Young Apple Fruit Research Articles

基于改进YOLOv5的苹果幼果检测方法

The intelligent detection of young apple fruits based on deep learning faced various challenges such as varying scale sizes and colors similar to the background, which increased the risk of misdetection or missed detection. To effectively address these issues, a method for young apple fruit detection based on improved YOLOv5 was proposed in this paper. Firstly, a young apple fruits dataset was established. Subsequently, a prediction layer was added to the detection head of the model, and four layers of CA attention mechanism were integrated into the detection neck (Neck). Additionally, the GIOU function was introduced as the model's loss function to enhance its overall detection performance. The accuracy on the validation dataset reached 94.6%, with an average precision of 82.2%. Compared with YOLOv3, YOLOv4, and the original YOLOv5 detection methods, the accuracy increased by 0.4%, 1.3%, and 4.6% respectively, while the average precision increased by 0.9%, 1.6%, and 1.2% respectively. The experiments demonstrated that the algorithm effectively recognized young apple fruits in complex scenes while meeting real-time detection requirements, providing support for intelligent apple orchard management.

Absolute Stereochemistry of TXIB, a Bioactive Plasticizer That Inhibits Oviposition of the Peach Fruit Moth, Carposina sasakii (Lepidoptera: Carposinidae)

TXIB (2,2,4-trimethyl-1,3-pentanediol diisobutyrate), a common plasticizer, inhibits the peach fruit moth, Carposina sasakii from ovipositing on young apple fruits. Using an insect assay and gas chromatography with an electroantennographic detector (GC-EAD) analysis, the stereochemistry of the bioactive compound was identified to be 3R, whereas (3S)-TXIB showed no activity. The inactive enantiomer did not inhibit the activity of commercially available TXIB, which was a racemic mixture. When the female moth was placed on the TXIB-treated fruits in the oviposition assay, she repeated grooming antennae. The reason why the moth detects this artificial compound is unknown, although the stereochemical structure of TXIB could have given an abnormality to the moth's antennae.

Triterpenes induced by young apple fruits in response to herbivore attack.

Apples Malus domestica, known as a rich source of triterpene acids, induced more variety and quantity of triterpene acids in response to herbivory or mechanical damage. There were 3 major induced compounds: pomaceic acid and euscaphic acid, both of which are known apple triterpene acids, and 2α,19α-dihydroxy-3-oxours-12-en-28-oic acid (named eriobotoric acid), which was first identified in apples. In this study, the 3 compounds' induction curves after damage, varietal differences in induction amounts, and physiological roles against pest insects were further investigated. Eriobotoric acid showed clear antifeedant activity against lepidopteran insect Spodoptera litura but not against apple pests.

Effect of Reflected Sunlight on Differential Expression of Anthocyanin Synthesis-Related Genes in Young Apple Fruit

ABSTRACT Anthocyanin accumulation is responsible for the red color of the skin of apple fruits (Malus × domestica Borkh.). Environmental stimuli, such as light, temperature, soil factors, tree factors, and the application of chemicals can alter the synthesis of anthocyanins. Herein, we examined the expression of genes related to anthocyanin biosynthesis in the fruit of apple cultivars, ‘Summer Prince’ and ‘Arisoo’ at the early stage of fruit development 60 DAFB (days after full bloom). The expression of genes, which included structural and regulatory genes involved in anthocyanin biosynthesis, and light-responsive genes was determined in fruits developed under the effect of sunlight exposure for seven days. Apple fruits were divided in to: ‘reflected sunlight’, ‘bagged’, and ‘control’ groups. The expression levels of the anthocyanin synthesis-related genes were significantly different among the groups and between the shaded and reflected sides. We also determined the difference in coloration patterns in the different groups using the colorimetric coordinates method. The shaded side of apple fruits quickly turned more redder after exposure to reflected sunlight and the coloration was almost similar to that on the exposed side after the treatment. Strong correlation coefficients between anthocyanin-related gene expression levels and coloration patterns were obtained. This study shows that sunlight plays an important role in stimulating the coloration of apple fruit by regulating the expression of genes involved in anthocyanin accumulation during the early stage of fruit development. The present study assumes importance because redder fruits, generated through a non-transgenic approach would be more acceptable to consumers.

Inhibitory substances contained in calcium carbonate wettable powder on the oviposition of the peach fruit moth, Carposina sasakii.

Spraying a calcium carbonate suspension “White Coat” on the fruit of apples significantly suppresses the oviposition of the peach fruit moth, Carposina sasakii. In gas chromatography (GC) with an electroantennographic detector analysis, adult female antennae showed responses to three compounds that were identified as 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB) and its two mono-hydrolyzed analogs, texanols (1- and 3-isobutyrates), all added as a plasticizer to the agents. An oviposition-choice test using adult moths revealed that TXIB has clear deterrent properties when applied to young apple fruits. Video recording analysis showed that female moths spent longer on self-grooming and searching around TXIB-treated fruits. In the same assay, pure calcium carbonate treatment prevented the moths from climbing up or landing on the fruits, while such was not the case with White Coat-treated fruits. TXIB, an adjuvant aimed to provide rain/wind resistance, weakened the slipperiness of the calcium carbonate coating but, coincidentally, maintained the oviposition inhibitory activity of the White Coat by its deterrent odorant.

Effects of Temperature and Moisture on the Infection and Development of Apple Fruit Rot Caused by Phytophthora cactorum.

Phytophthora fruit rot, caused by Phytophthora cactorum, is an important disease of apple in China, often causing more than 50% fruit rot in rainy years. We examined the effects of temperature and moisture on the development of the disease and effects of the variables on zoospore release and germination, infection, and lesion development. In vitro, a temperature range of 5 to 20°C had no significant effects on zoospore release dynamics but did significantly affect the quantities of released zoospores. The largest quantity of zoospores was released at 9.9°C according to a fitted model. Zoosporangia released zoospores within 15 min at the test temperatures (0 to 20°C), which peaked at the fourth hour. Zoospores germinated in vitro, requiring free water, at temperatures from 5 to 35°C. The optimum germination temperature was 25.1°C according to a fitted model. The minimum wetness duration required for zoospores to complete the infection process and induce visible lesions on Fuji fruit was 0.40 h at the optimal temperature of 23.0°C according to the fitted model, whereas observed values were 4.5, 1.5, 0.5, 1.5 and 8.5 h at 10, 15, 20, 25, and 30°C, respectively. The number of zoospore infections on fruit at various temperatures and wetness durations were well fitted by the modified Weibull model; based on the model, the optimal temperature for zoospore infections was 23.0°C. Young apple fruit infected by zoospores developed visible lesions from 10 to 30°C, with a predicted optimum of 23.5°C; no lesions developed at 5 or 35°C. The shortest incubation period of the disease was 4 days. These results can be used to develop disease forecasting models for improved fungicide control.

Effects of apple fruit fermentation (AFF) solution on growth and fruit quality of apple trees

It has been demonstrated that the use of organic materials in fruit orchards can effectively increase soil fertility, fruit production and fruit quality. Insect and disease damage, crop thinning, natural drop cause abscission and abscised parts are a source of organic additives for orchard production. In this study, we developed a fermented nutrient solution composed of young apple fruits, brown sugar, a fermenting agent and water. Diluted solutions (1:100 and 1:200) of this nutrient solution were sprayed on 2-year-old and 12-year-old apple (Malus domestica (Borkh.) ‘Fuji’) trees. The results showed that foliar spraying of the fermentation solutions significantly improved tree height, trunk circumference, shoot growth and leaf area of young apple trees, and increased the fruit weight, shape index, firmness, soluble solid content, volatile compound content and vitamin C content of adult apple trees, as compared to the control treatment. The effects of the 1:200 diluted nutrient solution were significantly greater than those of the 1:100 diluted nutrient solution. Foliar spray of a nutrient solution derived from young apple fruit promoted vegetative growth and fruit quality.

A Review of Sooty Blotch and Flyspeck Disease in German Organic Apple Production

Sooty blotch and flyspeck (SBFS) fungi colonise the surface of a range of fruits, especially apple, without penetrating the cuticle. Economic damage results from the exclusion of severely affected fruit batches from being marketed as table apples. A study of SBFS was conducted in 2007–2012 in the two largest German apple production areas, i.e. the Lake Constance and Lower Elbe regions. The absence of this disease complex from orchards under integrated pest management in both regions in all years was explained by the collateral effects of scab and storage-rot sprays with captan and quinone-outside inhibitors (QoI) such as trifloxystrobin. However, SBFS was economically relevant in organically managed orchards, being generally more severe in Southern Germany than in the North. In both regions, Peltaster cerophilus was the most frequently isolated SBFS fungus and was chiefly responsible for crop losses. Cyphellophora sessilis, Microcyclosporella mali and Schizothyrium pomi also contributed to SBFS in some organic orchards, whereas a diversity of additional species was confined to untreated orchards. Evidence was obtained that P. cerophilus overwinters within orchards, fruit mummies being one of presumably several colonised plant organs. Infections of young apple fruits were initiated at any time following the end of flowering, and P. cerophilus was capable of causing several infection cycles per season by means of conidial inoculum. The colonisation of sheets of waxed paper by P. cerophilus indicated that this species does not require fruit leachates for growth. No further expansion of colonies was observed during cold storage; instead, P. cerophilus was gradually displaced by other fungi. Differences in the susceptibility of apple varieties to P. cerophilus were due to fruit ripening, late-maturing cultivars being most heavily colonised, and to surface properties, varieties with a waxy bloom being conspicuously less strongly colonised than others. This fungus was unable to colonise russeted fruit areas. Repeated spray treatments with lime-sulphur and potassium bicarbonate throughout the season were effective and necessary to control SBFS in organic production. This strategy threatens the fungicide-saving potential offered by scab-resistant apple varieties. Cultural measures against SBFS include summer pruning as well as the manual removal of fruit mummies in winter.

Shading decreases the growth rate of young apple fruit by reducing their phloem import

This study investigates the effects of shading on the biophysical mechanisms of apple ( Malus Domestica Bork.) fruit growth by assessing how vascular and transpiration flows to/from the fruit are affected by shading. At 30 days after full bloom, a 90% neutral shading net was applied to four trees of the cv. Gala, for seven days, while four more trees, chemically thinned, were used as control. Fruit vascular and transpiration flows were assessed from two days before, to the end of shading. The daily patterns of fruit relative growth rate (RGR) and of phloem, xylem and transpiration flows were determined by continuous monitoring of fruit diameter by automatic fruit gauges. Before shading application, no differences between the two groups of trees selected were found for any of the parameters measured. Despite shading induced an immediate drop in canopy photosynthesis, both fruit daily RGR and phloem flow decreased gradually, until reaching 20% of the before treatment values after 7 days of shading. Differences in RGR and phloem flow appeared especially during the afternoon and night, i.e. post carbon assimilation by the tree, and fruit growth rates were higher in control trees. In the same period no, or very small differences were found between treatments for transpiration rates, while xylem flow was affected later than phloem and only at specific times during the day. These results suggest that the decrease in fruit growth rate under shading should be attributed to the reduction of canopy photosynthesis, rather than to a direct effect of shading on fruit sink strength.

Effects of 1-Methylcyclopropene and Naphthaleneacetic Acid on Fruit Set and Expression of Genes Related to Ethylene Biosynthesis and Perception and Cell Wall Degradation in Apple

The effects of 1-methylcyclopropene (1-MCP) and naphthaleneacetic acid (NAA) on fruit set and the expression of genes related to ethylene biosynthesis and perception and cell wall degradation in apple (Malus ×domestica Borkh.) were studied when applied during the normal chemical thinning period. 1-MCP at 209 mg·L−1 had a small negative effect or no effect on the final fruit set, depending on the experiment, but could cause a transient delay of June drop when applied at petal fall or the 10-mm stage in ‘Pioneer McIntosh’ apple. 1-MCP at 160 mg·L−1 had no effect on fruit abscission but induced ethylene production by leaves and fruit of ‘Golden Delicious’ apple. NAA at 6 or 15 mg·L−1 effectively increased fruit abscission in both apple cultivars. NAA enhanced the expression of genes related to ethylene biosynthesis (MdACS5A, MdACS5B, and MdACO1) or perception (MdETR1, MdETR1b, MdETR2, MdERS1, and MdERS2) and cell wall degradation (MdPG2). 1-MCP did not affect the expression of MdACS5A and MdACS5B in the fruit abscission zone (FAZ), although it enhanced the expression of these two genes in the fruit cortex (FC) from 6 hours to 1 day after treatment. The expression of MdACO1 in both tissues was increased by 1-MCP by 3 days post-treatment and thereafter. 1-MCP had only a small influence on the expression of most ethylene receptor genes, with the exception of MdETR1, which was upregulated in the FC to a level similar to that observed for NAA treatment. In response to 1-MCP, in the FAZ, the expression of MdCel1 and MdPG2 was upregulated at the beginning and the end, respectively, of the experiment, but otherwise remained at or below control levels. 1-MCP did not inhibit NAA-induced abscission of young apple fruit, suggesting that abscission does not solely depend on ethylene signal transduction, or that the periods of effectiveness for 1-MCP and ethylene were asynchronous.

Observation of the peach fruit moth, Carposina sasakii, larvae in young apple fruit by dedicated micro-magnetic resonance imaging

Infestation of young apple fruits by the larvae of the peach fruit moth, Carposina sasakii Matsumura (Lepidoptera: Carposinidae), was studied by a small dedicated micro-magnetic resonance imaging (MRI) apparatus using the three-dimensional (3D) gradient-echo method and the two-dimensional (2D) and 3D spin-echo methods. Changes from a young larva at 1.8 mm in length to a mature one ready to leave the fruit were observed in relation to the progression of infestation of the fruit tissues. The trace of larva intrusion was demonstrated by a series of sliced images in the 3D image data of an infested fruit, where it entered from outside the calyx, and migrated to near the vasculature around the carpel through the core. The small, dedicated MRI device was proven useful for ecological studies of the growth and movement of insect larvae in their food fruits. It can also be applied to detect the infestation of small fruits by insect larvae.

Can phyllosphere yeasts explain the effect of scab fungicides on russeting of Elstar apples?

In 1999 and 2000, the effects of scab fungicides on yeast composition and russeting of Elstar apples were assessed. Yeast composition of fungicide-treated and untreated young apple fruit with or without russet symptoms was investigated and enzyme activity of the yeasts was studied. Cryptococcus albidus, C.␣laurentii,Rhodotorula glutinis, Sporobolomyces roseus andMetschnikowia pulcherrima dominated the apple fruit surface. Russeted apple fruitlets had a higher red yeast density than non-russeted fruitlets. In␣vitro fungicide susceptibility of the dominant yeast species varied. Dithianon and dodine were active against all tested species, captan and tolylfluanid showed specificity for certain species, whereas pyrimethanil and bupirimate were largely ineffective. Fungicide treatment in the field had a clear effect on the yeast composition. Metschnikowia etschnikowia pulcherrima was eliminated from the phyllosphere and cryptococco$i species diminished by both captan and dithianon. The red yeast population was not significantly changed by either fungicide. Captan, dithianon, tolylfluanid and pyrimethanil reduced russet in the field in both years, dodine and kresoxim-methyl only in 2000. All yeast species had cutinolytic activity, all but M.␣pulcherrimaand Debaryomyces hansenii were lipolytic, and some of the isolates showed proteolytic activity.

Studies on locating the signal for fruit abscission in the apple tree

The abscission of young fruit occurring in apple trees was measured under various conditions in order to locate the possible source of the signal that induces fruit drop. The effect on fruit abscission of shading of leaves, girdling of conducting tissue, extracting seeds and defruiting pedicels was investigated. Complete shading of whole trees for 5 days, steam girdling of defoliated fruiting wood proximal to the abscission zone and removal of seeds from attached fruit resulted in 100% fruit drop when treatment was carried out prior to the June drop period. When the same treatment was applied after June drop no fruit abscised. However, fruit abscission took place before and after June drop when steam girdling was applied to the pedicel distal to the abscission zone. The same effect was observed in defruited pedicels, which always abscised after fruit removal throughout fruit development. The results show that during the pre-June drop period, abscission can be induced by treatments which reduce or block nutrient supply to the abscission zone of fruit. After that period the growing fruit becomes a sugar storage organ which is resistant to abscission. It is though likely that inhibition of abscission is related to the presence of stored carbohydrates already accumulated in the young fruit. An indication for the involvement of the sugar level, in particular glucose, in the control of the abscission process was provided by the results of measurements of individual sugar levels in conducting tissue distal and proximal to the abscission zone. It was found that during fruit development, glucose concentration in the pedicel was normally above the concentration found in fruiting wood proximal to the abscission zone. However, when abscission during the June drop period was induced, the glucose level dropped to a minimum in the pedicel, reaching the same value as in the fruiting wood. It is suggested that the glucose level in the pedicel of growing fruit may therefore be a factor in the control of the abscission process in young apple fruit, abscission occuring only in those fruit in which the glucose content in the pedicel is below a critical level. Fruit which remain on the tree have most likely reached a stage in their development at which sufficient amounts of sugar have accumulated to prevent abscission.

Sugar Accumulation and Changes in the Activities of Related Enzymes during Development of the Apple Fruit

Summary During the initial development of young apple fruits sucrose was not detectable and the concentrations of sorbitol, glucose, and fructose declined until two weeks before the onset of the June drop period. The subsequent storage of sugars was accompanied by significant changes in the activities of acid invertase and sorbitol dehydrogenase. A sharp decrease in the activity of acid invertase was noted during the pre-drop stage in which sucrose was absent. The decrease in enzyme activity was followed by a steady accumulation of sucrose. Sorbitol dehydrogenase, which catalyses the transformation of sorbitol to fructose, was absent in fruit from the pre-drop stage at a time when the level of sorbitol was relatively high. With the appearance of sorbitol dehydrogenase in sugar-accumulating fruits the sorbitol concentration decreased and the storage of fructose continued until fruit development ceased. The activity of sorbitol-6-phosphate dehydrogenase did not change significantly during fruit development. The results suggest that sucrose is the predominant C-source for cellular growth in the young fruit, whereas during the sugar storage phase sorbitol is the major substrate for fructose accumulation. It was further demonstrated that fruit abscission during the June drop period is not related to the carbohydrate concentration of the fruit. Using trees which had been thinned manually at full bloom to yield fruit with an enhanced assimilate supply and a lowered tendency to abscise it was shown that the patterns of sugar levels and enzyme activities in these fruits were the same as in fruits from unthinned trees.

Occurrence of the plant growth regulator jasmonic acid in plants

The natural occurrence of jasmonic acid and its methyl ester in plants has been studied using different methods such as GC, GC-MS, HPLC, radioimmunoassay, and bioassay. Jasmonic acid was detected in several Leguminosae plants and a number of species belonging to nine other Angiospermae families. Highest amounts occurred in fruit parts, especially the immature pericarp, but it was found also in flowers and vegetative plant parts, e.g. leaves, stems, and germs. Young apple fruits contain both jasmonic acid and methyl jasmonate, and in Douglas fir, the only Gymnospermae species studied, only the methyl ester could be detected. Jasmonic acid is discussed as an endogenous plant growth regulator widely distributed in higher plants.

Biosynthesis of hydroxyfatty acid polymers: Enzymatic hydration of 18-hydroxy- cis-9,10-epoxystearic acid to threo-9,10,18-trihydroxystearic acid by a particulate preparation from apple ( Malus pumila)

A 3000 g participate fraction prepared from homogenates of the skin of young apple fruit catalyzed the hydration of 18-hydroxy- cis-9,10-epoxystearic acid to threo-9,10,18-trihydroxystearic acid, a key step in the biosynthesis of cutin, the hydroxyfatty acid biopolymer of the plant cuticle. Similar preparations from the internal tissue of apple fruit contained less than 6% of this epoxide hydrase activity. The enzymatic product was identified by thin-layer chromatography on silica gel G and on boric acid-silica gel G, as well as by radio gas-liquid chromatography of its periodate oxidation product. The epoxide hydrase required no cofactors, had a pH optimum of 6.5, and it was located mainly (>90%) in the 3000 g particle fraction which contained the cuticular membranes. The rate of hydration of the epoxy acid was linear up to 75 min and up to a protein concentration of 0.8 mg/ml. The apparent K m and V of the enzyme was 4 × 10 −4 m and 170 μmol/1-h-mg of protein, respectively. p-Chloromercuribenzoate strongly inhibited the enzyme (80% inhibition at 10 −4 m), while iodoacetamide and N-ethylmaleimide were less potent inhibitors. 1,1,1-Trichloropropylene-2,3-oxide at 5 × 10 −3 m gave 60% inhibition of hydration of 18-hydroxy-9,10-epoxystearic acid. Diisopropylfluorophosphate was mildly inhibitory, and the enzyme was insensitive to ethylenediaminetetraacetic acid. Methyl 18-hydroxy-9,10-epoxystearate, 18-acetoxy-9,10-epoxystearic acid, methyl 18-acetoxy-9,10-epoxystearate, 9,10-epoxystearic acid, and styrene oxide were not readily hydrated by this plant epoxide hydrase showing that it has a fairly stringent substrate specificity, unlike the catabolic epoxide hydrases of animals. Particulate preparations capable of hydrating 18-hydroxy-9,10-epoxystearic acid to the trihydroxy acid were also obtained from Senecio odoris leaf epidermis and Spinacia oleracea leaves. This is the first report on the enzyme which catalyzes this important step in the biosynthesis of the protective biopolymer, cutin.

Identification of 18-oxo-9, 10-epoxystearic acid, a novel compound in the cutin of young apple fruits.

Abstract18‐Oxo‐9,10‐epoxystearic acid was identified in the cutin of young apple fruits by hydrogenolysis with LiAlH4, deuterolysis with LiAlD4, CrO3 oxidation of deuterated product followed by reduction with LiAlH4 and mass spectrometry of the products.

Studies on the Enzymic Browning of Apples II. Properties of Apple Polyphenoloxidase

The properties of a particulate polyphenoloxidase preparation from young apple fruit have been investigated. Chlorogenic acid, D-catechin, and hydrocaffeic acid were found to be the substrates most rapidly oxidized by this preparation, but its action on a number of other phenolic compounds was also investigated. The inhibition of the oxidation of phenolic compounds by cysteine and other thiol compounds was studied in detail.