F1 Generation Research Articles

Genetics of Fruit Yield and Its Traits in Okra [Abelmoschus esculentus (L.) Moench

A Half-diallel mating design involving nine okra genotypes was used to study the inheritance of fruit yield and its component characters in okra. Data from the F1 generation and parents were analysed using Hayman's (1954) method of diallel analysis. The estimated component of genetic variation revealed that additive component (D) was significant for number of branches per plant and fruit girth in E1 and fruit girth in E3 environment. However, additive component was non-significant in all three environments for fruit yield per plant. The dominant components (H1 and H2) were significant for all the characters in all the environments. These results revealed the importance of both additive and non-additive component of gene action in the expression of traits under study. The relative magnitude of dominant component (H1 and H2) was higher than additive component for most of the traits indicating that dominance gene action involved in expression of most of the characters under studied. The average degree of dominance for fruit yield per plant and most of the traits was more than unity in all the three environments which suggested over dominance effect in expression of all the traits. The proportion of genes with positive and negative effects in parents was deviated from 0.25 in all three environments suggesting asymmetrical distribution of positive as well as negative alleles among the parents for fruit yield per plant. The ratio of dominant and recessive genes in the parents were also greater than unity in all the three environments, indicated excess of dominant genes were present in the parents for fruit yield per plant. In the presence of overdominance for yield, reciprocal recurrent selection is the best recurrent scheme to develop hybrids.

Epigenetic transgenerational inheritance of toxicant exposure-specific non-coding RNA in sperm.

Environmentally induced epigenetic transgenerational inheritance of phenotypic variation and disease susceptibility requires the germ cell (sperm or egg) transmission of integrated epigenetic mechanisms involving DNA methylation, histone modifications, and non-coding RNA (ncRNA) actions. Previous studies have demonstrated that transgenerational exposure and disease-specific differential DNA methylation regions (DMRs) in sperm are observed and that ncRNA-mediated DNA methylation occurs. The current study was designed to determine if transgenerational exposure-specific ncRNAs exist in sperm. Specifically, toxicants with distinct mechanisms of action including the fungicide vinclozolin (anti-androgenic), pesticide dichlorodiphenyltrichloroethane (estrogenic), herbicide atrazine (endocrine disruptor at cyclic adenosine monophosphate level), and hydrocarbon mixture jet fuel (JP8) (aryl hydrocarbon receptor disruptor) were used to promote transgenerational disease phenotypes in F3 generation outbred rats. New aliquots of sperm, previously collected and used for DNA methylation analyses, were used in the current study for ncRNA sequencing analyses of nuclear RNA. Significant changes in transgenerational sperm ncRNA were observed for each transgenerational exposure lineage. The majority of ncRNA was small noncoding RNAs including piwi-interacting RNA, tRNA-derived small RNAs, microRNAs, rRNA-derived small RNA, as well as long ncRNAs. Although there was some overlap among the different classes of ncRNA across the different exposures, the majority of differentially expressed ncRNAs were exposure-specific with no overlapping ncRNA between the four different exposure lineages in the transgenerational F3 generation sperm nuclear ncRNAs. The ncRNA chromosomal locations and gene associations were identified for a small number of differential expressed ncRNA. Interestingly, an overlap analysis between the transgenerational sperm DMRs and ncRNA chromosomal locations demonstrated small populations of overlapping ncRNA, but a large population of non-overlapping ncRNAs. Observations suggest that transgenerational sperm ncRNAs have both exposure-specific populations within the different classes of ncRNA, as well as some common populations of ncRNAs among the different exposures. The lack of co-localization of many of the ncRNAs with previously identified transgenerational DMRs suggests a distal integration of the different epigenetic mechanisms. The potential use of ncRNA analyses for transgenerational toxicant exposure assessment appears feasible.

Genetic Component Analysis in Fruit Yield and Quality Traits in Okra [Abelmoschus esculentus (L.) Moench

A half-diallel cross involving nine okra genotypes was utilized to investigate the inheritance of fruit yield and its component traits. Data from the F1 generation and the parent genotypes were analysed using Hayman's (1954) diallel method. The additive genetic component (D) was found to be significant for the traits like days to last picking in environment E1, and for the number of fruits per plant in environments E2 and E3, but non-significant across all environments for fruit yield per plant. The dominant components (H1 and H2) were found significant for all traits studied under all environmental condition. This revealed that both additive and non-additive gene actions play a vital role in the expression of the traits studied. The dominant component's (H1 and H2) relative magnitude was greater than the additive component for most of the traits, suggesting the importance of dominance effects on expression of those traits. The average degree of dominance showed an overdominance effect for the traits studied. The ratio of dominant to recessive genes indicated that the parents had an excess of dominant genes for fruit yield per plant. Thus stated the presence of overdominance for yield, reciprocal technique is the most effective recurrent breeding scheme for producing improved hybrids.

Multigenerational expression of antimicrobial peptides in Aedes aegypti exposed to Metarhizium anisopliae: Is trans-generational immune priming involved?

We assessed, for the first time, a multigenerational expression of antimicrobial peptides (AMPs) in Aedes aegypti larvae exposed to the entomopathogenic fungus, Metarhizium anisopliae, and correlated it with a possible involvement in trans-generational immune priming (TGIP). Aedes aegypti larvae were first exposed to blastospores or conidia of M. anisopliae CG 489 for 24 and 48 h, and the relative expression of AMPs were measured using quantitative Real-Time PCR. A suspension of conidia was prepared, and two different survival tests were conducted with different larval generations (F0, F1, and F2). In the first bioassay, the survival curves of the three generations were conducted separately and compared with their respective control groups. In the other bioassay, the survival curves of the F0, F1, and F2 generations were compared simultaneously against a naïve group exposed to Tween 80. In both survival tests, the F0 generation was more susceptible to M. anisopliae than subsequent generations. For molecular analyses related to TGIP, F0, F1, and F2 larvae were exposed to conidia, and their expression of AMPs was compared with their control groups and a naïve group. There was no differential expression of cecropin, defensin A or cathepsin B between generations. Lysozyme C, however, showed an increase in expression across generations, suggesting a role in TGIP. These discoveries may help us develop biological insecticides against mosquito larvae based on entomopathogenic fungi.

Mixture effect of parental exposure to triazophos and fenvalerate on the early development of zebrafish offspring

Triazophos (TRI) and fenvalerate (FEN) have been extensively used in the world and frequently coexist in the water environments, might pose health risk to aquatic species. However, investigations of their mixture toxic effects on offspring after parental exposure have been neglected, especially for aquatic vertebrates such fish. To address this knowledge gap, parental zebrafish (F0 generation) were exposed to TRI, FEN and their mixture for 60 days, as well as the embryos (F1 generation) were hatched without or with continued corresponding exposures at the same concentrations until 7 days post fertilization. The results exhibited that exposure to TRI and FEN altered the expression levels of biomarkers associated with several biological processes, such as apoptosis and inflammatory response. Compared to individual exposure in the F1 generation, the co-exposure to TRI and FEN resulted in increased the expression of T4 and cc-chem mRNA and decreased the expression of ROS, trα, il-8, and gpx mRNA when the F0 generation was similarly exposed. These results revealed that the co-exposure to TRI and FEN has detrimental effects on fish progeny following parental exposure, even if the progeny are not directly exposed to the pesticides, and such negative effects may be intensified if the offspring continue to be exposed. This study enhances the understanding of the harmful impacts of parental exposure to the pesticide mixture on descendants and holds implications for the ecological risk assessment of pesticide mixtures in aquatic vertebrates. Further mechanistic studies are necessary to gain a deeper insight into the mixture effects of pesticides and other kinds of pollutants on subsequent offspring following parental exposure.

186 Evaluating the interaction between divergent genomic selection for heat stress tolerance in the F1 generation and in utero heat stress on piglet growth performance following weaning and transport

186 Evaluating the interaction between divergent genomic selection for heat stress tolerance in the F1 generation and in utero heat stress on piglet growth performance following weaning and transport

Genetic variability studies in F5 generation under direct seeded condition in rice (Oryza sativa L.)

Genetic variability studies in F5 generation under direct seeded condition in rice (Oryza sativa L.)

Genetic components analysis of F1 and F2 generations for seed yield and its component traits in green gram (Vigna radiata L. Wilczek)

Genetic components analysis of F1 and F2 generations for seed yield and its component traits in green gram (Vigna radiata L. Wilczek)

Genetic Analysis of Vitamin C Content in Rapeseed Seedlings by the Major Gene Plus Polygene Mixed Effect Model.

Rapeseed (Brassica napus L.) seedlings are rich in vitamin C (Vc), which is beneficial for humans. Understanding the genetic variance in Vc content has practical significance for the breeding of "oil-vegetable dual-purpose" rapeseed. In this study, the joint segregation analysis of a mixed genetic model of the major gene plus polygene was conducted on the Vc content in rapeseed seedlings. Six generations, including two parents, P1 (high Vc content) and P2 (low Vc content), F1, and the populations of F2, BC1P1, and BC1P2 from two crosses were investigated. Genetic analysis revealed that the genetic model MX2-A-AD was the most fitting genetic model, which indicates that Vc content is controlled by two additive major genes plus additive and dominance polygenes. In addition, the whole heritability in F2 and BC1P1 was higher than that in BC1P2. The largest coefficient of variation for Vc content appeared in the F2 generation. Therefore, for Vc content, the method of single cross recross or single backcross are suggested to transfer major genes, and the selection in F2 would be more efficient than that in other generations. Our findings provide a theoretical basis for the quantitative trait locus (QTL) mapping and breeding of Vc content in rapeseed seedlings.

Identification of candidate genes and genomic prediction of soybean fatty acid components in two soybean populations.

Soybean, a source of plant-derived lipids, contains an array of fatty acids essential for health. A comprehensive understanding of the fatty acid profiles in soybean is crucial for enhancing soybean cultivars and augmenting their qualitative attributes. Here, 180 F10 generation recombinant inbred lines (RILs), derived from the cross-breeding of the cultivated soybean variety 'Jidou 12' and the wild soybean 'Y9,' were used as primary experimental subjects. Using inclusive composite interval mapping (ICIM), this study undertook a quantitative trait locus (QTL) analysis on five distinct fatty acid components in the RIL population from 2019 to 2021. Concurrently, a genome-wide association study (GWAS) was conducted on 290 samples from a genetically diverse natural population to scrutinize the five fatty acid components during the same timeframe, thereby aiming to identify loci closely associated with fatty acid profiles. In addition, haplotype analysis and the Kyoto Encyclopedia of Genes and Genomes pathway analysis were performed to predict candidate genes. The QTL analysis elucidated 23 stable QTLs intricately associated with the five fatty acid components, exhibiting phenotypic contribution rates ranging from 2.78% to 25.37%. In addition, GWAS of the natural population unveiled 102 significant loci associated with these fatty acid components. The haplotype analysis of the colocalized loci revealed that Glyma.06G221400 on chromosome 6 exhibited a significant correlation with stearic acid content, with Hap1 showing a markedly elevated stearic acid level compared with Hap2 and Hap3. Similarly, Glyma.12G075100 on chromosome 12 was significantly associated with the contents of oleic, linoleic, and linolenic acids, suggesting its involvement in fatty acid biosynthesis. In the natural population, candidate genes associated with the contents of palmitic and linolenic acids were predominantly from the fatty acid metabolic pathway, indicating their potential role as pivotal genes in the critical steps of fatty acid metabolism. Furthermore, genomic selection (GS) for fatty acid components was conducted using ridge regression best linear unbiased prediction based on both random single nucleotide polymorphisms (SNPs) and SNPs significantly associated with fatty acid components identified by GWAS. GS accuracy was contingent upon the SNP set used. Notably, GS efficiency was enhanced when using SNPs derived from QTL mapping analysis and GWAS compared with random SNPs, and reached a plateau when the number of SNP markers exceeded 3,000. This study thus indicates that Glyma.06G221400 and Glyma.12G075100 are genes integral to the synthesis and regulatory mechanisms of fatty acids. It provides insights into the complex biosynthesis and regulation of fatty acids, with significant implications for the directed improvement of soybean oil quality and the selection of superior soybean varieties. The SNP markers delineated in this study can be instrumental in establishing an efficacious pipeline for marker-assisted selection and GS aimed at improving soybean fatty acid components.

The importance of reproductive isolation in driving diversification and speciation within Peruvian mimetic poison frogs (Dendrobatidae)

To explain how populations with distinct warning signals coexist in close parapatry, we experimentally assessed intrinsic mechanisms acting as reproductive barriers within three poison-frog species from the Peruvian Amazon belonging to a Müllerian mimetic ring (Ranitomeya variabilis, Ranitomeya imitator and Ranitomeya fantastica). We tested the role of prezygotic and postzygotic isolation barriers between phenotypically different ecotypes of each species, using no-choice mating experiments and offspring survival analysis. Our results show that prezygotic mating preference did not occur except for one specific ecotype of R. imitator, and that all three species were able to produce viable inter-population F1 hybrids. However, while R. variabilis and R. imitator hybrids were able to produce viable F2 generations, we found that for R. fantastica, every F1 hybrid males were sterile while females remained fertile. This unexpected result, echoing with Haldane’s rule of speciation, validated phylogenetic studies which tentatively diagnose these populations of R. fantastica as two different species. Our work suggests that postzygotic genetic barriers likely participate in the extraordinary phenotypic diversity observed within Müllerian mimetic Ranitomeya populations, by maintaining species boundaries.

Effect of microplastics on the demography of Brachionus calyciflorus Pallas (Rotifera) over successive generations

Microplastics (MPs) are becoming increasingly common in freshwater ecosystems. Rotifers may involuntarily ingest MPs through non-selective filtration, thus causing non-real satiety, leading to adverse effects on their demography. Here, we evaluated the acute and chronic effects of MPs (30 µm) on two successive generations of Brachionus calyciflorus s.s. at 20 and 25 °C. Demographic variables and ingestion rates were compared in the absence and presence of microplastics (550 spheres mL-1). For the life table experiments, cohorts of twenty neonates were introduced into 20 mL medium with four replicates per treatment. Ingestion rates of the rotifer were tested at both test temperatures in the absence and presence of the microplastics in 20 mL containers with 1 ind. mL-1 per container. The rotifer population growth rates ranged from 0.55 to 1.05 d-1 depending on the treatment. MPs decreased the fecundity by 20–24 %. The average lifespan of rotifers exposed to MPs in the F0 generation was lower than that in the F1 generation at both temperatures, indicating that pre-exposure of mothers may offer some protection to the offspring. The population growth rate was higher at 25 °C. The ingestion rates were significantly lower in the presence of the microplastics. Our observations indicated that this strain of B. calyciflorus was better adapted to 20 °C; microplastics and higher test temperature resulted in a pronounced changes in the demographic variables of the rotifer.

Comparison of Six Measures of Genetic Similarity of Interspecific Brassicaceae Hybrids F2 Generation and Their Parental Forms Estimated on the Basis of ISSR Markers.

Genetic similarity determines the extent to which two genotypes share common genetic material. It can be measured in various ways, such as by comparing DNA sequences, proteins, or other genetic markers. The significance of genetic similarity is multifaceted and encompasses various fields, including evolutionary biology, medicine, forensic science, animal and plant breeding, and anthropology. Genetic similarity is an important concept with wide application across different scientific disciplines. The research material included 21 rapeseed genotypes (ten interspecific Brassicaceae hybrids of F2 generation and 11 of their parental forms) and 146 alleles obtained using 21 ISSR molecular markers. In the presented study, six measures for calculating genetic similarity were compared: Euclidean, Jaccard, Kulczyński, Sokal and Michener, Nei, and Rogers. Genetic similarity values were estimated between all pairs of examined genotypes using the six measures proposed above. For each genetic similarity measure, the average, minimum, maximum values, and coefficient of variation were calculated. Correlation coefficients between the genetic similarity values obtained from each measure were determined. The obtained genetic similarity coefficients were used for the hierarchical clustering of objects using the unweighted pair group method with an arithmetic mean. A multiple regression model was written for each method, where the independent variables were the remaining methods. For each model, the coefficient of multiple determination was calculated. Genetic similarity values ranged from 0.486 to 0.993 (for the Euclidean method), from 0.157 to 0.986 (for the Jaccard method), from 0.275 to 0.993 (for the Kulczyński method), from 0.272 to 0.993 (for the Nei method), from 0.801 to 1.000 (for the Rogers method) and from 0.486 to 0.993 (for the Sokal and Michener method). The results indicate that the research material was divided into two identical groups using any of the proposed methods despite differences in the values of genetic similarity coefficients. Two of the presented measures of genetic similarity (the Sokal and Michener method and the Euclidean method) were the same.

Identification of a genetic region linked to tolerance to MRSA infection using Collaborative Cross mice.

Staphylococcus aureus (S. aureus) colonizes humans asymptomatically but can also cause opportunistic infections, ranging from mild skin infections to severe life-threatening conditions. Resistance and tolerance are two ways a host can survive an infection. Resistance is limiting the pathogen burden, while tolerance is limiting the health impact of a given pathogen burden. In previous work, we established that collaborative cross (CC) mouse line CC061 is highly susceptible to Methicillin-resistant S. aureus infection (MRSA, USA300), while CC024 is tolerant. To identify host genes involved in tolerance after S. aureus infection, we crossed CC061 mice and CC024 mice to generate F1 and F2 populations. Survival after MRSA infection in the F1 and F2 generations was 65% and 55% and followed a complex dominant inheritance pattern for the CC024 increased survival phenotype. Colonization in F2 animals was more extreme than in their parents, suggesting successful segregation of genetic factors. We identified a Quantitative Trait Locus (QTL) peak on chromosome 7 for survival and weight change after infection. In this QTL, the WSB/EiJ (WSB) allele was present in CC024 mice and contributed to their MRSA tolerant phenotype. Two genes, C5ar1 and C5ar2, have high-impact variants in this region. C5ar1 and C5ar2 are receptors for the complement factor C5a, an anaphylatoxin that can trigger a massive immune response by binding to these receptors. We hypothesize that C5a may have altered binding to variant receptors in CC024 mice, reducing damage caused by the cytokine storm and resulting in the ability to tolerate a higher pathogen burden and longer survival.

Mycotoxin zearalenone induces multi-/trans-generational toxic effects and germline toxicity transmission via histone methyltransferase MES-4 in Caenorhabditis elegans

Zearalenone (ZEN), an endocrine-disrupting mycotoxin, is prevalent and persists in the environment. ZEN has the potential to cause adverse health impacts extending over generations, yet there is a lack of relevant research. Therefore, we explored the ZEN-induced multi-/trans-generational locomotive and reproductive toxicities, as well as the underlying epigenetic mechanisms in Caenorhabditis elegans. In multi-generational analysis, the evolution tendency and toxicity latency were observed under sustained exposure to 0.1 and 1 μM ZEN across five generations (P0-F4). The toxic effects were found in filial generations even if the initial parental exposure showed no apparent effects. Trans-generational results indicated the toxic inheritance phenomenon of 10 and 50 μM ZEN, where a single generation of ZEN exposure was sufficient to affect subsequent generations (F1-F3). Additionally, the pattern of locomotion was relatively sensitive in both generational studies, indicating varying sensitivity between indicators. Regarding epigenetic mechanism of toxicity transmission, ZEN significantly decreased the parental expression of histone methyltransferase encoded genes set-2, mes-2, and mes-4. Notably, the downregulation of mes-4 persisted in the unexposed F1 and F2 generations under trans-generational exposure. Furthermore, the mes-4 binding and reproduction-related rme-2 also decreased across generations. Moreover, parental germline specific knockdown of mes-4 eliminated the inherited locomotive and reproductive toxic effects in offspring, showing that mes-4 acted as transmitter in ZEN-induced generational toxicities. These findings suggest that ZEN is an epigenetic environmental pollutant, with a possible genetic biomarker mes-4 mediating the germline dependent transmission of ZEN-triggered toxicity over generations. This study provides significant insights into ZEN-induced epigenotoxicity.

Transgenerational effects of stress on reproduction strategy in the mixed mating plant Lamium amplexicaule

BackgroundThe theory of Condition Dependent Sex predicts that – everything else being equal – less fit individuals would outcross at higher rates compared with fitter ones. Here we used the mixed mating plant Lamium amplexicaule, capable of producing both self-pollinating closed flowers (CL), alongside open flowers (CH) that allow cross pollination to test it. We investigated the effects of abiotic stress – salt solution irrigation – on the flowering patterns of plants and their offspring. We monitored several flowering and vegetative parameters, including the number and distribution of flowers, CH fraction, and plant size.ResultsWe found that stressed plants show an increased tendency for self-pollination and a deficit in floral and vegetative development. However, when parentally primed, stressed plants show a milder response. Un-stressed offspring of stressed parents show reversed responses and exhibit an increased tendency to outcross, and improve floral and vegetative development.ConclusionsIn summary, we found that stress affects the reproduction strategy in the plants that experienced the stress and in subsequent offspring through F2 generation. Our results provide experimental evidence supporting a transgenerational extension to the theories of fitness associate sex and dispersal, where an individual’s tendency for sex and dispersal may depend on the stress experienced by its parents.

Microplastics originated from agricultural mulching films affect enchytraeid multigeneration reproduction and soil properties

Microplastics (MPs) are increasingly entering agricultural soils, often from the breakdown of agricultural plastics (e.g., mulching films). This study investigates the effects of realistic MPs from different mulching films: two conventional polyethylene (PE-1 and PE-2) and two biodegradable (starch-blended polybutylene adipate co-terephthalate; PBAT-BD-1 and PBAT-BD-2). MPs were mixed into Lufa 2.2 soil at a concentration range from 0.005 % to 5 % (w/w dry soil), wide enough to reflect both realistic environmental levels and “worst-case scenarios”. Effects on Enchytraeus crypticus reproduction over two generations and six important soil properties were studied. PBAT MPs notably reduced enchytraeid reproduction in the F0 generation, with a maximum decrease of 35.5 ± 9.6 % at 0.5 % concentration. F1 generation was unaffected by PBAT contamination. PE MPs had a more substantial reproductive impact, with up to a 55.3 ± 9.7 % decrease at 5 % PE-1 concentration compared to the control, showing a dose-related effect except for 1 %. Both MP types also significantly affected soil water holding capacity, pH, and total carbon. Other soil properties remained unaffected. Our results highlight the potential negative impacts of MPs originating from real agricultural plastics on soil health and raise concerns about the role of agricultural plastics in sustainable agriculture and food safety.

Comparative growth, survival, and feed conversion factor of the F1 generation of two new strains of tilapia Oreochromis niloticus produced by mass selection

Growth, survival, and use of feed of the F1 generation of two new strains of tilapia Oreochromis niloticus (GenBank Strain Y = OK078792 to OK078796 and Strain A = OK078797 to OK078807) produced by mass selection was compared with a known fast-growing commercial strain in Mexico (GenBank Strain Q = OR744820 to OR744838), during a grow-out phase of 165 days. Genetic variability including observed (Ho) and expected (He) heterozygosity, inbreeding coefficient (Fis), and paired comparisons of strain fixation index (Fst) of the three strains were also compared, and an additional analysis of molecular variance (AMOVA) was performed. Twelve hapas of 8.2 m3 (four for each strain) were stocked at a density of 25 org m−3 of 4.58 ± 0.67 g, which were fed with 45 to 25% crude protein feed under a dynamic feeding scheme of 8 to 3% live weight. Growth was estimated by growth rates in weight and length, and by the weight-specific growth rate (SGR). The use of feed was estimated by the total feed consumption rate and the feed conversion factor (FCF). Results indicate no significant differences (P > 0.05) in growth parameters of the three strains, except in SGR which was significantly higher in the control strain (Q) (2.75% day−1) as compared with strains Y and A (2.51 and 2.59% day−1 respectively). The average final weight and size of the fish were 314.6 ± 11.8 g and 25.5 ± 0.4 cm respectively. No significant differences (P > 0.05) were found in survival and feed utilisation among strains, with average values of 96.4% survival, feed consumption of 3.91 g day−1, and FCF of 2.08. Results of genetic diversity indicate that there were no significant differences (P > 0.05) in Ho and He of the three strains, with average values of 0.310 and 0.280 respectively. Fis values were negative and similar for the three strains, with a mean value of −0.109 which indicates no consanguinity in their populations. Finally, the paired comparisons of Fst were significantly different (P < 0.001), showing relatively low values but different from 0 (Y vs. A = 0.025, A vs. Q = 0.041 and Y vs. Q = 0.055), indicating slight but significant population differentiation between strains. In conclusion, the performance and genetic variability of the F1 generation of the two new strains suggest that valuable broodstock is now available for mass production of fry, with similar performance as to one of the best strains of tilapia in Mexico.

Multivariate analysis and image-based phenotyping of cayenne fruit traits in selection and diversity mapping of multiple F1 cross lines

The phenomenon of fluctuating chili prices can be resolved in stages, one of which is through multiple crosses. However, this cross requires precise methods in the evaluation and selection process, especially regarding fruit characteristics. Image-based phenotyping 4.0 approaches can increase the potential precision of such evaluation genotypes, especially when this approach is combined with multivariate analysis. Therefore, both methods are needed to evaluate and select these cayenne multiple crosses. This research aims to identify the effectiveness of multivariate analysis and image-based explanatory characteristics of fruit phenotypes and to select multiple crosses that can continue to the F2 generation. The research was designed with a randomized complete block design of ten F1 multiple cross-genotypes and four check varieties. Each genotype was repeated three times, so there were 42 experimental units. Based on the results, multivariate was considered adequate in determining image explanatory characters based on fruit phenotype and genotype mapping of the population diversity of multiple crosses of cayenne pepper. The characteristics of fruit height, fruit area, and fruit Intden are image-based explanatory characters that can map the completeness of cayenne pepper fruit between multiple crosses well. This indicates that image-based phenotyping and multivariate analysis can provide more detailed image information of the potential of cayenne fruit from multiple crosses than just based on fruit weight. Therefore, both approaches are recommended for analyzing cayenne paper fruit potential, especially for multiple crosses. In addition, three crosses (MC4, MC8, and MC9) are optimal for the next generation to be recommended and continued.

Fine Mapping and Candidate Gene Analysis of Two Major Quantitative Trait Loci, qFW2.1 and qFW3.1, Controlling Fruit Weight in Pepper (Capsicum annuum).

Fruit weight is an important agronomic trait in pepper production and is closely related to yield. At present, many quantitative trait loci (QTL) related to fruit weight have been found in pepper; however, the genes affecting fruit weight remain unknown. We analyzed the fruit weight-related quantitative traits in an intraspecific Capsicum annuum cross between the cultivated species blocky-type pepper, cv. Qiemen, and the bird pepper accession, "129-1" (Capsicum annuum var. glatriusculum), which was the wild progenitor of C. annuum. Using the QTL-seq combined with the linkage-based QTL mapping approach, QTL detection was performed; and two major effects of QTL related to fruit weight, qFW2.1 and qFW3.1, were identified on chromosomes 2 and 3. The qFW2.1 maximum explained 12.28% of the phenotypic variance observed in two F2 generations, with the maximum LOD value of 11.02, respectively; meanwhile, the qFW3.1 maximum explained 15.50% of the observed phenotypic variance in the two F2 generations, with the maximum LOD value of 11.36, respectively. qFW2.1 was narrowed down to the 1.22 Mb region using homozygous recombinant screening from BC2S2 and BC2S3 populations, while qFW3.1 was narrowed down to the 4.61Mb region. According to the transcriptome results, a total of 47 and 86 differentially expressed genes (DEGs) in the candidate regions of qFW2.1 and qFW3.1 were identified. Further, 19 genes were selected for a qRT-PCR analysis based on sequence difference combined with the gene annotation. Finally, Capana02g002938 and Capana02g003021 are the most likely candidate genes for qFW2.1, and Capana03g000903 may be a candidate gene for qFW3.1. Taken together, our results identified and fine-mapped two major QTL for fruit weight in pepper that will facilitate marker-assistant breeding for the manipulation of yield in pepper.