Error-prone repair of radiation-induced DNA double-strand breaks (DSBs) results in DNA mutation that is essential for mutation breeding. Non-homologous end joining might be the principal DSB repair mechanism in eukaryotes, which is mediated and activated by Ku protein, a heterodimer of 70 and 80 kDa subunits. In this study, on the basis of complementary DNA (cDNA), the genomic sequences of TaKu70 and TaKu80 genes in all the three genomes of wheat were characterized. Only single-nucleotide substitutions and no insertions or deletions were detected in the exons of TaKu70 and TaKu80 genes. The size of the introns exhibited a slight variation between the sequences. Yeast two-hybrid analysis demonstrated that TaKu70 and TaKu80 formed a heterodimer, and electrophoretic mobility shift assays revealed that this heterodimer bound to double-stranded DNA, but not to single-stranded DNA. The quantitative polymerase chain reaction analysis revealed that the expression of TaKu70 and TaKu80 genes was up-regulated under γ-ray irradiation in a dose-dependent manner in the seedlings of wheat. These results suggest that TaKu70 and TaKu80 form a functional heterodimer and are associated with the repair of the induced DSBs in wheat.

Seed protein content is one of the most important traits controlled by quantitative trait loci (QTLs) in soybean. In this study, a Glycine soja accession (ZYD2738) was crossed with two elite cultivars Jidou 12 and Jidou 9 separately and subsequently the resulting F2:3 populations were used to identify QTLs associated with seed protein content. Protein contents in either population appeared to have a normal distribution with transgressive segregation. A total of five QTLs associated with high protein content were identified and mapped to chromosomes 2, 6, 13, 18 and 20, respectively. Of these QTLs, three (qPRO_2_1, qPRO_13_1 and qPRO_20_1) were identified in the same region in both the populations, whereas the other two (qPRO_6_1 and qPRO_18_1) were mapped in two different regions. qPRO_2_1 appears to be a novel protein QTL. qPRO_6_1, qPRO_18_1 and qPRO_20_1 had additive effects on seed protein content, while qPRO_13_1 had an over-dominant effect on seed protein content. These QTLs and their linked markers could serve as effective tools for marker-assisted selection to increase seed protein content.

Soybean is an important crop in Indonesia and its consumption has consistently surpassed local production in recent times. As the average yield is relatively low, a more efficient breeding programme that utilizes the latest technological developments in DNA analysis is required. To provide a genomic data resource for future breeding programmes, in this study, whole-genome sequencing was performed for five Indonesian soybean varieties, with an average sequencing depth of 34 reads. Comparison of these sequences with the Williams 82 reference sequence revealed 3,150,869 DNA variations, which averages to one variation in every 308 bases. Comparison of these variations with known single-nucleotide polymorphisms (SNPs) in the SoyKB database revealed that approximately 29% of them were novel SNPs unique to the Indonesian cultivars. Variations found within exons totalled 95,154. Of these, 57,171 were capable of causing mutations that would modify the amino-acid composition of the encoded proteins (nonsynonymous mutations). Phylogenetic analysis using a subset of these SNP data indicated that the cultivars had genetic similarities to landraces from China and Japan, which could provide clues to the origin of soybeans that were introduced into Indonesia.

Blackberry is a fruiting berry species with very high nutrient contents. With the recent increasing consumer demand for blackberries, new sources of germplasm and breeding techniques are required to improve blackberry production. This study was carried out to evaluate the genetic diversity (GD) and relationship among 55 blackberry (Rubus fruticosus) mutants derived from γ-ray treatment (52 lines) and N-methyl-N′-nitrosourea (MNU) treatment (three lines) using an inter-simple sequence repeat marker. A total of 18 bands were amplified with an average of 3.6 bands per primer. Among them, eight bands were identified to be polymorphic with a rate of 44.4%. In addition, the GD information content values were highest in the 60 Gy treatment population and the GD values were higher in the γ-ray treatment populations than in the MNU treatment population. According to a cluster analysis, all the mutant lines can be classified into five categories, and the genetic distance was greatest between the 80 Gy-irradiated population and other populations. These results indicate that mutant lines have high GD and can be effectively utilized for improving blackberry breeding.

A chickpea simple sequence repeat (SSR) marker reference kit has been developed based on the genotyping of the global chickpea composite collection (3,000 accessions) with 35 SSR markers. The kit consists of three pools of chickpea accessions along with supporting documentation on the SSR markers, polymerase chain reaction and detection conditions, and the expected allele sizes for each of the 35 SSR loci. These markers were selected based on quality criteria, genome coverage and locus-specific information content. Other important SSR selection criteria were quality of amplification products, locus complexity, polymorphism information content and well-dispersed location on a chickpea genetic map. The developed SSR kit has a wide range of applications, especially for genetic diversity studies in chickpea. Using the markers and reference accessions in the kit, scientists in other laboratories will be able to compare the genotypic data that they obtain for their germplasm with that obtained using the global composite collection.

VQ-domain proteins are known to interact with WRKY transcription factors and have been reported to be involved in plant defence responses to environmental stresses in Arabidopsis. Thus, elucidation of the defence mechanisms during the interaction of VQ-domain proteins and WRKY transcription factors could provide useful insights into the regulation of VQ-domain protein-mediated WRKY transcription factors. As the focus of this review, we summarize the genomic analysis of the VQ-domain proteins as one of the WRKY-interacting proteins and their biological effects during plant stress conditions in Arabidopsis and rice.

The RDA Genebank at the National Agrobiodiversity Center (NAAS, RDA, Republic of Korea) has conserved about 182,000 accessions in 1777 species and is working at preserving agricultural genetic resources for the conservation and sustainable utilization of genetic diversity. The detection of genetic variability in conserved resources is important for germplasm management, but the molecular evaluation tools providing genetic information are insufficient for underutilized crops, unlike those for major crops. In this regard, the Korean National Agrobiodiversity Center has been developing microsatellite markers for several underutilized crops. We designed 3640 primer pairs flanking simple sequence repeat (SSR) motifs for 6310 SSR clones in 21 crop species. Polymorphic loci were revealed in each species (7–36), and the mean ratio of polymorphic loci to all the loci tested was 12%. The average allele number was 5.1 (2.8–10.3) and the expected heterozygosity 0.51 (0.31–0.74). Some SSRs were transferable to closely related species, such as within the genera Fagopyrum and Allium. These SSR markers might be used for studying the genetic diversity of conserved underutilized crops.

In this study, the transcriptome of Vitis flexuosa leaves inoculated with Elsinoe ampelina was analysed to identify useful genes and elucidate their function and differential expression patterns through assembly and annotation gene ontology of data from sequencing short reads on the Illumina platform. We assembled ~121 million high-quality trimmed reads using Velvet and Oases with optimal parameters into a non-redundant set of 70,899 transcripts ( ≥ 200 bp in length). The transcripts exhibited an average length of 1138 bp and a N50 length of 1695 bp, with the largest contig length being 9623 bp. Functional categorization revealed the conservation of genes involved in various molecular functions, including protein binding (21.1%) and oxidoreductase activity (11.7%), in V. flexuosa. The V. flexuosa transcript set generated in this study will serve as a resource for gene discovery and development of functional molecular markers.

Non-destructive high-throughput phenotyping based on phenomics is an emerging technology for assessing the genetic diversity of various traits and screening in breeding programmes. In this study, non-destructive measurements of leaf temperature and chlorophyll fluorescence were conducted to investigate the physiological responses of soybean (Glycine max) to salt stress so as to set up a non-destructive screening method. Two-week-old seedlings of soybean in the V2 stage were treated with 0, 12.5, 25, 50 and 100 mM NaCl to induce salt stress. Three parameters, photosynthesis rate, stomatal conductance and chlorophyll fluorescence, decreased significantly, while soybean leaf temperature increased by exhibiting a positive correlation with NaCl concentration (P< 0.001). Soybean leaf temperature increased significantly at 50 mM NaCl when compared with the untreated control, although no visual symptom was observed. We selected leaf temperature as a major physiological parameter of salt stress as its measurement is much easier, faster and cheaper than that of other physiological parameters. Therefore, leaf temperature can be used for evaluating the responses to salt stress in soybean as a non-destructive and phenomic parameter. The results of this study suggest that non-destructive parameters such as chlorophyll fluorescence and leaf temperature are useful tools for assessing the genetic diversity of soybean with regard to salt stress tolerance and to screen salt stress-tolerant soybean for breeding.

Miscanthus is a promising bioenergy crop due to its high productivity and broad environmental adaptability to tropical and temperate climates. As important Miscanthus species such as M. sinensis and M. sacchariflorus are native to East Asia, implying more diverse Miscanthus genetic resources in this region, in this study, we collected about 300 Miscanthus accessions from East Asia, mainly in Korea. From the whole collections, 66 Miscanthus accessions representing geographical location and latitude were selected and tested through a 3-year field trial to investigate genetic diversity in their agronomic traits. Five agronomic traits associated with biomass production were assessed to investigate the relationships of agronomic traits with biomass yield and latitudes of locations where Miscanthus accessions were collected. Plant height, stem diameter, stem dry weight and heading date exhibited a significantly positive correlation with biomass yield with r= 0.465, 0.780, 0.817 and 0.450, respectively. Stem diameter (r= − 0.495), stem dry weight (r= − 0.393), heading date (r= − 0.914) and estimated yield (r= − 0.425) exhibited a significantly negative correlation with latitudes of the collection sites. The results of the study revealed the existence of considerable genetic diversity in agronomic traits in the Miscanthus accessions collected. The presence of a significant relationship between latitudes and agronomic traits suggests that accessions collected from different geographical latitudes will provide more genetically diverse materials for breeding. Therefore, the results of the present study can provide useful information and materials for Miscanthus breeding programmes.

Induction of mutations using chemical mutagens has proved to be a useful tool in crop improvement and has advantages over transgenic approaches in view of legislative restrictions and intellectual property. Among the chemical mutagens, ethyl methanesulfonate (EMS) has been widely used to generate novel traits. In this study, we constructed an EMS mutant population consisting of 3945 M2 mutant lines using a Korean landrace of Capsicum annuum ‘Yuwol-cho’. In total, 1480 M2 mutant lines were evaluated for novel traits. The mutant lines showed phenotypic variations such as plant growth (small size and dwarfism), development of leaves (variegation, colour and morphological changes), flowers (inflorescence, morphological and organ colour changes), and fruits (morphological and colour changes). Most of these mutant phenotypes were inherited recessively. Many of the mutant phenotypes were unique in pepper, while some were similar to those of known mutants in other plant species. These mutant lines will be useful for the study of gene function in C. annuum.

Terminal-repeat retrotransposon in miniature (TRIM) elements are a miniature form of retrotransposons and play an important role in genome organization. The Cassandra TRIM family has been identified in over 50 plant species, including both monocots and dicots. Cassandra elements carry an independently transcribed 5S RNA sequence in their terminal repeat regions, which is unique compared with other TRIM families. Although the existence of Cassandra elements has been documented in many plants, much work remains to characterize Cassandra family members and elucidate their distribution. In this study, we comparatively analysed the Cassandra family members in the Brassica oleracea, B. rapa and Arabidopsis thaliana genomes. A total of 602, 451 and 173 members, of which 130, 60 and 9 were relatively intact, were identified from the B. oleracea, B. rapa and A. thaliana genomes, respectively. Most of the Cassandra elements (1120/1226) were found in intergenic spaces, but 106 elements were inserted in genic regions such as introns, exons and untranslated regions. Our comparative analysis of the Cassandra family members in A. thaliana, B. rapa and B. oleracea reveals that some Cassandra elements have been commonly retained during the last 20 million years in three species and some elements have been uniquely evolved in Brassica species. This study promotes our understanding of the role and utility of Cassandra elements in the evolution of the Brassicaceae family.

In this study, a near-isogenic line (BC4F10) CR572 developed by introgressing a chromosomal segment from Oryza rufipogon (accession no. 105491) into the Oryza sativa subsp. japonica cv. Hwaseong was found to exhibit a significant increase in the number of spikelets per panicle (SPP) and grain weight compared with the recurrent parent Hwaseong. Quantitative trait locus (QTL) analysis in F2 generation derived from the cross between CR572 and Hwaseong revealed that two QTLs, qSPP1 and qTGW1, were linked to a simple sequence repeat marker, RM283, on chromosome 1. The additive effect of the O. rufipogon allele at qSPP1 was 13 SPP, and 21.6% of the phenotypic variance was explained by the segregation of RM283. The qTGW1 QTL explained 19.1% of the phenotypic variance for grain weight. Substitution mapping was carried out with five F3 lines derived from F2 plants having informative recombination breakpoints within the target region. Substitution mapping indicated the linkage of qSPP1 and qTGW1. The grain yield of CR572 was 18.2 and 15.8% higher than that of Hwaseong at two locations, respectively, mainly due to the increase in 1000-grain weight and SPP. These results are very useful for QTL cluster transfer by molecular marker-assisted selection in rice breeding programmes and for QTL gene cloning by map-based cloning.

Plant genetic resources are raw materials and their use in breeding is one of the most sustainable ways to conserve biodiversity. The ICRISAT has over 120,000 accessions of its five mandate crops and six small millets. The management and utilization of such large diversity are greatest challenges to germplasm curators and crop breeders. New sources of variations have been discovered using core and minicore collections developed at the ICRISAT. About 1.4 million seed samples have been distributed; some accessions with specific attributes have been requested more frequently. The advances in genomics have led researchers to dissect population structure and diversity and mine allelic variations associated with agronomically beneficial traits. Genome-wide association mapping in sorghum has revealed significant marker–trait associations for many agronomically beneficial traits. Wild relatives harbour genes for resistance to diseases and insect pests. Resistance to pod borer in chickpea and pigeonpea and resistance to rust and late leaf spot in groundnut have been successfully introgressed into a cultivated genetic background. Synthetics in groundnut are available to broaden the cultigen's gene pool. ICRISAT has notified the release of 266 varieties/cultivars, germplasm, and elite genetic stocks with unique traits, with some having a significant impact on breeding programs. Seventy-five germplasm lines have been directly released for cultivation in 39 countries.

In this study, the genetic variability among 130 accessions of the Portuguese germplasm collection of Cucurbita pepo L. maintained at the Banco Português de Germoplasma Vegetal was assessed using AFLP (amplified fragment length polymorphism) and RAPD (random amplified polymorphic DNA) techniques for the identification of a genetically diverse core group of accessions for field phenotypic analysis. The surprisingly completely different molecular patterns exhibited by multiple accessions was later confirmed in the distribution of the putative C. pepo plants into two clusters drastically separated at a very low level of genetic similarity (DICE coefficient = 0.37). Additional analyses with RAPD and ISSR (inter single sequence repeat) markers and the introduction of standard genotypes of C. maxima L. and C. moschata L. into the analyses allowed the identification of multiple accessions of the last species wrongly included in the C. pepo collection. This study is a good example of the usefulness of DNA markers in the establishment and management of plant germplasm collections.

In this study, 123 almond (Prunus dulcis (Mill.) D.A. Webb) trees identified among traditional orchards in the Algarve region and 53 trees of the local field collection managed by the regional office of the Portuguese Ministry of Agriculture (DRAALG) were assessed using isozyme, inter-single sequence repeat and simple sequence repeat or microsatellite techniques for the evaluation of genetic diversity and genetic relatedness and identification of new accessions for the field collection. The isozyme analysis allowed the distribution of the 176 plants into 13 different classes of enzyme similarity, while the use of DNA markers increased the distribution of the analysed trees among 140 discriminating DNA patterns. Multiple cases of homonymy and synonymy were identified in the local germplasm. Some traditional varieties, such as Lourencinha, appeared to be relatively homogeneous, while other local denominations, e.g. Galamba, included diverse genotypes. Of the 13 commercial varieties analysed in this study, 11 assembled in one major cluster clearly differentiated from the majority of the local genotypes. These results reinforced the perception that the Algarve traditional germplasm constitutes an important repository of genetic diversity, eventually carrying alleles of high agricultural interest such as the recently identified Phomopsis resistance in the traditional variety Barrinho Grado.

In this paper, we discuss stress-adapted wild Vigna plants and several important Vigna crops. Seeds, young shoots and/or tubers of many wild Vigna species are edible and are eaten by people in some locations where they grow. We propose the concept of ‘neo-domestication’ of stress-adapted wild edible Vigna species. As the causative change of the mutation resulting in a domestication gene is usually ‘loss-of-function’ type, ‘neo-domestication’ could be achieved by conventional mutation breeding together with screening by TILLING. The ‘neo-crops’ could play an important role in areas unsuitable for growing other crops to increase world food production. We also propose that wild Vigna species can be ‘new model plant species’ for the genetic study of natural adaptation to stresses (e.g. salt, acid, alkali, drought, flood, pests and diseases). To facilitate this, the Vigna Genome Project has been initiated. In addition, sustainable cropping systems may be enhanced by analysis of the nitrogen-fixing systems of stress-adapted Vigna species. Stress-adapted symbiotic bacteria produce nodules on stress-adapted Vigna species. Therefore, analyses of the genetic diversity of symbiotic bacteria and the process of symbiosis under stress environments should be conducted.

Annual wild soybean characterized with more number of branches and pods may contain favourable exotic genes/alleles for improving the yield potential of cultivated soybeans. To evaluate the wild alleles/segments, the chromosome segment substitution line population SojaCSSLP3 comprising 158 lines with N24852 (wild) as the donor and NN1138-2 (cultivated) as the recurrent parent was tested under three environments. The phenotypic data along with 198 simple sequence repeat markers were analysed for qualitative trait loci (QTL)/segments associated with the number of branches on the main stem (BN) and number of pods per plant (PN) using the inclusive composite interval mapping procedure (RSTEP-LRT-ADD model) of ICIM version 3.0. The analysis was carried out for individual environments due to a significant G × E interaction. A total of eight QTL/segments associated with BN and eight QTL/segments associated with PN were detected under the three environments, with all the wild segments having positive effects. Among these, two QTL/segments for each of the two traits could be detected under two or three environments and three QTL/segments could be detected for both traits. Four QTL/segments associated with BN and one QTL/segment associated with PN were identified only in SojaCSSLP3, not reported for cultivated crosses in the literature. The detected wild segments may provide materials for further characterization, cloning and pyramiding of the alleles conferring the two traits.