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The content of amino acids, monosaccharides, allantoin, diosgenin, trace elements, and total anthocyanins in purple and white Dioscorea alata were detected and analyzed using high-performance liquid chromatography, inductively coupled plasma emission spectroscopy (ICP-OES) and pH differential method. The content of water, protein, starch and other components was also determined. The results showed that there were certain differences in the nutritional and functional components between two different types of Dioscorea alata. The protein content of white was significantly higher than that of purple, while the content of water and starch were significantly lower than that of purple meat. The contents of Bi, Rb and Se in micronutrient was in the order of white > purple, but Mo, Ca and Mg was white < purple, and there was no significant difference among the other elements. The contents of essential amino acid and non-essential amino acid order was white > purple, rich in arginine, 297.60 mg/kg and 97.08 mg/kg, respectively. The content of allantoin in two colors of Dioscorea alata order was white > purple, 30.03 mg/kg and 24.53 mg/kg. The contents of monosaccharide, diosgenin and total anthocyanin were white < purple, among which the monosaccharide contents, in the order of glucose > galactose > mannose > galacturonic acid > xylose > ribose > arabinose>glucuronic acid>rhamnose>fucose. [ABSTRACT FROM AUTHOR]

The synthesis of betalain using microorganisms is an innovative developmental technology, and the excavation of microorganisms closely related to betalain can provide certain theoretical and technical support to this technology. In this study, the characteristics of soil microbial community structures and their functions in the rhizospheres of white-fleshed dragon fruit (Hylocereus undatus) and red-fleshed dragon fruit (Hylocereus polyrhizus) were analyzed. The results show that the soil bacterial and fungal compositions in the rhizospheres were shaped differently between H. undatus and H. polyrhizus. Bacterial genera such as Kribbella and TM7a were the unique dominant soil bacterial genera in the rhizospheres of H. undatus, whereas Bradyrhizobium was the unique dominant soil bacterial genus in the rhizospheres of H. polyrhizus. Additionally, Myrothecium was the unique dominant soil fungal genus in the rhizospheres of H. polyrhizus, whereas Apiotrichum and Arachniotus were the unique dominant soil fungal genera in the rhizospheres of H. undatus. Moreover, TM7a, Novibacillus, Cupriavidus, Mesorhizobium, Trechispora, Madurella, Cercophora, and Polyschema were significantly enriched in the rhizospheres of H. undatus, whereas Penicillium, Blastobotrys, Phialemonium, Marasmius, and Pseudogymnoascus were significantly enriched in the rhizospheres of H. polyrhizus. Furthermore, the relative abundances of Ascomycota and Penicillium were significantly higher in the rhizospheres of H. polyrhizus than in those of H. undatus. [ABSTRACT FROM AUTHOR]

IntroductionFlesh color is an essential trait in chieh-qua (Benincasa hispida Cogn. var. Chieh-qua How); however, the inheritance and molecular basis of green flesh trait remain unclear.MethodsIn the present study, two F2 populations, derived from 1742 (white flesh) × FJ3211 (green flesh) and J16 (white flesh) × FJ5 (green flesh), were used to identify the green flesh (Cqgf) locus.ResultsGenetic analysis revealed that the presence of green flesh was a quantitative trait that closely followed a normal distribution. Combining the results from QTL mapping and BSA-seq analysis, the Cqgf locus was preliminarily determined to be located on chromosome 05 and was narrowed down to a 2.55-Mb interval by linkage analysis. A large J16 × FJ5 F2 population comprising 3,180 individuals was subsequently used to screen the recombinants, and the Cqgf locus was fine-mapped to a region of 329.70 kb that harbors six genes. One of the candidate genes, Bch05G003700, the zinc-finger transcription factor LOL1 (lsd one like 1 protein; CqLOL1), was the strongest candidate gene for the Cqgf locus according to sequence variation and expression analysis. Additionally, a point mutation (A > C) in CqLOL1 resulted in the substitution of threonine (T) with proline (P) in the amino acid sequence, showing a complete relationship linked with flesh color in a panel of 45 germplasms.DiscussionThe study suggests that CqLOL1 promotes the accumulation of chlorophyll content in chieh-qua and lead to green flesh. Our findings establish a theoretical and technical foundation for breeding different flesh color lines and elucidating the underlying mechanisms of flesh color in chieh-qua.

Important quality components of red-fleshed kiwifruit which was grown in three different regions in North of Iran were investigated in this research. Fruits produced in the region with higher altitude and cool summer temperatures showed higher ascorbic acid content (AAC), total phenolic content, and antioxidant activity than the two other regions both at harvest time and storage. It was observed that the 1,1-diphenyl-2-picrylhydrazyl was positively correlated with the AAC (r = 0.98), total phenolic content (r = 0.94), and the ferric reducing antioxidant power was positively correlated with the AAC (r = 0.98), TPC (r = 0.93). Fruits harvested in region 2 with cool environments, presented dark red flesh color with the highest values of anthocyanin content at harvest (2.78 mg CGE/100 g), with a gradually increasing trend during storage to reach 3.47 mg CGE/100 g at the end of storage. Total anthocyanin content correlated positively with soluble solids content (SSC; r = 0.82), total Soluble sugars (TSS; r = 0.94), pH (r = 0.94), SSC/titratable acidity (TA; r = 0.83) and negatively with TA (r = −0.77). Fruits grown in region 2 received the highest SCC and TSS scores after sensory test evaluations made by the panelists. During storage fruits firmness and total acidity of kiwifruit decreased while SSC, TSS, and anthocyanin content increased. Additionally, antioxidant compounds and taste-related quality of kiwifruit had a positive relationship with the product region. Results showed that the growing region and storage duration considerably influenced the antioxidant compounds and nutritional quality of red flesh kiwifruit.

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The continued success of any conventional sweet potato breeding program is limited by knowledge of the inheritance of the traits under study, such as flesh color and tuberous root shape, because of the difficulty of segregating color frequencies by visual separation. The objective of this study was to understand the mode of inheritance of these genetic traits. The cross blocks were established at the Research Institute of Tropical Roots and Tuber Crops (INIVIT-Cuba). Eight parental genotypes of known compatibility were selected, with contrasting phenotypic characteristics to develop segregating populations. To express color objectively, the CIE L*a*b* color space was used (L*: lightness; a* and b*: chromatic coordinates), and four morphometric variables related to the shape and dimensions of the tuberous root were evaluated. From 2419 reciprocal crosses, 2045 botanical seeds and 1764 seedlings were obtained. Incomplete dominance of the white and purple flesh colors over the orange color was observed, as well as transgressive segregation for purple, orange, and white flesh colors and for the shape of the tuberous root. The results allowed us to propose a genetic model of biparental crosses for the improvement of the flesh color of sweet potato (Ipomoea batatas [L.] Lam.), as well as a predictive formula of the progeny to be selected.

The synthesis of betalain using microorganisms is an innovative developmental technology, and the excavation of microorganisms closely related to betalain can provide certain theoretical and technical support to this technology. In this study, the characteristics of soil microbial community structures and their functions in the rhizospheres of white-fleshed dragon fruit (Hylocereus undatus) and red-fleshed dragon fruit (Hylocereus polyrhizus) were analyzed. The results show that the soil bacterial and fungal compositions in the rhizospheres were shaped differently between H. undatus and H. polyrhizus. Bacterial genera such as Kribbella and TM7a were the unique dominant soil bacterial genera in the rhizospheres of H. undatus, whereas Bradyrhizobium was the unique dominant soil bacterial genus in the rhizospheres of H. polyrhizus. Additionally, Myrothecium was the unique dominant soil fungal genus in the rhizospheres of H. polyrhizus, whereas Apiotrichum and Arachniotus were the unique dominant soil fungal genera in the rhizospheres of H. undatus. Moreover, TM7a, Novibacillus, Cupriavidus, Mesorhizobium, Trechispora, Madurella, Cercophora, and Polyschema were significantly enriched in the rhizospheres of H. undatus, whereas Penicillium, Blastobotrys, Phialemonium, Marasmius, and Pseudogymnoascus were significantly enriched in the rhizospheres of H. polyrhizus. Furthermore, the relative abundances of Ascomycota and Penicillium were significantly higher in the rhizospheres of H. polyrhizus than in those of H. undatus.

The flesh color of watermelon is an important trait that is determined by carotenoid composition and affects consumers’ fruit desirability. Although a complete dominant control by C locus (Cllcyb) for canary yellow flesh (CY) over red flesh has been reported, red and CY colors frequently appear as a mixed pattern in the same flesh (incomplete canary yellow, ICY) in F1 and inbred lines carrying dominant C alleles. Therefore, we examined the genetic control of the mixed color pattern in ICY using whole-genome resequencing of three ICY (ICY group) and three CY inbred lines (CY group), as well as genetic linkage mapping of an F2 population. The segregation pattern in 135 F2 plants indicated that CY is controlled by a single locus (named C2) dominant over ICY. The whole-genome resequencing of ICY and CY inbred lines revealed an ICY/CYspecific region of approximately 27.60–27.88 Mb on Chr. 2 that was polymorphic between the ICY and CY groups. Our genetic map, using nine cleaved amplified polymorphic sequence markers developed based on the single-nucleotide polymorphisms from the ICY/CY-specific region, confirmed that C2 is located on Chr. 2 and cosegregated with the marker (M7) derived from a non-synonymous single-nucleotide polymorphism of the pentatricopeptide repeat (PPR) gene (ClPPR, Cla97C02G039880). Additionally, 27 watermelon inbred lines of ICY, CY, and red flesh were evaluated using previously reported Cllcyb (C locus)- based markers and our C2 locus-linked ClPPR-based marker (M7). As a result, dominant alleles at the C2 locus were required to produce CY, in addition to dominant alleles at the C locus, while a recessive homozygous genotype at the C locus gave the red flesh irrespective of the genotype at the C2 locus. Using a ClPPR-based cleaved amplified polymorphic sequence developed in this study and Cllcyb-based markers, watermelon cultivars with CY, ICY, and red flesh could be successfully discerned, implying that the combined use of these markers will be efficient for marker-assisted selection of flesh color in watermelon breeding. [ABSTRACT FROM AUTHOR]

The flesh color of watermelon is an important trait that is determined by carotenoid composition and affects consumers’ fruit desirability. Although a complete dominant control by C locus (Cllcyb) for canary yellow flesh (CY) over red flesh has been reported, red and CY colors frequently appear as a mixed pattern in the same flesh (incomplete canary yellow, ICY) in F1 and inbred lines carrying dominant C alleles. Therefore, we examined the genetic control of the mixed color pattern in ICY using whole-genome resequencing of three ICY (ICY group) and three CY inbred lines (CY group), as well as genetic linkage mapping of an F2 population. The segregation pattern in 135 F2 plants indicated that CY is controlled by a single locus (named C2) dominant over ICY. The whole-genome resequencing of ICY and CY inbred lines revealed an ICY/CY-specific region of approximately 27.60–27.88 Mb on Chr. 2 that was polymorphic between the ICY and CY groups. Our genetic map, using nine cleaved amplified polymorphic sequence markers developed based on the single-nucleotide polymorphisms from the ICY/CY-specific region, confirmed that C2 is located on Chr. 2 and cosegregated with the marker (M7) derived from a non-synonymous single-nucleotide polymorphism of the pentatricopeptide repeat (PPR) gene (ClPPR, Cla97C02G039880). Additionally, 27 watermelon inbred lines of ICY, CY, and red flesh were evaluated using previously reported Cllcyb (C locus)-based markers and our C2 locus-linked ClPPR-based marker (M7). As a result, dominant alleles at the C2 locus were required to produce CY, in addition to dominant alleles at the C locus, while a recessive homozygous genotype at the C locus gave the red flesh irrespective of the genotype at the C2 locus. Using a ClPPR-based cleaved amplified polymorphic sequence developed in this study and Cllcyb-based markers, watermelon cultivars with CY, ICY, and red flesh could be successfully discerned, implying that the combined use of these markers will be efficient for marker-assisted selection of flesh color in watermelon breeding.

Potato is one of the most commonly consumed non-grain staple food crops in the world therefore, the mineral nutrient content of the potato is extremely important for human nutrition. The lack of mineral nutrients causes significant health problems, thus, many of these nutrients are often taken as supplements. This study was carried out to investigate the effects of potato flesh color and location on different mineral nutrient contents under Niksar, Kazova and Artova locations in Tokat Province, Turkey, during 2013 and 2014 potato growing seasons. The experimental design in each location was randomized blocks with three replications. In this study, a total of 67 clones (including varieties and advanced breeding selections) with nine white, 10 cream, 30 light yellow, and 18 dark yellow flesh colors were used. Potatoes with cream flesh colors had the highest K (23.81 g kg-1), P (0.31 g kg-1), Mg (1.20 g kg-1), Zn (27.26 mg kg-1), Cu (8.28 mg kg-1) and Mn (7.21 mg kg-1) contents, and the lowest Ca (45.6 mg kg-1) content. The mineral contents (except K and Cu) of potatoes grown in Artova were higher compared to the other two locations. The results clearly suggested that Artova is the most suitable location to produce potatoes with a high mineral composition, and Kazova is suitable to cultivate potatoes with high K and Cu contents. In addition, the knowledge of nutrient rich potato accessions is valuable for developing biofortified potato genotypes. [ABSTRACT FROM AUTHOR]

Introduction: Sweet potato is an important staple food crop in the world and contains abundant secondary metabolites in its underground tuberous roots. The large accumulation of several categories of secondary metabolites result in colorful pigmentation of the roots. Anthocyanin, is a typical flavonoid compound present in purple sweet potatoes and it contributes to the antioxidant activity. Methods: In this study, we developed joint omics research via by combing the transcriptomic and metabolomic analysis to explore the molecular mechanisms underlying the anthocyanin biosynthesis in purple sweet potato. Four experimental materials with different pigmentation phenotypes, 1143-1 (white root flesh), HS (orange root flesh), Dianziganshu No.88 (DZ88, purple root flesh), and Dianziganshu No.54 (DZ54, dark purple root flesh) were comparably studied. ults and discussion: We identified 38 differentially accumulated pigment metabolites and 1214 differentially expressed genes from a total of 418 metabolites and 50893 genes detected. There were 14 kinds of anthocyanin detected in DZ88 and DZ54, with glycosylated cyanidin and peonidin as the major components. The significantly enhanced expression levels of multiple structural genes involved in the central anthocyanin metabolic network, such as chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4- reductase (DFR), anthocyanidin synthase/leucocyanidin oxygenase (ANS), and glutathione S-transferase (GST) were manifested to be the primary reason why the purple sweet potatoes had a much higher accumulation of anthocyanin. Moreover, the competition or redistribution of the intermediate substrates (i.e. dihydrokaempferol and dihydroquercetin) between the downstream production of anthocyanin products and the flavonoid derivatization (i.e. quercetin and kaempferol) under the regulation of the flavonol synthesis (FLS) gene, might play a crucial role in the metabolite flux repartitioning, which further led to the discrepant pigmentary performances in the purple and non-purple materials. Furthermore, the substantial production of chlorogenic acid, another prominent high-value antioxidant, in DZ88 and DZ54 seemed to be an interrelated but independent pathway differentiated from the anthocyanin biosynthesis. Collectively, these data from the transcriptomic and metabolomic analysis of four kinds of sweet potatoes provide insight to understand the molecular mechanisms of the coloring mechanism in purple sweet potatoes. [ABSTRACT FROM AUTHOR]

Introduction: Flesh color is an important trait in watermelon (Citrullus lanatus L.). Several flesh color genes have been identified in watermelon; however, the inheritance of and the molecular basis underlying the white flesh trait remain largely unknown. Methods: In this study, segregation populations were constructed by crossing the canary yellow flesh line HSH-F with the white flesh line Sanbai to fine-map the white flesh gene in watermelon. Results: Genetic analysis indicated that the white flesh trait is controlled by a single recessive locus, termed Clwf2. Map-based cloning delimited the Clwf2 locus to a 132.3-kb region on chromosome 6. The candidate region contains 13 putative genes, and four of them--Cla97C06G121860, Cla97C06G121880, Cla97C06G121890, and Cla97C06G121900--were significantly downregulated in the white flesh compared to the canary yellow flesh watermelon fruits. The Cla97C06G121890 gene, which encodes a tetratricopeptide repeat protein, showed almost no expression in the white flesh fruit before maturity, whereas it had a very high expression in the canary yellow flesh fruit at 18 days after pollination. Transmission electron microscopy revealed rounded and regularly shaped chromoplasts in both the canary yellow and white flesh fruits. Further quantitative real-time PCR analysis showed that the expression levels of several key plastid division genes and almost the entire carotenoid biosynthesis pathway genes were downregulated in the white flesh compared to the canary yellow flesh fruits. Discussion: This study suggests that the proliferation inhibition of chromoplasts and downregulation of the CBP genes block the accumulation of carotenoids in watermelon and lead to white flesh. These findings advance and extend the understanding of the molecular mechanisms underlying white flesh trait formation and carotenoid biosynthesis in watermelon. [ABSTRACT FROM AUTHOR]

Potato is one of the most commonly consumed non-grain staple food crops in the world therefore, the mineral nutrient content of the potato is extremely important for human nutrition. The lack of mineral nutrients causes significant health problems, thus, many of these nutrients are often taken as supplements. This study was carried out to investigate the effects of potato flesh color and location on different mineral nutrient contents under Niksar, Kazova and Artova locations in Tokat Province, Turkey, during 2013 and 2014 potato growing seasons. The experimental design in each location was randomized blocks with three replications. In this study, a total of 67 clones (including varieties and advanced breeding selections) with nine white, 10 cream, 30 light yellow, and 18 dark yellow flesh colors were used. Potatoes with cream flesh colors had the highest K (23.81 g kg−1), P (0.31 g kg−1), Mg (1.20 g kg−1), Zn (27.26 mg kg−1), Cu (8.28 mg kg−1) and Mn (7.21 mg kg−1) contents, and the lowest Ca (45.6 mg kg−1) content. The mineral contents (except K and Cu) of potatoes grown in Artova were higher compared to the other two locations. The results clearly suggested that Artova is the most suitable location to produce potatoes with a high mineral composition, and Kazova is suitable to cultivate potatoes with high K and Cu contents. In addition, the knowledge of nutrient rich potato accessions is valuable for developing biofortified potato genotypes.

During the development of yellow-fleshed kiwifruit (Actinidia chinensis), the flesh appeared light pink at the initial stage, the pink faded at the fastest growth stage, and gradually changed into green. At the maturity stage, it showed bright yellow. In order to analyze the mechanism of flesh color change at the metabolic and gene transcription level, the relationship between color and changes of metabolites and key enzyme genes was studied. In this study, five time points (20 d, 58 d, 97 d, 136 d, and 175 d) of yellow-fleshed kiwifruit were used for flavonoid metabolites detection and transcriptome, and four time points (20 d, 97 d, 136 d, and 175 d) were used for targeted detection of carotenoids. Through the analysis of the content changes of flavonoid metabolites, it was found that the accumulation of pelargonidin and cyanidin and their respective anthocyanin derivatives was related to the pink flesh of young fruit, but not to delphinidin and its derivative anthocyanins. A total of 140 flavonoid compounds were detected in the flesh, among which anthocyanin and 76% of the flavonoid compounds had the highest content at 20 d, and began to decrease significantly at 58 d until 175 d, resulting in the pale-pink fading of the flesh. At the mature stage of fruit development (175 d), the degradation of chlorophyll and the increase of carotenoids jointly led to the change of flesh color from green to yellow, in addition to chlorophyll degradation. In kiwifruit flesh, 10 carotenoids were detected, with none of them being linear carotenoids. During the whole development process of kiwifruit, the content of β-carotene was always higher than that of α-carotene. In addition, β-cryptoxanthin was the most-accumulated pigment in the kiwifruit at 175 d. Through transcriptome analysis of kiwifruit flesh, seven key transcription factors for flavonoid biosynthesis and ten key transcription factors for carotenoid synthesis were screened. This study was the first to analyze the effect of flavonoid accumulation on the pink color of yellow-fleshed kiwifruit. The high proportion of β-cryptoxanthin in yellow-fleshed kiwifruit was preliminarily found. This provides information on metabolite accumulation for further revealing the pink color of yellow-fleshed kiwifruit, and also provides a new direction for the study of carotenoid biosynthesis and regulation in yellow-fleshed kiwifruit. [ABSTRACT FROM AUTHOR]

The low availability of varieties adapted to different crop regions, mainly regarding edaphoclimatic conditions, is one of the causes of low sweet-potato crop yields. The objective of this work was to evaluate agronomic characteristics of sweet-potato plants, from the crossing between the genotypes Londrina and Uruguaiana, grown in the region of Presidente Prudente, SP, Brazil, to select materials with high commercial yield and desirable tuberous root shape and color. The natural crossing between the genotypes Londrina and Uruguaiana grown in alternating rows resulted in 2,430 potentially viable seeds. These seeds were used for growing seedlings whose vines were grown in the field for selecting genotypes with desirable characteristics. The results showed a high diversity in skin and flesh colors; number of tuberous roots per plant, shape, fresh and dry weights, and total and commercial yields of tuberous roots. The selected genotypes were then evaluated in three experiments. Several genotypes presented higher commercial yield than their parents. Three genotypes were approved as cultivars by presenting superior agronomic characteristics than their parents. [ABSTRACT FROM AUTHOR]

Low-density polyethylene (LDPE) plastic mulching films have an important function, but at the end of their lifetime pose an economic and environmental problem in terms of their removal and disposal. Biodegradable mulching films represent an alternative to LDPE with the potential to avoid these environmental issues. In this preliminary study, we employed a biodegradable film based on Mater-Bi® (MB) in comparison with low-density polyethylene to assess their effect on the yield and particular quality traits (organoleptic and nutraceutical composition of the fruits) of muskmelon (cv Pregiato) grown on soils with different textures (clay–loam—CL and sandy loam—SL) in two private farms in South Italy. Soil temperature under the mulch was also measured. During the monitored periods, mean soil temperature under LDPE was higher (about 1.3 °C) than that under the biodegradable film and was higher in SL soil than in CL soil, at 25.5° and 24.2 °C, respectively. However, the biodegradable film was able to limit the daily temperature fluctuation, which was 1.7 °C in both soils compared with 2.3 °C recorded for LDPE. Fruit yields were higher with MB film than LDPE (+9.5%), irrespective of soil texture. MaterBi® also elicited increases in total soluble solids, polyphenols, flavonoids, and antioxidant activity compared with LDPE films: 13.3%, 22.4%, 27.2%, and 24.6%, respectively. Color parameters of flesh, namely brightness, chroma, and hue angle were better in fruits grown on LDPE. Our findings suggest that Mater-Bi® based biodegradable mulching film is a potentially valid alternative to traditional LDPE, particularly for obtaining the agronomical benefits outlined above and for promoting environmental sustainability due to its favourable biodegradable properties. [ABSTRACT FROM AUTHOR]

In order to study the physicochemical and nutritional characteristics of kiwifruit varieties, 14 kiwifruits from different species with different flesh colors were selected for research. The pectin content was significantly higher in green-fleshed kiwifruits than those in red-fleshed and yellow-fleshed kiwifruits. Red-fleshed kiwifruits had the highest total flavonoid content, and green-fleshed kiwifruits in A. eriantha had the highest chlorophyll a content, chlorophyll b content and total carotenoid content. The energy and carbohydrate contents of yellow-fleshed kiwifruits were significantly lower than those of red-fleshed kiwifruit. Moreover, the protein contents in A. chinensis and A. chinensis var. deliciosa were higher than those in other species. The content of vitamin C in A. eriantha was far higher than in other kiwifruits. Red-fleshed kiwifruits had a significantly higher vitamin E and vitamin B1 content than green-fleshed kiwifruits. In addition, 1-pentanol, trans-2-hexen-1-ol, n-hexane and styrene presented only in red-fleshed kiwifruits. Therefore, these could be used as a characteristic fragrance for red-fleshed kiwifruits. Moreover, the varieties were ranked comprehensively by principal component analysis (PCA), among which the top four highest-ranking kiwifruits among the 14 varieties were 'Huate', 'MHYX', 'Jinkui' and 'Xuxiang', respectively. This study provides a reference for consumers and markets on quality improvement and processing. [ABSTRACT FROM AUTHOR]

Flesh color is an important target trait in peach [Prunus persica (L.) Batsch] breeding. In this study, two white-fleshed peach cultivars were crossed [Changsong Whitepeach (WP-1) x 'Xiacui'], and their hybrid F1 generation showed color segregation of white flesh (BF1) and yellow flesh (HF1). Metabolome analysis revealed that the flesh color segregation in the hybrid F1 generation was related to the carotenoid content. The decrease in β-carotene and β-cryptoxanthin in BF1 flesh and increase in β-cryptoxanthin oleate, rubixanthin caprate, rubixanthin laurate and zeaxanthin dipalmitate in HF1 flesh contributed to their difference in carotenoid accumulation. Transcriptome analysis demonstrated that compared with BF1, HF1 showed significant up-regulation and down-regulation of ZEP and CCD8 at the core-hardening stage, respectively, while significant down-regulation of NCED in the whole fruit development stage. The down-regulation of NCED might inhibit the breakdown of the violaxanthin and its upstream substances and further promote the accumulation of carotenoids, resulting in yellow flesh. Therefore, NCED may be a key gene controlling the fruit color traits of peach. In this study, targeted metabolomics and transcriptomics were used to jointly explore the mechanism controlling the fruit color of peach, which may help to identify the key genes for the differences in carotenoid accumulation and provide a reference for the breeding of yellow- fleshed peach. [ABSTRACT FROM AUTHOR]

ABSTRACT: Mesocarp color is an important agronomic trait of Cucurbita maxima and is determined mainly by the contents and compositions of the carotenoids. The two inbred lines with significant differences in fruit flesh color were used in the study, the orange ‘312-1’ and white ‘98-2’. Changes in seven carotenoid contents and compositions in the flesh of fruit produced by inbred lines ‘312-1’ and ‘98-2’ were analyzed during fruit development. The expression of eight key carotenoid biosynthesis genes in the fruit flesh were investigated during five fruit development stage in two inbred lines. As the flesh color intensified, the orange flesh color of ‘312-1’ was determined mainly by the increased contents of lutein, β-carotene and zeaxanthin and the lack of carotenoid accumulation led to the formation of white flesh in ‘98-2’ fruit. The expression of the LCY-e and CHYb genes was significantly stronger in ‘312-1’ than in ‘98-2’, and their expression was strongly correlated with lutein and β-carotene contents during fruit development. This study provides a deep understanding of the molecular mechanism of carotenoid biosynthesis in fruit flesh and provides a basis for additional studies on the highly refined improvement of squash quality.

Flesh color is an important target trait in peach [Prunus persica (L.) Batsch] breeding. In this study, two white-fleshed peach cultivars were crossed [Changsong Whitepeach (WP-1) × ‘Xiacui’], and their hybrid F1 generation showed color segregation of white flesh (BF1) and yellow flesh (HF1). Metabolome analysis revealed that the flesh color segregation in the hybrid F1 generation was related to the carotenoid content. The decrease in β-carotene and β-cryptoxanthin in BF1 flesh and increase in β-cryptoxanthin oleate, rubixanthin caprate, rubixanthin laurate and zeaxanthin dipalmitate in HF1 flesh contributed to their difference in carotenoid accumulation. Transcriptome analysis demonstrated that compared with BF1, HF1 showed significant up-regulation and down-regulation of ZEP and CCD8 at the core-hardening stage, respectively, while significant down-regulation of NCED in the whole fruit development stage. The down-regulation of NCED might inhibit the breakdown of the violaxanthin and its upstream substances and further promote the accumulation of carotenoids, resulting in yellow flesh. Therefore, NCED may be a key gene controlling the fruit color traits of peach. In this study, targeted metabolomics and transcriptomics were used to jointly explore the mechanism controlling the fruit color of peach, which may help to identify the key genes for the differences in carotenoid accumulation and provide a reference for the breeding of yellow-fleshed peach.

During natural evolution and artificial selection, the fruit color of many species has been repeatedly gained or lost and is generally associated with mutations in genes encoding R2R3-MYB transcription factors, especially MYB10. In this study, we show that a heterozygous frameshift mutation (FaMYB10AG-insert/FaMYB10wild) is responsible for the loss of anthocyanins in the flesh of cultivated strawberry. Comparative transcriptomic and metabolomic analyses of red- and white-fleshed strawberry indicated that the low expression level of FaUFGT (flavonol-O-glucosyltransferases) was responsible for the loss of anthocyanins and accumulation of proanthocyanidin in the white-fleshed strawberry and was the crucial gene that encodes enzymes of the anthocyanin biosynthesis pathway. Accordingly, overexpression and silencing of FaUFGT altered anthocyanin content and changed the flesh color of strawberry fruits. Furthermore, whole-genome resequencing analyses identified an AG insertion in the FaMYB10 coding region (FaMYB10AG-insert) of white-fleshed strawberry. Y1H and EMSA assays showed that FaMYB10wild was able to bind to the promoter of the FaUFGT gene, while the FaMYB10AG-insert could not. The skin and flesh color were tightly linked to the number of fully functional FaMYB10 copies in the selfing progeny of white-fleshed strawberry. Our results suggested that heterozygous frameshift mutation of FaMYB10 resulted in the loss of the ability to activate the expression of the FaUFGT gene, was responsible for the natural formation of red and white-fleshed strawberry. [ABSTRACT FROM AUTHOR]

Traditional destructive fruit assessment methodologies are currently being replaced by non-destructive alternatives. The Kiwi-Meter™ is promoted as a non-destructive device for assessment of kiwifruit maturation and ripening. In this study, three trials evaluated the feasibility of using the Kiwi-Meter and its IAD™ index data for monitoring maturation, ripening, and quality of Actinidia chinensis var. chinensis 'Donghong' kiwifruit. The findings from the trials suggest that the Kiwi-Meter provides a non-destructive tool for measuring the color or chlorophyll content of the outer tissues of 'Donghong' kiwifruit. Since the timing of harvest of kiwifruit is not determined solely by flesh color, the utility of the Kiwi-Meter in any wider evaluation of fruit maturation (or ripening or quality) is dependent on there being a strong association between other fruit characteristics of interest with flesh color. The 'Donghong' fruit used in this trial degreened fully before ripening and thus the Kiwi-Meter could not provide a measure of maturation, ripening, or fruit quality. It is concluded that the Kiwi-Meter can assess fruit for flesh color, although even for this purpose, it must be considered that the IAD measurement may be limited to only the outer area of the fruit flesh. [ABSTRACT FROM AUTHOR]

Abstract Background Ploidy manipulation is effective in seedless loquat breeding, in which flesh color is a key agronomic and economic trait. Few techniques are currently available for detecting the genotypes of polyploids in plants, but this ability is essential for most genetic research and molecular breeding. Results We developed a system for genotyping by quantitative PCR (qPCR) that allowed flesh color genotyping in multiple tetraploid and triploid loquat varieties (lines). The analysis of 13 different ratios of DNA mixtures between two homozygous diploids (AA and aa) showed that the proportion of allele A has a high correlation (R2 = 0.9992) with parameter b [b = a1/(a1 + a2)], which is derived from the two normalized allele signals (a1 and a2) provided by qPCR. Cluster analysis and variance analysis from simulating triploid and tetraploid hybrids provided completely correct allelic configurations. Four genotypes (AAA, AAa, Aaa, aaa) were found in triploid loquats, and four (AAAA, AAAa, AAaa, Aaaa; absence of aaaa homozygotes) were found in tetraploid loquats. DNA markers analysis showed that the segregation of flesh color in all F1 hybrids conformed to Mendel's law. When tetraploid B431 was the female parent, more white-fleshed triploids occurred among the progeny. Conclusions qPCR can detect the flesh color genotypes of loquat polyploids and provides an alternative method for analyzing polyploid genotype and breeding, dose effects and allele-specific expression.

The color of watermelon flesh is an important trait determined by a series of carotenoids. Herein, we used Cream of Saskatchewan (pale yellow flesh) and PI 186490 (white flesh) as parental materials for an F2 segregation and initial mapping using the bulked segregant analysis sequencing (BSA-seq) strategy. The BSA results revealed a flesh color-related QTL that spans approximately 2.45 Mb on chromosome 6. This region was preliminarily positioned in a 382-kb segment, and then narrowed down into a 66.8-kb segment with 1260 F2 individuals. A total of nine candidate genes were in the fine mapping interval, but only Cla007528 (encoding chlorophyllase) had non-synonymous mutations and was significantly expressed between the parental materials throughout flesh development. We also checked the expression patterns of the carotenoid metabolic pathway genes based on RNA-seq data and qRT-PCR validation. Three genes in the xanthophyll cycle (CICHYB, CINCED-1 and CINCED-7) exhibited differential expression patterns between the two parental lines at different flesh color formation stages. ClPSY1, CIPDS, CIZDS, CICHXE, CICRTISO and CILCYB also exhibited clearly different expression patterns accompanied by carotenoid accumulation.

Phytoene synthase (PSY) plays an essential role in carotenoid biosynthesis. In this study, three ClPSY genes were identified through the watermelon genome, and their full-length cDNA sequences were cloned. The deduced proteins of the three ClPSY genes were ranged from 355 to 421 amino acid residues. Phylogenetic analysis suggested that the ClPSYs are highly conserved with bottle gourd compared to other cucurbit crops PSY proteins. Variation in ClPSY1 expression in watermelon with different flesh colors was observed; ClPSY1 was most highly expressed in fruit flesh and associated with the flesh color formation. ClPSY1 expression was much lower in the white-fleshed variety than the colored fruits. Gene expression analysis of ClPSY genes in root, stem, leaf, flower, ovary and flesh of watermelon plants showed that the levels of ClPSY2 transcripts found in leaves was higher than other tissues; ClPSY3 was dominantly expressed in roots. Functional complementation assays of the three ClPSY genes suggested that all of them could encode functional enzymes to synthesize the phytoene from Geranylgeranyl Pyrophosphate (GGPP). Some of the homologous genes clustered together in the phylogenetic tree and located in the synteny chromosome region seemed to have similar expression profiles among different cucurbit crops. The findings provide a foundation for watermelon flesh color breeding with regard to carotenoid synthesis and also provide an insight for the further research of watermelon flesh color formation. [ABSTRACT FROM AUTHOR]

In this study, the carotenoid profiles and content in 132 cultivars of yellow-flesh peach having different fruit developmental periods (short, middle, and long), fruit surface indumenta (glabrous and pubescent skin), and flesh colors (yellow, golden, and orange) were investigated. We simultaneously analyzed and compared the levels of five carotenoids (lutein, zeaxanthin, β-cryptoxanthin, α-carotene, and β-carotene) through high-performance liquid chromatography. Large differences in carotenoid content among germplasms were observed, with coefficients of variation ranging from 21.24% to 67.78%. The carotenoid content, from high to low, was as follows: β-carotene > zeaxanthin > α-carotene > β-cryptoxanthin > lutein. We screened several varieties with high carotenoid content, including zeaxanthin in 'Ruiguang2', β-cryptoxanthin in 'NJN76' and 'TX4F244C', and β-carotene and total carotenoids in 'Jintong7', '77-26-7', and '77-20-5'. A longer fruit developmental period was associated with greater β-carotene accumulation but lowered the zeaxanthin and β-cryptoxanthin accumulation. The zeaxanthin, β-carotene, and total carotenoid concentrations significantly increased as the flesh color deepened, but the lutein and α-carotene levels remained similar among the three flesh colors. The classification index of the indumenta significantly affected the β-carotene and total carotenoid content (p < 0.05) and was higher in pubescent than glabrous skin. [ABSTRACT FROM AUTHOR]

Purple sweet potato is considered as a healthy food because of its high anthocyanins. To understand the coloring mechanism and quality change between purple-fleshed sweet potato (cv. Xuzi201) and its cream fleshed mutant (M1001), a combined metabolomic and transcriptomic analysis was performed. The metabolome data showed that 4 anthocyanins, 19 flavones, 6 flavanones, and 4 flavonols dramatically decreased in M1001, while the contents of 3 isoflavones, 3 flavonols, 4 catechins, and 2 proanthocyanins increased. Transcriptomic analyses indicated that the expression of 49 structural genes in the flavonoid pathway and transcription factors (TFs) (e.g., bHLH2, R2R3-MYB, MYB1) inducting anthocyanin biosynthesis were downregulated, but the repressor MYB44 was upregulated. The IbMYB1-2 gene was detected as a mutation gene in M1001, which is responsible for anthocyanin accumulation in the storage roots. Thus, the deficiency of purple color in the mutant is due to the lack of anthocyanin accumulation which was regulated by IbMYB1. Moreover, the accumulation of starch and aromatic volatiles was significantly different between Xuzi201 and M1001. These results not only revealed the mechanism of color mutation but also uncovered certain health-promoting compounds in sweet potato. [ABSTRACT FROM AUTHOR]

SUMMARY: Pineapple (Ananas comosus (L.) Merr.) is one of the most economically important tropical fruit species. The major aim of the breeding programs in several countries, including Japan, is quality improvement, mainly for the fresh market. 'Yugafu', a Japanese cultivar with distinctive pipe‐type leaf margin phenotype and white flesh color, is popular for fresh consumption. Therefore, genome sequencing of 'Yugafu' is expected to assist pineapple breeding. Here, we developed a haplotype‐resolved assembly for the heterozygous genome of 'Yugafu' using long‐read sequencing technology and obtained a pair of 25 pseudomolecule sequences inherited from the parental accessions 'Cream pineapple' and 'HI101'. The causative genes for leaf margin and fruit flesh color were identified. Fine mapping revealed a 162‐kb region on CLG23 for the leaf margin phenotype. In this region, 20 kb of inverted repeat was specifically observed in the 'Cream pineapple' derived allele, and the WUSCHEL‐related homeobox 3 (AcWOX3) gene was predicted as the key gene for leaf margin morphogenesis. Dominantly repressed AcWOX3 via RNAi was suggested to be the cause of the pipe‐type leaf margin phenotype. Quantitative trait locus (QTL) analysis revealed that the terminal region of CLG08 contributed to white flesh and low carotenoid content. Carotenoid cleaved dioxygenase 4 (AcCCD4), a key gene for carotenoid degradation underlying this QTL, was predicted as the key gene for white flesh color through expression analysis. These findings could assist in modern pineapple breeding and facilitate marker‐assisted selection for important traits. [ABSTRACT FROM AUTHOR]

Purple sweet potato is considered as a healthy food because of its high anthocyanins. To understand the coloring mechanism and quality change between purple-fleshed sweet potato (cv. Xuzi201) and its cream fleshed mutant (M1001), a combined metabolomic and transcriptomic analysis was performed. The metabolome data showed that 4 anthocyanins, 19 flavones, 6 flavanones, and 4 flavonols dramatically decreased in M1001, while the contents of 3 isoflavones, 3 flavonols, 4 catechins, and 2 proanthocyanins increased. Transcriptomic analyses indicated that the expression of 49 structural genes in the flavonoid pathway and transcription factors (TFs) (e.g., bHLH2, R2R3-MYB, MYB1) inducting anthocyanin biosynthesis were downregulated, but the repressor MYB44 was upregulated. The IbMYB1-2 gene was detected as a mutation gene in M1001, which is responsible for anthocyanin accumulation in the storage roots. Thus, the deficiency of purple color in the mutant is due to the lack of anthocyanin accumulation which was regulated by IbMYB1. Moreover, the accumulation of starch and aromatic volatiles was significantly different between Xuzi201 and M1001. These results not only revealed the mechanism of color mutation but also uncovered certain health-promoting compounds in sweet potato.

Abstract Background Fruit flesh color in watermelon (Citrullus lanatus) is a great index for evaluating the appearance quality and a key contributor influencing consumers’ preferences. But the molecular mechanism of this intricate trait remains largely unknown. Here, the carotenoids and transcriptome dynamics during the fruit development of cultivated watermelon with five different flesh colors were analyzed. Results A total of 13 carotenoids and 16,781 differentially expressed genes (DEGs), including 1295 transcription factors (TFs), were detected in five watermelon genotypes during the fruit development. The comprehensive accumulation patterns of carotenoids were closely related to flesh color. A number of potential structural genes and transcription factors were found to be associated with the carotenoid biosynthesis pathway using comparative transcriptome analysis. The differentially expressed genes were divided into six subclusters and distributed in different GO terms and metabolic pathways. Furthermore, we performed weighted gene co-expression network analysis and predicted the hub genes in six main modules determining carotenoid contents. Cla018406 (a chaperone protein dnaJ-like protein) may be a candidate gene for β-carotene accumulation and highly expressed in orange flesh-colored fruit. Cla007686 (a zinc finger CCCH domain-containing protein) was highly expressed in the red flesh-colored watermelon, maybe a key regulator of lycopene accumulation. Cla003760 (membrane protein) and Cla021635 (photosystem I reaction center subunit II) were predicted to be the hub genes and may play an essential role in yellow flesh formation. Conclusions The composition and contents of carotenoids in five watermelon genotypes vary greatly. A series of candidate genes were revealed through combined analysis of metabolites and transcriptome. These results provide an important data resource for dissecting candidate genes and molecular basis governing flesh color formation in watermelon fruit.

Anthocyanins are generally accumulated within a few layers, including the epidermal cells of leaves and stems in plants. Solanum tuberosum cv. 'Jayoung' (hereafter, JY) is known to accumulate anthocyanin both in inner tissues and skins. We discovered that anthocyanin accumulation in the inner tissues of JY was almost diminished (more than 95% was decreased) in tuber induction condition. To investigate the transcriptomic mechanism of anthocyanin accumulation in JY flesh, which can be modulated by growth condition, we performed mRNA sequencing with white-colored flesh tissue of Solanum tuberosum cv. 'Atlantic' (hereafter, 'Daeseo', DS) grown under canonical growth conditions, a JY flesh sample grown under canonical growth conditions, and a JY flesh sample grown under tuber induction conditions. We could identify 36 common DEGs (differentially expressed genes) in JY flesh from canonical growth conditions that showed JY-specifically increased or decreased expression level. These genes were enriched with flavonoid biosynthetic process terms in GO analysis, as well as gene set enrichment analysis (GSEA) analysis. Further in silico analysis on expression levels of anthocyanin biosynthetic genes including rate-limiting genes such as StCHS and StCHI followed by RT-PCR and qRT-PCR analysis showed a strong positive correlation with the observed phenotypes. Finally, we identified StWRKY44 from 36 common DEGs as a possible regulator of anthocyanin accumulation, which was further supported by network analysis. In conclusion, we identified StWRKY44 as a putative regulator of tuber-induction-dependent anthocyanin accumulation. [ABSTRACT FROM AUTHOR]

Anthocyanins are a class of water-soluble flavonoids widely present in fruits and vegetables responsible for the red flesh formation of peach fruit. Previously, several genes of the MYB family have been reported as transcriptional regulators of the anthocyanin biosynthetic pathway of structural genes in plants. In this study, through comparative transcriptome analysis of the white and red flesh peach cultivars of Harrow Blood and Asama Hakuto, a predicted transcription factor of the R2R3MYB family, PpMYB39, was identified to be associated with anthocyanin biosynthesis in peach fruit. In red-fleshed peach cultivars, the maximum amount of anthocyanin accumulated 95 days after full bloom (DAFB), at full maturity near ripening. Our results showed that, at this stage, PpMYB39 had the highest expression level among the 13 differentially expressed genes (DEGs) found in both red- and white-fleshed fruits, as well as a high correlation with total anthocyanin content throughout fruit development. Moreover, the expression analysis of the structural genes of the anthocyanin biosynthetic pathway in peach fruit revealed that Prunus persica Dihydroflavonol-4-reductase (PpDFR) was co-expressed and up-regulated with PpMYB39 at 95 DAFB, suggesting its possible role as a transcriptional activator of MYB39. This was further confirmed by a yeast one-hybrid assay and a dual luciferase reporter assay. Our results will be helpful in the breeding of peach cultivars and the identification and significance of color in peaches and related fruit species, in addition to providing an understanding of color formation in peach fruit for future research. [ABSTRACT FROM AUTHOR]

Flesh color (FC), skin color (SC), and anthocyanin content (AC) are three important traits being used for commodity evaluation in purple-fleshed sweet potato. However, to date, only a few reports are available on the inheritance of these traits. In this study, we used a biparental mapping population of 274 F1 progeny generated from a cross between a dark purple-fleshed (Xuzishu8) and white-fleshed (Meiguohong) sweet potato variety for genetic analyses. Correlation analysis showed a significant positive correlation among AC, SC, and FC. Medium-to-high heritability was observed for these traits. We detected single nucleotide polymorphisms (SNPs) by specific length amplified fragment sequencing (SLAF-seq) with the average sequencing depth of 51.72 and 25.76 for parents and progeny, respectively. Then we constructed an integrated genetic map consisting of 15 linkage groups (LGS) of sweet potato spanning on 2,233.66 cm with an average map distance of 0.71 cm between adjacent markers. Based on the linkage map, ten major quantitative trait loci (QTLs) associated to FC, SC, and AC were identified on LG12 between 0 and 64.97 cm distance, such as one QTL for SC and FC, respectively, which explained 36.3 and 45.9% of phenotypic variation; eight QTLs for AC, which explained 10.5–28.5% of the variation. These major QTLs were highly consistent and co-localized on LG12. Positive correlation, high heritability, and co-localization of QTLs on the same LG group confirm the significance of this study to establish a marker-assisted breeding program for sweet potato improvement. [ABSTRACT FROM AUTHOR]

Jinyan (Actinidia eriantha × A. chinensis) is one of the gold-fleshed kiwifruit cultivars currently being promoted in south China. However, its fruit dry matter is usually less than 16%, which seriously affects fruit quality including taste and flavor. This causes a financial loss to growers: not only are the prices paid for the fruit low because of their bad reputation for quality, but some orchards have been removed. Improvement of fruit quality is essential. In this study, a method is described for squeezing and twisting flowering shoots before flowering and removing the distal vegetative parts of flowering shoots after fruit set. The effects on fruit quality were determined. The dry matter of fruit was increased by 6.6%. Fruit size also increased as did the chlorophyll a content and the chlorophyll:carotenoid ratio. The significantly increased fruit dry matter, resulting in significant increases in fruit soluble solids concentrations (P < 0.01), thereby possibly improving fruit taste. Fruit weight, fruit length, and carotenoid and ascorbic acid concentrations were significantly enhanced in comparison with controls (P < 0.01), increasing by 20%, 7%, 12%, and 19%, respectively. However, there was no significant difference in soluble sugar concentrations, titratable acid concentrations, and the reduced chlorophyll b concentrations. This research provides a practical method to increase fruit dry matter, and hence a way to allow fruit quality to reach commercial requirements for cultivars such as Jinyan, which under previous management systems had significant shortcomings in fruit flavor and taste.

Flesh color (FC), skin color (SC), and anthocyanin content (AC) are three important traits being used for commodity evaluation in purple-fleshed sweet potato. However, to date, only a few reports are available on the inheritance of these traits. In this study, we used a biparental mapping population of 274 F1 progeny generated from a cross between a dark purple-fleshed (Xuzishu8) and white-fleshed (Meiguohong) sweet potato variety for genetic analyses. Correlation analysis showed a significant positive correlation among AC, SC, and FC. Medium-to-high heritability was observed for these traits. We detected single nucleotide polymorphisms (SNPs) by specific length amplified fragment sequencing (SLAF-seq) with the average sequencing depth of 51.72 and 25.76 for parents and progeny, respectively. Then we constructed an integrated genetic map consisting of 15 linkage groups (LGS) of sweet potato spanning on 2,233.66 cm with an average map distance of 0.71 cm between adjacent markers. Based on the linkage map, ten major quantitative trait loci (QTLs) associated to FC, SC, and AC were identified on LG12 between 0 and 64.97 cm distance, such as one QTL for SC and FC, respectively, which explained 36.3 and 45.9% of phenotypic variation; eight QTLs for AC, which explained 10.5–28.5% of the variation. These major QTLs were highly consistent and co-localized on LG12. Positive correlation, high heritability, and co-localization of QTLs on the same LG group confirm the significance of this study to establish a marker-assisted breeding program for sweet potato improvement.

During the development of yellow-fleshed kiwifruit (Actinidia chinensis), the flesh appeared light pink at the initial stage, the pink faded at the fastest growth stage, and gradually changed into green. At the maturity stage, it showed bright yellow. In order to analyze the mechanism of flesh color change at the metabolic and gene transcription level, the relationship between color and changes of metabolites and key enzyme genes was studied. In this study, five time points (20 d, 58 d, 97 d, 136 d, and 175 d) of yellow-fleshed kiwifruit were used for flavonoid metabolites detection and transcriptome, and four time points (20 d, 97 d, 136 d, and 175 d) were used for targeted detection of carotenoids. Through the analysis of the content changes of flavonoid metabolites, it was found that the accumulation of pelargonidin and cyanidin and their respective anthocyanin derivatives was related to the pink flesh of young fruit, but not to delphinidin and its derivative anthocyanins. A total of 140 flavonoid compounds were detected in the flesh, among which anthocyanin and 76% of the flavonoid compounds had the highest content at 20 d, and began to decrease significantly at 58 d until 175 d, resulting in the pale-pink fading of the flesh. At the mature stage of fruit development (175 d), the degradation of chlorophyll and the increase of carotenoids jointly led to the change of flesh color from green to yellow, in addition to chlorophyll degradation. In kiwifruit flesh, 10 carotenoids were detected, with none of them being linear carotenoids. During the whole development process of kiwifruit, the content of β-carotene was always higher than that of α-carotene. In addition, β-cryptoxanthin was the most-accumulated pigment in the kiwifruit at 175 d. Through transcriptome analysis of kiwifruit flesh, seven key transcription factors for flavonoid biosynthesis and ten key transcription factors for carotenoid synthesis were screened. This study was the first to analyze the effect of flavonoid accumulation on the pink color of yellow-fleshed kiwifruit. The high proportion of β-cryptoxanthin in yellow-fleshed kiwifruit was preliminarily found. This provides information on metabolite accumulation for further revealing the pink color of yellow-fleshed kiwifruit, and also provides a new direction for the study of carotenoid biosynthesis and regulation in yellow-fleshed kiwifruit.

In order to study the physicochemical and nutritional characteristics of kiwifruit varieties, 14 kiwifruits from different species with different flesh colors were selected for research. The pectin content was significantly higher in green-fleshed kiwifruits than those in red-fleshed and yellow-fleshed kiwifruits. Red-fleshed kiwifruits had the highest total flavonoid content, and green-fleshed kiwifruits in A. eriantha had the highest chlorophyll a content, chlorophyll b content and total carotenoid content. The energy and carbohydrate contents of yellow-fleshed kiwifruits were significantly lower than those of red-fleshed kiwifruit. Moreover, the protein contents in A. chinensis and A. chinensis var. deliciosa were higher than those in other species. The content of vitamin C in A. eriantha was far higher than in other kiwifruits. Red-fleshed kiwifruits had a significantly higher vitamin E and vitamin B1 content than green-fleshed kiwifruits. In addition, 1-pentanol, trans-2-hexen-1-ol, n-hexane and styrene presented only in red-fleshed kiwifruits. Therefore, these could be used as a characteristic fragrance for red-fleshed kiwifruits. Moreover, the varieties were ranked comprehensively by principal component analysis (PCA), among which the top four highest-ranking kiwifruits among the 14 varieties were ‘Huate’, ‘MHYX’, ‘Jinkui’ and ‘Xuxiang’, respectively. This study provides a reference for consumers and markets on quality improvement and processing.

Background: Ploidy manipulation is effective in seedless loquat breeding, in which flesh color is a key agronomic and economic trait. Few techniques are currently available for detecting the genotypes of polyploids in plants, but this ability is essential for most genetic research and molecular breeding. Results: We developed a system for genotyping by quantitative PCR (qPCR) that allowed flesh color genotyping in multiple tetraploid and triploid loquat varieties (lines). The analysis of 13 different ratios of DNA mixtures between two homozygous diploids (AA and aa) showed that the proportion of allele A has a high correlation (R2 = 0.9992) with parameter b [b = a1/(a1 + a2)], which is derived from the two normalized allele signals (a1 and a2) provided by qPCR. Cluster analysis and variance analysis from simulating triploid and tetraploid hybrids provided completely correct allelic configurations. Four genotypes (AAA, AAa, Aaa, aaa) were found in triploid loquats, and four (AAAA, AAAa, AAaa, Aaaa; absence of aaaa homozygotes) were found in tetraploid loquats. DNA markers analysis showed that the segregation of flesh color in all F1 hybrids conformed to Mendel's law. When tetraploid B431 was the female parent, more white-fleshed triploids occurred among the progeny. Conclusions: qPCR can detect the flesh color genotypes of loquat polyploids and provides an alternative method for analyzing polyploid genotype and breeding, dose effects and allele-specific expression. [ABSTRACT FROM AUTHOR]

Traditional destructive fruit assessment methodologies are currently being replaced by non-destructive alternatives. The Kiwi-Meter™ is promoted as a non-destructive device for assessment of kiwifruit maturation and ripening. In this study, three trials evaluated the feasibility of using the Kiwi-Meter and its IAD™ index data for monitoring maturation, ripening, and quality of Actinidia chinensis var. chinensis ‘Donghong’ kiwifruit. The findings from the trials suggest that the Kiwi-Meter provides a non-destructive tool for measuring the color or chlorophyll content of the outer tissues of ‘Donghong’ kiwifruit. Since the timing of harvest of kiwifruit is not determined solely by flesh color, the utility of the Kiwi-Meter in any wider evaluation of fruit maturation (or ripening or quality) is dependent on there being a strong association between other fruit characteristics of interest with flesh color. The ‘Donghong’ fruit used in this trial degreened fully before ripening and thus the Kiwi-Meter could not provide a measure of maturation, ripening, or fruit quality. It is concluded that the Kiwi-Meter can assess fruit for flesh color, although even for this purpose, it must be considered that the IAD measurement may be limited to only the outer area of the fruit flesh.

This study aimed to assess the effects of Penicillium expansum (P. expansum) infection on the quality and flavor of Jinmi (JM) and Jinyan (JY) kiwifruit. Kiwifruit were inoculated with P. expansum and stored at 0 ± 1°C, and the changes in quality indicators and volatile substances (VCs) at different stages of disease were determined. Results showed that in wound‐inoculated kiwifruit, the soluble solid content (SSC) increased. Conversely, their titratable acidity and vitamin C (VC) content, firmness, lightness, and saturation decreased. The taste‐related parameters and nutritional value of kiwifruit declined after infection. VCs such as ethanol, 3‐methyl‐1‐butanol, and 2‐methylisoborneol were detected only in the diseased fruit and gradually increased as the disease aggravated, suggesting that they may be the main sources of odor during P. expansum infection. Therefore, VCs detection can be used to determine possible P. expansum infection, as well as the degree of infection in kiwifruit. Practical applications: In practical application, we can use the results of this study to determine possible Penicillium expansum infection, as well as the degree of infection in kiwifruit according to the indicators such as volatile substances. Kiwifruit enterprises can use the nondestructive detection model established in this study to screen out the kiwifruit infected with P. expansum more efficiently, quickly, and accurately, in order to prevent harm to the health of consumers. [ABSTRACT FROM AUTHOR]

In this study, the carotenoid profiles and content in 132 cultivars of yellow-flesh peach having different fruit developmental periods (short, middle, and long), fruit surface indumenta (glabrous and pubescent skin), and flesh colors (yellow, golden, and orange) were investigated. We simultaneously analyzed and compared the levels of five carotenoids (lutein, zeaxanthin, β-cryptoxanthin, α-carotene, and β-carotene) through high-performance liquid chromatography. Large differences in carotenoid content among germplasms were observed, with coefficients of variation ranging from 21.24% to 67.78%. The carotenoid content, from high to low, was as follows: β-carotene > zeaxanthin > α-carotene > β-cryptoxanthin > lutein. We screened several varieties with high carotenoid content, including zeaxanthin in ‘Ruiguang2’, β-cryptoxanthin in ‘NJN76’ and ‘TX4F244C’, and β-carotene and total carotenoids in ‘Jintong7’, ‘77-26-7’, and ‘77-20-5’. A longer fruit developmental period was associated with greater β-carotene accumulation but lowered the zeaxanthin and β-cryptoxanthin accumulation. The zeaxanthin, β-carotene, and total carotenoid concentrations significantly increased as the flesh color deepened, but the lutein and α-carotene levels remained similar among the three flesh colors. The classification index of the indumenta significantly affected the β-carotene and total carotenoid content (p < 0.05) and was higher in pubescent than glabrous skin.

Maturity at harvest is a determining factor in fruit storage potential, especially in such perishable species as plums (Prunus salicina L.). However, harvest´s logistics is very complex, and a large percentage of fruits are harvested at a more advanced stage of maturity than the optimum recommended for long storage. Treatment with 1-MCP has shown to be effective in reducing the post-harvest deterioration rate of Japanese plums, but the effectiveness of this treatment may be reduced in late harvested fruit. The aim of this trial was to determine the efficiency of treatment with 0.4 µL L-1 of 1-MCP in Larry Ann plums harvested at 4 different maturity stages. The results showed that the treatment was effective in reducing the ripening rate of the fruit at all harvest timings. The duration of this effect and the number of parameters affected decreased as harvest was delayed. In maturity stage 1 (M1, ~62 N) and maturity stage 2 (M2, ~58 N), 1-MCP delayed ethylene production rate during shelf life after 30, 40, and 50 days of storage at 0 ºC and reduced loss of flesh firmness, and acidity. At the maturity stage 3 (M3, ~50N) 1-MCP delayed ethylene production rate during shelf life after 30 and 40 days of storage at 0 ºC and maintained higher flesh firmness values. In fruit harvested at the maturity 4 (M4, ~35 N), 1-MCP did not affect ethylene production rate, but reduced loss of flesh firmness during shelf life, supporting the hypothesis that the treatment has a direct inhibitory effect on softening enzymes, independent of ethylene.

This study was conducted to examine growth, yield and quality performances of five turmeric genotypes. The experiment was laid out in randomized complete block design with three replications. Results showed that different genotypes significantly influenced on plant growth, yield and quality of turmeric. The highest germination (97 %), number of leaves (8.16), plant height (69.51 cm), weight of rhizome (47.06 g/plant) and yield (6.01 t/ha) was found from “Sinduri Holud” (BARI Holud-2). But this genotype scored the lowest percentage in curcumin (0.30 %) and low dry matter (22.54 %). While local genotype (“Mota Holud”) performed the lowest germination (87.57 %) and minimum plant height (53.52 cm), leaf area (127.42 cm2), number of fingers per rhizome (3.73), weight of rhizome (34.16 g/plant) and yield (4.78 t/ha). But this genotype contained the highest curcumin (2.10 %), and “Mala Holud” attained maximum dry matter (25.20%). Based on flesh color, dry matter and curcumin contents local turmeric genotypes performed superior than that of the check varieties. From the findings of this investigation, it can be concluded that local genotypes can be used in breeding program for development of high quality turmeric in Bangladesh.

Background: Fruit flesh color in watermelon (Citrullus lanatus) is a great index for evaluating the appearance quality and a key contributor influencing consumers' preferences. But the molecular mechanism of this intricate trait remains largely unknown. Here, the carotenoids and transcriptome dynamics during the fruit development of cultivated watermelon with five different flesh colors were analyzed. Results: A total of 13 carotenoids and 16,781 differentially expressed genes (DEGs), including 1295 transcription factors (TFs), were detected in five watermelon genotypes during the fruit development. The comprehensive accumulation patterns of carotenoids were closely related to flesh color. A number of potential structural genes and transcription factors were found to be associated with the carotenoid biosynthesis pathway using comparative transcriptome analysis. The differentially expressed genes were divided into six subclusters and distributed in different GO terms and metabolic pathways. Furthermore, we performed weighted gene co-expression network analysis and predicted the hub genes in six main modules determining carotenoid contents. Cla018406 (a chaperone protein dnaJ-like protein) may be a candidate gene for β-carotene accumulation and highly expressed in orange flesh-colored fruit. Cla007686 (a zinc finger CCCH domain-containing protein) was highly expressed in the red flesh-colored watermelon, maybe a key regulator of lycopene accumulation. Cla003760 (membrane protein) and Cla021635 (photosystem I reaction center subunit II) were predicted to be the hub genes and may play an essential role in yellow flesh formation. Conclusions: The composition and contents of carotenoids in five watermelon genotypes vary greatly. A series of candidate genes were revealed through combined analysis of metabolites and transcriptome. These results provide an important data resource for dissecting candidate genes and molecular basis governing flesh color formation in watermelon fruit. [ABSTRACT FROM AUTHOR]

This study investigated how the ploidy level of the kiwifruit pollinizer cultivars "CK3" (diploid), "T line" (tetraploid), "Pohwa" (hexaploid) and "Chieftain" (hexaploid) affected fruit set, fruit quality, and seed formation in the tetraploid kiwifruit cultivars "Halla Gold" and "Sweet Gold" cultivated in an unheated greenhouse in Jeju, Korea. Pollen tubes growing in the pistil reached and combined with the ovule 3 days after artificial pollination, and their patterns differed depending on the ploidy level of the pollen parent. The number of pollen tubes observed in "Halla Gold" and "Sweet Gold" pistils was significantly lower following pollination by "CK3" than with the other pollen donors. In all pollen treatments, the fruit set rates were > 90%. The fruit weight of both "Halla Gold" and "Sweet Gold" were high following pollination with "Chieftain" and "Pohwa". The dry matter content, soluble solids, and acidity were not significantly different among all pollination treatments. Fruit firmness was higher following pollination with "Chieftain" and "Powha." Colorimeter h˚ values for flesh of "Halla Gold" was low following pollination with "CK3," but there were no differences for "Sweet Gold" among all pollinations. The number of seeds showed a similar trend to fruit weight, but the 100-seed weight was highest with "T line" as the pollinizer. The results indicate that the ploidy level of the pollen donor affects fruit quality more than fruit set. Also, the pollen most suitable for cultivation of "Halla Gold" and "Sweet Gold" is considered to be tetraploid "T line" and hexaploid "Pohwa" and "Chieftain," which showed favorable effects on the weight and firmness of fruits, and the number and weight of seeds without adversely influencing fruit set and dry matter content. [ABSTRACT FROM AUTHOR]

Anthocyanins are a class of water-soluble flavonoids widely present in fruits and vegetables responsible for the red flesh formation of peach fruit. Previously, several genes of the MYB family have been reported as transcriptional regulators of the anthocyanin biosynthetic pathway of structural genes in plants. In this study, through comparative transcriptome analysis of the white and red flesh peach cultivars of Harrow Blood and Asama Hakuto, a predicted transcription factor of the R2R3MYB family, PpMYB39, was identified to be associated with anthocyanin biosynthesis in peach fruit. In red-fleshed peach cultivars, the maximum amount of anthocyanin accumulated 95 days after full bloom (DAFB), at full maturity near ripening. Our results showed that, at this stage, PpMYB39 had the highest expression level among the 13 differentially expressed genes (DEGs) found in both red- and white-fleshed fruits, as well as a high correlation with total anthocyanin content throughout fruit development. Moreover, the expression analysis of the structural genes of the anthocyanin biosynthetic pathway in peach fruit revealed that Prunus persica Dihydroflavonol-4-reductase (PpDFR) was co-expressed and up-regulated with PpMYB39 at 95 DAFB, suggesting its possible role as a transcriptional activator of MYB39. This was further confirmed by a yeast one-hybrid assay and a dual luciferase reporter assay. Our results will be helpful in the breeding of peach cultivars and the identification and significance of color in peaches and related fruit species, in addition to providing an understanding of color formation in peach fruit for future research.