Peanut, an important oilseed crop cultivated worldwide as a dietary food, is a good food source with health benefits. To explore the potential benefits of peanuts as a food resource, 301 peanut accessions were evaluated to determine the effect of seed weight and genotype on total oil content and fatty acid composition. Total oil was extracted using the Soxhlet method and fatty acids were analyzed by gas chromatography mass spectrometry. Wide variations in the 100-seed weight, total oil content, and fatty acid profile were observed among genotypes and accession types. An effect of seed weight on the fatty acid composition of peanut seeds was observed. Increases in the oleic acid content and decreases in the linoleic acid content occurred in association with increases in the 100-seed weight. Moreover, the 100-seed weight, total oil content, and individual and total fatty acid contents, except arachidic acid, differed significantly (p < 0.001 or 0.05) among the accession types of landrace, cultivar, breeding line, and unknown. The discovery of this high diversity could contribute to further studies of peanut domestication and evolutionary classification. Our findings are important for the selection of peanut seeds with health benefits and development of new varieties of peanut with health benefits.

Melon (Cucumis melo L.) is an economically important horticultural crop with abundant morphological and genetic variability. Complex genetic variations exist even among melon varieties and remain unclear to date. Therefore, unraveling the genetic variability among the three different melon varieties, muskmelon (C. melo subsp. melo), makuwa (C. melo L. var. makuwa), and cantaloupes (C. melo subsp. melo var. cantalupensis), could provide a basis for evolutionary research. In this study, we attempted a systematic approach with genotyping-by-sequencing (GBS)-derived single nucleotide polymorphisms (SNPs) to reveal the genetic structure and diversity, haplotype differences, and marker-based varieties differentiation. A total of 6406 GBS-derived SNPs were selected for the diversity analysis, in which the muskmelon varieties showed higher heterozygote SNPs. Linkage disequilibrium (LD) decay varied significantly among the three melon varieties, in which more rapid LD decay was observed in muskmelon (r² = 0.25) varieties. The Bayesian phylogenetic tree provided the intraspecific relationships among the three melon varieties that formed, as expected, individual clusters exhibiting the greatest genetic distance based on the posterior probability. The haplotype analysis also supported the phylogeny result by generating three major networks for 48 haplotypes. Further investigation for varieties discrimination allowed us to detect a total of 52 SNP markers that discriminated muskmelon from makuwa varieties, of which two SNPs were converted into cleaved amplified polymorphic sequence markers for practical use. In addition to these markers, the genome-wide association study identified two SNPs located in the genes on chromosome 6, which were significantly associated with the phenotypic traits of melon seed. This study demonstrated that a systematic approach using GBS-derived SNPs could serve to efficiently classify and manage the melon varieties in the genebank.

Tea has received attention due to its phytochemicals. For the direct use of tea germplasm in breeding programs, a core collection that retains the genetic diversity and various phytochemicals in tea is needed. In this study, we evaluated the content of eight phytochemicals over two years and the genetic diversity through 33 SSR (simple sequence repeats) markers for 462 tea accessions (entire collection, ENC) and developed a target-oriented core collection (TOCC). Significant phytochemical variation was observed in the ENC between genotypes and years. The genetic diversity of ENC showed high levels of molecular variability. These results were incorporated into developing TOCCs. The TOCC showed a representation of the ENC, where the mean difference percentage, the variance difference percentage, the variable rate of coefficient of variance percentage, and the coincidence rate of range percentage were 7.88, 39.33, 120.79, and 97.43, respectively. The Shannon’s diversity index (I) and Nei’s gene diversity (H) of TOCC were higher than those of ENC. Furthermore, the accessions in TOCC were shown to be selected proportionally, thus accurately reflecting the distribution of the overall accessions for each phytochemical. This is the first report describing the development of a TOCC retaining the diversity of phytochemicals in tea germplasm. This TOCC will facilitate the identification of the genetic determinants of trait variability and the effective utilization of phytochemical diversity in crop improvement programs.

Safflower is an important oilseed crop cultivated primarily for its seeds, which have pharmaceutical properties. Color is an important agronomical trait that appears to be a prior parameter for evaluating the internal quality of plant seeds. This study employs 197 safflower accessions seeds to analyze how their seed coat and flower colors affect their total oil content, fatty acid composition, total phenolic content (TPC), N-(p-coumaroyl)serotonin (CS) and N-feruloylserotonin (FS) contents, and [2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)] radical scavenging activities. Significant variations were observed in the targeted metabolite contents and antioxidant properties among genotypes. Notably, the linoleic acid content, total unsaturated fatty acid content, the ratio of total unsaturated fatty acid to total saturated fatty acid, CS, FS, ABTS, and DPPH scavenging capacities varied significantly based on seed coat color, with white-seeded genotypes having the highest average values of these parameters. Moreover, the linoleic acid content differed significantly (p < 0.05) among the genotypes with varying flower colors, with white-flowered accessions having the highest average content. Furthermore, genotypes K185105 (No. 75) and K175278 (No. 146) were identified as promising genetic resources with health benefits. Overall, these findings reveal that seed coat and flower colors distinctly affect metabolite contents and antioxidant properties in safflower seeds.

Wheat is one of the most important food crops worldwide. Numerous studies have shown that genetic diversity lost the process of wheat breeding because of the pursuit of earlier heading date and higher yield. Reduced genetic diversity leads to decreased adaptability to the environment and resistance to pests and diseases posing a serious threat to wheat production safety. This study investigated the genetic diversity of a global wheat collection stored at the National Agrobiodiversity Center of South Korea. A total of 397 global wheat core collections were selected from 19,698 accessions, with associated traits accumulated from 1984 to 2017. The genetic diversity of the core collections was analyzed using 198 neutral SNPs and KASP markers to explore the population structure and genetic diversity within the global wheat collection. The results indicate that cultivars developed in the past decade exhibit higher genetic diversity than both the cultivars deposited before 2015 and the landraces. This suggests that the genetic diversity observed in the newly developed cultivars may originate from the introduction of novel wild germplasms or artificially induced mutant breeding materials. In addition, the traits prediction system established using the KASP marker genotyping results can explain 52.7% of the heading date variation and 42.9% of the 1000-grain weight variation. Overall, this study monitored the genetic diversity of wheat cultivars bred in the past decade and concluded that modern wheat breeding model have reversed the trend of continuous reduction in genetic diversity of cultivars. The trait prediction system established using KASP markers could provide a platform for the selection of new wheat materials for future breeding.