 2016), there is only a small probability that the recessive QPm.GZ1-2A is one of them. However, one of them could be the PmHNK54 gene (Xu et al, 2011). Nevertheless, confirmation of the assumptions would require further work.…”

Identification of a Pm4 Allele as a Powdery Mildew Resistance Gene in Wheat Line Xiaomaomai

“…In addition, the two alleles Pm4c and Pm4e were detected in common wheat cultivars [18,19]. Besides the Pm4 locus, few other genes were also mapped to chromosome 2AL and demonstrated to be allelic or closely linked to Pm4, such as PmPS5A [20], pmLK906 [21], PmHNK54 [22], pmX [23], and Pm50 [24]. Therefore, they have been considered to be members of the Pm4 locus.…”

The gene PmYB confers broad-spectrum powdery mildew resistance in the multi-allelic Pm2 chromosome region of the Chinese wheat cultivar YingBo 700

“…In China, some cultivars have been reported to show resistance to powdery mildew by a large number of powdery mildew isolates Song et al 2012). On chromosome arm 2AL, two Pm genes PmYm66 linked to Ksum193 and PmHNK54 flanked by Barc5 and Gwm312 were identified in Yumai 66 and Zheng 9754, respectively (Hu et al 2008a;Xu et al 2011). In Tangmai 4, the Pm gene PmTm4 was flanked by Gwm611 and EST92 on chromosome arm 7BL (Hu et al 2008b).…”