Genetic improvement of Egyptian cotton (Gossypium barbadense L.) for high yield and fiber quality properties under semi arid conditions.

Between 2016 and 2018, the Agriculture Research Center's Sakha Agriculture Research Station conducted two rounds of pedigree selection on a segregating population of cotton (Gossypium barbadense L.) using the F2, F3, and F4 generations resulting from crossing Giza 94 and Suvin. In 2016, the top 5% of plants from the F2 population were selected based on specific criteria. The superior families from the F3 generation were then selected to produce the F4 families in 2017, which were grown in the 2018 summer season in single plant progeny rows and bulk experiments with a randomized complete block design of three replications. Over time, most traits showed increased mean values in the population, with the F2 generation having higher Genotypic Coefficient of Variance (GCV) and Phenotypic Coefficient of Variance (PCV) values compared to the succeeding generations for the studied traits. The magnitude of GCV and PCV in the F3 and F4 generations was similar, indicating that genotype had played a greater role than the environment. Moreover, the mean values of heritability in the broad sense increased from generation to generation. Selection criteria I2, I4, and I5 were effective in improving most of the yield and its component traits, while selection criterion I1 was efficient in improving earliness traits. Most of the yield and its component traits showed a positive and significant correlation with each other, highlighting their importance in cotton yield. This suggests that selecting to improveone or more of these traits would improve the others. Families number 9, 13, 19, 20, and 21 were the best genotypes for relevant yield characters, surpassing the better parent, check variety, and giving the best values for most characters. Therefore, the breeder could continue to use these families in further generations as breeding genotypes to develop varieties with high yields and its components.

Silver nanoparticle-induced in vitro flowering in Dendrocalamus strictus (Roxb.) nees and genetic fidelity assessment of regenerants using molecular markers.

BACKGROUND: Dendrocalamus strictus (Roxb.) Nees, generally referred to as 'Male bamboo,' is a globally prevalent and highly significant species of bamboo. It is a versatile species and possesses notable industrial significance. However, despite its numerous applications, the production of this plant is insufficient to fulfill the worldwide demand. The challenges that impede the dissemination of D. strictus encompass the unpredictable blooming pattern (30-70 years), low seed production, and limited seed viability. Therefore, tissue culture presents a reliable and effective option for the mass production of standardized planting material. METHODOLOGY AND RESULTS: This study investigated the effects of silver nanoparticles (AgNPs) at a concentration of 6.0 mg L- 1 in the Murashige and Skoog (MS) nutrient medium fortified with pre-optimized plant growth regulators (3.0 mg L- 1 6-benzylaminopurine + 0.5 mg L- 1 α-naphthalene acetic acid) on the induction of flowering in a controlled environment in D. strictus. The use of AgNPs in the media induced a maximum of 14 inflorescences per culture vessel, 9 flowers per inflorescence, and improved the performance of the micropropagated plantlets during acclimatization in the greenhouse and field. The ISSR and SCoT amplified polymorphic DNA analysis of the regenerants resulted in the formation of 49 bands (300 to 2000 bp size) and 36 scorable bands (350 to 2000 bp) respectively. All the PCR amplicons produced by SCoT and ISSR were monomorphic confirming the genetic uniformity of the tissue cultured plants of D. strictus with the mother plant. CONCLUSIONS: It can be inferred that the incorporation of AgNPs during the shoot proliferation phase has the potential to stimulate in vitro flowering in D. strictus. This finding could provide valuable insights into innovative strategies for enhancing crop productivity and genetic manipulation for accelerated breeding and agricultural advancement.

Automated imaging coupled with AI-powered analysis accelerates the assessment of plant resistance to Tetranychus urticae.

The two-spotted spider mite (TSSM), Tetranychus urticae, is among the most destructive piercing-sucking herbivores, infesting more than 1100 plant species, including numerous greenhouse and open-field crops of significant economic importance. Its prolific fecundity and short life cycle contribute to the development of resistance to pesticides. However, effective resistance loci in plants are still unknown. To advance research on plant-mite interactions and identify genes contributing to plant immunity against TSSM, efficient methods are required to screen large, genetically diverse populations. In this study, we propose an analytical pipeline utilizing high-resolution imaging of infested leaves and an artificial intelligence-based computer program, MITESPOTTER, for the precise analysis of plant susceptibility. Our system accurately identifies and quantifies eggs, feces and damaged areas on leaves without expert intervention. Evaluation of 14 TSSM-infested Arabidopsis thaliana ecotypes originating from diverse global locations revealed significant variations in symptom quantity and distribution across leaf surfaces. This analytical pipeline can be adapted to various pest and host species, facilitating diverse experiments with large specimen numbers, including screening mutagenized plant populations or phenotyping polymorphic plant populations for genetic association studies. We anticipate that such methods will expedite the identification of loci crucial for breeding TSSM-resistant plants.

Chromosome-level genome assembly of milk thistle (Silybum marianum (L.) Gaertn.).

Silybum marianum (L.) Gaertn., commonly known as milk thistle, is a medicinal plant belonging to the Asteraceae family. This plant has been recognized for its medicinal properties for over 2,000 years. However, the genome of this plant remains largely undiscovered, having no reference genome at a chromosomal level. Here, we assembled the chromosome-level genome of S. marianum, allowing for the annotation of 53,552 genes and the identification of transposable elements comprising 58% of the genome. The genome assembly from this study showed 99.1% completeness as determined by BUSCO assessment, while the previous assembly (ASM154182v1) showed 36.7%. Functional annotation of the predicted genes showed 50,329 genes (94% of total genes) with known protein functions in public databases. Comparative genome analysis among Asteraceae plants revealed a striking conservation of collinearity between S. marianum and C. cardunculus. The genomic information generated from this study will be a valuable resource for milk thistle breeding and for use by the larger research community.

Genome-wide identification and in-silico expression analysis of CCO gene family in sunflower (Helianthus annnus) against abiotic stress.

Carotenoid cleavage oxygenases (CCOs) enzymes play an important role in plant growth and development by producing a wide array of apocarotenoids and their derivatives. These compounds are vital for colouring flowers and fruits and synthesizing plant hormones such as abscisic acid and strigolactones. Despite their importance, the gene family responsible for CCO enzymes in sunflowers has not been identified. In this study, we identify the CCO genes of the sunflower plant to fill this knowledge gap. Phylogenetic and synteny analysis indicated that the Helianthus annnus CCO (HaCCO) genes were conserved in different plant species and they could be divided into three subgroups based on their conserved domains. Analysis using MEME tool and multiple sequence alignment identified conserved motifs in the HaCCO gene sequence. Cis-regulatory elements (CREs) analysis of the HaCCO genes indicated the presence of various responsive elements related to plant hormones, development, and responses to both biotic and abiotic stresses. This implies that these genes may respond to plant hormones, developmental cues, and drought stress, offering potential applications in the development of more resistant crops. Genes belonging to the 9-cis-epoxy carotenoid dioxygenases (NCED) subgroups predominantly exhibited chloroplast localization, whereas the genes found in other groups are primarily localized in the cytoplasm. These 21 identified HaCCOs were regulated by 60 miRNAs, indicating the crucial role of microRNAs in gene regulation in sunflowers. Gene expression analysis under drought stress revealed significant up-regulation of HaNCED16 and HaNCED19, genes that are pivotal in ABA hormone biosynthesis. During organ-specific gene expression analysis, HaCCD12 and HaCCD20 genes exhibit higher activity in leaves, indicating a potential role in leaf pigmentation. This study provides a foundation for future research on the regulation and functions of the CCO gene family in sunflower and beyond. There is potential for developing molecular markers that could be employed in breeding programs to create new sunflower lines resistant to biotic and abiotic stresses.

A chromosomal-scale genome assembly of modern cultivated hybrid sugarcane provides insights into origination and evolution.

Sugarcane is a vital crop with significant economic and industrial value. However, the cultivated sugarcane's ultra-complex genome still needs to be resolved due to its high ploidy and extensive recombination between the two subgenomes. Here, we generate a chromosomal-scale, haplotype-resolved genome assembly for a hybrid sugarcane cultivar ZZ1. This assembly contains 10.4 Gb genomic sequences and 68,509 annotated genes with defined alleles in two sub-genomes distributed in 99 original and 15 recombined chromosomes. RNA-seq data analysis shows that sugar accumulation-associated gene families have been primarily expanded from the ZZSO subgenome. However, genes responding to pokkah boeng disease susceptibility have been derived dominantly from the ZZSS subgenome. The region harboring the possible smut resistance genes has expanded significantly. Among them, the expansion of WAK and FLS2 families is proposed to have occurred during the breeding of ZZ1. Our findings provide insights into the complex genome of hybrid sugarcane cultivars and pave the way for future genomics and molecular breeding studies in sugarcane.

Mapping the race between crop phenology and climate risks for wheat in France under climate change.

Climate change threatens food security by affecting the productivity of major cereal crops. To date, agroclimatic risk projections through indicators have focused on expected hazards exposure during the crop's current vulnerable seasons, without considering the non-stationarity of their phenology under evolving climatic conditions. We propose a new method for spatially classifying agroclimatic risks for wheat, combining high-resolution climatic data with a wheat's phenological model. The method is implemented for French wheat involving three GCM-RCM model pairs and two emission scenarios. We found that the precocity of phenological stages allows wheat to avoid periods of water deficit in the near future. Nevertheless, in the coming decades the emergence of heat stress and increasing water deficit will deteriorate wheat cultivation over the French territory. Projections show the appearance of combined risks of heat and water deficit up to 4 years per decade under the RCP 8.5 scenario. The proposed method provides a deep level of information that enables regional adaptation strategies: the nature of the risk, its temporal and spatial occurrence, and its potential combination with other risks. It's a first step towards identifying potential sites for breeding crop varieties to increase the resilience of agricultural systems.

Molecular mapping of the broad bean wilt virus 2 resistance locus bwvr in Capsicum annuum using BSR-seq.

KEY MESSAGE: Bulked segregant RNA seq of pools of pepper accessions that are susceptible or resistant to Broad bean wilt virus 2 identifies a gene that might confer resistance to this devastating pathogen. The single-stranded positive-sense RNA virus Broad bean wilt virus 2 (BBWV2) causes substantial damage to pepper (Capsicum annuum) cultivation. Here, we describe mapping the BBWV2 resistance locus bwvr using a F7:8 recombinant inbred line (RIL) population constructed by crossing the BBWV2-resistant pepper accession 'SNU-C' with the susceptible pepper accession 'ECW30R.' All F1 plants infected with the BBWV2 strain PAP1 were susceptible to the virus, and the RIL population showed a 1:1 ratio of resistance to susceptibility, indicating that this trait is controlled by a single recessive gene. To map bwvr, we performed bulked segregant RNA-seq (BSR-seq). We sequenced pools of resistant and susceptible lines from the RILs and aligned the reads to the high-quality 'Dempsey' reference genome to identify variants between the pools. This analysis identified 519,887 variants and selected the region from 245.9-250.8 Mb of the Dempsey reference genome as the quantitative trait locus region for bwvr. To finely map bwvr, we used newly designed high-resolution melting (HRM) and Kompetitive allele specific PCR (KASP) markers based on variants obtained from the BSR-seq reads and the PepperSNP16K array. Comparative analysis identified 11 SNU-C-specific SNPs within the bwvr locus. Using markers derived from these variants, we mapped the candidate bwvr locus to the region from 246.833-246.949 kb. SNU-C-specific variants clustered near DEM.v1.00035533 within the bwvr locus. DEM.v1.00035533 encodes the nitrate transporter NPF1.2 and contains a SNP within its 5' untranslated region. The bwvr locus, which contains four genes including DEM.v1.00035533, could represent a valuable resource for global pepper breeding programs.

Morphological and pomological assessments of seedling-originated walnut (Juglans regia L.) trees to select the promising late-leafing genotypes.

BACKGROUND: In many parts of the world, including Iran, walnut (Juglans regia L.) production is limited by late-spring frosts. Therefore, the use of late-leafing walnuts in areas with late-spring frost is the most important method to improve yield. In the present study, the phenotypic diversity of 141 seedling genotypes of walnut available in the Senejan area, Arak region, Markazi province, Iran was studied based on morphological traits to obtain superior late-leafing genotypes in the cropping seasons of 2022 and 2023. RESULTS: Based on the results of the analysis of variance, the studied genotypes showed a significant variation in terms of most of the studied morphological and pomological traits. Therefore, it is possible to choose genotypes for different values ​​of a trait. Kernel weight showed positive and significant correlations with leaf length (r = 0.32), leaf width (r = 0.33), petiole length (r = 0.26), terminal leaflet length (r = 0.34), terminal leaflet width (r = 0.21), nut length (r = 0.48), nut width (r = 0.73), nut weight (r = 0.83), kernel length (r = 0.64), and kernel width (r = 0.89). The 46 out of 141 studied genotypes were late-leafing and were analyzed separately. Among late-leafing genotypes, the length of the nut was in the range of 29.33-48.50 mm, the width of the nut was in the range of 27.51-39.89 mm, and nut weight was in the range of 8.18-16.06 g. The thickness of shell was in the range of 1.11-2.60 mm. Also, kernel length ranged from 21.97-34.84 mm, kernel width ranged from 21.10-31.09 mm, and kernel weight ranged from 3.10-7.97 g. CONCLUSIONS: Based on important and commercial traits in walnut breeding programs, such as nut weight, kernel weight, kernel percentage, kernel color, and ease of kernel removal from nuts, 15 genotypes, including no. 92, 91, 31, 38, 33, 18, 93, 3, 58, 108, 16, 70, 15, 82, and 32 were superior and could be used in walnut breeding programs in line with the introduction of new cultivars and the revival of traditional walnut orchards to commercialize them.

Biological characteristics of Cordyceps militaris single mating-type strains.

Cordyceps militaris has been extensively cultivated as a model cordyceps species for commercial purposes. Nevertheless, the problems related to strain degeneration and breeding technologies remain unresolved. This study assessed the physiology and fertility traits of six C. militaris strains with distinct origins and characteristics, focusing on single mating-type strains. The results demonstrated that the three identified strains (CMDB01, CMSY01, and CMJB02) were single mating-type possessing only one mating-type gene (MAT1-1). In contrast, the other three strains (CMXF07, CMXF09, and CMMS05) were the dual mating type. The MAT1-1 strains sourced from CMDB01, CMSY01, and CMJB02 consistently produced sporocarps but failed to generate ascospores. However, when paired with MAT1-2 strains, the MAT1-1 strains with slender fruiting bodies and normal morphology were fertile. The hyphal growth rate of single mating-type strains (CMDB01, CMSY01, and CMJB02) typically surpassed that of dual mating-type strains (CMXF07, CMXF09, and CMMS05). The growth rates of MAT1-2 and MAT1-1 strains were proportional to their ratios, such that a single mating-type strain with a higher ratio exhibited an increased growth rate. As C. militaris matured, the adenosine content decreased. In summary, the C. militaris strains that consistently produce sporocarps and have a single mating type are highly promising for production and breeding.

Deciphering the differential expression patterns of yield-related negative regulators in hexaploid wheat cultivars and hybrids at different growth stages.

BACKGROUND: Hexaploid bread wheat underwent a series of polyploidization events through interspecific hybridizations that conferred adaptive plasticity and resulted in duplication and neofunctionalization of major agronomic genes. The genetic architecture of polyploid wheat not only confers adaptive plasticity but also offers huge genetic diversity. However, the contribution of different gene copies (homeologs) encoded from different subgenomes (A, B, D) at different growth stages remained unexplored. METHODS: In this study, hybrid of elite cultivars of wheat were developed via reciprocal crosses (cytoplasm swapping) and phenotypically evaluated. We assessed differential expression profiles of yield-related negative regulators in these cultivars and their F1 hybrids and identified various cis-regulatory signatures by employing bioinformatics tools. Furthermore, the preferential expression patterns of the syntenic triads encoded from A, B, and D subgenomes were assessed to decipher their functional redundancy at six different growth stages. RESULTS: Hybrid progenies showed better heterosis such as up to 17% increase in the average number of grains and up to 50% increase in average thousand grains weight as compared to mid-parents. Based on the expression profiling, our results indicated significant dynamic transcriptional expression patterns, portraying the different homeolog-dominance at the same stage in the different cultivars and their hybrids. Albeit belonging to same syntenic triads, a dynamic trend was observed in the regulatory signatures of these genes that might be influencing their expression profiles. CONCLUSION: These findings can substantially contribute and provide insights for the selective introduction of better cultivars into traditional and hybrid breeding programs which can be harnessed for the improvement of future wheat.

Characterization and expression profiles of the ZmLBD gene family in Zea mays.

BACKGROUND: The Lateral Organ Boundaries Domain (LBD) gene family is a family of plant-specific transcription factors (TFs) that are widely involved in processes such as lateral organ formation, stress response, and nutrient metabolism. However, the function of LBD genes in maize remains poorly understood. METHODS AND RESULTS: In this study, a total of 49 ZmLBD genes were identified at the genome-wide level of maize, they were classified into nine branches based on phylogenetic relationships, and all of them were predicted to be nuclear localized. The 49 ZmLBD genes formed eight pairs of segmental duplicates, and members of the same branches' members had similar gene structure and conserved motif composition. The promoters of ZmLBD genes contain multiple types of cis-acting elements. In addition, by constructing the regulatory network of ZmLBD and other genes and miRNAs, 12 and 22 ZmLBDs were found to be involved in the gene regulatory network and miRNA regulatory network, respectively. The expression pattern analysis suggests that ZmLBD genes may be involved in different biological pathways, and drought stress induced the expressions of two inbred lines. CONCLUSIONS: The findings enhance our comprehension of the potential roles of the ZmLBD gene family in maize growth and development, which is pivotal for genetic enhancement and breeding efforts pertaining to this significant crop.

Evaluation of the effect of Carica papaya seed on the growth performance of fattening rabbits.

Successful breeding depends on feeding. The present study aims to evaluate the Carica papaya seed effect on the growth performance of rabbits. The zootechnical parameters studied are weight growth, average daily gain, Feed Conversion Ratio, and carcass characteristics of kits. The experiment was conducted on 48 rabbits, divided into 4 groups, for 6 weeks. Forty-eight rabbits were divided into four (04) groups of 3 repetitions of 4 rabbits. The animals were fed diets containing various levels of papaya seed powder at variable contents: 0% (group T0), 4% (group T1), 6% (group T2), and 8% (group T3). At the end of the experiment, three animals were slaughtered in each animal group to assess the quality of the carcasses and organs. 6% of the seeds of Carica papaya significantly improved (p < 0.05) the average daily gain of the kits: T2 (22.40 g / d) compared to the T0 group (11.32 g / d), T1 (12.20 g / d) and T3 (17.53 g / d). The best Feed Conversion Ratio (0.80) was recorded in the animals of group T2. In contrast, the highest carcass yield was recorded in the rabbits of group T3 (62.70%). In conclusion, 6% was optimal in the feed rations of fattened rabbits to improve production performance. Breeders can consider the benefits of introducing Carica papaya seeds into the rabbits' diet.

Peanut LEAFY COTYLEDON1-type genes participate in regulating the embryo development and the accumulation of storage lipids.

KEY MESSAGE: Two peanut LEC1-type genes exhibit partial functional redundancy. AhNFYB10 could complement almost all the defective phenotypes of lec1-2 in terms of embryonic morphology, while AhNF-YB1 could partially affect these phenotypes. LEAFY COTYLEDON1 (LEC1) is a member of the nuclear factor Y (NF-Y) family of transcription factors and has been identified as a key regulator of embryonic development. In the present study, two LEC1-type genes from Arachis hypogeae were identified and designated as AhNF-YB1 and AhNF-YB10; these genes belong to subgenome A and subgenome B, respectively. The functions of AhNF-YB1 and AhNF-YB10 were investigated by complementation analysis of their defective phenotypes of the Arabidopsis lec1-2 mutant and by ectopic expression in wild-type Arabidopsis. The results indicated that both AhNF-YB1 and AhNF-YB10 participate in regulating embryogenesis, embryo development, and reserve deposition in cotyledons and that they have partial functional redundancy. In contrast, AhNF-YB10 complemented almost all the defective phenotypes of lec1-2 in terms of embryonic morphology and hypocotyl length, while AhNF-YB1 had only a partial effect. In addition, 30-40% of the seeds of the AhNF-YB1 transformants exhibited a decreasing germination ratio and longevity. Therefore, appropriate spatiotemporal expression of these genes is necessary for embryo morphogenesis at the early development stage and is responsible for seed maturation at the mid-late development stage. On the other hand, overexpression of AhNF-YB1 or AhNF-YB10 at the middle to late stages of Arabidopsis seed development improved the weight, oil content, and fatty acid composition of the transgenic seeds. Moreover, the expression levels of several genes associated with fatty acid synthesis and embryogenesis were significantly greater in developing AhNF-YB10-overexpressing seeds than in control seeds. This study provides a theoretical basis for breeding oilseed crops with high yields and high oil content.

Identification of superior and rare haplotypes to optimize branch number in soybean.

KEY MESSAGE: Using the integrated approach in the present study, we identified eleven significant SNPs, seven stable QTLs and 20 candidate genes associated with branch number in soybean. Branch number is a key yield-related quantitative trait that directly affects the number of pods and seeds per soybean plant. In this study, an integrated approach with a genome-wide association study (GWAS) and haplotype and candidate gene analyses was used to determine the detailed genetic basis of branch number across a diverse set of soybean accessions. The GWAS revealed a total of eleven SNPs significantly associated with branch number across three environments using the five GWAS models. Based on the consistency of the SNP detection in multiple GWAS models and environments, seven genomic regions within the physical distance of ± 202.4 kb were delineated as stable QTLs. Of these QTLs, six QTLs were novel, viz., qBN7, qBN13, qBN16, qBN18, qBN19 and qBN20, whereas the remaining one, viz., qBN12, has been previously reported. Moreover, 11 haplotype blocks, viz., Hap4, Hap7, Hap12, Hap13A, Hap13B, Hap16, Hap17, Hap18, Hap19A, Hap19B and Hap20, were identified on nine different chromosomes. Haplotype allele number across the identified haplotype blocks varies from two to five, and different branch number phenotype is regulated by these alleles ranging from the lowest to highest through intermediate branching. Furthermore, 20 genes were identified underlying the genomic region of ± 202.4 kb of the identified SNPs as putative candidates; and six of them showed significant differential expression patterns among the soybean cultivars possessing contrasting branch number, which might be the potential candidates regulating branch number in soybean. The findings of this study can assist the soybean breeding programs for developing cultivars with desirable branch numbers.

Identification of a novel marker and its associated laccase gene for regulating ear length in tropical and subtropical maize lines.

KEY MESSAGE: This study revealed the identification of a novel gene, Zm00001d042906, that regulates maize ear length by modulating lignin synthesis and reported a molecular marker for selecting maize lines with elongated ears. Maize ear length has garnered considerable attention due to its high correlation with yield. In this study, six maize inbred lines of significant importance in maize breeding were used as parents. The temperate maize inbred line Ye107, characterized by a short ear, was crossed with five tropical or subtropical inbred lines featuring longer ears, creating a multi-parent population displaying significant variations in ear length. Through genome-wide association studies and mutation analysis, the A/G variation at SNP_183573532 on chromosome 3 was identified as an effective site for discriminating long-ear maize. Furthermore, the associated gene Zm00001d042906 was found to correlate with maize ear length. Zm00001d042906 was functionally annotated as a laccase (Lac4), which showed activity and influenced lignin synthesis in the midsection cells of the cob, thereby regulating maize ear length. This study further reports a novel molecular marker and a new gene that can assist maize breeding programs in selecting varieties with elongated ears.

Coadaptation of coexisting plants enhances productivity in an agricultural system.

Growing crops in more diverse crop systems (i.e., intercropping) is one way to produce food more sustainably. Even though intercropping, compared to average monocultures, is generally more productive, the full yield potential of intercropping might not yet have been achieved as modern crop cultivars are bred to be grown in monoculture. Breeding plants for more familiarity in mixtures, i.e., plants that are adapted to more diverse communities (i.e., adaptation) or even to coexist with each other (i.e., coadaptation) might have the potential to sustainably enhance productivity. In this study, the productivity benefits of familiarity through evolutionary adaptation and coevolutionary coadaptation were disentangled in a crop system through an extensive common garden experiment. Furthermore, evolutionary and coevolutionary effects on species-level and community-level productivity were linked to corresponding changes in functional traits. We found evidence for higher productivity and trait convergence with increasing familiarity with the plant communities. Furthermore, our results provide evidence for the coevolution of plants in mixtures leading to higher productivity of coadapted species. However, with the functional traits measured in our study, we could not fully explain the productivity benefits found upon coevolution. Our study investigated coevolution among randomly interacting plants and was able to demonstrate that coadaptation through coevolution of coexisting species in mixtures occurs and promotes ecosystem functioning (i.e., higher productivity). This result is particularly relevant for the diversification of agricultural and forest ecosystems, demonstrating the added value of artificially selecting plants for the communities they are familiar with.

[Metabolomics of quality formation of different cultivars of Peucedanum praeruptorum].

This study aims to reveal the quality formation of different cultivars of Peucedanum praeruptorum based on the metabolic differences and provide a theoretical basis for the development and utilization of this medicinal herb. The non-target metabonomics analysis based on ultra-high performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS) was conducted for six cultivars(YS, H, LZ, LY, LX, and Z) of P. praeruptorum of the same origin and at the same development stage. The principal component analysis, orthogonal partial least squares discriminant analysis, and univariate statistical analysis were carried out to screen the differential metabolites of different cultivars. The potential biomarkers associated with quality formation were predicted based on the mass-to-charge ratio, Kyoto Encyclopedia of Genes and Genomes pathway enrichment, information of relevant literature, and correlation analysis. The results showed that metabolites differed significantly among the six cultivars, and 571 and 465 differential metabolites were obtained in the positive and negative ion modes, respectively. From the differential metabolites, 22 potential biomarkers related to quality formation were predicted, which involved 9 metabolic pathways, including phenylalanine, tyrosine and tryptophan biosynthesis, biosynthesis of phenylpropanoids, and biosynthesis of plant hormones. Compared with the YS cultivar, other cultivars showed decreased concentrations of psoralen, imperatorin, and luvangetin and increased concentrations of 7-hydroxycoumarine, esculetin, columbianetin, and jasmonic acid, which were involved in the biosynthesis of phenylpropanoids. The concentrations of 2-succinylbenzoate, heraclenol, and L-tyrosine involved in other metabolic pathways decreased, especially in the Z and H cultivars. Therefore, regulating the biosynthesis of phenylpropanoids is one of the key mechanisms for improving the cultivar quality of P. praeruptorum. The Z and H cultivars have better quality and metabolic processes than other cultivars and thus can be used for the screening and breeding of high-quality germplasm.

[Simultaneous determination of seven artemisinin-related compounds in Artemisia annua by UPLC-QQQ-MS/MS].

A variety of compounds in Artemisia annua were simultaneously determined to evaluate the quality of A. annua from multiple perspectives. A method based on ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry(UPLC-QQQ-MS/MS) was established for the simultaneous determination of seven compounds: amorpha-4,11-diene, artemisinic aldehyde, dihydroartemisinic acid, artemisinic acid, artemisinin B, artemisitene, and artemisinin, in A. annua. The content of the seven compounds in different tissues(roots, stems, leaves, and lateral branches) of A. annua were compared. The roots, stems, leaves, and lateral branches of four-month-old A. annua were collected and the content of seven artemisinin-related compounds in different tissues was determined. A multi-reaction monitoring(MRM) acquisition mode of UPLC-QQQ-MS/MS was used, with a positive ion mode of atmospheric pressure chemical ion source(APCI). Chromatographic separation was achieved on an Eclipse Plus RRHD C_(18) column(2.1 mm×50 mm, 1.8 µm). The gradient elution was performed with the mobile phase consisted of formic acid(0.1%)-ammonium formate(5 mmol·L~(-1))(A) and the methanol(B) gradient program of 0-8 min, 55%-100% B, 8-11 min, 100% B, and equilibrium for 3 min, the flow rate of 0.6 mL·min~(-1), the column temperature of 40 ℃, the injection volume of 5 µL, and the detection time of 8 min. Through methodological investigation, a method based on UPLC-QQQ-MS/MS was established for the simultaneous quantitative determination of seven representative compounds involved in the biosynthesis of artemisinin. The content of artemisinin in A. annua was higher than that of artemisinin B, and the content of artemisinin and dihydroartemisinic acid were high in all the tissues of A. annua. The content of the seven compounds varied considerably in different tissues, with the highest levels in the leaves and neither artemisinene nor artemisinic aldehyde was detected in the roots. In this study, a quantitative method based on UPLC-QQQ-MS/MS for the simultaneous determination of seven representative compounds involved in the biosynthesis of artemisinin was established, which was accurate, sensitive, and highly efficient, and can be used for determining the content of artemisinin-related compounds in A. annua, breeding new varieties, and controlling the quality of Chinese medicinal materials.

QTL mapping and candidate gene analysis reveal two major loci regulating green leaf color in non-heading Chinese cabbage.

KEY MESSAGE: Two major-effect QTL GlcA07.1 and GlcA09.1 for green leaf color were fine mapped into 170.25 kb and 191.41 kb intervals on chromosomes A07 and A09, respectively, and were validated by transcriptome analysis. Non-heading Chinese cabbage (NHCC) is a leafy vegetable with a wide range of green colors. Understanding the genetic mechanism behind broad spectrum of green may facilitate the breeding of high-quality NHCC. Here, we used F2 and F7:8 recombination inbred line (RIL) population from a cross between Wutacai (dark-green) and Erqing (lime-green) to undertake the genetic analysis and quantitative trait locus (QTL) mapping in NHCC. The genetic investigation of the F2 population revealed that the variation of green leaf color was controlled by two recessive genes. Six pigments associated with green leaf color, including total chlorophyll, chlorophyll a, chlorophyll b, total carotenoids, lutein, and carotene were quantified and applied for QTL mapping in the RIL population. A total of 7 QTL were detected across the whole genome. Among them, two major-effect QTL were mapped on chromosomes A07 (GlcA07.1) and A09 (GlcA09.1) corresponding to two QTL identified in the F2 population. The QTL GlcA07.1 and GlcA09.1 were further fine mapped into 170.25 kb and 191.41 kb genomic regions, respectively. By comparing gene expression level and gene annotation, BraC07g023810 and BraC07g023970 were proposed as the best candidates for GlcA07.1, while BraC09g052220 and BraC09g052270 were suggested for GlcA09.1. Two InDel molecular markers (GlcA07.1-BcGUN4 and GlcA09.1-BcSG1) associated with BraC07gA023810 and BraC09g052220 were developed and could effectively identify leaf color in natural NHCC accessions, suggesting their potential for marker-assisted leaf color selection in NHCC breeding.