Helicoverpa assulta (Lepidoptera: Noctuidae) exhibits a specialized herbivorous diet, primarily targeting select Solanaceae plants. Despite its significant economic impact as a pest, causing substantial harm to crops like hot pepper and tobacco, it has received comparatively limited attention in research compared to its generalist counterparts, H. armigera and H. zea.We introduce a chromosome level genome assembly using a Korean H. assulta (Pyeongchang strain, K18). This assembly was achieved through a combined approach utilizing Nanopore long-read sequencing (approximately 78X coverage) and Illumina NovaSeq short-read sequencing (approximately 54X coverage). The total assembled genome spans 424.36 Mb, designated as ASM2961881v1, comprises 62 scaffolds, with 98.7% of the genome contained within 31 scaffolds, confirming the insect's chromosome count (n = 31). The completeness of the assembly is reflected in BUSCO assessment, with values reaching 99.0%, while the repeat content accounts for 33.01%, and 18,593 CDS were annotated. Additionally, 137 genes were identified within 15 orthogroups that have rapidly expanded in H. assulta, while 149 genes in 95 orthogroups have rapidly contracted. This genome draft serves as a valuable resource to explore various aspects of the specialist's biology, enabling research into host-range evolution, chemical communication, insecticide resistance, and comparative investigations with other Heliothine species.

Comparative analysis is a typically useful tool for translating genomic information from one species to another. However, currently available softwares are relatively difficult to directly use for researchers that are not familiar with use of bioinformatic tools. Therefore, we intended to develop a new platforms and/or interface through which one can use in more comfortable way, based on the concept of interactive comparative analysis. Towards this direction, we, firstly, constructed relational database to store the information on abiotic stress genes identified from multiple plant species using various resources, such as the TAIR (http://www.arabidopsis.org), gene expression profiles and relevant literatures, and linked with comparative analysis interface. For purposes of comparative analysis and identification of synteny blocks, cross-species orthologous genes were determined using a combination of tBlastX and BlastP homology searches. We adapted and developed a Circos-like format to present resulting comparative maps. Users can readily choose analysis parameters, for example individual genes and specific chromosomes for chosen species, in the pane of analysis DB, which is useful feature to avoid complexity of comparative genomic analysis. This DB-associated comparative analysis tool, developed in this study, will be able to provide customer-friendly interface for comparative analysis and extend its utility across a broader range of plant genomes.

Genetic resources play a great role in crop breeding because of containing a broad array of useful genes. Currently, the harder are rice breeders trying to develop new rice cultivars with the improved traits, they are more often handicapped by the limited availability of germplasm resources. Thus, a desirable core or heuristic (HS) set of germplasm with maximum genetic diversity can be usefully exploited to breakthrough the present and future challenges of the rice breeding. As such we previously developed the rice HS sets of 166 diverse accessions out of a total 24,368 rice germplasms. Here, we report a large-scale analysis of the patterns of genome-wide genetic variations accumulated in the HS as well as Korean rice over the time. We characterized a total of about 11.8 millions of single nucleotide polymorphisms (SNPs) across the rice genome from resequencing a total of 295 rice genomes including 137 HS and 158 KB rice sets, with an average of approximately 10x depth and > 90% coverage. Using about 460,000 high-quality SNPs (HQSNPs), we specified the population structure, confirming our HS set covers all the rice sub-populations. We further traced the relative nucleotide variabilities of HQSNPs and found the level of the diversity was dynamically changing across the KB genome, which reveals the selection history of KB lines in the past and present. In addition, the results of our genome wide association study (GWAS) suggests that our HS can be also a good reservoir of valuable alleles, pinpointing those alleles underlying the important rice agronomical traits. Overall, the resequencing of our HS set re-illuminates the past, present of the germplasm utilization, which will support the Korean rice breeding in the future.

Although much effort has been made to find agronomically important loci in the soybean plant, extensive linkage disequilibrium and genome duplication have limited efficient genome-wide linkage analyses that can identify important regulatory genes. In this respect, recombination block-based analysis of cultivated plant genomes is a potential critical step for molecular breeding and target locus screening. We propose a new three-step method of detecting recombination blocks and comparative genomics of bred cultivars. It utilizes typical reshuffling features of their genomes, which have been generated by the recombination processes of breeding ancestral genomes. To begin with, mutations were detected by comparing genomes to a reference genome. Next, sequence blocks were examined for likenesses and difference with respect to the reference genome. The boundaries between the blocks were taken as recombination sites. All recombination sites found in the cultivar set were used to split the genomes, and the resulting sequence fragments were named as core recombination blocks (CRBs). Finally, the genomes were compared at the CRB level, instead of at the sequence level. In the genomes of the five Korean soybean cultivars used, the CRB-based comparative genomics method produced long and distinct CRBs that are as large as 22.9 Mb. We also demonstrated efficiency in detecting functionally useful target loci by using indel markers, each of which represents a CRB. We further showed that the CRB method is generally applicable to both monocot and dicot crops, by analyzing publicly available genomes of 31 soybeans and 23 rice accessions.

In recent years, genomic resources and information have accumulated at an ever increasing pace, in many plant species, through whole genome sequencing, large scale analysis of transcriptomes, DNA markers and functional studies of individual genes. Well-characterized species within key plant taxa, co-called "model systems", have played a pivotal role in nucleating the accumulation of genomic information and databases, thereby providing the basis for comparative genomic studies. In addition, recent advances to "Next Generation" sequencing technologies have propelled a new wave of genomics, enabling rapid, low cost analysis of numerous genomes, and the accumulation of genetic diversity data for large numbers of accessions within individual species. The resulting wealth of genomic information provides an opportunity to discern evolutionary processes that have impacted genome structure and the function of genes, using the tools of comparative analysis. Comparative genomics provides a platform to translate information from model species to crops, and to relate knowledge of genome function among crop species. Ultimately, the resulting knowledge will accelerate the development of more efficient breeding strategies through the identification of trait-associated orthologous genes and next generation functional gene-based markers.

A single recessive gene, rxp, controls bacterial leaf pustule (BLP) resistance in a soybean. The Rxp locus appears to be linked to the malate dehydrogenase (Mdh) locus and Satt372 on linkage group (LG) D2. Around the Rxp locus, four bacterial artificial chromosome (BAC) clones are anchored by Satt486, Satt498, BARC-022037-04263, and BARC-040963-07870. Using these BAC clone sequences, possible orthologous region of Rxp locus was identified: Medicago truncatula contig 962 at chromosome 3 and contig 283 and contig 1108 at chromosome 8. Sequence analysis of contig 962 had revealed microsynteny with three soybean BAC clones on LG A1, which are duplicated with other two soybean BAC clones anchored by Satt486 and Satt498. After BLAST search was performed with M. truncatula contig 962 against soybean ESTs, several soybean ESTs were identified. With developed single nucleotide polymorphism (SNP) markers and the RIL population from the cross of Pureunkong and Jinpumkong 2, SNP genotyping was able to locate twos oybean ESTs: CO979743 at 1 cM away from Satt195 on LG C1 and BE021935 at 5 cM away from Satt363 on LG C2. Thus, our results indicate that structure of soybean genome around Rxp locus is very complicated.