SCAR markers linked to Phytophthora capsici and Meloidogyne incognita resistance in Piper sp.

Abstract

Black pepper (Piper nigrum) cultivation suffers from pathogenic Phytophthora capsici and Meloidogyne incognita, causing tremendous yield loss. To solve this problem, genetically sustainable disease‐resistant accessions need to be selected and bred. However, the lack of genomic DNA data for Piper sp. could be a major obstacle. In this study, we created R‐pools and S‐pools from resistant and susceptible accessions in bulked segregant analysis (BSA), respectively, selected DNA fragments associated with resistance or susceptibility to P. capsici and M. incognita from RAPD markers and then converted them into SCAR markers. This is the first publication showing the potential of molecular markers, specifically the SCAR marker, to select Piper sp. accessions resistant to both P. capsici and M. incognita. Based on BSA, four RAPD primers were selected: UBC#377, UBC#359, UBC#360 and UBC#408. Five resistance and susceptibility‐specific fragments were isolated, cloned and sequenced to synthesize 16 SCAR primers. We converted the UBC#377 marker into a 46‐377F2R1 marker and the UBC#360 marker into a 30‐360F1R2 marker. While the 46‐377F2R1 marker has the potential to identify P. capsici‐resistant accessions with a 350 bp resistance‐associated band, the 30‐360F1R2 marker showed the potential to find M. incognita‐resistant accessions with a 230 bp resistance‐linked band.