Genome wide association analysis identifies candidate genes for fruit quality and yield in Actinidia eriantha

Quality and yield are the primary concerns in kiwifruit breeding,but research on the genetic mechanisms of fruit size,shape,and ascorbic acid(ASA)content is currently very limited,which restricts the development of kiwifruit molecular breeding.In this study,we obtained a total of 8.88 million highly reliable single nucleotide polymorphism(SNP)markers from 140 individuals from the natural hybrid offspring of Actinidia eriantha cv.‘White’using whole genome resequencing technology.A genome-wide association study was conducted on eight key agronomic traits,including single fruit weight,fruit shape,ASA content,and the number of inflorescences per branch.A total of 59 genetic loci containing potential functional genes were located,and candidate genes related to single fruit weight,fruit length,ASA content,number of inflorescences per branch and other traits were identified within the candidate interval,such as AeWUSCHEL,AeCDK1(cell cycle dependent kinase),AeAO1(ascorbic oxidase)and AeCO1(CONSTANS-like 4).After constructing an RNAi vector for AeAO1 and injecting it into the fruit of cv.‘Midao 31’to interfere with the expression of the AeAO1 gene,the results showed that the activity of ascorbic oxidase in the fruit of‘Midao 31’significantly decreased,while the content of ASA significantly increased.This study provides valuable insights into the genetic basis of variation in A.eriantha fruit traits,which may benefit molecular marker-assisted breeding efforts.

Pear genomes display significant genetic diversity and provide novel insights into the fruit quality traits differentiation

The pear(Pyrus spp.)is well known for diverse flavors,textures,and global horticultural importance.However,the genetic diversity responsible for its extensive phenotypic variations remains largely unexplored.Here,we de novo assembled and annotated the genomes of the maternal(PsbM)and paternal(PsbF)lines of the hybrid‘Yuluxiang'pear and constructed the pear pangenome of 1.15 Gb by combining these two genomes with five previously published pear genomes representing cultivated and wild germplasm.Using the constructed pangenome,we identified 21224 gene PAVs(Presence-absence variation)and 1158812 SNPs(Single Nucleotide Polymorphism)in the non-reference genome that were absent in the PsbM reference genome.Compared with SNP markers,PAV-based analysis provides additional insights into the pear population structure.In addition,some genes associated with pear fruit quality traits have differential occurrence frequencies and differential gene expression between Asian and European populations.Moreover,our analysis of the pear pangenome revealed a mutated SNP and an insertion in the promoter region of the gene PsbMGH3.1 potentially enhance sepal shedding in‘Xuehuali'which is vital for pear quality.PsbMGH3.1 may play a role in the IAA pathway,contributing to a distinct low-auxin phenotype observed in plants by heterologously overexpressing this gene.This research helps capture the genetic diversity of pear populations and provides genomic resources for accelerating breeding.

Effects of Different Rootstocks on the Growth and Fruit Quality of‘Huangjinmi’Grape in Hefei

[Objectives]This study was conducted to enrich grape varieties.[Methods]The growth and fruit quality of grape with different rootstock and scion combinations were compared and analyzed taking CR2,CR3 and CR9 as rootstocks and‘Huangjinmi’as grafted seedlings and own-rooted seedlings as control.[Results]The comprehensive scores of‘Huangjinmi’grape with different rootstock and scion combinations showed an order of HJM/CR9,HJM/CR2 and HJM/CR3 from high to low.The three rootstock and scion combinations obviously promoted the growth and adaptability of grape trees,increased fruit size and improved fruit quality.Through the quality analysis of untreated and treated fruits,HJM/CR9 was superior to ZGM.Different fruit management measures can be adopted for‘Huangjinmi’grape to produce fruit with different quality according to market demand.[Conclusions]This study has a guiding significance for screening grape varieties suitable for adverse environments such as high soil viscosity,high temperature and high humidity.

Effect of Various Citrus Rootstock-scion Combinations on Tree Growth,Fruit Quality,and Photosynthetic Characteristics under Red Loam Soil Conditions

[Objectives]To investigate the effects of 15 distinct citrus rootstock-scion combinations on tree growth,fruit quality,and photosynthetic characteristics under red loam soil conditions and provide a theoretical foundation for the selection of appropriate citrus rootstock-scion combinations in the Zhaoqing region.[Methods]A total of 15 citrus rootstock-scion combinations were utilized as test materials for a comprehensive analysis of their phenological periods(budding,flowering,and fruiting),tree growth indicators(tree height,crown diameter,and growth),and fruit quality(appearance quality and intrinsic quality).The photosynthetic characteristics of the test materials,including the net photosynthetic rate(Pn),transpiration rate(Tr),water use efficiency(WUE),apparent quantum yield(AQY),and carboxylation efficiency(CE),were analyzed to determine their significance.Additionally,the leaf photosynthetic physiological indicators,such as soluble protein,specific leaf weight,chlorophyll,and carotenoids,were evaluated.[Results]There were notable differences observed in the phenological period,growth potential of trees,fruit quality,and photosynthetic characteristics among various citrus rootstock-scion combinations.The phenological periods exhibited variation contingent on the grafting varieties.In terms of tree growth potential,the Citrus tangerina Tanaka‘Hongju’and C.haniana Hort.‘Suanju’rootstocks demonstrated greater tree height,crown growth,and overall tree strength;however,they were also prone to excessive growth.Conversely,the C.limonia Osbeck‘Hongningmeng’and C.sinensis×P.trifoliata‘Zhicheng’rootstocks displayed medium growth potential,while the Poncirus trifoliate(L)Raf.‘Zhike’rootstock resulted in shorter trees.In terms of fruit quality,the single fruit weight of C.flamea Hort.‘Shatangju’ranged from 33 to 50 g,exhibiting a flat and round shape.The total soluble solids and titratable acid content of‘Shatangju’grafted onto the‘Zhike’rootstock were notably high.In contrast,the single fruit weight of C.haniana Hort.‘Chuntianju’varied between 65 and 81 g,characterized by a high flat round shape.The‘Suanju’rootstock demonstrated a higher sugar and acid content compared to other rootstocks.Additionally,the single fruit weight of C.nobilis Lour.‘Gonggan’ranged from 62 to 145 g,with the fruit shape being either round or oval.The soluble sugar and total soluble solids content associated with the‘Zhike’rootstock was also elevated.In relation to photosynthetic characteristics,the photosynthetic performance of the‘Shatangju’variety was superior when grafted onto the‘Zhike’and‘Hongju’rootstocks.Similarly,the‘Chuntianju’variety exhibited enhanced photosynthetic performance on the‘Zhike’,‘Zhicheng’,and‘Hongju’rootstocks.Furthermore,the‘Gonggan’variety demonstrated improved photosynthetic performance when grafted onto the‘Zhike’and‘Suanju’rootstocks.[Conclusions]Based on the characteristics of the red loam soil in the Zhaoqing region,the rootstocks‘Zhike’and‘Hongju’are conducive to the cultivation of the‘Shatangju’variety.Additionally,the rootstocks‘Zhike’,‘Zhicheng’,and‘Hongju’are optimal for the growth of the‘Chuntianju’variety,while the rootstocks‘Zhike’and‘Suanju’are appropriate for the growth of the‘Gonggan’variety.

Study of Effects of Plant Growth Regulators on Fruit Quality of Table Grape

The effects of different treatments on the seedlessness and fruit quality of‘Miguang’table grape was studied by using plant growth regulators,gibberellin acid(GA 3)and forchlorfenuron(CPPU),under different concentrations and application time.The results showed that the effects of different treatments on the seedlessness and fruit quality were different.Seedless rate,cluster weight,berry weight,berry shape index,soluble solid content,total acid content,soluble solids to acidity ratio,pulling resistance,turgor pressure and flesh firmness without skin were comprehensively evaluated,as a result of which,the optimum treatment on‘Miguang’table grape was to apply with GA 320 mg/L+SM 200 mg/L at one week before bloom and GA 325 mg/L+CPPU 3 mg/L at two weeks after bloom.

Improvement of Wolfberry(Lycium barbarum L.)Fruit Yield and Quality and Enhancement of Soil Fertility by Nitrogen Reduction Combined with Organic Fertilizers

Excessive amounts of nitrogen(N)fertilizers are applied during wolfberry production,resulting in some soil problems as well as potential environmental risks in the Qinghai-Tibet Plateau.In this study,organic fertilizers were used to replace part of the N fertilizer in wolfberry fields with different fertility levels.N fertilizer rates had 0,50,100,150,200,and 250 g N/plant.Organic fertilizer rates had 0,2,4,6,8,and 10 kg organic fertilizer/plant.The experimental treatments included 6 combinations of N0M10,N50M8,N100M6,N150M4,N200M2,and control was N250M0.The results showed that in the high-fertility soils,combinations of N150M4,N100M6 and N50M8 treatments were increased in yields,fruit shape index,flavonoid content,total phenol content,mineral nutrient content,and antioxidant activity of wolfberry fruits.Also they were improved in soil fertility and decreased in residual nitrate through the soil depth of 0-300 cm.In the soil with less fertility,fruit yield,amino acid contents,flavonoids,total phenols,mineral nutrients and antioxidant activity of fruits were increased by the N200M2,N150M4 and N100M6 treatments and soil fertility was improved as well.Also more residual nitrate was found in the depth of 0-100 cm of soil with both chemical and organic fertilizer compared with the control.Therefore,in the Qinghai-Tibet Plateau,combining decreased N fertilizer with organic fertilizer rather than chemical fertilizer alone could help farmers achieve satisfactory yields and quality of wolfberry fruits and reduce the risk of nitrate leaching.In conclusion,50-150 g/plant of N fertilizer combined with 4-8 kg/plant of organic fertilizer in high-fertility gardens and 100-200 g/plant of N fertilizer combined with 2-6 kg/plant of organic fertilizer in low-fertility gardens are recommended for wolfberry cultivation.

Study and Application of Partial Least Squares Regression on Relationship between Soil Nutrient and Fruit Quality

[Objective] The objective of the study was to elucidate the duplicate collinearity diagnosis method for soil nutrient and provide basis for establishment of multiple regression model of relationship between independent variable and depen- dent variable in fruit trees. [Method] An investigation on soil nutrients and ＇Fuji＇ fruit quality was conducted at 153 commercial apple orchards in the production re- gions of 51 counties in China from 2011 to 2012. At first, the regression equation was used to do the duplicate collinearity diagnosis, and then the partial least squares regression was used to analyze the weights of different soil nutrients that affected the fruit quality and screen out main soil nutrients. [Result] The results showed the conditional number between soil nutrients was 61.31, and the correlation coefficient of soil pH and available calcium, iron was 0.82 and -0.824 respectively, which demonstrated that there was multicollinearity between various soil nutrient contents. The soil organic matter, total nitrogen, available potassium, available nitro- gen, available phosphorus, available zinc, available iron and available boron showed positive effect Ioadings on fruit quality, while the }oadings and weights of the effects of available calcium and pH on fruit quality were negative. The variable importance for projection method was adopted to get the orders of the effects of major soil nu- trients on fruit quality, which was in the order of soil available calcium, nitrogen, available iron, available phosphorous, organic matter and available boron. The solu- ble solid content of the fruit was affected by soil organic matter, available phospho- rus, available iron, available boron and soil pH. [Conclusion] This study provided an analysis method and theoretical basis for the study and analysis on the relationships between dependent variables and multi-objective optimization, as well as the effects of soil nutrients on fruit quality in fruit tree.

Effects of Microbial Fertilizer and Compound Feritlizer Mixed Application on Yield and Fruit Quality and Flowering and Fruit Setting of Following Year of Apple

In order to study the application effect of microbial fertilizer and compound fertilizer mixed application on microirrigation apple, three types of fertilizers were applied in spring which were urea（CK, 15 kg/plant）, microbial fertilizer（5.0 kg/plant）,microbial fertilizer and compound fertilizer mixed（each 2.5 kg/plant） to study the effect of different fertilizer treatments on yield, fruit quality, flowering and fruit setting of Xinshijie apple. The results showed that application of microbial fertilizer could increase the yield, fruit weight and fruit shape index, significantly increase the flowering rates and inflorescence fruit setting rate of following year, while reduce the fruit hardness and soluble solids content, and the effect of microbial fertilizer and compound fertilizer mixed application on increasing fruit weight and yield was higher than that of microbial fertilizer separate application, the effect of the two was not obvious in other aspects. Therefore, microbial fertilizer could be used instead of some chemical fertilizer and organic fertilizer in apple production to reach the aim of increasing yield and efficiency, and the effect of microbial fertilizer and compound fertilizer mixed application was best.

Comparative Analysis on Fruit Qualities of 7 Litchi Varieties from Vietnam

[Objective] The aim was to screen litchi varieties suitable for local production in Vietnam. [Method] The fruit botanical and quality characteristics of the seven litchi varieties introduced into Northern Mountainous Agriculture and Forestry Science Institute of Vietnam Academy of Agriculture Sciences were compared and analyzed. [Result] Three varieties with good general qualities including Lai Phu Ho,Thach Binh and Hung Long which were suitable to be cultivated in the local area were selected. In addition,Phu Dong was the available,early-maturing germplasm resource. [Conclusion] This research will provide reference for litchi production and breeding in northern mountainous area.

Comparative Analysis on Fruit Qualities of Longan Varieties form Vietnam

[Objective] The aim was to screen longan varieties suitable for local production in Vietnam.[Method] The fruit botanical characteristics and quality characteristics of longan varieties introduced into Northern Mountainous Agriculture and Forestry Science Institute of Vietnam Academy of Agriculture Sciences were compared and analyzed.[Result] Two varieties with good general qualities including PMP6 and PHS1-1 which were suitable to be cultivated in the local area were selected.In addition,Phu Dong was the available processed germplasm resource.[Conclusion] This research will provide reference for longan production and breeding in Northern Mountainous.

Correlation Analysis between Quality Characteristics and Fruit Mineral Element Contents in 'Fuji' Apples

[Objective] The aims were to explore the relationship between the contents of fruit mineral elements and quality features of the ＇Fuji＇ apple, screen major mineral elements of the fruit affecting fruit quality features, and set up optimum proposals of fruit mineral elements for good fruit qualities, so as to provide a theoretical basis for the reasonable orchard soil and foliar fertilizer applications to increase fruit quality and reduce the physiological diseases related to the ＇Fuji＇ apple. [Methods] The fruit mineral elements and quality indicators of ＇Fuji＂ apples were in- vestigated and analyzed, which were collected from the 153 commercial apple or- chards of ＂Fuji＇ apple located in 51 counties. The variable importance for projection （VlP） of partial least squares regression （PLS） method was used to analyze the model effect and weight analysis impact of the fruit mineral element contents to fruit quality, screen out major factors of fruit mineral elements influencing the different fruit qualities, and set up the regression equation of the fruit qualities and major fruit mineral elements. Linear programming was used to obtain optimum proposals of the fruit mineral elements to achieve good ＇Fuji＇ apple qualities. [Results] The mineral elements content and quality characteristics in ＂Fuji＇ apple fruit had great differences in the different produce regions in which the maximum content of nitro- gen, iron, zinc and boron in the ＇Fuji＇ fruit were12.06, 6.17, 7.7, and 10.08 times greater than the minimum respectively, and the differences for titratable acid and the SSC/TA ratio were 2.33 and 2.16 times respectively. The correlation analysis between the fruit mineral element contents and qualities showed that the nitrogen content of fruit had a significantly negative correlation with the soluble solid content, SSC/TA ratio and red color area, while the calcium and iron contents in the fruit were in significantly positive correlation with the soluble solid content and SSC/TA ratio. The model effect and weight analysis showed that the content of nitrogen and iron in the fruit had a greater influence on the integral fruit quality, followed by phosphorus, potassium and calcium. The variable importance for projection （VlP） technology of PLS found that the mean fruit weight was primarily affected by nitro- gen, phosphorus and potassium, and the soluble solid was primarily affected by ni- trogen, calcium and iron, while the red color area was primarily affected by nitro- gen, potassium, calcium, iron and zinc. The regression equation between fruit quality and mineral element contents showed that the mean fruit weight had a greater pos- itive effect coefficient with the content of phosphorus and potassium, and a greater negative effect coefficient with the content of nitrogen in the fruit. Moreover, the sol- uble solid had the largest negative effect coefficient with nitrogen and largest posi- tive effect coefficient with calcium and iron in the fruit. [Conclusion] The maximum content of soluble solid and titratable acid were 1.5 times more than the minimum, and nitrogen, iron, zinc and boron were 6 times more than in the ＇Fuji＇ apple fruit in the different produce regions. Therefore, it is a key technological measure to improve the overall qualities of the ＂Fuji＇ apple by decreasing the content of nitrogen, and increasing the contents of iron, phosphorus, potassium and calcium in the fruit.

Effects of a Complex Amendment on the Quality of Cucumber Fruit under Cd Contamination Stress

Pot experiments were carried out to investigate the effects of a complex amendment on the soil organic matter content, pH, microbial quantity, Cd uptake and nutritional quality of the fruit of cucumber （Cucumis sativus L.） planted in two levels （CdCl2·2.5H2O mg/kg and 4 mg/kg） of Cd-contaminated soil in which different concentrations of complex amendments （0, 600, 900, 1 200 mg/kg） were added. The results showed that when applying 1 200 mg/kg amendment, the organic mat-ter content, bacterial number and total microorganism amounts in 2 and 4 mg/kg Cd-contaminated soil increased by 23.17% and 32.89%, 87.61% and 96.02%, 59.95% and 55.81%, respectively. When 900 mg/kg amendment was applied, the fungi number in 2 and 4 mg/kg Cd-contaminated soil reached the maximum, in-creasing by 137.50% and 106.72% respectively. However, applying the amendment had no significant effect on the pH of soil. The security and nutritional quality of cu-cumber fruits were obviously improved comparing with control. The Cd content in cucumber fruits decreased by 31.40% and 24.35%, respectively, in 2 and 4 mg/kg Cd-contaminated soil. Furthermore, Vc, soluble sugar and soluble fixation content in cucumber fruits of 2 and 4 mg/kg Cd-contaminated soil went up by 25.00% and 91.42%, 37.03% and 27.06%, 14.29% and 58.80%, respectively. lt was indicated that the complex amendment can obviously improve the quality of cucumber fruit and thus can be used in the in situ_repair of Cd-contaminated soil.

Investigation of Punica granatum L.Germplasm Resources in Binchuan and Comparative Analysis of Major Fruit Qualities

[Objective] This study aimed to provide a basis for enriching the Punica granatum L. germplasm resources through investigating Punica granatum L. vari- eties in Binchuan. [Method] In this study, biological traits of Punica granatum L. vari- eties in Binchuan （including two local varieties-＇Binchuan Red Coat＇ and ＇Binchuan Green Coat＇, ＇Cyan Coat and Soft Seeds＇ and ＇Little Red Coat＇ introduced from Huili, Sichuan, ＇Acid Pomegranate＇ introduced from Shandong Province and ＂Ma Pomegranate＂ from Fengqiu, Henan） were investigated and their major fruit qualities were also analyzed. [Result] ＂Cyan Coat and Soft Seeds＇ and ＂Ma Pomegranate＇ grew well with good fruit quality, which adapted well to the climate and environment in Binchuan; ＂Little Red Coat＇ showed average performance in growth and major fruit qualities with inferior flavour; ＂Binchuan Red Coat＇ and ＇Binchuan Green Coat＇ also showed average performance in major fruit qualities and and inferior flavour; ＇Acid Pomegranate＇ grew while was inferior in flavour. [Conclusion] This study pro- vides references for presenting the directions for studies of P. granatum L. germplasm resources and determining the genetic relationship among germplasm resources, as well as breeding, introduction and cultivation of P. granatum L., further providing a variety basis for pomegranate production.

The chemical treatments combined with antagonistic yeast control anthracnose and maintain the quality of postharvest mango fruit

During the storage and transportation of the mango fruit, the major source of disease is anthracnose, caused by the fungus Colletotrichum gloeosporioides. The objective of this study is to find an appropriate method that not only reduces mango decay but also maintains its postharvest quality. The effects of chemicals, the use of the yeast species Metschnikowia pulcherrima and their combination on storage quality, focusing on the enzyme activity related to disease of Tainong mangos was studied. By immersing the mangoes in M. pulcherrima suspension(1.0×10~8 cfu mL^(–1)), salicylic acid(SA) solution(50 mg L^(–1)) or calcium chloride(CaCl_2) solution(1.0 g L^(–1)), the lesion expansion and decay of the mango fruit caused by C. gloeosporioides could be significantly delayed. These treatments also delayed the changes in quality traits(a~* value, firmness, contents of total soluble solids(TSS) and vitamin C(Vc), while the activities of anti-disease enzymes such as polyphenol oxidase(PPO), phenylalanine ammonia lyase(PAL), chitinase(CHT) and β-1,3-glucanase(GUN) were enhanced as compared to the control treatment. Furthermore, the combination of SA solution, CaCl_2 solution and M. pulcherrima suspension presented an additive effect, increasing the efficacy in controlling the disease and maintaining the storage quality of mango fruits. Taken together, our data suggest that the integration of chemical treatments combined with M. pulcherrima could be an alternative to the use of fungicides in postharvest treatment of the mango fruit, specifically for improving storage quality as well as the control of the anthracnose.

Replanting Affects the Tree Growth and Fruit Quality of Gala Apple

Apple replant disease（ARD） causes the inhibition of root system development, stunts tree growth and so on. To further investigate the effects of ARD on apple fruits, a 25-year-old apple orchard was remediated to establish a replant orchard between November 2008 and March 2009. A rotational cropping orchard was established on an adjacent wheat field. The cultivar and rootstock-scion combination used in the newly established orchards was Royal Gala/M26/Malus hupehensis Rehd. Ripe fruits were collected in mid-August 2011 and mid-August 2012, meanwhile, the following indices were measured： yield per plant; fruit weight; the fruit shape index; the contents of anthocyanin, carotenoid and chlorophyll; the soluble sugar content in the flesh; titratable acid; the sugar-acid ratio; firmness; and aroma components; apple plant ground diameter, plant height increment and the total length of the current-year shoots. The results showed that compared to rotational cropping, continuous cropping yielded statistically significant reductions in fruit weight and yield per plant of 39.8 and 76.5%, respectively. However, there were no changes in the fruit shape index. The anthocyanin and carotenoid contents decreased by 81.7 and 37.7%, respectively, while the chlorophyll content increased by 251.0%. All of these differences in content were statistically significant. The soluble sugar levels and sugar-acid ratio decreased by 25.4 and 60.9%, respectively, but the titratable acid levels and fruit firmness increased by 90.9 and 42.8%, respectively. Ten of the most important esters contributing to the apple aroma were analyzed, and the following changes were observed： hexyl acetate, butyl acetate, hexyl butyrate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, butyl butyrate, 2-methyl-butyl butyrate, hexyl propionate and hexyl hexanoate decreased by 25.5, 78.4, 89.1, 55.5, 79.5, 77.2, 86.8, 69.9, 61.2, and 68.1%, respectively. The contents of three other aroma components,（E）-2-hexenal, hexanal and 1-hexanol, significantly increased. Eight characteristic aroma components were found in the rotational cropping fruits： hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, 2-methyl- butyl butyrate, hexyl acetate and hexyl propionate. There were four characteristic ester components（hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate） and two characteristic aldehyde aroma components（（E）-2-hexenal and hexanal） in the continuous cropping fruits. Compared with the rotational cropping fruits, four characteristic ester components were declined and two characteristic aldehyde aroma components were increased. Compared with the control, replanted apple plant ground diameter, plant height increment and the total length of the current-year shoots were reduced by 27.6, 40.6 and 72.2%, respectively.

Effects on Sucrose Metabolism,Dry Matter Distribution and Fruit Quality of Tomato Under Water Deficit

Four irrigation treatments were designed with 2,4,6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose and fructose content of tomato's fruit were increased but sucrose content was decreased with fruit growth and development. In different stages, carbohydrate content of tomato fruit in the treatment 3 was the highest, in the treatment 2 was higher, and in the other treatments was the lowest. SS(sucrose synthase)activity was decreased but SPS(sucrose phosphate synthase)activity was increased with development of tomato. SS and SPS activity were increased but acid invertase and neutral invertase activity of ripe stage were decreased under deficit irrigation. Glucose and fructose content were increased in leaves of tomato under water deficit. Soluble sugars, organic acid and the ratio of sugar/acid in tomato fruits were increased and dry matter accumulation of plant was enhanced under water deficit. But the growth of fruits upside the plant and its dry matter accumulation were badly affected under water stress.

Pre-harvest fruit bagging influences fruit color and quality of apple cv. Delicious

An attempt was made to observe the effect of pre-harvest bagging with spun-bound fabric bags on color and quality of Delicious apple. Bagging was done about a month before harvesting and removed 3-day before harvesting. Bagged and non-bagged fruits were stored at 2℃ ± 1℃ and 90%-95% RH. Observations were recorded on color and fruit quality attributes such as total phenolics, AOX activity, fruit Ca contents, LOX activity, SSC and ascorbic acid contents at harvest and during storage. Our studies have revealed that bagged fruits have better color development (Hunter “a” = 52) than non-bagged fruits at harvest (Hunter “a” = 38), which declined slightly during storage. Similarly, at harvest, bagged fruits contained high amounts of Ca (5.38 mg/100g) and total phenolics (9.3 mg GAE/100gpulp) exhibited higher AOX activity (12.6 μmoles Trolox g-1), and had better SSC and ascorbic acid contents than non-bagged fruits, and there was a decline in all recorded parameters during storage. Bagged fruits exhibited lower LOX activity (1.38 μmoles min-1 g-1 FW) at harvest than non-bagged fruits (2.14 μmoles min-1 g-1 FW), indicating that non-bagged fruits were more senescent than bagged fruits. Further, LOX activity increased during storage both in bagged and non-bagged apples but increase in LOX activity was slower in bagged apples than in non-bagged apples.

Peach yield and fruit quality is maintained under mild deficit irrigation in semi-arid China

We conducted a two-year study of deficit irrigation impact on peach yield and quality in semi-arid northwest China. Over two years, four-year-old peach trees were irrigated at 100, 75, 50 and 25% of peach evapotranspiration （ETc）, here, ETc= Coefficient （Kc）×Local reference evapotranspiration （ET0）. During the April-July fruit production season we measured root zone soil water depletion, sap flow velocity, net photosynthetic rate （Pn）, transpiration rate （Tr）, stomatal conductance （Gs）, water use efficiency （WUE=Pn/Tr）, fruit quality, and yield under a mobile rain-out shelter. Increased soil water depletion reasonably mirrored decreasing irrigation rates both years, causing progressively greater water stress. Progressive water stress lowered Gs, which in turn translated into lower T as measured by sap flow. However, mild deficit irrigation （75% ETc） constricted T more than Pn. Pn was not different between 100 and 75% ETc treatments in both years, and it decreased only 5-8% in June with higher temperature than that in May with cooler temperature. Concurrently under 75% ETc treatment, was reduced, and WUE was up to 13% higher than that under 100% ETc treatment. While total fruit yield was not different under the two treatments, because 75% ETc treatment had fewer but larger fruit than 100% ETc trees, suggesting mild water stress thinned fruit load. By contrast, sharply decreased T and Pn of the driest treatments （50 and 25% ETo） increased WUE, but less carbon uptake impacted total fruit yield, resulting 13 and 33% lower yield compared to that of 100% ETc treatment. Irrigation rates affected fruit quality, particularly between the 100 and 75% ETc trees. Fewer but larger fruit in the mildly water stressed trees （75% ETc） resulted in more soluble solids and vitamin C, firmer fruit, and improved sugar：acid ratio and fruit color compared to the 100% ETo treatment. Overall, trees deficit irrigated at 75% ETc maintained yield while improving fruit quality and using less water.

Advances in Genomic,Transcriptomic,and Metabolomic Analyses of Fruit Quality in Fruit Crops

Fruit quality is the main factor determining market competitiveness;it represents the combination of fruit flavor,color,size,and the contents of aromatic and bioactive substances.Research on the genetic basis of fruit quality can provide new information about fruit biology,promote genomic-assisted breeding,and provide technological support for the regulation of fruit quality via habitat selection and/or the control of environmental conditions.High-throughput sequencing is a powerful research method for studying fruit quality traits,and reference genome sequences for many important fruit crops have provided vast amounts of genomic data.To study fruit quality,it is important to select appropriate omics strategies and to analyze omics data meaningfully.Here,we summarize genomic mechanisms of fruit quality formation:gene duplication,transposable element insertion,structural variations and genome methylation in functional genes.We review the genomic,transcriptomic,and metabolomic strategies that have been used to study the genetic basis of fruit quality traits.We also describe some of the genes associated with fruit traits;these genes are a valuable resource for genomics-assisted breeding and are useful models for deciphering the mechanisms of agronomic traits,such as fruit color,size,hardness,aroma components,sugar and acid content.Finally,to maximize the application of omics information,we propose some further directions for research using omics strategies.

Correlation between Leaf Size and Fruit Quality of Kiwi

[Objective] This study aimed to investigate the effect of leaf size on fruit quality of kiwi and relevant mechanism. [Method] The correlation between leaf shape and fruit quality of kiwi was studied during 2013-2015. [Result] The results of statistical analysis showed that the sing weight, longitudinal diameter, width, thickness, shape index and juice sugar content of fruit were 75.86±1.68 g, 73.284± 0.70 mm, 41.18±0.51 mm, 35.30±0.25 mm, 1.92±0.01 and （15.66±0.26）%, respec- tively; the length, width, shape index and area of leaf were 14.77±0.20 cm, 14.25± 0.16 cm, 0.94±0.09 and 152.39±3.26 cm^2, respectively; and the length and diameter of petiole were 11.03±0.25 cm and （31.50±0.79 mm）/10, respectively. The results of correlation analysis showed that the single fruit weight of kiwi was strongly positively related to fruit longitudinal diameter, fruit width, fruit thickness and leaf shape index, was significantly positively related to leaf length, was weakly positively related to petiole length, was positively related to leaf area, was weakly negatively related to leaf width and petiole diameter, and was negatively related to juice sugar content. The results of regression analysis showed that there was significant difference be- tween single fruit weight and juice sugar content （F=0.851 8, P〈0.01）, instead of fruit longitudinal diameter （F=0.000 6, P〉0.05）, fruit width （F=0.001 4, P〉0.05） and fruit thickness （F=0.005 4, P〉0.05）; there was significant correlation between single fruit weight and leaf area （F=0.671 5, P〈0.01）, instead of leaf length （F=0.139 3, P〉0.05）, leaf width （F=0.358 5, P〉0.05） and leaf shape index （F=0.294 0, P〉0.05）; there were significant correlations between juice sugar content and leaf length （F= 0.816 1, P〈0.01）, leaf width （F=0.970 1, P〈0.01）, leaf area （F=0.560 6, P〈0.01） and leaf shape index （F=0.885 1, P〈0.05）. [Conclusion] Fruit single weight and oth- er quality properties could be predicted from leaf size, and leaf size can be used as the main basis for judging the quality of fruit.