Glucosinolates are sulfur-containing phytochemicals generally abundant in cruciferous vegetables such as pak choy. Glucosinolates participate in a range of biological activities essential for promoting a healthy human body. In this study, we aimed to elucidate glucosinolate variability present in pak choy germplasm that are under conservation at the Rural Development Administration Genebank, Jeonju, Republic of Korea. The Acquity Ultra-Performance Liquid Chromatography (UHPLC) analytical system was used in profiling the glucosinolate content in leaf samples of various accessions. We identified a total of 17 glucosinolates in the germplasm. Based on principal compoment analysis performed, three separate groups of the accessions were obtained. Group 1 contained the cultivar cheongsacholong which recorded high content of glucobrassicin (an indole), glucoerucin (aliphatic), gluconasturtiin (aromatic) and glucoberteroin (aliphatic). Group 2 consisted of six accessions, BRA77/72, Lu ling gaogengbai, 9041, Wuyueman, RP-75 and DH-10, predominatly high in aliphatic compounds including glucoiberin, glucocheirolin, and sinigrin. Group 3 comprised the majority of the accessions which were characterized by high content of glucoraphanin, epiprogoitrin, progoitrin, and glucotropaeolin. These results revealed the presence of variability among the pak choy germplasm based on their glucosinolate content, providing an excellent opprtunity for future breeding for improved glucosinolate content in the crop.

In this study, the variability of major glucosinolates in the leaf lamina of 134 Chinese cabbage accessions was investigated using Acquity ultra-performance liquid chromatography (UPLC-ESI-MS/MS). A total of twenty glucosinolates were profiled, of which glucobrassicanapin and gluconapin were identified as the predominant glucosinolates within the germplasm. These two glucosinolates had mean concentration levels above 1000.00 μmol/kg DW. Based on the principal component analysis, accessions IT186728, IT120044, IT221789, IT100417, IT278620, IT221754, and IT344740 were separated from the rest in the score plot. These accessions exhibited a higher content of total glucosinolates. Based on the VIP values, 13 compounds were identified as the most influential and responsible for variation in the germplasm. Sinigrin (r = 0.73), gluconapin (r = 0.78), glucobrassicanapin (r = 0.70), epiprogoitrin (r = 0.73), progoitrin (r = 0.74), and gluconasturtiin (r = 0.67) all exhibited a strong positive correlation with total glucosinolate at p < 0.001. This indicates that each of these compounds had a significant influence on the overall glucosinolate content of the various accessions. This study contributes valuable insights into the metabolic diversity of glucosinolates in Chinese cabbage, providing potential for breeding varieties tailored to consumer preferences and nutritional demands.

Proso millet (Panicum miliaceum L.) or broomcorn millet is among the most important food crops to be domesticated by humans; it is widely distributed in America, Europe, and Asia. In this study, we genotyped 578 accessions of P. miliaceum using 37 single-sequence repeat (SSR) markers, to study the genetic diversity and population structure of each accession. We also investigated total phenolic content (TPC) and superoxide dismutase (SOD) activity and performed association analysis using SSR markers. The results showed that genetic diversity and genetic distance were related to geographic location and the fixation index (Fst). Population structure analysis divided the population into three subpopulations. Based on 3 subpopulations, the population is divided into six clusters in consideration of geographical distribution characteristics and agronomic traits. Based on the genetic diversity, population structure, pairwise Fst, and gene flow analyses, we described the topological structure of the six proso millet subpopulations, and the geographic distribution and migration of each cluster. Comparison of the published cluster (cluster 1) with unique germplasms in Japan and South Korea suggested Turkey as a possible secondary center of origin and domestication (cluster 3) for the cluster. We also discovered a cluster domesticated in Nepal (cluster 6) that is adapted to high-latitude and high-altitude cultivation conditions. Differences in phenotypic characteristics, such as TPC, were observed between the clusters. The association analysis showed that TPC was associated with SSR-31, which explained 7.1% of the total variance, respectively. The development of markers associated with TPC and SOD will provide breeders with new tools to improve the quality of proso millet through marker-assisted selection.

Lettuce (Lactuca sativa) is a globally significant leafy vegetable, valued for both its economic and nutritional contributions. The efficient conservation and use of the lettuce germplasm are crucial for breeding and genetic improvement. This study examined the genetic diversity and population structure of a core collection of the lettuce germplasm using genotyping by sequencing (GBS). A total of 7136 high-quality single-nucleotide polymorphisms (SNPs) were identified across nine chromosomes. Population analysis through Bayesian clustering and discriminant analysis of principal components (DAPC) revealed three distinct genetic clusters. Cluster 2 exhibited the greatest genetic diversity (He = 0.29, I = 0.44), while Cluster 3 had high levels of inbreeding (F = 0.79). Agro-morphological trait evaluation further identified significant differences in leaf length, plant weight, and head height across clusters. These findings provide valuable insights into the genetic and phenotypic diversity of lettuce, facilitating the development of more robust breeding programs. Additionally, the core collection established in this study offers a representative subset of the lettuce germplasm for future genomic research and conservation efforts.

This study evaluated glucosinolate (GSL) composition and phenotypic traits in 72 radish (Raphanus sativus L. var. sativus) accessions, including 69 germplasm and 3 cultivars. Seven GSLs: glucoraphanin, glucoraphenin, glucoerucin, glucoraphasatin, glucobrassicin, glucobarbarin, and glucoberteroin were quantified using UPLC (mg/kg DW). Under the evaluated conditions, accession 10 (IT203308, Russia) showed high glucobarbarin (3976.9), while 38 (IT262009, Germany) and 39 (IT262067, North Korea) accumulated glucoraphasatin above 3500. Accession 40 (IT262091, North Korea) exhibited the highest glucoraphenin (612.9), and glucoerucin was enriched in 12 (IT204244, Israel), 19 (IT215036, Republic of Korea), and 35 (IT261962, Russia). Principal component analysis identified outliers: 10 (IT203308, Russia), 12 (IT204244, Israel), 19 (IT215036, Republic of Korea), 35 (IT261962, Russia), 38 (IT262009, Germany), 40 (IT262091, North Korea), 34 (IT261948, Kyrgyzstan), and 59 (IT306725, Malaysia), separated from central accessions. Multivariate analyses indicated that GSL accumulation and phenotypic variation were not consistently associated. These findings identify high-GSL and PCA-defined outlier accessions as potential donor resources for the breeding of radish with improved glucosinolate-related nutritional quality, while demonstrating that glucosinolate profiles cannot be reliably predicted from external phenotypes.