APPLIED POWDERY MILDEW RESISTANCE BREEDING IN ROSES

Powdery mildew of wheat, caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive disease of wheat. Cultivation of resistant varieties is the most cost-effective disease management strategy. Previous studies reported that chromosome 3Sl#2 present in Chinese Spring (CS)-Aegilops longissima 3Sl#2(3B) disomic substitution line TA3575 conferred resistance to powdery mildew. In this study, we further located the powdery mildew resistance gene(s) to the short arm of chromosome 3Sl#2 (3Sl#2S) by evaluating for Bgt-resistance of newly developed CS-Ae. longissima 3Sl#2 translocation lines. Meanwhile, TA7545, a previously designated CS-Ae. longissima 3Sl#3 disomic addition line, was re-identified as an isochromosome 3Sl#3S addition line and evaluated to confer resistance to powdery mildew, thus locating the resistance gene(s) to the short arm of chromosome 3Sl#3 (3Sl#3S). Based on transcriptome sequences of TA3575, ten novel chromosome 3SlS-specific markers were developed, of which, five could be used to distinguish between 3Sl#2S and 3Sl#3S derived from Ae. longissima accessions TL20 and TA1910 (TAM4), and the remaining five could identify both 3Sl#2S and 3Sl#3S. Besides, CL897, one of five markers specific to both 3Sl#2S and 3Sl#3S, could be used to detect Pm13 located at chromosome 3Sl#1S from Ae. longissima accession TL01 in diverse wheat genetic backgrounds. The powdery mildew resistance genes on chromosomes 3Sl#2S and 3Sl#3S, the CS-Ae. longissima 3Sl#2 translocation lines, and the 3SlS-specific markers developed in this study will provide new germplasm resources for powdery mildew resistance breeding and facilitate the transfer of Bgt-resistance genes into common wheat.

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Introgression of the Powdery Mildew Resistance Genes Pm60 and Pm60b from Triticum urartu to Common Wheat Using Durum as a ‘Bridge’

Pathogens ◽

10.3390/pathogens11010025 ◽

2021 ◽

Vol 11 (1) ◽

pp. 25

Author(s):

Qiang Zhang ◽

Yinghui Li ◽

Yiwen Li ◽

Tzion Fahima ◽

Qian-Hua Shen ◽

...

Keyword(s):

Molecular Markers ◽

Powdery Mildew ◽

Common Wheat ◽

Resistance Genes ◽

Powdery Mildew Resistance ◽

Resistance Breeding ◽

Introgression Lines ◽

Synthetic Hexaploid Wheat ◽

Triticum Urartu ◽

Mildew Resistance

Powdery mildew, caused by the fungus Blumeria graminis f. sp. tritici (Bgt), has limited wheat yields in many major wheat-production areas across the world. Introducing resistance genes from wild relatives into cultivated wheat can enrich the genetic resources for disease resistance breeding. The powdery mildew resistance gene Pm60 was first identified in diploid wild wheat Triticum urartu (T. urartu). In this study, we used durum as a ‘bridge’ approach to transfer Pm60 and Pm60b into hexaploid common wheat. Synthetic hexaploid wheat (SHW, AABBAuAu), developed by crossing T. urartu (AuAu) with durum (AABB), was used for crossing and backcrossing with common wheat. The Pm60 alleles were tracked by molecular markers and the resistance to powdery mildew. From BC1F1 backcross populations, eight recombinant types were identified based on five Pm60-flanking markers, which indicated different sizes of the introgressed chromosome segments from T. urartu. Moreover, we have selected two resistance-harboring introgression lines with high self-fertility, which could be easily used in wheat breeding system. Our results showed that the durum was an excellent ‘bridge’ for introducing the target gene from diploid T. urartu into the hexaploid cultivated wheat. Moreover, these introgression lines could be deployed in wheat resistance breeding programs, together with the assistance of the molecular markers for Pm60 alleles.

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Inheritance of er1-Based Broad-Spectrum Powdery Mildew Resistance in Pea (Pisum sativum L.)

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha4129144 ◽

2013 ◽

Vol 41 (2) ◽

pp. 485 ◽

Cited By ~ 1

Author(s):

Muhammad Abubakkar AZMAT ◽

Asif Ali KHAN

Keyword(s):

Powdery Mildew ◽

Broad Spectrum ◽

Powdery Mildew Resistance ◽

Resistance Breeding ◽

Disease Assessment ◽

Mildew Resistance ◽

Disease Response ◽

Broad Spectrum Resistance ◽

Recessive Form ◽

Highly Virulent

The knowledge about the nature and number of gene(s) controlling resistance is the pre-requisite for the success of powdery mildew resistance breeding program in pea. Seven biparental cross combinations involving three highly resistant (It-96, No. 267 and JI 2302) and two highly susceptible (Climax and PF-400) pea genotypes were evaluated for their response to powdery mildew disease. The quantitative microscopic scale of disease assessment coupled with detached leaf assay was employed for the evaluation of disease response of the crosses and their generations (F1, F2, BCs, and BCr) against two highly virulent conidial isolates of Erysiphe pisi. The disease response of 677 F2 plants has revealed a typical monohybrid Mendelian 3 (susceptible): 1 (resistant) segregation, moreover, the evaluation of 254 BCr plants gave a perfect 1 (susceptible): 1(resistant) segregation. No complementation was observed among all the F1 plants of three complementation crosses, suggesting that the same allele (er-1) conditions complete and broad-spectrum resistance in all the powdery mildew resistant pea genotypes in homozygous recessive form.

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