Yellow Fruit Color Research Articles

A mutation in Zeaxanthin epoxidase contributes to orange coloration and alters carotenoid contents in pepper fruit (Capsicum annuum).

Phytoene synthase (PSY1), capsanthin-capsorubin synthase (CCS), and pseudo-response regulator 2 (PRR2) are three major genes controlling fruit color in pepper (Capsicum spp.). However, the diversity of fruit color in pepper cannot be completely explained by these three genes. Here, we used an F2 population derived from Capsicum annuum 'SNU-mini Orange' (SO) and C. annuum 'SNU-mini Yellow' (SY), both harboring functional PSY1 and mutated CCS, and observed that yellow color was dominant over orange color. We performed genotyping-by-sequencing and mapped the genetic locus to a 6.8-Mb region on chromosome 2, which we named CaOr. We discovered a splicing mutation in the zeaxanthin epoxidase (ZEP) gene within this region leading to a premature stop codon. HPLC analysis showed that SO contained higher amounts of zeaxanthin and total carotenoids in mature fruits than SY. A color complementation assay using Escherichia coli harboring carotenoid biosynthetic genes showed that the mutant ZEP protein had reduced enzymatic activity. Transmission electron microscopy of plastids revealed that the ZEP mutation affected plastid development with more rod-shaped inner membrane structures in chromoplasts of mature SO fruits. To validate the role of ZEP in fruit color formation, we performed virus-induced gene silencing of ZEP in the yellow-fruit cultivar C. annuum 'Micropep Yellow' (MY). The silencing of ZEP caused significant changes in the ratios of zeaxanthin to its downstream products and increased total carotenoid contents. Thus, we conclude that the ZEP genotype can determine orange or yellow mature fruit color in pepper.

Phytoene synthase 2 can compensate for the absence of PSY1 in the control of color in Capsicum fruit.

Phytoene synthase 1 (PSY1) and capsanthin-capsorubin synthase (CCS) are two major genes responsible for fruit color variation in pepper (Capsicum spp.). However, the role of PSY2 remains unknown. We used a systemic approach to examine the genetic factors responsible for the yellow fruit color of C. annuum 'MicroPep Yellow' (MY) and to determine the role of PSY2 in fruit color. We detected complete deletion of PSY1 and a retrotransposon insertion in CCS. Despite the loss of PSY1 and CCS function, both MY and mutant F2 plants from a cross between MY and the 'MicroPep Red' (MR) accumulated basal levels of carotenoids, indicating that other PSY genes may complement the loss of PSY1. qRT-PCR analysis indicated that PSY2 was constitutively expressed in both MR and MY fruits, and a color complementation assay using Escherichia coli revealed that PSY2 was capable of biosynthesizing a carotenoid. Virus-induced gene silencing of PSY2 in MY resulted in white fruits. These findings indicate that PSY2 can compensate for the absence of PSY1 in pepper fruit, resulting in the yellow color of MY fruits.

Study on the Profile of Capsanthin-Capsurobin Synthase (Ccs) Gene responsible for Carotenoid Synthesis in Chili Pepper (Capsicum frutescens L.) Mutants G1M6 M2 Generation

The Capsanthin-capsorubin synthase (Ccs) is one of the enzymes that play a role in carotenoid pigment bio-synthesis. Mutations in the Ccs gene cause the formation of yellow or orange fruit colour instead of red. This study aims to analyze the genetic profile of the Ccs gene and its effect on the carotenoid content of the chili pepper mutant G1M6 M2generation. The profile of the Ccs gene was analyzed using Polymerase Chain Reaction (PCR) continued with sequencing methods.The carotenoid content was measured from chili fruit harvested at 35 and 65 days after planting. Comparison of the partial sequence of Ccs gene of the mutants and the Capsicum annuum var. Landrace, showed a substitution of adenine into guanine in the 124 bp nucleotide base sequence and the cytosine nucleotide substitution to thymine in the 556 bp nucleotide base sequence. However there was no difference between the Ccs gene sequence of the chili pepper G1M6/13, G1M6/7, G1M6/8 compared to the control plant (G1K1). The consistency showed by these sequence did not reflect the carotenoid content. Carotenoid content in the three mutant plants varied compared to control plants. The G1M6/8 mutant had higher carotenoid content, while the G1M6/13 mutant had a lower carotenoid content compared to the control plant. Since there was no differences on the partial sequence of the Ccs gene observed, the deviation of carotenoid content between mutant and control plants maybe governed by other part of the gene.

English

Tomato is a vegetable of great economic importance in Burkina Faso. This study evaluated agromorphological diversity within 40 tomato accessions from Burkina Faso and Mali. Trials were conducted during 2015 growing season and IPGRI descriptors were considered in collecting data on field as well as in laboratory. Results revealed the collection to be interestingly diversified. All studied characters presented several modalities, with heterogeneous one predominant. Leaf type, external color of both immature and mature fruit was the most variables showing 5 homogeneous modalities in each case. Peruvianum leaf type was predominant (17.5%) followed by standard type (5%) while red was the main fruit color at maturity in 25% of accessions. Rare interesting traits, that is, Hirsutum, dwarf, potato leaf types, and yellow and orange mature fruit color could be highlighted by detailed investigation on heterogeneous accessions. PCA clustered accessions in 4 groups, with G1 (cherry fruit) and G3 (large and flattened fruit) the most distinctive ones. The strongest positive correlations were observed between number of inflorescences per branch and average number of fruits per plant. This entire variability could be used in tomato breeding program, especially to enhance the β-carotene content in Burkina Faso tomato local varieties. Key words: Tomato, accessions, variability, Burkina Faso, Mali. &nbsp

Distinguishing two genetic factors that control yellow fruit color in tomato

Carotenoids are tetraterpenes (40-carbon isoprenoids) derived from the five-carbon isoprene units, isopentenyl diphosphate (IDP) and its isomer dimethylallyl diphosphate (DMADP). These molecules are the major determinants of fruit pigmentation in many plant species, including tomato. The IDP isomerase (IDI) catalyzes the isomerization of IDP to DMADP. Phytoene synthase (PSY) catalyzes the dimerization of two diterpenes from geranylgeranyl pyrophosphate to phytoene, which is the rate-limiting step in carotenoid biosynthesis. Mutations in the tomato PSY1, yellow flesh, are widely used for breeding yellow tomatoes. We report a series of allelic variations in yellow flesh, and in the newly identified apricot, which has yellow fruit as a result of a mutation in IDI1. In HPLC analysis, both the cultivars showed yellow ripe fruits that lacked carotenoids. However, unlike wild type and yellow flesh, apricot mutants had reduced carotenoid levels in flowers. The allelic variations in yellow flesh were determined to have a deletion in the promoter region and a nonsense mutation in the PSY1 gene, whereas apricot contained a ‘T’ insertion that resulted in premature termination codon in the IDI1 gene. DNA markers to identify allelic variations in two yellow flesh and three apricot mutant lines were developed. These markers and germplasms would be useful for breeding yellow tomatoes.

Single nucleotide mutation in FvMYB10 may lead to the yellow fruit in Fragaria vesca

The color of strawberry mainly results from the accumulation of anthocyanins. However, the regulatory mechanism of anthocyanins accumulation in strawberry is not fully understood. To identify the key gene responsible for anthocyanins synthesis, we firstly did complementation test in yellow strawberry (Fragaria vesca accession ‘Yellow Wonder’) with FvF3H from red strawberry (F. vesca accession ‘Ruegen’) which was considered co-segregation with c (yellow fruit color) locus. However, overexpression of FvF3H from red strawberry did not restore the red fruit phenotype and the transgenic lines still showed yellow color. Next, we did genetic mapping of c locus by constructing a F2 population and delimited the candidate gene to 718 kb genomic region. Then, comparative genomic analyses between Arabidopsis thaliana and Fragaria vesca on a genome-wide level was conducted for screening the candidate gene involved in anthocyanins biosynthesis. Interestingly, only one anthocyanin-related gene, FvMYB10, was found in the candidate region based on mapping data and comparative genomic analyses. A single nucleotide mutation in the coding region of MYB10 co-segregated with the fruit phenotype in F2 population and different strawberry varieties and lines. Thus, it was the most likely candidate gene for c locus. Moreover, the mutation region was located in MYB transcription factor R2 DNA-binding domain. Gene expression of FvMYB10 was no significant difference between yellow and red fruit strawberry, which indicated point mutation may affect FvMYB10 protein or structural genes expression instead of transcript level of FvMYB10. This information will provide a platform for understanding the regulatory mechanism of anthocyanin biosynthesis in strawberry.

Effect of different treatments of ethrel on ripening behaviour and post- harvest quality of mango (Mangiferaindica L.) during storage

An experiment was done to assess the effect of various post -harvest treatments of ethrel on ripening behaviour and post -harvest quality of mango cv. Amrapali (Mangiferaindica L.) during storage at Punjab Agricultural University, Regional Research Station, Gurdaspur during the years 2013-14 and 2014-15. The experiment was planned under completely randomized design (CRD) with three replications. The treatment units was six fruits per replication. Total five treatments and control were applied. The objective of this work was to evaluate the effects of various concentrations of ethrel (500 ppm, 750 ppm, 1000 ppm,1250 ppm, 1500 ppm and control ) on shelf life of mango fruits when stored under ambient conditions. The treated fruits were assessed for physiological changes fruit colour, flavour/aroma, organoleptic taste, marketability, ripening, specific gravity, moisture loss, decay, physiological loss in weight (PLW), total soluble solids (TSS), acidity and sugars. The observations were recorded at 5, 8 and 11 days after storage. At 11th day of storage these mangoes exhibited deep yellow fruit colour with excellent flavour, organoleptic taste and highly acceptable marketability at 1000 ppm ethrel treatment as compared to other ethrel doses. Fruit ripening (100%), specific gravity (0.84), TSS(23°Brix) and sugars(20.65%) were highest in the fruits treated with 1000ppm ethrel as compared to rest of treatments at 11th day of storage. Lowest moisture loss (8.5%), decay (1%), PLW(12.50%) and acidity(0.12%) were observed in the fruits treated with 1000ppm of ethrel as compared to rest of treatments at 11th day of storage. The beneficial effect of the present study is to overcome the problem of uneven and late ripening of Amrapali mango by postharvest treatment of ethrel at 1000 ppm at their mature green stage to develop typical fruit flavour with excellent fruit quality.

Genome-scale DNA variant analysis and functional validation of a SNP underlying yellow fruit color in wild strawberry.

Fragaria vesca is a species of diploid strawberry being developed as a model for the octoploid garden strawberry. This work sequenced and compared the genomes of three F. vesca accessions: ‘Hawaii 4′, ‘Rügen’, and ‘Yellow Wonder’. Genome-scale analyses of shared and distinct SNPs among these three accessions have revealed that ‘Rügen’ and ‘Yellow Wonder’ are more similar to each other than they are to ‘Hawaii 4’. Though all three accessions are inbred seven generations, each accession still possesses extensive heterozygosity, highlighting the inherent differences between individual plants even of the same accession. The identification of the impact of each SNP as well as the large number of Indel markers provides a foundation for locating candidate mutations underlying phenotypic variations among these F. vesca accessions and for mapping new mutations generated through forward genetics screens. Through systematic analysis of SNP variants affecting genes in anthocyanin biosynthesis and regulation, a candidate SNP in FveMYB10 was identified and then functionally confirmed to be responsible for the yellow color fruits made by many F. vesca accessions. As a whole, this study provides further resources for F. vesca and establishes a foundation for linking traits of economic importance to specific genes and variants.

How crossing with East-Asian raspberry-relative species affects fruit color and shoot pigmentation in the seedlings of cultivated raspberry (Rubus idaeusL.)

This research work represents the evaluation of fruit colour and red pigmentation of vegetative shoots of selected raspberry hybrid species. The selected hybrids are derived from the crossing of Rubus idaeus and Rubus parvifolius. The aim of the experiment was to integrate the vitality and resistance of wild raspberry and the fruit quality of the cultivated one with several backcrossings. In fruit quality, colour plays an important role by influencing market demand. During the analysis of colour inheritance, we assumed the presence of a second yellow gene (Y2), due to the significantly higher rate of segregation at the yellow fruit colour hybrids. A wide range of shades of yellow can be identified from light yellow to apricot. Several other genes are involved in the regulation of the production of yellow and red colour. Identification of these genes requires further research work. The C gene determines the shoot colour of raspberry. During the observation of wild raspberries we have revealed the role of a dominant Pr gene. The linkage of the Y and Pr genes are descended. The value of the crossing over is approximately 15%. The anthocyanin production inhibitory effect - caused by the Y gene - extends only for the fruit. By observing the shoots of yellow fruit plants, we have noticed strong anthocyanin production.

Pepper Weevil (Coleoptera: Curculionidae) Preferences for Specific Pepper Cultivars, Plant Parts, Fruit Colors, Fruit Sizes, and Timing.

Peppers (Capsicum spp.) are an important crop in the USA, with about 32,000 ha cultivated in 2007, which resulted in $588 million in farm revenue. The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is the most troublesome insect pest of peppers in the southern United States. It is therefore urgent to find different vulnerabilities of pepper cultivars, fruit and plants parts, fruit colors and sizes, and timing to infestation by A. eugenii. Also relevant is testing whether fruit length and infestation state affect fruit numbers, weights, and proportions of fruit that are infested. Counts of A. eugenii adults and marks from oviposition and feeding suggested that C. chinense Jacquin “Habanero” was least susceptible, and C. annuum L. cultivars “SY” and “SR” were most susceptible. Comparison of plant parts and fruit sizes revealed that A. eugenii preferred the peduncle, calyx, and top of pepper fruits over the middle, bottom, leaves, or remainder of flowers. Anthonomus eugenii does not discriminate between green or yellow fruit color nor vary diurnally in numbers. Based on adult counts, medium to extra-large fruits (≥1.5 cm long) attracted more weevils than small fruits (<1.5 cm). However based on proportions of fruit numbers or fruit weights that were infested, there were no differences between large and small fruits. Choice of pepper cultivar can thus be an important part of an IPM cultural control program designed to combat A. eugenii by reduced susceptibility or by synchronous fruit drop of infested fruits. Our results are potentially helpful in developing scouting programs including paying particular attention to the preferred locations of adults and their sites of feeding and oviposition on the fruit. The results also suggested the potential value of spraying when the fruits are still immature to prevent and control infestation.

Development of a codominant CAPS marker for allelic selection between canary yellow and red watermelon based on SNP in lycopene β-cyclase (LCYB) gene

Flesh color of watermelon is an agronomically important trait that is predominantly determined by a network of the carotenoid biosynthetic pathway, which also contributes to the nutritional value of the fruit through the health-promoting function of carotenoids. We have identified a key gene, lycopene β-cyclase (LCYB) that may determine canary yellow and red flesh color of watermelon and developed a zero-distance molecular marker that identifies a critical single nucleotide polymorphism (SNP) that distinguishes different alleles of the LCYB gene. Analysis of the flesh color inheritance in segregating populations indicated that a single gene determines the color difference between canary yellow and red flesh in watermelon. The sequence comparison of full-length cDNA of LCYB, which was isolated using degenerate PCR and RACE, identified three SNPs in the coding region of LCYB between canary yellow and red. These SNPs showed perfect co-segregation with flesh color phenotypes. One of the SNPs introduces an amino acid replacement of evolutionarily conserved Phe226 to Val, which may impair the catalytic function of LCYB. This SNP was used to develop a cleaved amplified polymorphic sequence (CAPS) marker, which perfectly cosegregated with flesh color phenotype. Our results strongly suggest that LCYB may be the genetic determinant for canary yellow or red flesh color and our CAPS marker will allow breeders to economically distinguish between canary yellow and red watermelon fruit color at the seedling stage.

Genotype Analysis of Fruit Color using a Molecular Marker in Watermelon [Citrul luslanatus (Thunb.) Matsum &amp; Nakai

Fruit color and carotenoid composition are important traits in watermelon. Watermelon fruit color inheritance has revealed that several genes are involved in color determination. Carotenoids are known to have various functions in plants and animals, such as providing antioxidant activity and other health benefits for humans, and UV protection and pigmentation for plants. Differential gene activity in the carotenoid biosynthetic pathway may result in different color determination of mature fruit. Eight genes encoding enzymes involved in the pathway were isolated and their structures were characterized. While obtaining full-length cDNA of these enzymes, two single-nucleotide polymorphisms were detected in a coding region of lycopene β-cyclase (LCYB). These SNP markers showed cosegregation with red and canary yellow fruit color based on the genotyping of two segregating populations. This will lead to development of a codominant molecular marker for the selection of LCYB allele, which may allow breeders to distinguish between red and canary yellow watermelon fruit colors at the seedling stage.

Inheritance of fruit colour and of shoot's pigmentation in the case of interspecific raspberry hybrids

In our research, fruit colour and the shoot's red pigmentation were evaluated in the hybrids of Rubus idaeus and Rubus parvifolius crossings. Y and Ys genes beside the T genes determine the fruit colour of interspecific hybrids, which is characteristic for raspberry. For the explanation of the significantly higher results of segregation then expected at the yellow fruit colour hybrids, we have supposed the presence of a second yellow gene (Y2). In the yellow colour, a lot of different shade colours can be identified from light yellow to the apricot colour. In the regulation of the production of yellow and red colour, several other genes can participate also. Identification of these genes would require more additional research. The C gene determines the shoot colour of raspberry and in the case of wild raspberries we have revealed the role of a dominant Pr gene. The Y and Pr genes are descended linked. The value of crossing over is approximately 15%. The anthocyanin production inhibitory effect of the Y gene extends only for fruit. At the shoots of yellow fruit plants, strong anthocyanin production was observed.

Molecular identification of the yellow fruit color (c) locus in diploid strawberry: a candidate gene approach

A candidate gene approach was used to determine the likely molecular identity of the c locus (yellow fruit color) in Fragaria vesca, a diploid (2n=2x=14) strawberry. Using PCR with degenerate primer pairs, intron-containing segments of structural genes coding for chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS) and one Del-like regulatory gene in the anthocyanin biosynthetic pathway, were amplified, cloned and sequenced. Intron length polymorphisms for each of these genes were detected among three diploid varieties: F. vesca Alpine variety ’Yellow Wonder’ (YW) (Europe); DN1C, a F. vesca clone collected from Northern California; and Fragaria nubicola FRA520, a U.S.D.A. accession collected in Pakistan. Using F2 generations of the crosses DN1C×YW and YW×FRA520 as mapping populations, the six candidate genes were mapped in relation to previously mapped randomly amplified polymorphic DNA (RAPD) markers and morphological markers. The F3H gene was linked without recombination to the c locus in linkage group I, while the other five candidate genes mapped to different linkage groups. These results suggest that the wild-type allele (C) of the c (yellow fruit color) locus encodes an F3H necessary for red fruit color in F. vesca.

Molecular genetics of the y locus in pepper: its relation to capsanthin-capsorubin synthase and to fruit color

Classical genetic studies have determined that the yellow fruit color in pepper is recessive to red in the locus y. We studied the relation of the y locus with the gene coding for capsanthin-capsorubin synthase (CCS) that synthesizes the red carotenoid pigments in the mature fruit. Cosegregation of y and CCS in populations derived from crosses between plants bearing red×white and red×yellow fruits indicated the correspondence of the two genes. We obtained indications for the occurrence of a deletion in the CCS gene in plants containing the recessive y allele. This deletion did not contain the distal 220 bp of the 3′ end of the gene. We used the CCS gene to determine the genotype of peppers with different fruit colors at the y locus. In BC1 segregants from a red×white cross, the red and peach-fruited progenies had the wild-type allele at the CCS locus, while the orange, yellow and white-fruited progenies had the mutant allele. Screening orange-fruited cultivars with CCS as well as segregation analysis of CCS in an additional red×white cross indicated two possible genotypes of the orange fruit color in this locus.

Inheritance of fruit color and pigment changes in a yellow tomato (Lycopersicon esculentum Mill.) mutant

A naturally occurring yellow tomato fruit mutant cv. Santa Clara was reciprocally crossed with the red wild type, after which F1 plants were self pollinated or backcrossed with both parents. Plants from F1 generations produced all fruits with a homogeneous deep red color when ripe. F2 plants showed a 3:1 red:yellow segregation of fruit color, and 100% red when backcrossed with red wild type or 1:1 red:yellow segregation in backcrosses with the yellow mutant; hence, yellow fruit color was determined by a recessive allele. Based on reciprocal crosses, fruit color is unlikely to be determined by maternal genes. Accumulation of lycopene dropped by 99.3% and&lt;FONT FACE="Symbol"&gt; b&lt;/font&gt;-carotene by 77% in ripe yellow fruits, compared to the red wild type. Leaf and flower chlorophyll and total carotenoid concentrations were not affected by the yellow mutation. However, the mutant fruit had a higher rate of chlorophyll degradation during fruit ripening, whilst fruit from the F1 generation showed lower rates of degradation, similar to that observed in red wild type fruits.

Fruit colour and correlations with orchard factors and post-harvest characteristics in apple cv. Mutsu

SummaryTo improve the quality of `Mutsu' apples after storage, relationships were studied between various orchard factors and fruit quality in an orchard survey performed in 1996 and 1997. Quality aspects included were fruit colour as related to fruit firmness and contents of starch, sugar and acid. Fruit colour was strongly correlated with firmness and sugar content, whereas starch and acid content correlations were not consistent from green to intermediate and yellow fruit. Compared with 1996, yields were higher and the development of fruit colour poorer in 1997, probably caused by climatic variations. No correlations were found between ratings for tree density, tree vigour and tree openness vs. fruit colour, whereas crop load was highly correlated to both green, intermediate and yellow fruit colour, respectively. In addition, significant correlations were found between leaf N, leaf K, and fruit colour. It is suggested that possible cultural practices for obtaining good fruit quality of `Mutsu', therefore, may be a low to moderate supply of nitrogen, a relatively high supply of potassium and thinning to achieve an optimal crop load.

Shikimate Dehydrogenase Allozymes: Inheritance and Close Linkage to Fruit Color in the Diploid Strawberry

The inheritance of shikimate dehydrogenase (SDH) allozymes, and their linkage relationships with phosphoglucoisomerase (PGI-2) and a locus governing red versus yellow fruit color were studied in the diploid (2n = 2x = 14) strawberry. SDH behaved as a monomeric enzyme with alternate, codominant alleles at a single locus. In the F2 generation of reciprocal crosses between Fragaria vesca Alpine cultivars Baron Solemacher (red fruit) and Yellow Wonder (yellow fruit), SDH segregated in a 1:2:1 ratio, and fruit color segregated 3 red/1 yellow. The SDH and fruit color segregations were highly correlated, with a recombination frequency of 1.1%. Diploid USDA accession FRA 364 was heterozygous with respect to both SDH and PGI-2. Both isozymes segregated 1:1, and assorted independently of each other in the F1 generation of crosses between FRA 364 (as male) and the two Alpine cultivars. The close (1.1 cM) linkage detected between the SDH and fruit color loci constitutes the first report of quantified genetic linkage in the strawberry

The Inheritance of Mature Fruit Color in Capsicum pubescens R. &amp; P.1

Abstract Red and yellow mature fruit color in Capsicum pubescens is controlled by a single gene with yellow (y) recessive to red (y+).

The Inheritance of Mature Fruit Color in Capsicum pubescens R. &amp; P.1

Abstract Red and yellow mature fruit color in Capsicum pubescens is controlled by a single gene with yellow (y) recessive to red (y+).