Cultivated peanut (Arachis hypogaea L.) is one of the most important oilseed crops worldwide. Pod-related traits, including pod length (PL), pod width (PW), ratio of PL to PW (PL/W) and 100-pod weight (100-PW), are crucial factors for pod yield and are key target traits for selection in peanut breeding. However, the studies on the natural variation and genetic mechanism of pod-related traits are not clear in peanut. In this study, we phenotyped 136 peanut accessions for four pod-related traits in two consecutive years and genotyped the population using a re-sequencing technique. Based on 884,737 high-quality single nucleotide polymorphisms (SNPs), genome-wide association studies (GWAS) were conducted for four pod-related traits using a fixed and random model uniform cyclic probability (FarmCPU) model. The results showed that a total of 36 SNPs were identified by GWAS, among which twenty-one, fourteen and one SNPs were significantly associated with PL, PL/W and 100-PW, respectively. The candidate regions where the four peak SNPs (10_76084075, 11_138356586, 16_64420451, and 18_126782541) were located were used for searching genes, and nineteen candidate genes for pod-related traits were preliminarily predicted based on functional annotations. In addition, we also compared the expression patterns of these nineteen candidate genes in different tissues of peanut, and we found that eight genes were specifically highly expressed in tender fruit, immature pericarp, or seed, so we considered these genes to be the potential candidate genes for pod-related traits. These results enriched the understanding of the genetic basis of pod-related traits and provided an important theoretical basis for subsequent gene cloning and marker-assisted selection (MAS) breeding in peanut.

Arachis pintoi Krapov. & W.C.Greg. is an important leguminous forage grass species that have extremely wide ranges of distribution in the tropical and sub-tropical regions. It has high feeding value and horticultural value. In this study, we sequenced and assembled the complete chloroplast genome of A. pintoi. The chloroplast genome is 156,185 bp in length, containing a pair of inverted repeated (IR) regions of 25,820 bp that are separated by a large single copy (LSC) region of 85,637 bp, and a small single copy (SSC) region of 18,908 bp. The complete chloroplast genome contains 112 unique genes, including 80 protein-coding genes, 28 transfer RNA genes (tRNAs), and four ribosomal RNA genes (rRNAs). The overall GC content was 36.4%. The phylogenetic analysis demonstrated that A. pintoi formed a single branch among genus Arachis. The whole chloroplast genome of A. pintoi will be a useful resource for future studies on phylogeny and conservation in Arachis.

Chenopodium album is an annual herb from Amaranthaceae with worldwide distribution. It is a leafy vegetable as well as an important subsidiary grain crop with high nutritional value and medicinal value. In this study, we reported the complete chloroplast genome of C. album. The total chloroplast genome was 152,167 bp in length, containing a large single-copy region (LSC, 83,676 bp), a small single-copy region (SSC, 18,105 bp), and a pair of inverted repeat regions (IRs, 25,193 bp). The complete chloroplast genome contains 110 genes, including 78 protein-coding genes, 28 transfer RNA (tRNA) genes, and 4 ribosomal RNA (rRNA) genes with an overall GC content of 37.3%. Phylogenetic analysis showed that C. album was sister to C. acuminatum within Chenopodioideae. The complete chloroplast genome of C. album will provide useful resources for the development and utilization of this species and the phylogenetic study of Amaranthaceae.