Fruit Flesh Color Research Articles

Transcriptomic and metabolomic profiling provide novel insights into fruit development and flesh coloration in Prunus mira Koehne, a special wild peach species

BackgroundFlesh color is one of the most important traits for the commercial value of peach fruit. To unravel the underlying regulatory network in Prunus mira, we performed an integrated analysis of the transcriptome and metabolome of 3 fruit types with various flesh pigmentations (milk-white, yellow and blood) at 3 developmental stages (pit-hardening, cell enlargement and fruit ripening).ResultsTranscriptome analysis showed that an intense transcriptional adjustment is required for the transition from the pit-hardening to the cell enlargement stage. In contrast, few genes were differentially expressed (DEGs) from the cell enlargement to the fruit ripening stage and importantly, the 3 fruits displayed diverse transcriptional activities, indicating that difference in fruit flesh pigmentations mainly occurred during the ripening stage. We further investigated the DEGs between pairs of fruit types during the ripening stage and identified 563 DEGs representing the ‘core transcriptome’ associated with major differentiations between the 3 fruit types, including flesh pigmentation. Meanwhile, we analyzed the metabolome, particularly, at the ripening stage and uncovered 40 differential metabolites (‘core metabolome’) between the 3 fruit types including 5 anthocyanins, which may be the key molecules associated with flesh coloration. Finally, we constructed the regulatory network depicting the interactions between anthocyanins and important transcripts involved in fruit flesh coloration.ConclusionsThe major metabolites and transcripts involved in fruit flesh coloration in P. mira were unraveled in this study providing valuable information which will undoubtedly assist in breeding towards improved fruit quality in peach.

Resequencing of 414 cultivated and wild watermelon accessions identifies selection for fruit quality traits

Fruit characteristics of sweet watermelon are largely the result of human selection. Here we report an improved watermelon reference genome and whole-genome resequencing of 414 accessions representing all extant species in the Citrullus genus. Population genomic analyses reveal the evolutionary history of Citrullus, suggesting independent evolutions in Citrullus amarus and the lineage containing Citrullus lanatus and Citrullus mucosospermus. Our findings indicate that different loci affecting watermelon fruit size have been under selection during speciation, domestication and improvement. A non-bitter allele, arising in the progenitor of sweet watermelon, is largely fixed in C. lanatus. Selection for flesh sweetness started in the progenitor of C. lanatus and continues through modern breeding on loci controlling raffinose catabolism and sugar transport. Fruit flesh coloration and sugar accumulation might have co-evolved through shared genetic components including a sugar transporter gene. This study provides valuable genomic resources and sheds light on watermelon speciation and breeding history.

Whole genome resequencing of watermelons to identify single nucleotide polymorphisms related to flesh color and lycopene content.

Cultivated watermelon (Citrullus lanatus) is one of the most important food crops in the Cucurbitaceae family. Diversification after domestication has led cultivated watermelons to exhibit diverse fruit flesh colors, including red, yellow, and orange. Recently, there has been increased interest in red-fleshed watermelons because they contain the antioxidant cis-isomeric lycopene. We performed whole genome resequencing (WGRS) of 24 watermelons with different flesh colors to identify single-nucleotide polymorphisms (SNPs) related to high lycopene content. The resequencing data revealed 203,894–279,412 SNPs from read mapping between inbred lines and the 97103 reference genome. In total, 295,065 filtered SNPs were identified, which had an average polymorphism information content of 0.297. Most of these SNPs were intergenic (90.1%) and possessed a transversion (Tv) rate of 31.64%. Overall, 2,369 SNPs were chosen at 0.5 Mb physical intervals to analyze genetic diversity across the 24 inbred lines. A neighbor-joining dendrogram and principal coordinate analysis (PCA) based on the 2,369 SNPs revealed that the 24 inbred lines could be grouped into high and low lycopene-type watermelons. In addition, we analyzed SNPs that could discriminate high lycopene content, red-fleshed watermelon from low lycopene, yellow or orange watermelon inbred lines. For validation, 19 SNPs (designated as WMHL1–19) were chosen randomly, and cleavage amplified polymorphic sequence (CAPS) markers were designed. Genotyping of the above 24 lines and 12 additional commercial cultivars using WMHL1–19 CAPS markers resulted in match rates of over 0.92 for most validated markers in correlation with the flesh color phenotypes. Our results provide valuable genomic information regarding the high lycopene content phenotype of red-fleshed cultivated watermelons, and the identified SNPs will be useful for the development of molecular markers in the marker-assisted breeding of watermelons with high lycopene content.

Near infrared spectroscopy to predict internal quality of mangoes

Consumers have high demands regarding the quality of mangoes. Fruits with internal defects lead to disappointment after sale and a decrease in purchases. The aim of this study is to predict internal quality of mangoes using non-destructive near infrared (NIR) measurements. The internal browning was measured from 3000 mangoes grown and harvested in Brazil, transported to the Netherlands and ripened. The results show a good correlation between the occurrence of internal defects and the loss of fruit firmness and increase in fruit flesh colour. NIR measurements allow sorting of mangoes for internal defects in a non-destructive manner, to ensure only mangoes without internal defects reach the consumers. This not only prevents consumer disappointment but also contributes to less waste and a more sustainable mango chain.

The effect of micro-climate to quality and existence of Gedong Gincu Mango

Indonesia as tropical country has various of agro-climate that affected to spread of plants, of course for mango plant. Gedong Gincu mango as a competitive commodities in west java, spread. In three district of west java, Cirebon, Majalengka and Indramayu district. The aims of this research was to analyze the effect of physical environmental components to Gedong Gincu mango characteristics in three districts of west Java, Indonesia. The research was performed in Indramayu, Cirebon, and Majalengka in January-June 2017. The methods of this research was descriptive qualitative. The results showed that the difference of micro-climate, including (rainfall, temperature, and humidity), effected Gedong Gincu mango characteristics, especially size, shape, color and texture of fruit flesh. Gedong Gincu mango from Indramayu has spherical shape, a small size, a strong red color, a hard and thin flesh, a fragrant flavor, and very sweet taste. Gedong Gincu mango from Cirebon has oval shape, a medium size, red color, medium and rather thick flesh, a fragrant flavour and sweet taste. Gedong Gincu mango from Majalengka has a sprawl, large size, yellowish red color, fine meat and thick flesh, a medium flavour and less sweet taste.

Characterization of Genetic Diversity in Accessions of Prunus salicina Lindl: Keeping Fruit Flesh Color Ideotype While Adapting to Water Stressed Environments

The genetic diversity of 14 Japanese plum (Prunus salicina Lindl) landraces adapted to an ecosystem of alternating flooding and dry conditions was characterized using neutral simple sequence repeat (SSR) markers. Twelve SSRs located in six chromosomes of the Prunus persica reference genome resulted to be polymorphic, thus allowing identification of all the evaluated landraces. Differentiation between individuals was moderate to high (average shared allele distance (DAS) = 0.64), whereas the genetic diversity was high (average indices polymorphism information content (PIC) = 0.62, observed heterozygosity (Ho) = 0.51, unbiased expected heterozygosity (uHe) = 0.70). Clustering and genetic structure approaches grouped all individuals into two major groups that correlated with flesh color. This finding suggests that the intuitive breeding practices of growers tended to select plum trees according to specific phenotypic traits. These neutral markers were adequate for population genetic studies and cultivar identification. Furthermore, we assessed the SSR flanking genome regions (25 kb) in silico to search for candidate genes related to stress resistance or associated with other agronomic traits of interest. Interestingly, at least 26 of the 118 detected genes seem to be related to fruit quality, plant development, and stress resistance. This study suggests that the molecular characterization of specific landraces of Japanese plum that have been adapted to extreme agroecosystems is a useful approach to localize candidate genes which are potentially interesting for breeding.

Inventory and Morphological Diversity Characterization of Local Durian [Durio zibethinus Murr.] in South Sulawesi Province

<p>South Sulawesi is one of the provinces in Indonesia which is famous for its durian fruit, especially the local one. These local durians are having several advantages such as resistance to major pests/diseases and high productivity. However, because of the lack of information, many local durians that actually have economic potential are not known by the community. The purpose of<br />this research was to inventory and characterize local Durian in South Sulawesi as the initial step for the registration of varieties. In accordance with the applicable regulations, registration of varieties is a requirement for a variety to be developed economically in local and global markets. This research was conducted in Luwu, Sinjai, and Bulukumba Regencies, South Sulawesi Province, from January to December 2015. The research was using descriptive method and sampling was conducted by purposive sampling<br />method. Direct observation was carried out on trees, leaves, and fruit as primary data, while secondary data was obtained through interviews with the owners of the plant. Eighteenth accessions of durian that have been tested showed that the morphological characters were quite diverse with a genetic similarity coefficient between 0.08–0.50. The dendrogram was divided into four groups. Lagalenrong and Laissong accessions had the greatest genetic similarity (0.50), while the smallest genetic similarity (0.08) were accessions of Simas with Laissong, Simas with Lanangka, Mentega with Lauro 1, Pagolla with Lauro 2, and Simas with Taramatekkeng 2. The superior characters such as medium fruit weight, medium-thinner skin thickness, and sweet taste, were observed on Pagolla, Mentega, and Taramatekkeng 2 accessions, while for attractive fruit flesh color were observed from Simas accession.</p>

Genetic Analysis for Fruit Phenolics Content, Flesh Color, and Browning Related Traits in Eggplant (Solanum melongena).

Eggplant varieties rich in bioactive chlorogenic acid along with less browning are preferred by consumers. Therefore, genetics of fruit phenolics, fruit flesh colour, and browning related traits were studied in the genotypes of eggplant, comprising of nine cultivated varieties and one accession of eggplant‘s primary genepool wild relative Solanum insanum (INS2). These accessions were genotyped based on the 7335 polymorphic single-nucleotide polymorphisms (SNP) markers. After that, genotypes were crossed in half diallel fashion to produce 45 hybrids. The INS2 displayed the highest values for the total phenolics and chlorogenic acid content (CGA). For all of the biochemical traits studied, significant values of general and specific combining ability (GCA and SCA) effects were determined. The baker ratio estimates were high (>0.75) for all of the traits. Highly significant and positive heterosis (%) was determined for the dry matter, total phenolics, CGA, and area (%) of CGA content. The phenolics content of the fruit (total phenolics and CGA) was not significantly correlated with flesh colour and browning related traits. However, when the path coefficient analysis was performed considering the CGA as a dependent variable, it was determined that the flesh colour related traits most considerably affected the CGA. The genetic distance showed a diminutive correlation with the hybrid means, heterosis, and SCA values. Overall, this study provides important information regarding the underlying genetics of important biochemical traits of eggplant fruit.

GENETIC VARIABILITY OF INDONESIAN PAPAYA ACCESSIONS AS REVEALED BY RANDOM AMPLIFIED POLYMORPHIC DNA AND MORPHOLOGICAL CHARACTERIZATION

<p class="abstrakinggris">Diverse papaya (<em>Carica</em> sp.) accessions are found in many regions in Indonesia, but their genetic diversity have not yet been studied. Random Amplified Polymorphic DNA (RAPD) is a simple yet accurate method that can be used to examine the genetic diversity of papaya. The study aimed to examine the genetic diversity of Indonesian papaya accessions using RAPD markers and morphological characters. The RAPD was applied on 23 papaya accessions using 30 primers. The appearing bands were further analyzed with the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) and Principal Component Analysis (PCA). The molecular results were then compared to the fruit morphological data, including fruit shape, size, flesh color, texture, and flavor. The RAPD analysis revealed that the 23 papaya accessions clustered into six main clades with Dice-Sorensen coefficient similarity ranged from 0.71 to 0.98. The first group consisted of 11 accessions, including both the hybrids and local accessions. The second group consisted of eight accessions especially six Indonesian hybrids, a Mexican Hybrid and a Hawaiian hybrid. The other four groups had a single member namely Sicincin Panjang, Lokal Sumani, Cariso, and Carica. The molecular grouping, however, did not align with the fruit character grouping. Overall, it was implied that the Indonesian papaya accessions were genetically narrow, of which some accessions were closely related to Hawaiian and Mexican accessions. These results can be used as a reference on papaya crossbreeding program in Indonesia.</p>

Effects of bagging on fruit flavor quality and related gene expression of AsA synthesis in Actinidia eriantha

Three lines of Actinidia eriantha with high AsA content were used to determine the effects of bagging and control (never bagged) on fruit external and internal qualities, as well as transcript levels for key genes involved in ascorbic acid (AsA) synthesis. Compared with the control, there was no significant difference between bagging and control in soluble solid, dry matter, soluble sugar and titrable acid, but bagging would significantly improve fruit appearance and flesh color, reduced the content of chlorophyll, carotenoid and AsA. The key gene expression involved in AsA synthesis showed that the expressions of GME, GMP, GGP, GPP and GalDH in bagging were inconsistent with the control on three lines. Whereas GalLDH, GalUR and DHAR had the same expression trend and significantly lower than the control. Therefore, we speculated that the different expression of GalLDH, GalUR and DHAR was the key factors for decrease of AsA after bagging. Bagging on A. eriantha can effectively improve the appearance and flesh color of the fruit, improve the ornamental value of the fruit, and has little effect on the sugar and acid content of the fruit. Although the AsA content was reduced, the AsA content (>1250 mg/100 g) was still at a high level.

Analysis of flesh color-related carotenoids and development of a CRTISO gene-based DNA marker for prolycopene accumulation in watermelon

Fourteen watermelon cultivars with different fruit flesh colors (red, salmon yellow, orange, and canary yellow) were analyzed for carotenoid contents (prolycopene, lycopene, β-carotene, ζ-carotene, and neoxanthin). Genes encoding the carotenoid biosynthesis enzymes carotenoid isomerase (encoded by CRTISO), which catalyzes the isomerization of prolycopene to lycopene, and β-carotene hydroxylase (CHYB), which catalyzes the conversion of β-carotene to xanthophyll, were also analyzed. High-performance liquid chromatography showed that the salmon yellow and orange flesh accumulated either prolycopene (orange-P flesh) or β-carotene (orange-β flesh), whereas lycopene and neoxanthin were the main carotenoids in the red and canary yellow flesh, respectively. Quantitative real-time polymerase chain reaction indicated that CRTISO and CHYB were mainly expressed during fruit maturation, regardless of the flesh color, and there was no significant association between differential gene expression and flesh color. Importantly, transcript sequencing revealed a non-synonymous single-nucleotide mismatch (T > C1976) in exon 13 of CRTISO between orange-P-fleshed and other cultivars, suggesting CRTISO as a candidate gene for high prolycopene accumulation. However, in β-carotene-accumulating cultivars, there were no mutations in CHYB transcripts. A cleaved amplified polymorphic sequence marker was developed for T > C1976, and its applicability for marker-assisted selection of orange-P flesh was validated in 105 watermelon accessions.

The Diversity of Breadfruit Plants (Artocarpus Altilis) Based on Morphological Characters

<p>Breadfruit (Artocarpus altilis) is a plant common are all part of it can be used by humans. The research aims to determine the character of morphological breadfruit and knowing the characterization of morphological breadfruit in Yogyakarta. This research was carried out in June to October 2017 in Sleman Regency (Cangkringan, Ngemplak, Ngaglik), Gunung Kidul (Patuk, Nglipar, Gedangsari), and Bantul (Bantul, Pajangan, Imogiri) in Yogyakarta. Variables are observations include the environmental research and morphology of (trees, leaves, fl owers, and fruits). The data of the morphology are analyzed by NTSYS program. The results showed that the breadfruit trees has a plant height 16,7-17,9 m, the diameter of crown 6,1-8,8 m, shape of crown of the pyramidal, broadly pyramidal, elliptical, irregular, the patterns of branching of erect, opposite, and irregular. The length of leaf 42,2-78,6 cm, width of leaf 30,2-59,2 cm, shape of leaf ovate, and leaf colour dark green. The length of male flowers 9,0-13,4 cm, shape of female flowers globose, shape of male flowers ellipsoid, the colour of female flowers light green, the colour of male flowers light green when young, and brown when old. The length of fruit 12,2 -19,0 cm,diameter of fruit 12,8-16,4 cm, weight of fruit 0,7-1,7 kg, shape of fruit sperical and oblong, fruit skin colour greenish yellow, fruit flesh colour white and light yellow. The diversity of morphology of the breadfruit plants ranging from 3-30%.</p>

Assessment of variability pattern of flesh color in ‘Harumanis’ mango (Mangifera indica L.) from diverse Perlis geographical origin

Harumanis’ (Mangifera indica L) is one of the mango cultivars which has high market value because of the excellent quality of the fruit which has attractive color, good aroma, delicious taste and high nutritive values. In this study, fifty accessions from five different collection sites which belonging to North (Paya Kelubi and Chelong Balik Bukit, Padang Besar), West (Santan, Kangar), East (Alor Ara Timur, Arau) and South (Simpang Empat, Kangar) region of Perlis were analyzed according to flesh color traits based on their region of origin. The analysis of variance using Kruskal-Wallis test resulted in significant differences among the geographical region for traits of fruit flesh color such as L*, a*, chroma and hue at (P<0.05). The correlation result shows that the intensity pattern of the orange color of the fruit samples mesocarp was associated by an increase in the values of a*, b* and C*, and a decrease in the values of L* and h. By performing Cluster analysis using Ward’s method and Euclidian distance, five distinct clusters were successfully identified. The finding shows a high distribution of ‘Harumanis’ accessions from different locations in each distinct group. This study also reveals the relationship of variability in fruit traits with their places of origin. However, these differences cannot be explained in firm via morphological characterization only. Other methods such as molecular characterization are strongly recommended.

Modeling ‘Tommy Atkins’ mango cooling time based on fruit physicochemical quality

Mango physicochemical quality can potentially affect fruit cooling time. In that case, an efficient cooling time should take into account fruit quality parameters. The objective of this study was to develop models that can be used to predict ‘Tommy Atkins’ mango cooling time based on fruit physicochemical quality. The prediction models were developed using 150 fruit harvested at maturity stages ranging from 2 to 4. Two thermocouples were fixed in each fruit, one immediately below the epidermis and the other close to the endocarp. From the total number of fruit, 83 were subjected to hydrothermal treatment and 67 were maintained at room temperature (25 °C). The hydrothermal treatment was applied by keeping the mangoes in water bath at 46 °C for 75 min. This treatment is commercially used as a phytosanitary method for mangoes exported to North America and Asian countries. After hydrothermal treatment, treated and non-treated fruit were kept in a cold room to determine the cooling time of the flesh immediately below the epidermis and close to the endocarp, until reaching 12 °C. After reaching storage temperature, each fruit was evaluated for physicochemical characteristics, which were used to obtain the cooling time prediction models. Quality attributes presenting the highest to the lowest influence on fruit cooling time were fruit weight, flesh and skin color (Chroma, Hue angle and Lightness), soluble solids, dry matter, fruit diameter, fruit length, flesh thickness and seed thickness. Cooling time prediction models were generated with these variables by multiple linear regression (MLR) and exhibited high prediction accuracy for fruit without hydrothermal treatment (R²SEC = 88% RMSEC 42.1% R²SEP = 85.5% RMSEP = 52.2%) and with hydrothermal treatment (R²SEC = 72.2% RMSEC 42.4% R²SEP = 73.6% RMSEP = 47.2%). According to the results, the models developed based on physicochemical parameters can predict with relatively high accuracy the cooling time of ‘Tommy Atkins’ mangoes. These models can be used in the mango industry to determine the most effective cooling time required to maintain fruit quality.

Genetic mapping reveals a marker for yellow skin in watermelon (Citrullus lanatus L.).

As a diverse species, watermelon [Citrullus lanatus (Thunb.) Matsum. &Nakai var. lanatus] has different kinds of fruit sizes, shapes, flesh colors and skin colors. Skin color is among the major objectives for breeding. Yellow skin is an important trait in watermelon, but the underlying genetic mechanism is unknown. In this study, we identified a locus for yellow skin through BSA-seq and GWAS. A segregation analysis in F2 and BC1 populations derived from a cross of two inbred lines ‘94E1’(yellow skin) and ‘Qingfeng’(green skin) suggested that skin color is a qualitative trait. BSA-seq mapping confirmed the locus in the F2 population, which was detected on chromosome 4 by GWAS among 330 varieties. Several major markers, namely, 15 CAPS markers, 6 SSR markers and 2 SNP markers, were designed to delimit the region to 59.8 kb region on chromosome 4. Utilizing the two populations consisting of 10 yellow and 10 green skin watermelons, we found a tightly linked functional SNP marker for the yellow skin phenotype. The application of this marker as a selection tool in breeding programs will help to improve the breeder’s ability to make selections at early stages of growth, thus accelerating the breeding program.

Genetic mapping of ovary colour and quantitative trait loci for carotenoid content in the fruit of Cucurbita maxima Duchesne

The high content of carotenoids, sugars, dry matter, vitamins and minerals makes the fruit of winter squash (Cucurbita maxima Duchesne) a valuable fresh-market vegetable and an interesting material for the food industry. Due to their nutritional value, long shelf-life and health protective properties, winter squash fruits have gained increased interest from researchers in recent years. Despite these advantages, the genetic and genomic resources available for C. maxima are still limited. The aim of this study was to use the genetic mapping approach to map the ovary colour locus and to identify the quantitative trait loci (QTLs) for high carotenoid content and flesh colour. An F6 recombinant inbred line (RIL) mapping population was developed and used for evaluations of ovary colour, carotenoid content and fruit flesh colour. SSR markers and DArTseq genotyping-by-sequencing were used to construct an advanced genetic map that consisted of 1824 molecular markers distributed across linkage groups corresponding to 20 chromosomes of C. maxima. Total map length was 2208 cM and the average distance between markers was 1.21 cM. The locus affecting ovary colour was mapped at the end of chromosome 14. The identified QTLs for carotenoid content in the fruit and fruit flesh colour shared locations on chromosomes 2, 4 and 14. QTLs on chromosomes 2 and 4 were the most meaningful. A correlation was clearly confirmed between fruit flesh colour as described by the chroma value and carotenoid content in the fruit. A high-density genetic map of C. maxima with mapped loci for important fruit quality traits is a valuable resource for winter squash improvement programmes.

Pre-harvest zinc spray impact on enzymatic browning and fruit flesh color changes in two apple cultivars

Abstract Enzymatic browning (EB) in apple occurred during processing or fresh consumption as fresh cut. EB in response to pre-harvest Zn spray at two apple cultivars was investigated. Trees of apple (Malus domestica cultivar ‘Delbard Estival’ and ‘Kohanz’) were sprayed with water (control), 0.13% of Chelated Zn (C-Zn) or 0.13% of Nano-Chelated Zn (NC-Zn) three or four weeks before harvest. Assessments were carried at spray time, three or four weeks (H1 and H2) after spray and also after 3 weeks of storage (H1 + 3 W and H2 + 3 W) at 4 °C with 95% (RH). The browning index (BI) and total color changes (ΔE) decreased from spray time until harvest time. BI and ΔE in treated fruit were lower than control at all time points except in H1. Starch index was delayed in fruit treated with C-Zn or NC-Zn. The highest firmness of ‘Delbard Estival’ and ‘Kohanz’ cultivars was observed in NC-Zn than other treatments at all sampling times. Titratable acidity, soluble solids content and total phenol showed no distinct changes during time. The ascorbic acid, total antioxidant activity and superoxide dismutase in C-Zn or NC-Zn treatments were higher than control in both cultivars except superoxide dismutase activity at H1 for NC-Zn. The polyphenol oxidase activity in both cultivars treated with C-Zn or NC-Zn was lower than control at all sampling time except at H1 in ‘Kohanz’ cultivar. These findings suggest that the pre-harvest spray with Zn and especially NC-Zn can improve flesh color changes and quality parameters in apples.

Deciphering genetic factors that determine melon fruit-quality traits using RNA-Seq-based high-resolution QTL and eQTL mapping.

Combined quantitative trait loci (QTL) and expression-QTL (eQTL) mapping analysis was performed to identify genetic factors affecting melon (Cucumis melo) fruit quality, by linking genotypic, metabolic and transcriptomic data from a melon recombinant inbred line (RIL) population. RNA sequencing (RNA-Seq) of fruit from 96 RILs yielded a highly saturated collection of > 58 000 single-nucleotide polymorphisms, identifying 6636 recombination events that separated the genome into 3663 genomic bins. Bin-based QTL analysis of 79 RILs and 129 fruit-quality traits affecting taste, aroma and color resulted in the mapping of 241 QTL. Thiol acyltransferase (CmThAT1) gene was identified within the QTL interval of its product, S-methyl-thioacetate, a key component of melon fruit aroma. Metabolic activity of CmThAT1-encoded protein was validated in bacteria and invitro. QTL analysis of flesh color intensity identified a candidate white-flesh gene (CmPPR1), one of two major loci determining fruit flesh color in melon. CmPPR1 encodes a member of the pentatricopeptide protein family, involved in processing of RNA in plastids, where carotenoid and chlorophyll pigments accumulate. Network analysis of > 12 000 eQTL mapped for > 8000 differentially expressed fruit genes supported the role of CmPPR1 in determining the expression level of plastid targeted genes. We highlight the potential of RNA-Seq-based QTL analysis of small to moderate size, advanced RIL populations for precise marker-assisted breeding and gene discovery. We provide the following resources: a RIL population genotyped with a unique set of SNP markers, confined genomic segments that harbor QTL governing 129 traits and a saturated set of melon eQTLs.

Fruit flesh color due to the quantity of brown specks as affected by the number of seeds in fruits of ‘Fuyu’ persimmon

The terms pollination constant (PC) and pollination variant (PV), respectively, define persimmon cultivars as those exhibiting no change in flesh color due to seed formation in the fruit and as those exhibiting a change due to brown specks by seed formation in flesh color. 'Fuyu' is the most produced persimmon cultivar in the world, and it has been regarded as a PC and non-astringent cultivar (PCNA). A total of 557 and 101 'Fuyu' persimmon fruits were collected in 1981 and 1982, respectively, from trees grown at Akitsu at the National Institute of Japan and were evaluated for the number of seeds contained in each fruit (SN) and scored according to the quantity of brown specks (BS) in the flesh. The regression of the BS scores on seed numbers was positive and highly significant (P<0.001) in both years. These results showed that fruit flesh color was slightly changed by seed formation in the 'Fuyu' fruits. This change was lower than that observed in most PV cultivars. 'Fuyu' seeds exude ethanol and acetaldehyde, which are responsible for the coagulation and oxidation of tannin substances in the flesh in PV cultivars. The slight change of flesh color in 'Fuyu' is possibly caused by these volatile compounds. The results lead to classifying 'Fuyu' into PV in a strict sense of Hume's classification. To eliminate the confusion, we propose that the term “PCNA” should be redefined with a synonym for Kajiura's term of “perfect non-astringent”, i.e., non-astringent at maturity with no influence of seeds, apart from Hume's classification.

Sunlight Differentially Affects the Fruit Skin, Flesh, and Core Coloration of the Type 2 Red-fleshed Apple ‘Kurenainoyume’: Optimization of Fruit Bagging Treatment

Sunlight Differentially Affects the Fruit Skin, Flesh, and Core Coloration of the Type 2 Red-fleshed Apple ‘Kurenainoyume’: Optimization of Fruit Bagging Treatment