Genotyping by Sequencing-Based Discovery of SNP Markers and Construction of Linkage Map from F5 Population of Pepper with Contrasting Powdery Mildew Resistance Trait.

Eun-Young Yang,Tae-Hwan Jun,Yul-Kyun Ahn,Do-Sun Kim,Abinaya Manivannan,Sena Choi,Jin-Hee Kim,Eun-Su Lee,Hye-Eun Lee,Gustavo Graciano Fonseca

doi:10.1155/2021/6673010

Abstract

Powdery mildew (PM) is a common fungal disease infecting pepper plants worldwide. Molecular breeding of pepper cultivars with powdery mildew resistance is desirable for the economic improvement of pepper cultivation. In the present study, 188 F5 population derived from AR1 (PM resistant) and TF68 (PM sensitive) parents were subjected to high-throughput genotyping by sequencing (GBS) for the identification of single nucleotide polymorphism (SNP) markers. Further, the identified SNP markers were utilized for the construction of genetic linkage map and QTL analysis. Overall read mapping percentage of 87.29% was achieved in this study with the total length of mapped region ranging from 2,956,730 to 25,537,525 bp. A total of 41,111 polymorphic SNPs were identified, and a final of 1,841 SNPs were filtered for the construction of a linkage map. A total of 12 linkage groups were constructed corresponding to each chromosome with 1,308 SNP markers with the map length of 2506.8 cM. Further, two QTLs such as Pm-2.1 and Pm-5.1 were identified in chromosomes 2 and 5, respectively, for the PM resistance. Overall, the outcomes of the present endeavor can be utilized for the marker-assisted selection of pepper with powdery mildew-resistant trait.

Highlights

Powdery mildew (PM) is a widely occurring disease in Solanaceae plants caused by an obligate fungus Leveillula taurica (Lev.) from the ascomycete family
A total of 188 F5 population were inoculated with the fungus, and the disease symptoms occurred after 20 days of inoculation
The disease index (DI) was classified in the scale of 0-4 denoting resistance to sensitive based on the percentage of plants affected (Figure 1)

Summary

Introduction

Powdery mildew (PM) is a widely occurring disease in Solanaceae plants caused by an obligate fungus Leveillula taurica (Lev.) from the ascomycete family. The incidence of powdery mildew has been rising in both greenhouse and field grown pepper plants [1]. The inevitable requirement of genetic resistance lines to powdery mildew arises. In order to provide a more rapid solution, the molecular marker-assisted breeding aided by modern sequencing technologies is evolving as the current breeding method of choice. Among the NGS approaches, genotyping by sequencing (GBS) has been noted for its wide-range utilization for high-throughput analysis [6]. This process employs restriction enzyme-based complexity reduction coupled with

Methods

Results

Discussion

Conclusion