Analysis of Fruit Length Using Mixed Major Gene and Polygene Inheritance Model in Summer Squash

[Objective]The aim was to provide scientific basis for breeding on the fruit length of summer squash.[Method]Inheritance of the fruit length of summer squash in P1,P2,F1,B1,B2 and F2 from two crosses q-1 ×23-4G（cross 1） and q-1 ×A-7（cross 2） was investigated by the mixed major gene and polygene inheritance model of quantitative traits.[Result]The results showed that the fruit length was controlled by D2 model;Genetic effect of fruit length of cross 1 was mainly additive effect,but genetic effect of fruit length of cross 2 was mainly dominant effect.Heritability values of the genes of F2 were relatively high and the environmental effect was relatively low.[Conclusion]The fruit length breeding of summer squash should be selected in early generation selection.

Analysis of Fruit Width Using Mixed Major Gene and Polygene Inheritance Model in Summer Squash

[Objective] The aim was to provide scientific basis for breeding on the fruit width of summer squash.[Method] Inheritance of the fruit width traits of summer squash in P1,P2,F1,BC1,BC2 and F2 from two crosses q-1×23-4G（cross 1）and q-1×A-7（cross 2）was investigated by the mixed major gene and polygene inheritance model of quantitative traits.[Result] The fruit width was controlled by B-1 model.Heritability values of the major genes of F2 were relatively high and the environmental effect was relatively low.[Conclusion] The fruit width breeding of summer squash should be selected in early generation selection.

Propylene Effects on Ethylene Biosynthesis in Relation to Gene Expression of ACS,ACO in Persimmon Fruit

Influences of propylene treatment on fruit softening and ethylene biosynthesis of persimmon genotype, 'Hiratanenashi' were investigated. The treatment with propylene could accelerate the softening and enhance ethylene biosynthesis, with higher sensitivity of immature fruit to the propylene was consistent with mRNA increase derived from transcription of ACS and ACO genes. Furthermore, ethylene synthesis increase in immature fruits was controlled and regulated mainly by DK-ACS1, DK-ACS2, DK-ACO1 and DK-ACO2, but regulated only by DK-ACS1 and DK-ACO1 in mature fruits.

Influence of Water Stress on the Citric Acid Metabolism Related Gene Expression in the Ponkan Fruits

To explore the influence of water stress on fruit quality and gene expression related to citrate metabolism of ponkan. The test were conducted from May 15 to December 24 in 2013 using six-year-old ponkan (C. blanco cv. Ponkan) trees with 40% soil water conditions by taken regular watering as control. The content of acids in fruit were determined by HPLC, and relative expression of related genes of citric acid metabolic were determined by relative fluorescence quantitative PCR. The results showed that the content of citric acid, malic acid, quinic acid and total organic acids per gram sarcocarp were extremely increased by 285.2%, 320%, 480% and 299.1%, and the content of per-fruit organic acid were 77.39%, 89.64%, 117.24% and 75.9% respectively compared to those control in the fruit mature stage. Relative expression of CitCS1, CitCS2 were higher than control, and relative expression of CitAco1, CitAco2, CitAco3 had a certain increase in the late fruit development, were lower in mature stage. Three relative expression of CitIDH gene were higher than control in mature stage. Low CitGAD4 relative expression and undetectable in mature stage, the relative expression of CitGAD5 gene had a role in promoting under water stress. Furthermore, the relative expression of CitCS1, CitCS2, CitACO1, CitACO3, CitIDH1, CitIDH2, CitIDH3, CitGAD4 and CitGAD5 were influenced by water stress through the correlation analysis. Water stress caused the accumulation of citric acid, declined fruit quality, leaded to change of the genetic rela- tive expression about citric acid synthesis and degradation. The down-regulation of CitACO1, CitGAD4 and up-regulation of CitCS1, CitCS2 might be one of the reasons that promoted to the accumulation of citric acid.

Mapping of fruit apex shape related QTLs across multi-genetic backgrounds in cucumber(Cucumis sativus L.)

The shape of fruit apex is critical to appearance quality in cucumber(Cucumis sativus L.),of which the genetic basis was poorly understood,and the use of marker-assisted breeding for fruit apex improvement is not available yet.In this study,the variation of fruit apex in different cucumber ecotypes was evaluated by fruit apex angle(variation coefficient from 7.1%to 15.7%)and fruit apex index(variation coefficient from 8.8%to 22.6%).Fruit apex associated QTLs were mapped by using 145 F_(2:3) families and 155 F_(2:6) population that were derived from the cross of different ecotype cucumbers.Phenotyping of the mapping populations were conducted in four experiments in 2 years.Four majoreffect QTLs,Bfal4.1,Bfai4.1,Bfad6.1 and Bfai6.1 were consistently and reliably detected across two environments which could explain 11.6%-33.6%phenotypic variations(R^(2))in the F_(2:3) families.Three major-effect QTLs,Ofai4.1(R^(2)=13.4%-15.5%),Ofal4.1(R^(2)=10.7%-12.8%),and Ofad6.1(R^(2)=11.6%-12.4%)were stably detected in the F_(2:6) population in two experiments.Bfai4.1,Bfal4.1,Ofai4.1 and Ofal4.1 were integrated to be consensus QTL fa4.1,within which 11 candidate genes were predicted.Bfai6.1 and Bfad6.1 were integrated to be consensus QTL fa6.1.QTL interaction analysis showed that Bfai6.1 has epistatic effect with Bfai4.1.This study revealed two reliable major-effect fruit apex related QTLs across multi-genetic backgrounds and environments in cucumber.The possible candidate genes regulating the shape of fruit apex,and the relationship between cell division and fruit apex morphogenesis were discussed.

Cloning,localization and expression analysis of two fw2.2-like genes in small-and large-fruited pear species

Fruit size is one of the most important agronomic characters,which is mainly determined by cell number and cell size.However,our current knowledge about pear is largely unknown.Through counting of pear mesocarp cells at different stages,we found that the cell number,rather than the cell size,is responsible for the differences between small- and large-fruited cultivars.Fruit weight-2.2（fw2.2） is an important quantitative trait locus（QTL） affecting fruit weight in tomato and functions as a negative regulator in carpel cell division.To get more insights into this QTL in pear fruit development,we isolated two putative homologous fw2.2 genes,which were designated as fw2.2-like（PbFWL） genes.PbFWLs encode Cys-rich proteins with the CCXXXXCPC motif and belong to the PLAC8 superfamily.In addition,results from the subcellular localization indicated that PbFWLs were localized in the plasma membrane.The expression profile of the PbFWL genes by qRT-PCR showed they expressed higher in small-sized fruit cultivar than that in large-sized fruit cultivar during the cell division period.In summary,our data suggest that these two PbFWLs might be negatively related to the cell division in pear fruit.

Analysis of short fruiting branch gene and Marker-assisted selection with SNP linked to its trait in upland cotton

Background： With the rapid development of genomics, many functional genes have been targeted. Molecular marker assisted selection can accelerate the breeding process by linking selection to functional genes. Methods： In a study of upland cotton （Gossypium hirsutum L.）, the F2 segregated population was constructed by crossing X1570 （short branches） with Ekangmian 13 （long branches） to identify the short fruiting branch gene and marker assisted selection with SNP（Single Nucleotide Polymorphisms, SNP） linked to its trait. Result： The result demonstrated that linked SSR marker BNL3232 was screened by BSA（Bulked segregant analysis, BSA） method; one SNP locus was found, which was totally separated from the fruiting branches trait in upland cotton. Conclusion： It was verified that this SNP marker could be used for molecular assisted selection of cotton architecture

Mining Heat Stress Associated Genes in Tomato Fruit (Solanum lycopersicum L.) Through RNA-seq

Tomato(Solanum lycopersicum L.)is a thermophilic vegetable crop,but sensitive to high temperature stress,especially under the greenhouse conditions.Due to global climate changes,heat stress has now become a great threat to tomato production and fruit quality.Many studies have been conducted to determine the functions of genes in tomato responsive to abiotic and biotic stresses,but transcriptomic information on heat stress responses of tomato fruit is still limited.To investigate heat stress associated genes in tomato fruit,a cDNA library was constructed using fruit harvested from tomato cv.P19-9 plants grown under 42℃for 0,1,2 and4 h and the expression profiles of heat stress responsive genes in tomato fruit were analyzed through RNA-seq.A total of 632224558 clean high quality paired-end reads were obtained and then mapped to reference genome for RNA-seq analysis.After quality control analysis,alignment analysis and transcript assembly,a total of 55457 RNA transcripts were obtained with functional annotations.Overall,6869 differentially expressed genes(DEGs)were identified with a significant response to one or more of the three heat stress treatment times.Based on GO enrichment analysis,22 genes potentially involved in tomato thermo-tolerance were selected and validated for their expressions through qPCR.The expression profile of tomato fruit genes obtained in this study could shed light on the mechanism and gene editing breeding projects for tomato thermo-tolerance.These findings could also benefit improvement of harvest and storage of tomato in greenhouse.

Cloning and Sequence Analysis of Lipoxygenase Gene cDNA from Cucumber Fruit (Cucumis sativus L.)

Lipoxygenases are nonheme-iron-containing dioxygenases that catalyze the hydroperoxidation of unsatrated fatty acids containing a cis, cis-1,4-pentadiene structure producing hydroperoxy acids with conjugated dienes.

Identification of Differentially Expressed Genes During Ethylene Climacteric of Melon Fruit by Suppression Subtractive Hybridization

Melon （Cucumis melo L.） is an important horticultural crop worldwide. Ethylene regulates the ripening process and affects the ripening rate. To screen genes that are differentially expressed at the burst of ethylene climacteric in melon fruit, we performed suppression subtractive hybridization （SSH） to generate forward and reverse libraries, for which we sequenced 439 and 445 clones, respectively. Our BLAST analysis showed that the genes from the 2 libraries were involved in metabolism, signal transduction, cell structure, transcription, translation, and defense. Six genes were analyzed by qRT-PCR during the differential developmental stage of melon fruit. Our results provide new insight into the understanding of climacteric ripening of melon fruit.

The Influence of Co-Suppressing Tomato 1-Aminocyclopropane-1-Carboxylic Acid OxidaseⅠon the Expression of Fruit Ripening-Related and Pathogenesis-Related Protein Genes

The purpose of this study is to explore the influence of co-suppressing tomato ACC oxidase Ⅰ on the expression of fruit ripening-related and pathogenesis-related protein genes, and on the biosynthesis of endogenous ethylene and storage ability of fruits. Specific fragments of several fruit ripening-related and pathogenesis-related protein genes from tomato （Lycopersicon esculentum） were cloned, such as the l-aminocyclopropane-1-carboxylic acid oxidase 1 gene （LeAC01）, 1- aminocyclopropane-l-carboxylic acid oxidase 3 gene （LeAC03）, EIN3-binding F-box 1 gene （LeEBF1）, pathogenesis-related protein 1 gene （LePR1）, pathogenesis-related protein 5 gene （LePR5）, and pathogenesis-related protein osmotin precursor gene （LeNP24） by PCR or RT-PCR. Then these specific DNA fragments were used as probes to hybridize with the total RNAs extracted from the wild type tomato Ailsa Craig （AC＋＋） and the LeAC01 co-suppression tomatoes （V1187 and T4B）, respectively. At the same time, ethylene production measurement and storage experiment of tomato fruits were carded out. The hybridization results indicated that the expression of fruit ripening-related genes such as LeACO3 and LeEBF1, and pathogenesis-related protein genes such as LePR1, LePR5, and LeNP24, were reduced sharply, and the ethylene production in the fruits, wounded leaves decreased and the storage time of ripening fruits was prolonged, when the expression of LeACO1 gene in the transgenic tomato was suppressed. In the co-suppression tomatoes, the expression of fruit ripening-related and pathogenesis-related protein genes were restrained at different degrees, the biosynthesis of endogenous ethylene decreased and the storage ability of tomato fruits increased.

Transcript Profiles of Auxin Efflux Carrier and IAA-Amido Synthetase Genes Suggest the Role of Auxin on Apple (<i>Malus</i>×<i>domestica</i>) Fruit Maturation Patterns

Auxin has been suggested to play an essential role in regulating apple fruit maturation and ripening, though the molecular function of auxin and its interaction with ethylene during apple fruit development are largely unknown. To understand the function of auxin during apple fruit maturation and ripening, auxin efflux carrier and IAA-amido synthetase encoding genes were identified from the apple genome based on the results of previous microarray analysis. The expression patterns of these genes were analyzed using qRT-PCR during 10 - 12 weeks of fruit maturation for two apple cultivars: “Golden Delicious” (GD) and “Cripps Pink” (CP), which have the distinct patterns of maturation progression. Our results showed that the expressions of auxin efflux carrier and IAA-amido synthetase genes have a correlation with the timing of ethylene biosynthesis pathway activation in both cultivars. The earlier and stronger expression of MdGH3.102 and MdAECFP1 in the fruit of GD, a mid-season cultivar, correlates with the earlier activation of a pre-climacteric ethylene biosynthesis gene of MdACS3, compared with that in CP, a late-ripening apple cultivar. Results of exogenous IAA treatment indicated that the expression patterns of the genes were regulated in a fruit maturity dependent manner. Our results suggested that the dynamics of the auxin level in apple fruit cortex could be one of the key factors influencing the timing of ethylene biosynthesis pathway activation and consequently contributed to the control of the apple maturation progression.

Genome-wide identification of the CONSTANS-LIKE(COL)family and mechanism of fruit senescence regulation by PpCOL8 in sand pear(Pyrus pyrifolia)

Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic acid(SA),a well-known phytohormone,can delay fruit senescence and improve shelf life.However,the mechanism by which SA regulates CONSTANS-LIKE genes(COLs)during fruit senescence and the role of COL genes in mediating fruit senescence in sand pear are poorly understood.In this study,22 COL genes were identified in sand pear,including four COLs(Pp COL8,Pp COL9a,Pp COL9b,and Pp COL14)identified via transcriptome analysis and 18 COLs through genome-wide analysis.These COL genes were divided into three subgroups according to the structural domains of the COL protein.Pp COL8,with two B-box motifs and one CCT domain,belonged to the first subgroup.In contrast,the other three Pp COLs,Pp COL9a,Pp COL9b,and Pp COL14,with similar conserved protein domains and gene structures,were assigned to the third subgroup.The four COLs showed different expression patterns in pear tissues and were preferentially expressed at the early stage of fruit development.Moreover,the expression of Pp COL8 was inhibited by exogenous SA treatment,while SA up-regulated the expression of Pp COL9a and Pp COL9b.Interestingly,Pp COL8 interacts with Pp MADS,a MADS-box protein preferentially expressed in fruit,and SA up-regulated its expression.While the production of ethylene and the content of malondialdehyde(MDA)were increased in Pp COL8-overexpression sand pear fruit,the antioxidant enzyme(POD and SOD)activity and the expression of Pp POD1 and Pp SOD1 in the sand pear fruits were down-regulated,which showed that Pp COL8 promoted sand pear fruit senescence.In contrast,the corresponding changes were the opposite in Pp MADS-overexpression sand pear fruits,suggesting that Pp MADS delayed sand pear fruit senescence.The co-transformation of Pp COL8 and Pp MADS also delayed sand pear fruit senescence.The results of this study revealed that Pp COL8 can play a key role in pear fruit senescence by interacting with Pp MADS through the SA signaling pathway.

A 1-bp deletion in the MC04g1399 is highly associated with failure to produce fruit wart in bitter gourd

Fruit wart is an important appearance trait influencing consumer preferences of bitter gourd(Momordica charantia L.).The molecular genetic mechanisms underlying fruit wart formation in bitter gourd are largely unknown.In this study,genetic analysis based on four generations showed that fruit wart formation in bitter gourd was controlled by a single dominant locus named as Fwa.The Fwa locus was initially mapped into a 4.82 Mb region on pseudochromosome 4 by BSA-seq analysis and subsequently narrowed down to a 286.30 kb region by linkage analysis.A large F2population consisting of 2360 individuals was used to screen recombinants,and the Fwa locus was finally fine mapped into a 22.70 kb region harboring four protein-coding genes through recombination analysis.MC04g1399,encoding an epidermal patterning factor 2-like protein,was proposed as the best candidate gene for Fwa via sequence variation and expression analysis.In addition,a 1-bp insertion and deletion(InDel)variation within MC04g1399 was converted to a cleaved amplified polymorphic sequence(CAPS)marker that could precisely distinguish between the warty and non-warty types with an accuracy rate of 100%among a wide panel of 126 bitter gourd germplasm resources.Our results not only provide a scientific basis for deciphering the molecular mechanisms underlying fruit wart formation but also provide a powerful tool for efficient genetic improvement of fruit wart via marker-assisted selection.

Cloning and Sequencing the Full-length cDNA of Annexin from Strawberry Fruit

采用RACE技术从草莓 (FragariaananassaDuch .)成熟果实中分离克隆了膜联蛋白 (annexin)基因的cDNA 5′_端未知序列 ,并通过测序确定了翻译的起始密码位点、终止密码位点及完整的读码框 ,从而首次获得了草莓果实膜联蛋白基因的cDNA全序列 ,命名为annfaf(annexinofFragariaananassafruit)基因。

Searching Development-deficient Genes in Edible Mushroom by Self-crossing

[Objective] This study aimed to investigate the effect of mating factor recombination on the development of edible mushroom,and explore the possibility for using self-crossing to breed sporeless/low sporing mushroom strains.[Method] Selecting Agrocybe salicacola strain YAASM0711 as the self-crossing material,six self-crossed combinations were directionally constructed with single spore growth rate as an indicator,to carry out comprehensive analysis of the qualitative traits（color,deformity and growth characteristics）,quantitative traits（shape,yield,size and number of fruit bodies） and mating types of its self-crossed F1 progenies.[Result] After mating factor recombination,self-crossed single spore progenies showed serious genetic differentiation,the average mycelial growth rate and agronomic traits of inbred progenies were lower than those of the parents.The phenotype in fruiting body formation could be divided into normal fruiting and abnormal fruiting（including abnormal fruiting bodies,sporeless or low sporing fruiting bodies,no fruiting）.To be specific,18% self-crossed strains had superior agronomic traits to the parents,which can be used for selecting predominant strains from self-crossed progeny populations based on different breeding purposes.[Conclusion] The genes controlling mycelial growth rate of single spore were linked with mating factors.The mating factor-recombinant single spore strains could be selected according to the correlation between mating type and growth rate.The fruiting result of self-crossed strains indicated that the genes related to sporeless/low sporing development were recessive.Not only genetic materials harboring development-deficient genes in edible mushroom can be obtained by self-crossing,but also the sporeless/low sporing mutant strains with important application prospects can be bred.

QTL Mapping for Cucumber Fruit Size and Shape with Populations from Long and Round Fruited Inbred Lines

To gain insight into the molecular and genetic basis of fruit size and shape in cucumber,we conducted Quantitative Trait Locus(QTL)mapping with F2 and BC1F1 populations derived froma cross between the Northern-China type inbred line CNS21 and the Southern-China type inbred line RNS7.Populations were evaluated during two developmental stages,ovary at anthesis and commercial fruit(immature fruit).A total of 13 major-effect QTLs(R2>10%)were detected for six traits,and one of them,fruit shape index 2.1,explained more than 50%of phenotypic variation.All QTLs distributed on chromosome(chr)1 and 2.We constructed a physical map containing almost all of the QTLs with their physical location from previous studies.For fruit size and shape,the highest number of QTLs were mapped on chr1 and chr6,and the fewest number were mapped on chr2 and chr7.At least one consensus region was presented on each chromosome.In addition,three candidate genes were predicted between the long-fruited and round-fruited inbred lines by comparing the sequences of the consensus region of chr3,where many QTLs for marketable fruit length had been detected.Our results provide a base for additional QTLs and molecular markers for fruit size and shape in cucumber breeding.

Comparative transcriptome analysis of shortened fruit mutant in woodland strawberry (Fragaria vesca) using RNA-Seq

Genes controlling fruit appearance determine fruit shape and size. In ethylmethane sulfonate （EMS）-mutagenized lines of Fragaria vesca accession Yellow Wonder （YW）, two fruit shapes are observed： wild-type long fruit and mutated shortened fruit （sf）. In this study, we first characterized sf based on morphology, histology, cytology and physiology. The sf was identified as a gibberellin （GA）-deficient mutant, and four complementary DNA （cDNA） libraries separately constructed from flower buds and small green fruits of YW and sfwere sequenced to comparatively analyze transcriptome differences. A total of 29 differentially expressed GA pathway genes were identified by comparisons between YWl and sfl, and 28 differentially expressed GA pathway genes were identified between YW2 and sf2. In addition, the expression patterns of 45 differentially expressed genes were validated by quantificational real-time PCR （qRT-PCR）, and the results were highly concordant with the RNA-Seq results.＇ This transcriptome analysis provides valuable information for understanding the molecular mechanisms of fruit development of strawberry.

Manual thinning increases fruit size and sugar content of Citrus reticulata Blanco and affects hormone synthesis and sugar transporter activity

Manual fruit thinning(MFT)in fruit trees has been previously shown to increase fruit size and enhance fruit quality,but the effect of MFT on Ponkan(Citrus reticulata Blanco)and the underlying mechanisms remain poorly understood.In this study,efforts were made to elucidate how MFT influences the fruit quality of Ponkan.The results showed that MFT substantially increased fruit size and elevated fruit total soluble solids in comparison with the fruit from the unthinned trees(used as control).Expression analyses demonstrated that m RNA abundance of three important sugar transporter genes,including CrSUT1,CrSTP1 and CrTMT1,was evidently elevated in the flesh of thinned fruit when compared with those of the control.In addition,MFT prominently up-regulated the transcript levels of various auxin and gibberellin(GA)biosynthesis and signaling genes,including CrYUC6,CrAUX/IAA,CrGA20ox1 and CrGA3ox1.Concurrently,the contents of endogenous IAA and GA3,measured at 90 d after fruit thinning,were notably elevated in the fruit from trees with the thinning treatment relative to the control,although no difference was detected in the two groups before the thinning manipulation.Taken together,these results indicate that manual fruit thinning could greatly improve fruit quality,which may be attributed to promoting fruit expansion due to the increased auxin levels and expediting sugar accumulation through the up-regulation of sugar transporter genes.

Preharvest application of 1-methylcyclopropene and Ethephon altered cuticular wax biosynthesis and fruit quality of apples at harvest and during cold storage

To investigate the roles of Harvista(a sprayable 1-methylcyclopropene,1-MCP,available component is 150 g·hm^(-2))and Ethephon(1 mL·L^(-1))applied at preharvest in apple(Malus domestica Borkh.'Golden Delicious')fruit cuticular wax biosynthesis,the expression of genes related to fruit cuticular wax biosynthesis and ethylene biosynthesis and signaling,ethylene production rate,respiration rate,wax constituents and structure,and fruit quality were determined at harvest and during cold storage.The results showed that 1-MCP inhibited the expression levels of ethylene biosynthesis and signaling-related genes,decreased fruit ethylene production,and inhibited the expression of Md LACS1,Md CER6,Md CER4 and Md WSD1,which resulted in decreases in alcohols,acids,and esters content in fruit cuticular wax.1-MCP also reduced fruit dropping rate from 17.17%to 12%;maintained fruit firmness,soluble solids,titratable acidity during cold storage;showed about as one fifth in the total length and one third in the widest width of wax crack as that in control at harvest.In contrast,Ethephon produced the opposite effects.In conclusion,1-MCP inhibited fruit ethylene biosynthesis and signaling,and influenced fruit cuticular wax biosynthesis.Thus,the fruit cuticular wax constituents and structure was altered,and the fruit quality were maintained at harvest and during cold storage.The results provide a new technology for improving apple fruit harvest and postharvest quality by preharvest application of sprayable 1-MCP.