Pleurotus eryngii, an edible white-rot fungus, is widespread in Eurasia and northern Africa. It has become a major cultivated mushroom in Asia, with a current global production rate of approximately 3 × 10 5 metrictons/yr. To improve the quality or productivity through breeding, a genetic linkage map is an important component. In this study, genetic linkage map of the P. eryngii was constructed using 98 monokaryotic progeny derived from dikaryon of parental KNR2312 strain derived from haploid meiotic spores. The whole genome sequence of P5 monokaryon from P. eryngii KNR2312 strain by Next Generation Sequencing (NGS) strategy was used to design the SSR markers. 484 primers pairs were identified by SSR Locator I and tested polymorphism via PCR. A total of 241 loci were mapped using Joinmap 4.0, comprising 222 SSR markers, 2 mating type factors, and the 13 INDEL markers. The map consisted of 14 linkage groups spanning 1003 cM at an average marker interval of 4.2 cM. The mating loci, A and B were mapped on linkage groups 4 and 11, respectively. The established linkage map and the genetic information based on NGS could be used for QTL mapping of agronomic traits, marker-assisted breeding that may ultimately lead to outstanding phenotypic characteristics. [Supported by a grant from the IPET (213003-04-3-SBY20), MIFAFF, Republic of Korea.]

Differentiation of Pleurotus eryngii is laborious and time-consuming tasks especially in mycelial status. For development of a method for differentiation of P. eryngii cultivars, simple sequence repeats (SSR) from whole genomic DNA sequence analysis was used for genotyping and two multiplex-SSR primer sets were developed. These SSR primer sets were employed to distinguish 12 cultivars and strains. Five polymorphic markers were selected based on the genotypes. PCR with the each primer produced one to four distinct bands ranging in size from 200 to 300 bp. Polymorphism information content (PIC) values of the five markers were in range of 0.6627 to 0.6848 with an average of 0.6775. Unweighted pair-group method with arithmetic mean clustering analysis based on genetic distances using five SSR markers classified 12 cultivars into 2 clusters. Cluster I and II comprised of 4 and 8 cultivars, respectively. Two multiplex sets, Multi-1 (SSR312 and SSR366) and Multi-2 (SSR178 and SSR277) completely discriminated 12 cultivar and strains with 21 allele with a PIC value of 0.9090. These results might be useful to provide an efficient method for the identification of P. eryngii cultivars with separate PCR reactions. (This work was supported by a grant from the Gold Seed Project [Supported by a grant from the IPET (213003-04-3-WTI11), MIFAFF, Republic of Korea.]

In Korea, chilli pepper (Capsicum annum L.) is a major vegetable crop. The pepper seed market is about $35 million and the whole sale market including processed products is equivalent to $2 billion, representing the second highest market value among crops, next to rice in Korea. Since the development of elite pepper variety is so competitive, vegetable seed companies usually run two important programs to keep the credibility of seed quality. One program is to deliver F1 hybrid seeds with a high purity test to farmers. The purity control of parents and F1 hybrid to avoid any contamination is conducted by DNA markers because pepper seeds are obtained using MS line. The other program is to identify the F1 variety from other varieties by analyzing the polymorphism so that the company and/or breeder protects the intellectual property from copying by others or from non-intentional contamination. We have developed about 900 EST-SSR sets from pepper and used to both programs. A total of 66 markers were selected to identify 32 F1 varieties and their own parents. Using these markers, the purity control of F1 hybrid rose up to the highest degree. We also found several SSR markers to distinguish F1 variety from other varieties and these markers could be useful to find the uniqueness of F1 cultivar.