Breeding Of Cultivars Research Articles

Lint percentage and boll weight QTLs in three excellent upland cotton (Gossypium hirsutum): ZR014121, CCRI60, and EZ60

BackgroundUpland cotton (Gossypium hirsutum L.) is the most economically important species in the cotton genus (Gossypium spp.). Enhancing the cotton yield is a major goal in cotton breeding programs. Lint percentage (LP) and boll weight (BW) are the two most important components of cotton lint yield. The identification of stable and effective quantitative trait loci (QTLs) will aid the molecular breeding of cotton cultivars with high yield.ResultsGenotyping by target sequencing (GBTS) and genome-wide association study (GWAS) with 3VmrMLM were used to identify LP and BW related QTLs from two recombinant inbred line (RIL) populations derived from high lint yield and fiber quality lines (ZR014121, CCRI60 and EZ60). The average call rate of a single locus was 94.35%, and the average call rate of an individual was 92.10% in GBTS. A total of 100 QTLs were identified; 22 of them were overlapping with the reported QTLs, and 78 were novel QTLs. Of the 100 QTLs, 51 QTLs were for LP, and they explained 0.29–9.96% of the phenotypic variation; 49 QTLs were for BW, and they explained 0.41–6.31% of the phenotypic variation. One QTL (qBW-E-A10-1, qBW-C-A10-1) was identified in both populations. Six key QTLs were identified in multiple-environments; three were for LP, and three were for BW. A total of 108 candidate genes were identified in the regions of the six key QTLs. Several candidate genes were positively related to the developments of LP and BW, such as genes involved in gene transcription, protein synthesis, calcium signaling, carbon metabolism, and biosynthesis of secondary metabolites. Seven major candidate genes were predicted to form a co-expression network. Six significantly highly expressed candidate genes of the six QTLs after anthesis were the key genes regulating LP and BW and affecting cotton yield formation.ConclusionsA total of 100 stable QTLs for LP and BW in upland cotton were identified in this study; these QTLs could be used in cotton molecular breeding programs. Putative candidate genes of the six key QTLs were identified; this result provided clues for future studies on the mechanisms of LP and BW developments.

Determination of optimal plant growth regulators for breaking seed dormancy and micropropagation of Sorbus aucuparia L.

Sorbus aucuparia L. is an important forest tree used in the reforestation of high-altitude mountainous areas, which carries significant pharmaceutical, industrial, ornamental, food, and ecological properties. However, the seed propagation and micropropagation of mature trees of S. aucuparia L., presents various difficulties which are integral aspects for the re-propagation and breeding of novel cultivars. In this study, we isolated the mature embryo-containing seeds of selected varieties of S. aucuparia L. from their seed coat and used them directly as explants in vitro to investigate and determine the optimal dose of cytokinin in breaking seed dormancy and micropropagation. 3 mg/L of benzyl adenine (BA) in addition to different concentrations and combinations of kinetin (0.5, 1, and 2 mg/L), indole-3-butyric acid (IBA) (0, 1, 0.5, and 1 mg/L), and 1-naphthalene acetic acid (NAA) (0, 1, 0.5, and 1 mg/L) were applied within a Murashige and Skoog (1962) (MS) medium at germination inhibition, shoot elongation, and shoot proliferation. In the MS mediums containing BA and kinetin, germination was achieved at the end of 1 week, and shoot proliferation was achieved at the end of 3 weeks. The most successful germination (96%), tallest shoot length (mean 5.1 cm), most shoot proliferation (mean 7.2 pieces), and number of nodes (mean 9.7 pieces) were identified in the MS containing 3 mg/L BA and 1 mg/L kinetin. Direct root formation with shoot elongation occurred in 25% of explants which germinated in the MS medium. For shoots propagated without roots in this medium, 62% of these achieved rooting at the highest dose of 1 mg/L indole-3-acetic acid (IAA) using a two-stage rooting method. Rooted shoots were successfully transferred to an ex vitro medium. These results provide a basis for breaking seed dormancy of selected Sorbus L. genotypes quicker, leading to more effective clonal production. Keywords: Sorbus aucuparia L., rowanberry, tissue culture, seed dormancy, micropropagation, in vitro

Cotton heterosis and hybrid cultivar development

Cotton, the most important economic crop in the world, displays strong hybrid vigor, and has long been a subject for hybrid cultivar breeding. Here, advances in the theoretical and applied research in cotton heterosis along with its hybrid cultivar development by hand-emasculation and pollination (HEP), cytoplasmic (CMS) and genic male sterile lines (GMS) mainly in China during the past few decades are presented in this review. Three types of hybrids produced by HEP, CMS and GMS facilitating hybrid seed production with hand-pollination have been developed and are being planted simultaneously in cotton production. However, most hybrids commercially planted in production are produced by HEP, therefore, F2 seeds are being extensively planted due to the high cost to produce F1 seed. F2 generations of these combinations exceed the check cultivars in yield usually up to 5~15%. GMS genes (ms2 and ms5ms6) used in hybrid seed production and casual mitochondrial genes for G. harknessii CMS have been cloned. Challenges and opportunities in cotton heterosis and future hybrid cultivar development in cotton are discussed.

Identification of wheat stem rust resistance genes in wheat cultivars from Hebei province, China.

Wheat stem rust is caused by Puccinia graminis f. sp. tritici. This major disease has been effectively controlled via resistance genes since the 1970s. The appearance and spread of new races of P. graminis f. sp. tritici (eg., Ug99, TKTTF, and TTRTF) have renewed the interest in identifying the resistance gene and breeding cultivars resistant to wheat stem rust. In this study, gene postulation, pedigree analysis, and molecular detection were used to determine the presence of stem rust resistance genes in 65 commercial wheat cultivars from Hebei Province. In addition, two predominant races 21C3CTHTM and 34MRGQM were used to evaluate the resistance of these cultivars at the adult-plant stage in 2021-2022. The results revealed that 6 Sr genes (namely, Sr5, Sr17, Sr24, Sr31, Sr32, Sr38, and SrTmp), either singly or in combination, were identified in 46 wheat cultivars. Overall, 37 wheat cultivars contained Sr31. Sr5 and Sr17 were present in 3 and 3 cultivars, respectively. Gao 5218 strong gluten, Jie 13-Ji 7369, and Kenong 1006 contained Sr24, Sr32, and Sr38, respectively. No wheat cultivar contained Sr25 and Sr26. In total, 50 (76.9%) wheat cultivars were resistant to all tested races of P. graminis f. sp. tritici in field test in 2021-2022. This study is important for breeding wheat cultivars with resistance to stem rust.

Convergently selected NPF2.12 coordinates root growth and nitrogen use efficiency in wheat and barley.

Understanding the genetic and molecular function of nitrate sensing and acquisition across crop species will accelerate breeding of cultivars with improved nitrogen use efficiency (NUE). Here, we performed a genome-wide scan using wheat and barley accessions characterized under low and high N inputs that uncovered the NPF2.12 gene, encoding a homolog of the Arabidopsis nitrate transceptor NRT1.6 and other low-affinity nitrate transporters that belong to the MAJOR FACILITATOR SUPERFAMILY. Next, it is shown that variations in the NPF2.12 promoter correlated with altered NPF2.12 transcript levels where decreased gene expression was measured under low nitrate availability. Multiple field trials revealed a significantly enhanced N content in leaves and grains and NUE in the presence of the elite allele TaNPF2.12TT grown under low N conditions. Furthermore, the nitrate reductase encoding gene NIA1 was up-regulated in npf2.12 mutant upon low nitrate concentrations, thereby resulting in elevated levels of nitric oxide (NO) production. This increase in NO correlated with the higher root growth, nitrate uptake, and N translocation observed in the mutant when compared to wild-type. The presented data indicate that the elite haplotype alleles of NPF2.12 are convergently selected in wheat and barley that by inactivation indirectly contribute to root growth and NUE by activating NO signaling under low nitrate conditions.

Ab Initio Modelling of the Structure of ToxA-like and MAX Fungal Effector Proteins

Pathogenic fungal diseases in crops are mediated by the release of effector proteins that facilitate infection. Characterising the structure of these fungal effectors is vital to understanding their virulence mechanisms and interactions with their hosts, which is crucial in the breeding of plant cultivars for disease resistance. Several effectors have been identified and validated experimentally; however, their lack of sequence conservation often impedes the identification and prediction of their structure using sequence similarity approaches. Structural similarity has, nonetheless, been observed within fungal effector protein families, creating interest in validating the use of computational methods to predict their tertiary structure from their sequence. We used Rosetta ab initio modelling to predict the structures of members of the ToxA-like and MAX effector families for which experimental structures are known to validate this method. An optimised approach was then used to predict the structures of phenotypically validated effectors lacking known structures. Rosetta was found to successfully predict the structure of fungal effectors in the ToxA-like and MAX families, as well as phenotypically validated but structurally unconfirmed effector sequences. Interestingly, potential new effector structural families were identified on the basis of comparisons with structural homologues and the identification of associated protein domains.

Is the activity of antioxidant enzymes, some biochemical properties and essential oil content affected by salinity stress in different species of mint?

Mint is one of the important medicinal plants with important properties in industry, medicine, and pharmacy. Salinity stress is one of the limiting factors for plant growth that also affects plants' physiological and biochemical properties. In this study, effects of salinity on biochemical and enzymatic properties of 18 ecotypes of mint from six different species, were studied. The experimental results showed that salinity and increased with increasing stress integrity influenced enzymatic properties, proline content, electrolyte leakage, hydrogen peroxide, malondialdehyde, and essential oil content. Cluster analysis and principal component analysis grouped the studied species on the basis of biochemical characteristics. Based on biplot results, piperita and rotundifolia showed better stress tolerance, but longifolia was identified as salt sensitive. The experimental results also showed that six species of the mint had diverse reactions in terms of biochemical properties at different levels of salinity stress.

Genetic diversity of Kappaphycus malesianus (Solieriaceae, Rhodophyta) from the Philippines

Kappaphycus farming for carrageenan production is characterized by a strong selective pressure at the genetic level. Traits of agronomic importance are compromised due to domestication bottlenecks and the subsequent events of possible selective breeding of founding cultivars. Kappaphycus malesianus is farmed in Malaysia and the Philippines, and is distributed within the Malesian region. While the majority of genetically characterized specimens of this species are from Malaysia, those from the Philippines are poorly explored. Here, we assessed the genetic diversity of K. malesianus from the Philippines based on cox1 sequences. Of the 15 identified haplotypes, 14 specimens represent three novel haplotypes (wild specimens) that form a group distinct from the main clade comprising most K. malesianus haplotypes known to date. An additional haplotype from a cultivated specimen was identical to that of the most widely distributed haplotype. Our findings demonstrate that the K. malesianus is genetically more diverse than previously recognized. It is expected that higher genetic diversity may be revealed through additional sampling from a wider geographic range and careful application of integrative approaches. Future selective breeding programs in Kappaphycus would benefit from the incorporation of the genetic resources, as provided in this study.

Global experience in the commercial cultivation of peony flowers: 30 years of research and development

Herbaceous peony is an ancient ornamental and medicinal crop, cultivated for thousands of years in China and Japan. Numerous varieties are popular garden plants in different continents and countries, and recently peony has gained a new reputation as cut flowers. Only in Europe, in last 30 years, trade in cut peony has increased 50-fold. This demand has led to biological research and the development of production technologies. Today, more than 25 countries produce cut peony flowers, with primary markets in Europe, Asia and the USA. However, several factors still restrict peony production - challenges in mass propagation, a complicated flowering physiology, and postharvest handling. Here we summarize the contribution of research in plant physiology to the development of new technologies of peony production and flowering. Further research of molecular and biochemical mechanisms, breeding of new cultivars will contribute to the further development of peony industry. Biotechnological applications and long-term postharvest technologies will facilitate creation of Global Peony Chain for successful marketing of this flower.

Embryogenesis induction of carrot (Daucus carota L.) in isolated microspore culture

Haploid technologies are used to create homozygous lines for accelerated breeding. We aimed to optimize the technology for using the isolated microspore culture in vitro to obtain doubled haploids of the carrot (Daucus carota L.).
 We studied two carrot varieties with different responsiveness to embryogenesis, Altajskaya lakomka and Breeding line 17. Carrot microspores were isolated from buds and cultivated in liquid nutrient media supplemented with an antibiotic and activated carbon in vitro. They were exposed to different thermal treatments.
 The experiment showed the benefits of combining cold pre-treatment of buds (5°C for 1 day) with heat shock of isolated microspores in vitro (32°C for 2 days). The induction of embryogenesis on the NLN-13 medium was twice as high as on the MSm-13 medium. The use of 1% activated carbon in 0.5% agarose increased the yield of embryoids by more than 1.5 times. 100 mg/L of ampicillin was found to be the most efficient concentration. After 30 days of cultivation under optimized conditions, the yield was 161.3 and 44.0 embryoids per Petri dish for the cultivar Altajskaya lakomka and Breeding line 17, respectively.
 The induction of carrot embryogenesis is determined by the type and duration of thermal stress, the composition of the nutrient medium, the use of activated carbon as a sorbent, the addition of β-lactam antibiotics, and the type of explant exposed to thermal treatment. Our technology enabled us to obtain homozygous doubled haploid lines of carrots during a year, and these lines were included in the breeding process to create F1 hybrids.

Comparative analysis of volatile aromatic compounds from a wide range of pear (Pyrus L.) germplasm resources based on HS-SPME with GC–MS

Aroma is one of the most important sensory characteristics of fruit quality. Here, the aroma composition of mature fruits of 202 pear cultivars was detected by headspace solid-phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC–MS). As a result, 221 major volatile components were detected, among which aldehydes, esters and alcohols were the most dominant aroma components. We also found Pyrus communis L. had the highest volatile content, followed by Pyrus sinkiangensis Yu, Pyrus ussuriensis Maxim., Pyrus bretschneideri Rehd., Hybrid Breeding cultivar group, Chinese sand pears (Pyrus pyrifolia Nakai), and Japanese and Korean (J&K) sand pears (Pyrus pyrifolia Nakai). In addition, the aroma composition and contents varied greatly among the different ripening-period groups. Finally, the fruits of pear germplasms also showed geographical flavor characteristics. These basic data and results could help us better understanding the variations of aroma quality among pear varieties and promote the development of pear breeding program.

Variance Components, Correlation and Path Coefficient Analysis of Morpho-Physiological and Yield Related Traits in Spider Plant (Gynandropsis gynandra (L.) Briq.) under Water-Stress Conditions

Drought is the most complex abiotic stress for crop production at the global level. Therefore, developing new African spider plant genotypes tolerant to drought stress is one of the best approaches to achieving and optimizing high yield potential with water use efficiency. Advances in the selection of this crop can be determined by an understanding of genetic variability, heritability, and the associations that exist among different traits. The aim of this study was to gather information that will aid in the breeding of African spider plant cultivars with improved drought tolerance. A randomized complete block design (RCBD) experiment with eighteen genotypes and four replications was carried out across three water regimes: severe drought (30% field capacity), intermediate drought (50% field capacity), and well-watered (100% field capacity), in two seasons. Data on twelve morpho-physiological traits were recorded. The analysis of variance showed significant differences among genotypes (p < 0.05) in leaf yield and yield-related traits. The phenotypic coefficient of variation (PCV) was greater than the genotypic coefficient of variation (GCV) for all 12 traits evaluated. High to moderate heritability estimates combined with a high to moderate genetic advance were observed for number of leaves, leaf width, plant height and stem diameter under drought stress conditions, indicating that these traits are controlled by additive gene action. Because of their predominant additive gene effects, correlation with leaf yield and favorable direct and indirect effects via the other yield-attributing traits, number of leaves per plant, plant height, days to 50% flowering, relative water content, net photosynthesis and leaf length could be used as target traits to improve spider plant leaf yield under drought-stressed conditions.

Combined Metabolome and Transcriptome Analysis Elucidates Sugar Accumulation in Wucai (Brassica campestris L.).

Wucai (Brassica campestris L.) is a leafy vegetable that originated in China, its soluble sugars accumulate significantly to improve taste quality during maturation, and it is widely accepted by consumers. In this study, we investigated the soluble sugar content at different developmental stages. Two periods including 34 days after planting (DAP) and 46 DAP, which represent the period prior to and after sugar accumulation, respectively, were selected for metabolomic and transcriptomic profiling. Differentially accumulated metabolites (DAMs) were mainly enriched in the pentose phosphate pathway, galactose metabolism, glycolysis/gluconeogenesis, starch and sucrose metabolism, and fructose and mannose metabolism. By orthogonal projection to latent structures-discriminant s-plot (OPLS-DA S-plot) and MetaboAnalyst analyses, D-galactose and β-D-glucose were identified as the major components of sugar accumulation in wucai. Combined with the transcriptome, the pathway of sugar accumulation and the interact network between 26 DEGs and the two sugars were mapped. CWINV4, CEL1, BGLU16, and BraA03g023380.3C had positive correlations with the accumulation of sugar accumulation in wucai. The lower expression of BraA06g003260.3C, BraA08g002960.3C, BraA05g019040.3C, and BraA05g027230.3C promoted sugar accumulation during the ripening of wucai. These findings provide insights into the mechanisms underlying sugar accumulation during commodity maturity, providing a basis for the breeding of sugar-rich wucai cultivars.

Characterization of Yield-Related Traits and Pasting and Texture Properties of Glutinous Rice Cultivars by Cultivation Times in the Honam Plain, Korea

Other SectionsAbstractThe cultivated area of glutinous rice in the Homan Plain of Korea is increasing to diversify the cropping system. Depending on the time of transplanting, glutinous rice can be divided into early, ordinary, and late cultivation. Eight glutinous rice cultivars (Baegseolchal, Baekogchal, Boramchal, Boseogchal, Dongjinchal, JJ644wx, Nunbora, and Sinseonchal) were used to evaluate yield, pasting properties, and texture according to cultivation time and to analyze the genotype-environment relationship. There were nine yield-related, six pasting-related, and four texture-related traits studied. Heading date and culm length were shortened as cultivation time increased, while panicle length, number of spikelets, and 1,000-grain weight increased. Furthermore, late cultivation time also reduced pasting properties, peak viscosity, trough viscosity, and final viscosity. Hardness and adhesiveness among the texture properties increased with cultivation time, but stickiness decreased. The variation in 1,000-grain weight is mostly dominated by genotype, whereas heading date and yield are heavily influenced by environmental factors. All pasting property characteristics varied with environment changes, and genotype variation was dominant for all texture properties. Boramchal yielded the most in early and ordinary cultivation and Sinseonchal, together with Boramchal, yielded the most in late cultivation. Cultivars with excellent grain quality were Sinseonchal in early cultivation and Baegseolchal and Baekogchal in ordinary and late cultivation. A comparative analysis of characteristics based on cultivation time can assist in the selection of glutinous rice suitable for the Honam Plain and in the breeding of cultivars with improved yield and excellent grain quality.Keywords : breeding, glutinous rice, yield, pasting property, texture property

Genetic characteristics and linkage of virulence genes of the Puccinia striiformis f. sp. tritici TSA-6 isolate to Yr5 host resistance.

To understand inheritance of the TSA-6 Puccinia striiformis f. sp. tritici isolate, virulent to Yr5, that was recently detected in China, we analyzed avirulence and virulence of 120 selfed progeny lines from Berberis shensiana. The results showed that the TSA-6 isolate is virulent against the Yr5 resistance gene, and overall progeny lines were categorized into 73 virulence phenotypes (VPs), and of these, 72 VPs differed from the isolate TSA-6, and only 1 VP including 3 progeny was identical to the parental isolate. The analyses indicated that the TSA-6 isolate is homozygous for avirulence at Yr10, Yr15 and Yr26 resistance loci, and virulence at YrA resistance locus. The TSA-6 isolate is heterozygous for avirulence at the Yr2, Yr3, Yr5, Yr7 and Yr8 resistance loci, which are controlled by a dominant/recessive relationship. The Yr1, Yr6, Yr9, Yr17, Yr27, Yr25, Yr28, Yr29, Yr32, YrTr1 and YrSP resistance loci are governed by two complementary dominant/recessive genes. Avirulence against heterozygous Yr4, Yr43，Yr44, Yr76 and YrExp2 resistance loci is regulated by a dominant and recessive, or a dominant and suppressor gene pairs. Totally, 117 multi-locus genotypes (MLGs) were detected at 24 KASP-SNP marker loci among the 120 progeny. Using these marker loci, we constructed a linkage map with a genetic distance interval spanning 624.5 cM. Quantitative trait loci (QTL) corresponding to phenotypic segregation for virulence at 20 Yr resistance loci in addition to the Yr1 resistance locus were identified. These results facilitate our understanding of Pst virulence evolution, and simplify breeding of wheat cultivars with effective resistance to wheat stripe rust.

Application of tissue culture technology of medicinal plants in sustainable development of Chinese medicinal resources

Chinese medicinal resources are the cornerstone of the sustainable development of traditional Chinese medicine industry. However, due to the fecundity of species, over-exploitation, and limitations of artificial cultivation, some medicinal plants are depleted and even endangered. Tissue culture, a breakthrough technology in the breeding of traditional Chinese medicinal materials, is not limited by time and space, and can allow the production on an annual basis, which plays an important role in the protection of Chinese medicinal resources. The present study reviewed the applications of tissue culture of medicinal plants in the field of Chinese medicinal resources, including rapid propagation of medicinal plant seedlings, breeding of novel high-yield and high-quality cultivars, construction of a genetic transformation system, and production of secondary metabolites. Meanwhile, the current challenges and suggestions for the future development of this field were also proposed.

Apple cultivar breeding for multigenic resistance to multiple diseases: the New Zealand experience

Apple cultivar breeding for multigenic resistance to multiple diseases: the New Zealand experience

Identifications of QTLs and Candidate Genes Associated with Pseudomonas syringae Responses in Cultivated Soybean (Glycine max) and Wild Soybean (Glycine soja)

Soybeans (Glycine max) are a key food crop, serving as a valuable source of both oil and plant-derived protein. Pseudomonas syringae pv. glycinea (Psg) is among the most aggressive and prevalent pathogens affecting soybean production, causing a form of bacterial spot disease that impacts soybean leaves and thereby reduces crop yields. In this study, 310 natural soybean varieties were screened for Psg resistance and susceptibility. The identified susceptible and resistant varieties were then used for linkage mapping, BSA-seq, and whole genome sequencing (WGS) analyses aimed at identifying key QTLs associated with Psg responses. Candidate Psg-related genes were further confirmed through WGS and qPCR analyses. Candidate gene haplotype analyses were used to explore the associations between haplotypes and soybean Psg resistance. In addition, landrace and wild soybean plants were found to exhibit a higher degree of Psg resistance as compared to cultivated soybean varieties. In total, 10 QTLs were identified using chromosome segment substitution lines derived from Suinong14 (cultivated soybean) and ZYD00006 (wild soybean). Glyma.10g230200 was found to be induced in response to Psg, with the Glyma.10g230200 haplotype corresponding to soybean disease resistance. The QTLs identified herein can be leveraged to guide the marker-assisted breeding of soybean cultivars that exhibit partial resistance to Psg. Moreover, further functional and molecular studies of Glyma.10g230200 have the potential to offer insight into the mechanistic basis for soybean Psg resistance.

Brassica rapa orphan gene BR1 delays flowering time in Arabidopsis.

Orphan genes are essential to the emergence of species-specific traits and the process of evolution, lacking sequence similarity to any other identified genes. As they lack recognizable domains or functional motifs, however, efforts to characterize these orphan genes are often difficult. Flowering is a key trait in Brassica rapa, as premature bolting can have a pronounced adverse impact on plant quality and yield. Bolting resistance-related orphan genes, however, have yet to be characterized. In this study, an orphan gene designated BOLTING RESISTANCE 1 (BR1) was identified and found through gene structural variation analyses to be more highly conserved in Chinese cabbage than in other available accessions. The expression of BR1 was increased in bolting resistant Chinese cabbage and decreased in bolting non-resistant type, and the expression of some mark genes were consist with bolting resistance phenotype. BR1 is primarily expressed in leaves at the vegetative growth stage, and the highest BR1 expression levels during the flowering stage were observed in the flower buds and silique as compared to other tissue types. The overexpression of BR1 in Arabidopsis was associated with enhanced bolting resistance under long day (LD) conditions, with these transgenic plants exhibiting significant decreases in stem height, rosette radius, and chlorophyll content. Transcriptomic sequencing of WT and BR1OE plants showed the association of BR1 with other bolting resistance genes. Transcriptomic sequencing and qPCR revealed that six flowering integrator genes and one chlorophyll biosynthesis-related gene were downregulated following BR1 overexpression. Six key genes in photoperiodic flowering pathway exhibited downward expression trends in BR1OE plants, while the expression of floral repressor AtFLC gene was upregulated. The transcripts of these key genes were consistent with observed phenotypes in BR1OE plants, and the results indicated that BR1 may function through vernalization and photoperiodic pathway. Instead, the protein encoded by BR1 gene was subsequently found to localize to the nucleus. Taken together, we first propose that orphan gene BR1 functions as a novel regulator of flowering time, and these results suggested that BR1 may represent a promising candidate gene to support the selective breeding of Chinese cabbage cultivars with enhanced bolting resistance.

Revealing Genetic Variations Associated with Chip-Processing Properties in Potato (Solanum tuberosum L.)

Although the potato chip industry is booming, and distinct chip-processing clones have been released over the past 60 years, the genetic architecture of their chip-processing characteristics remains largely unknown. Case-control genome-wide association studies (GWAS) with SolCAP SNP array data for chip-processing clones versus all other market classes in the 393-line potato diversity panel were performed using the GWASpoly R package, enabling detection of significant signals on chromosome 10. Our results were replicated using internal replication of a strata-corrected 190-line panel. Furthermore, the genomic scans employing selective sweep approaches such as the cross-population composite likelihood ratio method (XP-CLR) and PCAdapt redetected the same signals as those in our GWAS. Through applications of four selective sweep approaches, various genetic variants were found across the genome that had been differentially selected. These genomic regions under selection along with transcriptomic data analysis are involved in carbohydrate metabolism-related genes or loci and transcription factors, indicating to be associated with the improvement of chip-processing performance of potato cultivars. Kompetitive allele-specific PCR (KASP) assays were designed for the causal SNPs to use in validating the chip-processing clones. The results could have implications for genomics-assisted breeding of the promising chip-processing cultivars in potato.