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Jatropha curcas L. is a potential bioenergy crop but has a lack of improved cultivars with high yields and oil content. Therefore, increasing our understanding of J. curcas germplasm is important for designing breeding strategies. This study was performed to investigate the genetic diversity and population structure of Indonesian J. curcas populations from six different islands. To construct a reference, we de novo assembled the scaffolds (N50 = 355.5 kb) using 182 Gb Illumina HiSeq sequencing data from Thai J. curcas variety Chai Nat. Genetic diversity analysis among 52 Indonesian J. curcas accessions was conducted based on yield traits and single nucleotide polymorphism (SNP) markers detected by mapping genotyping-by-sequencing reads from Indonesian population to Chai Nat scaffolds. Strong variation in yield traits was detected among accessions. Using J. integerrima as an outgroup, 13,916 SNPs were detected. Among J. curcas accessions, including accessions from other countries (Thailand, the Philippines and China), 856 SNPs were detected, but only 297 SNPs were detected among Indonesian J. curcas populations, representing low genetic diversity. Through phylogenetic and structural analysis, the populations were clustered into two major groups. Group one consists of populations from Bangka and Sulawesi in the northern part of Indonesia, which are located at a distance of 1572.59 km. Group two contains populations from islands in the southern part: Java, Lombok-Sumbawa, Flores and Timor. These results indicate that introduction of diverse J. curcas germplasms is necessary for the improvement of the genetic variation in the Indonesian collections.

Jatropha curcas (physic nut), a non‐edible oilseed crop, represents one of the most promising alternative energy sources due to its high seed oil content, rapid growth and adaptability to various environments. We report ~339 Mbp draft whole genome sequence of J. curcas var. Chai Nat using both the PacBio and Illumina sequencing platforms. We identified and categorized differentially expressed genes related to biosynthesis of lipid and toxic compound among four stages of seed development. Triacylglycerol (TAG), the major component of seed storage oil, is mainly synthesized by phospholipid:diacylglycerol acyltransferase in Jatropha, and continuous high expression of homologs of oleosin over seed development contributes to accumulation of high level of oil in kernels by preventing the breakdown of TAG. A physical cluster of genes for diterpenoid biosynthetic enzymes, including casbene synthases highly responsible for a toxic compound, phorbol ester, in seed cake, was syntenically highly conserved between Jatropha and castor bean. Transcriptomic analysis of female and male flowers revealed the up‐regulation of a dozen family of TFs in female flower. Additionally, we constructed a robust species tree enabling estimation of divergence times among nine Jatropha species and five commercial crops in Malpighiales order. Our results will help researchers and breeders increase energy efficiency of this important oil seed crop by improving yield and oil content, and eliminating toxic compound in seed cake for animal feed.

Adzuki bean (Vigna angularis var. angularis) is a dietary legume crop in East Asia. The presumed progenitor (Vigna angularis var. nipponensis) is widely found in East Asia, suggesting speciation and domestication in these temperate climate regions. Here, we report a draft genome sequence of adzuki bean. The genome assembly covers 75% of the estimated genome and was mapped to 11 pseudo-chromosomes. Gene prediction revealed 26,857 high confidence protein-coding genes evidenced by RNAseq of different tissues. Comparative gene expression analysis with V. radiata showed that the tissue specificity of orthologous genes was highly conserved. Additional re-sequencing of wild adzuki bean, V. angularis var. nipponensis and V. nepalensis, was performed to analyze the variations between cultivated and wild adzuki bean. The determined divergence time of adzuki bean and the wild species predated archaeology-based domestication time. The present genome assembly will accelerate the genomics-assisted breeding of adzuki bean.

Mungbean (Vigna radiata) is a fast-growing, warm-season legume crop that is primarily cultivated in developing countries of Asia. Here we construct a draft genome sequence of mungbean to facilitate genome research into the subgenus Ceratotropis, which includes several important dietary legumes in Asia, and to enable a better understanding of the evolution of leguminous species. Based on the de novo assembly of additional wild mungbean species, the divergence of what was eventually domesticated and the sampled wild mungbean species appears to have predated domestication. Moreover, the de novo assembly of a tetraploid Vigna species (V. reflexo-pilosa var. glabra) provides genomic evidence of a recent allopolyploid event. The species tree is constructed using de novo RNA-seq assemblies of 22 accessions of 18 Vigna species and protein sets of Glycine max. The present assembly of V. radiata var. radiata will facilitate genome research and accelerate molecular breeding of the subgenus Ceratotropis.