Red Fuji Research Articles

Analysis of Phenolic Components and Related Biological Activities of 35 Apple (Malus pumila Mill.) Cultivars.

Apple (Malus pumila Mill.) is a popular fruit with high economic values and various biological activities that are beneficial to human health. In this study, 35 apple cultivars were collected and were evaluated for their basic quality indexes, phenolic compositions, antioxidant activity, anti-tumour, and anti-diabetic activities. The compositions of phenolics were detected by using high-performance liquid chromatography (HPLC) and high-resolution mass spectroscopy (HRMS) assays. The antioxidant activities of peel and pulp extracts from 35 apple cultivars were evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay and ferric reducing antioxidant power (FRAP) assay. Results showed that the contents of phenolic acids and proanthocyanidins showed significant correlations with the antioxidant activities. Phenolic-rich extracts significantly inhibited HepG2 cell proliferation, with the inhibition activity varied significantly between cultivars. ‘Gold Delicious’ pulp extract, ‘Xiboliyabaidian’ peel and pulp extracts showed protective effects on H2O2-induced injury of human umbilical vein endothelial cells (HUVEC). ‘Red Fuji’ peel extract, ‘Xiboliyabaidian’ peel and pulp extracts, as well as ‘Gold Delicious’ peel extract, significantly increased glucose consumption of HepG2 cells, in a dose-dependent manner. This research may provide theoretical guidance for further nutritional investigation of the apple resources.

Quantitative trait loci-based genomics-assisted prediction for the degree of apple fruit cover color.

Apple fruit cover color is an important appearance trait determining fruit quality, high degree of fruit cover color or completely red fruit skin is also the ultimate breeding goal. MdMYB1 has repeatedly been reported as a major gene controlling apple fruit cover color. There are also multiple minor-effect genes affecting degree of fruit cover color (DFC). This study was to identify genome-wide quantitative trait loci (QTLs) and to develop genomics-assisted prediction for apple DFC. The DFC phenotype data of 9,422 hybrids from five full-sib families of Malus asiatica 'Zisai Pearl', M. domestica 'Red Fuji', 'Golden Delicious', and 'Jonathan' were collected in 2014-2017. The phenotype varied considerably among hybrids with the same MdMYB1 genotype. Ten QTLs for DFC were identified using MapQTL and bulked segregant analysis via sequencing. From these QTLs, ten candidate genes were predicted, including MdMYB1 from a year-stable QTL on chromosome 9 of 'Zisai Pearl' and 'Red Fuji'. Then, kompetitive allele-specific polymerase chain reaction (KASP) markers were designed on these candidate genes and 821 randomly selected hybrids were genotyped. The genotype effects of the markers were estimated. MdMYB1-1 (represented by marker H162) exhibited a partial dominant allelic effect on MdMYB1-2 and showed non-allelic epistasis on markers H1245 and G6. Finally, a non-additive QTL-based genomics assisted prediction model was established for DFC. The Pearson's correlation coefficient between the genomic predicted value and the observed phenotype value was 0.5690. These results can be beneficial for apple genomics-assisted breeding and may provide insights for understanding the mechanism of fruit coloration.

Nitrification Inhibitor 3,4-Dimethylpyrazole Phosphate Application During the Later Stage of Apple Fruit Expansion Regulates Soil Mineral Nitrogen and Tree Carbon-Nitrogen Nutrition, and Improves Fruit Quality.

In order to solve the problems of nitrogen (N) losses and fruit quality degradation caused by excessive N fertilizer application, different dosages of the nitrification inhibitor, 3,4-dimethylpyrazole phosphate (DMPP) (0, 0.5, 1, 2, and 4 mg kg–1 soil), were applied during the later stage of ‘Red Fuji’ apple (Malus domestica Borkh.) fruit expansion in 2017 and 2018. The effects of DMPP on soil N transformation, carbon (C)–N nutrition of tree, and fruit quality were investigated. Results revealed that DMPP decreased the abundance of ammonia-oxidizing bacteria (AOB) amoA gene, increased the retention of NH4+-N, and decreased NO3–-N concentration and its vertical migration in soil. DMPP reduced 15N loss rates and increased 15N residual and recovery rates compared to the control. 13C and 15N double isotope labeling results revealed that DMPP reduced the capacity of 15N absorption and regulation in fruits, decreased 15N accumulation in fruits and whole plant, and increased the distribution of 13C from vegetative organs to fruits. DMPP increased fruit anthocyanin and soluble sugar contents, and had no significant effect on fruit yield. The comprehensive analysis revealed that the application of 1 mg DMPP kg–1 soil during the later stage of fruit expansion effectively reduced losses due to N and alleviated quality degradation caused by excessive N fertilizer application.

Crop Load Influences Growth and Hormone Changes in the Roots of "Red Fuji" Apple.

Crop load has a substantial impact on growth of the aerial and belowground parts of apple trees. Here, we examined the effects of different crop loads on growth and hormone levels in apple roots. A crop load of 1.5 (T1.5) fruits per cm2 trunk cross-sectional area (TCSA) treatment resulted in lower root growth vigor, while non-fruiting (T0) and T0.4 conditions showed higher root growth vigor. In all treatments, dead roots increased in length 90 days after full bloom (DAFB), whereas live roots were more abundant at about 50 and 170 DAFB, showing a bimodal curve. During each root growth peak, levels of cytokinins (CTKs), indole acetic acid (IAA), and gibberellic acid (GA3) were higher. Moreover, hormone levels gradually decreased with increasing crop load within each peak. Root turnover tended to decrease with decreasing crop load. These findings indicate that root growth and hormone contents were positively correlated during the fruit growth phase, and that the negative impact of crop load on root growth may have been caused by hormone level decreases.

MicroRNA156 (miR156) Negatively Impacts Mg-Protoporphyrin IX (Mg-Proto IX) Biosynthesis and Its Plastid-Nucleus Retrograde Signaling in Apple.

Plastid-nucleus retrograde signaling (PNRS) play essential roles in regulating nuclear gene expression during plant growth and development. Excessive reactive oxygen species can trigger PNRS. We previously reported that in apple (Malus domestica Borkh.) seedlings, the expression of microRNA156 (miR156) was significantly low in the adult phase, which was accompanied by high levels of hydrogen peroxide (H2O2) accumulation in chloroplasts. However, it was unclear whether adult-phase-specific chloroplast H2O2 may induce PNRS and affect miR156 expression, or miR156 triggers adult phase PNRS during the ontogenesis. In this paper, we examined the relationship between miR156 levels and six PNRS components in juvenile and adult phase leaves from ‘Zisai Pearl’בRed Fuji’ hybrids. We found that PNRS generated by singlet oxygen (1O2), the photosynthetic redox state, methylerythritol cyclodiphosphate (MEcPP), SAL1-3-phosphoadenosine 5-phosphate (PAP) and WHIRLY1 were not involved. The accumulation of Mg-protoporphyrin IX (Mg-Proto IX), the expression of the synthetic genes MdGUN5 and MdGUN6, and Mg-Proto IX PNRS related nuclear genes increased with ontogenesis. These changes were negatively correlated with miR156 expression. Manipulating Mg-Proto IX synthesis with 5-aminolevulinic acid (ALA) or gabaculine did not affect miR156 expression in vitro shoots. In contrast, modulating miR156 expression via MdGGT1 or MdMIR156a6 transgenesis led to changes in Mg-Proto IX contents and the corresponding gene expressions. It was concluded that the Mg-Proto IX PNRS was regulated downstream of miR156 regardless of adult-phase-specific plastid H2O2 accumulation. The findings may facilitate the understanding of the mechanism of ontogenesis in higher plants.

Effect of young apple (Malus domestica Borkh. cv. Red Fuji) polyphenols on alleviating insulin resistance

Insulin resistance (IR) has an important role in the development of type 2 diabetes (T2DM). This study aimed to investigate the effect of young apple (Malus domestica Borkh. cv. Red Fuji) polyphenols (YAP) on IR in HepG2 cells. It was found that YAP and its two main components, phlorizin and chlorogenic acid, could increase glucose uptake, glucose consumption and glycogen content. YAP and phlorizin activated the insulin receptor substrate 2/phosphatidylinositol 3-kinase/phosphorylation of the protein kinase B (IRS2/PI3K/AKT) signal pathway, as well as its downstream proteins glycogen synthase kinase-3β (GSK3β) and forkhead box protein O1 (FOXO1), which were further confirmed by application of the PI3K inhibitor LY294002. YAP and phlorizin also improved mitochondrial dysfunction by reducing mitochondrial reactive oxygen species (ROS) accumulation, restoring ATP production and the mitochondrial membrane potential (MMP). This study suggested that YAP has the potential to alleviate T2DM symptoms.

Comparative Analysis of Stylet Penetration Behaviors of Eriosoma lanigerum (Hemiptera: Aphididae) on Main Apple Cultivars in China

The preference and behavioral mechanism of the feeding behavior of the woolly apple aphid, Eriosoma lanigerum (Hausmann), on Chinese apple cultivars was investigated using the electrical penetration graph (EPG) technique. Feeding of adult aphids was assessed for the four main cultivars of apple in China (Red Fuji, Ralls Genet, Starkrimson, and Jonagold) over an 8-h monitoring period, what that of fourth-instar nymphs was assessed for 8 h on Jonagold only. EPG waveforms representing the details of probing behaviors, parameters were measured for analysis. We found that at the nonphloem phase, the total duration of the nonpenetration (np) waveform and the total duration of the stylet pathway phase (the 'C wave') on Ralls Genet and Starkrimson were significantly longer than on Red Fuji. In addition, the phloem-feeding phase, the total duration of 'release of saliva into the phloem', (the E1 waveform) was significantly longer on Ralls Genet and Jonagold than on Red Fuji. The total duration of the 'ingestion from sieve cells' phase (the E2 waveform) on Red Fuji, meanwhile, was significantly longer than on Ralls Genet or Starkrimson. At the same time, when combined with EPG parameters, Red Fuji was found to have no obvious resistance to woolly apple aphid and to be a susceptible cultivar. This experiment also recorded the feeding waveform of fourth-instar aphid nymphs. Based on the phloem and nonphloem parameters recorded in this study, it was inferred that adult aphids are more likely than nymphs to feed on apple trees.

Effect of 1-methylcyclopropene treatment on storage quality of red Fuji apple

Effect of 1-methylcyclopropene treatment on storage quality of red Fuji apple

Study on Quality Characteristics and Feasibility Analysis of Hail-proof Plastic Bagging of 5000 Mu in Gansu

The effects of bagging of bare fruits, plastic bagging, hail-proof plastic bagging and bagging on the quality of red Fuji apples in different periods were studied. Red Fuji apples in Qingyang City of Gansu Province were used as test materials to determine the fruit quality indices of bagged and bagged apples in different periods, such as light consistency, color, and fruit firmness, total sugar, reducing sugar, sucrose and total acid. With the postponement of bagging period, apple fruit surface smoothness, color and hardness gradually decreased, while total sugar, reducing sugar and sucrose content gradually increased. With the delay of bagging time, the smoothness of apples decreases. Total sugars, reducing sugars and sucrose had the same growth and decline pattern as those of fruits without bagging, but their contents were always lower than those of the control. Hail-proof Apple plastic suction bagging has been proved by a lot of research and experiments that this kind of apple bagging has the characteristics of low price, fast bagging speed and reusability. It can also prevent and control diseases, insects, birds, rats, bees and other harmful effects on fruits and reduce fruit rust. It can also avoid friction between branches and leaves, prevent sunburn and reduce hail. At the same time, bagging efficiency is fast, improving work efficiency, reducing environmental pollution and reducing the workload of fruit growers.

Exogenous Abscisic Acid Regulates Distribution of 13C and 15N and Anthocyanin Synthesis in 'Red Fuji' Apple Fruit Under High Nitrogen Supply.

In order to improve the problem of poor coloring caused by high fruit nitrogen in apple production, we studied the effects of different concentrations of abscisic acid (ABA: 0, 50, 100, and 150 mg/L) and fluridone (ABA biosynthesis inhibitor) on the fruit of ‘Red Fuji’ apple (Malus Domestica Borkh.) in the late stage of apple development (135 days after blooming) in 2017 and 2018. The effects of these treatments on the distribution of 13C and 15N and anthocyanin synthesis in fruit were studied. The results showed that the expression levels of ABA synthesis and receptor genes in the peel and flesh were upregulated by exogenous ABA treatment. An appropriate concentration of ABA significantly increased the expression of anthocyanin synthesis genes and transcription factors and increased the content of anthocyanin in the peel. The results of 13C and 15N double isotope labeling showed that exogenous ABA coordinated the carbon–nitrogen nutrient of apple fruit in the late stage of the development, reduced the accumulation of fruit nitrogen, increased the accumulation of fruit carbon and sugar, provided a substrate for anthocyanin synthesis, or promoted anthocyanin synthesis through the sugar signal regulation mechanism. Comprehensive analysis showed that the application of 100 mg/L ABA effectively improved the problem of poor coloring caused by high fruit nitrogen in the late stage of apple development and is beneficial to the accumulation of carbon in fruit and the formation of color.

Research on Dynamic Forecast of Flowering Period Based on Multivariable LSTM and Ensemble Learning Classification Task

The flowering forecast provides recommendations for orchard cleaning, pest control, field management and fertilization, which can help increase tree vigor and resistance. Flowering forecast is not only an important part of the construction of agro-meteorological index system, but also an important part of the meteorological service system. In this paper, by analyzing local meteorological data and phenological data of “Red Fuji” apples in Fen County, Linfen City, Shanxi Province, with the help of machine learning and neural networks, we proposed a method based on the combination of time series forecasting and classification forecasting is proposed to complete the dynamic forecasting model of local flowering in Ji County. Then, we evaluated the effectiveness of the model based on the number of error days and the number of days in advance. The implementation shows that the proposed multivariable LSTM network has a good effect on the prediction of meteorological factors. The model loss is less than 0.2. In the two-category task of flowering judgment, the idea of combining strategies in ensemble learning improves the effect of flowering judgment, and its AUC value increases from 0.81 and 0.80 of single model RF and AdaBoost to 0.82. The proposed model has high applicability and accuracy for flowering forecast. At the same time, the model solves the problem of rounding decimals in the prediction of flowering dates by the regression method.

First Report of a Postharvest Fruit Rot on Apple Caused by <i>Diaporthe phaseolorum</i> var. <i>caulivora</i> in China: A Note

Brown rots of Red Fuji apples were observed in Hangzhou city (Zhengjiang Province, China). The causal agent was isolated and identified in both morphological and molecular genetic levels. The phenotype and phylogenetic analysis revealed that the isolate was Diaporthe phaseolorum var. caulivora, and its pathogenicity on apple fruit was confirmed by re-inoculation experiment. To our knowledge, this is the first report of D. phaseolorum var. caulivora causing postharvest fruit rot on apple in China.

Morphological and photosynthetic responses differ among eight apple scion-rootstock combinations

‘Red Fuji’ apple (Malus × domestica Borkh.) scions were grafted onto eight size-controlling rootstock combinations (dwarfing, semi-dwarfing, and vigorous types). During the third year after grafting, morphological and physiological parameters, such as growth, hydraulic conductance, non-structural carbohydrates, gas exchange and chlorophyll fluorescence, as well as leaf anatomy, were examined and instantaneous whole-canopy photosynthetic assimilation was modelled. Compared with Baleng, rootstocks M.9 and B.9 resulted in reduced growth vigour and photosynthetic capacity. Significantly lower soil-to-leaf hydraulic conductance, stomatal density and palisade/spongy parenchyma ratios were also observed in ‘Red Fuji’ grafted on M.9 and B.9. We propose that the down-regulated hydraulic conductance contributed to the decline in photosynthetic rate, which in turn caused a reduction in instantaneous whole-canopy photosynthetic assimilation. These results provide evidence that the limited photosynthetic capacity and leaf area are major causes of the reduced canopy photosynthetic assimilation observed in M.9 and B.9 grafted apple trees. The reduced photosynthetic assimilation may partly result from a sustained lower photochemical efficiency. However, dwarfing and semi-dwarfing rootstocks grafted plants contained more starch, which may be a significant factor underlying the observed advanced precocity.

Effect of 100 kPa O2 pretreatments time on physiology and quality of vacuum packed and coated fresh‐cut apples

AbstractThis research used different 100 kPa O2 pretreatments time (0, 2, 4, and 6 hr) to investigate their effects on qualities of fresh‐cut “Red Fuji” apples during cold storage. Fresh‐cut apples were dipped in acid solution (composed of 1.53% ascorbic acid, 1.10% citric acid, and 0.51% CaCl2) for 15 min and 5 g/L carboxymethylcellulose sodium edible coating (composed of 0.5% CMC, 0.01% Natamycin, and 0.015% Nisin) for 5 min. Then the slices were exposed to 100 kPa O2 for different time before being vacuumed in polyethylene bags. The results showed that pretreatment with 100 kPa O2 inhibited the surface browning, polyphenol oxidase and peroxidase activity and malondialdehyde. Moreover, 100 kPa O2 pretreatment for 4 hr was more effective than other pretreatments time. Intact tissue structure and fewest molds and yeast count during 90 days of storage were also observed in pretreated for 4 hr samples during storage.

Systematic identification of long noncoding RNAs expressed during light-induced anthocyanin accumulation in apple fruit.

Anthocyanin pigments contribute to the red color of apple (Malus×domestica) fruit and have a major influence on their ornamental, dietary and market value. In this study, we investigated the potential role of long noncoding RNAs (lncRNAs) in anthocyanin biosynthesis. RNA-seq analysis of apple peels from the 'Red Fuji' cultivar during light-induced rapid anthocyanin accumulation revealed 5297 putative lncRNAs. Differential expression analysis further showed that lncRNAs were induced during light treatment and were involved in photosynthesis. Using the miRNA-lncRNA-mRNA network and endogenous target mimic (eTM) analysis, we predicted that two differentially expressed lncRNAs, MLNC3.2 and MLNC4.6, were potential eTMs for miRNA156a and promoted the expression of the SPL2-like and SPL33 transcription factors. Transient expression in apple fruit and stable transformation of apple callus showed that overexpression of the eTMs and SPLs promoted anthocyanin accumulation, with the opposite results in eTM and SPL-silenced fruit. Silencing or overexpressing of miR156a also affected the expression of the identified eTMs and SPLs. These results indicated that MLNC3.2 and MLNC4.6 function as eTMs for miR156a and prevent cleavage of SPL2-like and SPL33 by miR156a during light-induced anthocyanin biosynthesis. Our study provides fundamental insights into lncRNA involvement in the anthocyanin biosynthetic pathway in apple fruit.

Identification of True and False Aksu Apple Based on NIRS and PLS-DA

A method for the identification of true and false Aksu Red Fuji apple varieties based on near-infrared spectroscopy (NIRS) and partial least squares discrimination (PLS-DA) was proposed and established. Authentic Xinjiang Aksu Red Fuji and ordinary Red Fuji (Shandong and Shanxi Red Fuji) were purchased from supermarkets. There were 42 samples in each variety, with totaling 126 samples. Near infrared diffuse reflectance spectra of all samples were collected in the range of 4000-12000 cm−1. On the basis of studying the characteristics of NIR spectra, the principal component analysis (PCA) was carried out. It is pointed out that PCA method cannot fully realize the identifcation of three kinds Red Fuji Apples. Finally, the partial least squares discriminant analysis model of three kinds Red Fuji Apples was established, and the correct discrimination rates of the three kinds Red Fuji Apples were 100% for samples in calibration set and prediction set.

The infiltration efficiency of Agrobacterium-mediated transient transformation in four apple cultivars

Studies of gene function in apple fruits (Malus domestica) have been hindered by the long juvenile period of apple fruit trees. Transient gene expression is a relatively simple method for gene functional analyses, and has been broadly applied to several plant species; however, few studies have reported a method for systematic transient expression in apple fruits. Here, we developed a highly efficient and robust Agrobacterium-mediated transient expression system for apple fruit, which allows rapid analysis of diverse gene functions. Using a β-glucuronidase gene (GUS) as a reporter for Agrobacterium-mediated transformation, we found that the most suitable infiltration pressure for gene function assays in ‘Red Fuji’, ‘Granny Smith’ and ‘Royal Gala’ fruits was −90 kPa, but −70 kPa in ‘Golden Delicious’. The infiltration efficiency of ‘Golden Delicious’ was higher than that of the other apple cultivars. Transient silencing of MdMYB10, an anthocyanin biosynthesis regulator, altered anthocyanin content in ‘Red Fuji’, demonstrating that vacuum infiltration with Agrobacterium can be used for gene functional analysis. Also a significant positive correlation was found between microcrack density and infiltration efficiency. We conclude that this method represents a general tool for efficient and targeted transient regulation of gene expression in apple fruits.

Effect of cultivars on tree growth, yield and quality attributes of apple on espalier architecture under high density planting system

Annual extension growth (AEG), an indicator of tree vigor, was recorded maximum (145.63 cm) in Granny Smith and minimum (111.04cm) in Spartan, where as correlation matrix showed negative relation between trunk cross sectional area (TCSA) and AEG. Granny Smith exhibited maximum (184.09 g) fruit weight and it was minimum (128.68 g) in Spartan, the correlation matrix between fruit weight and yield efficiency exhibited significant positive correlation over the years. Yield tree-1 was maximum (29.45 kg tree-1) in Coe red Fuji and minimum (16.04 kg/tree) in Spartan. Significant and positive correlation coefficient (0.870) observed between yield and TCSA. TCSA has positive correlation with fruit weight and yield efficiency, maximum mean yield efficiency (1.11 kg/cm2) was recorded in Granny Smith. All the cultivars trained on this architecture had high chroma values (color intensity).

Effect of cultivars on tree growth, yield and quality attributes of apple on espalier architecture under high density planting system

Annual extension growth (AEG), an indicator of tree vigor, was recorded maximum (145.63 cm) in Granny Smith and minimum (111.04cm) in Spartan, where as correlation matrix showed negative relation between trunk cross sectional area (TCSA) and AEG. Granny Smith exhibited maximum (184.09 g) fruit weight and it was minimum (128.68 g) in Spartan, the correlation matrix between fruit weight and yield efficiency exhibited significant positive correlation over the years. Yield tree-1 was maximum (29.45 kg tree-1) in Coe red Fuji and minimum (16.04 kg/tree) in Spartan. Significant and positive correlation coefficient (0.870) observed between yield and TCSA. TCSA has positive correlation with fruit weight and yield efficiency, maximum mean yield efficiency (1.11 kg/cm2) was recorded in Granny Smith. All the cultivars trained on this architecture had high chroma values (color intensity).

Standardization of tree architectural techniques for higher apple productivity on dwarfing rootstock

There was a significant and positive correlation between yield and Trunk cross Sectional Area (TCSA). Consistently high productivity (16.7, 52.29, 96.05, 102.35 and 61.84 t/ha) with medium-sized and large number of fruits were recorded in Coe Red Fuji, and minimum (6.0, 30.72, 22.28, 86.45 and 58.01 t/ha) in Spartan during 2011–13. The TCSA is reliable criteria to estimate tree vigor, crop load and yield efficiency, maximum TCSA (25.99, 27.90, 33.31, 37.02 and 38.83) over the years were noted in Coe Red Fuji. The TCSA has positive correlation with fruit weight and yield efficiency. Maximum mean yield efficiency (1.11 kg/cm2) was recorded in Granny Smith. High chroma (color intensity) observed in all varieties on espalier architecture.