Breeders typically use core collections of a specific trait or core collections selected by a few genotypes to efficiently select breeding materials or to study functional genes. As a result, many accessions have been deemed redundant or duplicated and are no longer considered for use. This study aimed to investigate the agronomical characteristics and genetic diversity of 1,514 previously unused and unstudied wheat germplasms and to confirm their value as breeding materials using population structure analysis. The performance of these wheat germplasms was compared with that of 8,878 wheat breeding materials and 72 known Korean wheat cultivars. The results of agronomic trait diversity comparison showed that the germplasm populations used for breeding research did not completely encompass the unused germplasm populations. The agronomic traits of wheat germplasms varied greatly. ANOVA and PCA results revealed the greatest differences in growth habits (CV=0.339), panicle length (CV=0.330), and awn length (CV=0.296). To accurately assess the value of unused wheat germplasms as breeding materials, 106 SSR markers were extracted from the analysis of four representative Korean cultivars: Geuru, Geumgang, Uri, and Jokyoung. Among these, 24 SSR markers were chosen, and 129 wheat resources were subjected to population structure analysis, which revealed five subpopulations. Most of the 34 germplasms that originated in Korea were distributed in subpopulation 1 (18 accessions, 52.9%) and subpopulation 4 (12 accessions, 35.3%). Subgroups 2, 3, and 5 differed significantly in agronomic traits and genotypes, indicating their potential as breeding materials. The findings of this study could serve as a foundation for breeders and aid in the discovery and utilization of new wheat breeding materials.

Pepper mild mottle virus (PMMoV), a member of the genus Tobamovirus, is one of the most threatening pathogens affecting commercial pepper production, and it is classified into pathotypes P_1,2 and P_1,2,3. As chemical and physical treatments show limited success in controlling PMMoV, resistant pepper varieties are considered the most effective means of disease control. Two hundred pepper germplasms, including 167 accessions of Capsicum chinense and 5 reference accessions known as resistant L alleles, were assessed using a bioassay to select germplasms resistant to PMMoV. Six accessions, including IT261210, were resistant to both PMMoV pathotypes P_1,2 and P_1,2,3 as they developed necrotic local lesions only on inoculated leaves, whereas no symptoms were observed on the upper leaves. Moreover, RT-PCR results of the upper leaves of these accessions were also negative. Thus, the identified accessions may be a novel source of genetic resistance against present or emerging new pathotypes and may be useful for differentiating L alleles.

In this study, watermelon accessions introduced from the USDA were characterized for 12 morphological characteristics of leaf, flower, fruit, and seed, according to the National Agrobiodiversity Center descriptor list. In addition, to confirm the genetic composition of each watermelon accession, genetic profiling was performed using 20 simple sequence repeat (SSR) markers. A total of 154 watermelon accessions from the USDA were collected from 31 different countries, among which, 12.3% (19 accessions) were from Turkey. Morphological characterization revealed that the accessions displayed a large diversity. Genetic profiling using 20 SSR markers showed that six accessions (K192117, K192028, K193400, K192376, K192499, and K192800) were expected to be inbred lines among the 154 watermelon accessions. The 12 characters scored were analyzed using discriminant analysis of principal components (DAPC). The result revealed 68.1% of the total variability and indicated variations among accessions, mainly based on fruit stripes and fruit shape along the longitudinal section. The accessions were divided into eight groups according to DAPC, although the geographical origin was not a great source for the grouping. Our results will be helpful for the efficient management of germplasms and in understanding and selecting watermelon accessions for the breeding process.