Acid Content Of Fruits Research Articles

Identification of Key Genes Controlling Sugar and Organic Acid Accumulation in Wampee Fruit (Clausena lansium) via Genome Assembly and Genome-wide Association Analysis.

Wampee (Clausena lansium) is an economically significant subtropical fruit tree widely cultivated in Southern China. To provide high-quality genomic resources for C. lansium, we report a chromosome-level genome sequence for the "JinFeng" cultivar. The 297.1 Mb C. lansium genome contained nine chromosomes with a scaffold N50 of 29.2 Mb and encoded 23,468 protein-coding genes. Selective sweep analysis between sweet and sour C. lansium varieties and genome-wide association analysis identified 14 candidate genes putatively involved in sugar and acid accumulation. ClERF061, encoding an ethylene response factor, and ClSWEET7, encoding a Sugars Will Eventually be Exported Transporters (SWEET) family protein, were proposed as key regulators of the sweet and sour tastes of the wampee fruit. ClERF061 and ClSWEET7 overexpression in tomatoes increased the total sugar and acid content in fruits. ClSWEET7 promoter activation by ClERF061 was confirmed via Nicotiana benthamiana transient expression. Our study provides valuable genomic resources for C. lansium genetics and breeding.

Agronomic, Biochemical, and Physiological Responses to Magnesium (Mg) Application in Tomato (Solanum lycopersicum L.) under Greenhouse Conditions

Magnesium fertilization positively impacts various physiological processes in plants, leading to increased yield and fruit quality. In the present study, we determined the effects of the foliar application of magnesium on the yield, fruit quality, fruit biochemical content, and enzyme activity of tomato plants. The study was performed in a plastic greenhouse. The study evaluated magnesium sulfate application through drip irrigation at a single dose of 0.005 kg m2 and foliar application at rates of 0%, 0.25%, 0.5%, and 0.75%. As a consequence, the highest average fruit weight was obtained with the foliar application of 0.50% Mg. In terms of the fruit color’s a* value, the best results were again obtained with the application of 0.50% Mg. Mg applications proportionally increased the leaf chlorophyll content. Similarly, the highest leaf Mg content, the leaf relative water content, the fruits’ malic acid content, and the best fruit juice pH value were determined with the application of 0.75%. On the other hand, the application of 0.25% Mg produced the best results on the leaves’ K, Ca, and Na content, as well as in the fruits’ ascorbic acid content. Significant differences were not found in terms of the effects of the treatments on antioxidant activity, total protein amount, and enzyme activity. The application of 0.50% Mg contributed to the fruit color; 0.75% Mg application contributed to the chlorophyll, pH, and malic acid content; and the application of 0.25% Mg contributed to an increase in ascorbic acid. In conclusion, for greenhouse tomato production, a foliar application of 0.50% Mg is recommended to achieve larger, red-colored fruits. A 0.75% Mg application is suggested for increasing the chlorophyll content, lowering fruit juice pH, and enhancing malic acid content in fruits. A 0.25% Mg application is recommended to increase ascorbic acid content in fruits.

Determination of the Protein and Amino Acid Content of Fruit, Vegetables and Starchy Roots for Use in Inherited Metabolic Disorders.

Amino acid (AA)-related inherited metabolic disorders (IMDs) and urea cycle disorders (UCDs) require strict dietary management including foods low in protein such as fruits, vegetables and starchy roots. Despite this recommendation, there are limited data on the AA content of many of these foods. The aim of this study is to describe an analysis of the protein and AA content of a range of fruits, vegetables and starchy roots, specifically focusing on amino acids (AAs) relevant to AA-related IMDs such as phenylalanine (Phe), methionine (Met), leucine (Leu), lysine (Lys) and tyrosine (Tyr). AA analysis was performed using high-performance liquid chromatography (HPLC) on 165 food samples. Protein analysis was also carried out using the Dumas method. Foods were classified as either 'Fruits', 'Dried fruits', 'Cruciferous vegetables', 'Legumes', 'Other vegetables' or 'Starchy roots'. 'Dried fruits' and 'Legumes' had the highest median values of protein, while 'Fruits' and 'Cruciferous vegetables' contained the lowest median results. 'Legumes' contained the highest and 'Fruits' had the lowest median values for all five AAs. Variations were seen in AA content for individual foods. The results presented in this study provide useful data on the protein and AA content of fruits, vegetables and starchy roots which can be used in clinical practice. This further expansion of the current literature will help to improve diet quality and metabolic control among individuals with AA-related IMDs and UCDs.

Boosting genome-wide association power and genomic prediction accuracy for date palm fruit traits with advanced statistics

The date palm is economically vital in the Middle East and North Africa, providing essential fibres, vitamins, and carbohydrates. Understanding the genetic architecture of its traits remains complex due to the tree's perennial nature and long generation times. This study aims to address these complexities by employing advanced genome-wide association (GWAS) and genomic prediction models using previously published data involving fruit acid content, sugar content, dimension, and colour traits. The multivariate GWAS model identified seven QTL, including five novel associations, that shed light on the genetic control of these traits. Furthermore, the research evaluates different genomic prediction models that considered genotype by environment and genotype by trait interactions. While colour- traits demonstrate strong predictive power, other traits display moderate accuracies across different models and scenarios aligned with the expectations when using small reference populations. When designing the cross-validation to predict new individuals, the accuracy of the best multi-trait model was significantly higher than all single-trait models for dimension traits, but not for the remaining traits, which showed similar performances. However, the cross-validation strategy that masked random phenotypic records (i.e., mimicking the unbalanced phenotypic records) showed significantly higher accuracy for all traits except acid contents. The findings underscore the importance of understanding genetic architecture for informed breeding strategies. The research emphasises the need for larger population sizes and multivariate models to enhance gene tagging power and predictive accuracy to advance date palm breeding programs. These findings support more targeted breeding in date palm, improving productivity and resilience to various environments.

Evaluation of different genotypes of sponge gourd (Luffa cylindrica L.) under foothill condition of Nagaland

A field experiment was conducted during Kharif season of 2022 at the Experimental Farm of Department of Horticulture, School of Agricultural Sciences, Medziphema Campus, Nagaland University to evaluate different genotypes of sponge gourd for their growth, yield and quality under foothill condition of Nagaland. Twenty three (23) genotypes of sponge gourd were evaluated in randomized block design with three replications. The experimental material comprised 23 genotypes i.e., NUSG-21-1, NUSG-21-2, NUSG-21-3, NUSG-21-4, NUSG-21-8, NUSG-21-10, NUSG-21-11, NUSG-21-13, NUSG-21-15, NUSG-21-16, NUSG-21-18, NUSG-21-19, NUSG-21-20, NUSG-21-21, NUSG-21-22, NUSG-21-23, NUSG-21-24, NUSG-21-25, NUSG-21- 26, NUSG-21-27, NUSG-21-29, NUSG-21-31 and Kashi Divya. Studies showed that among all the genotypes, genotype NUSG-21-18 exhibited maximum vine length (4.67 m), average fruit weight (334.67 g) and yield (185.67 q ha-1). Genotype NUSG-21-4 taken shortest time to produce 1st male flower (39.33 days) and genotype NUSG-21-21 taken shortest time to produce 1st female flower (43 days). Ascorbic acid content in fruit was found to be highest (5.16 mg 100g-1) in genotype NUSG-21-19. Whereas, maximum TSS (4.13⁰B) was found in genotype NUSG-21-20. Based on the experimental findings, it can be concluded that genotype NUSG-21-18 was proved to be potential yielder over other genotypes under foothill condition of Nagaland.

Influence of myoinositol on post-ripening and softening of Prunus salicina ‘Wushan plum’

To investigate the impact of myoinositol (MI) immersion treatment on the storage characteristics of Prunus salicina ‘Wushan Plum’, we assessed myoinositol content, ascorbic acid content, weight loss, decay rate, alteration in color, titratable acidity (TA), soluble solids (TSS), firmness, cell wall metabolism-related compounds, enzyme activities, and levels of gene expression throughout a 15-day storage period at 25 °C. The results revealed that MI treatment could increase myoinositol and ascorbic acid contents of fruit during the pre-storage period, effectively delay the color transformation and decay progression of P. salicina ‘Wushan Plum’ while maintaining elevated levels of TA and TSS. Furthermore, it suppressed the increase in weight loss and the decline in firmness. Notably, the delay in softening was more pronounced in the group treated with 100 mg L−1 MI compared to other groups. MI treatment regulated the expression levels of various genes associated with cell wall metabolism, which resulted in reduced activities of polygalacturonase (PG), pectate lyase (PL), pectin methylesterase (PME), cellulase (Cx), and β-glucosidase (β-Glu), and increased activities of phenylalanine ammonia-lyase (PAL) and cinnamyl alcohol dehydrogenase (CAD). Furthermore, MI treatment maintained higher levels of covalently bound pectin (CSP), cellulose, and lignin, while decreasing the levels of water-soluble pectin (WSP) in the fruit. As a result, MI treatment could delay the depolymerization of cell wall polysaccharides and further delay the quality deterioration of P. salicina ‘Wushan Plum’ fruits under ambient storage environment and prolong the storage period.

Ascorbic acid content in summer apple tree varieties fruit depending of rootstock and metrological conditions of vegetable

One of the quality indicators of fruits is their chemical composition, which depends on the cultivar, growing conditions, degree of maturity and a number of other factors. It varies in less stable cultivars with sudden changes in the weather conditions of the growing season. Apples contain one of the important antioxidant vitamins - ascorbic acid. In the temperate zone of horticulture, the average content of ascorbic acid in apple fruits is 10-15 mg/100 g. The correct selection of graft-rootstock combinations is important, since the rootstock affects the metabolic processes occurring in the fruit plant, including the chemical composition of the fruit. The objects of the studies were summer apple cultivars Orlinka and Yablochny Spas on various types of rootstocks - vegetatively propagated 62-396 and intercalary 62-396 and 3-17-38, grown at the site of variety studies at the Russian Research Institute of Fruit Crop Breeding (VNIISPK). As a result of the conducted five-year studies, it was found that the meteorological conditions of the growing season had the greatest influence. The maximum content of ascorbic acid was observed in a year with excessive moisture during the active formation and development of the ovary and with drought during fruit ripening. Having conducted a comparative characterization of Yablochny Spas and Orlinka on clone rootstock 62-396 and dwarf intercalaries 62-396 and 3-17-38 in terms of ascorbic acid content in fruits, it was revealed that there were no significant differences between graft-rootstock combinations and cultivars.

Effects of Methyl Jasmonate on Fruit Coloration and Quality Improvement in Pears (Pyrus bretschneideri)

Red-skinned pears with a bright red color and abundant health benefits are favored by consumers. However, fruit coloration and inner quality are usually affected by adverse factors, which lead to a decline in fruit quality and commerciality. Methyl jasmonate (MeJA) has been reported to be involved in many plant processes, including anthocyanin accumulation, while the value of MeJA application for fruit coloration and quality improvement in red-skinned pears is still largely unclear. The application of 0, 0.5, 1.0, or 2.0 mM MeJA at different fruit development stages significantly promoted red coloration in ‘Danxiahong’ pears. Moreover, MeJA treatment increased the fruit soluble solids, improved the total sugar content, decreased the fruit acid content, and significantly increased the total sugar/total acid ratio. However, no significant effect was observed on the fruit’s shape or longitudinal or transverse diameters. RT-qPCR analysis indicated that the expression of anthocyanin biosynthetic regulatory and structural genes, including PbrMYB10, PbrbHLH3, PbrWD40, PbrPAL, PbrCHI, PbrDFR, and other genes, was induced by MeJA treatments. Overall, our findings demonstrate that the application of MeJA plays a significant role in promoting anthocyanin accumulation in pear peels, leading to enhanced fruit coloration. Furthermore, MeJA treatment also positively impacts the improvement of the inner fruit quality. These results not only provide valuable insights into the mechanism of MeJA-mediated coloration but also contribute to a better understanding of the overall role of MeJA in pear fruit development and quality enhancement.

Effect of vermicompost, Mycorrhiza and humic acid on some bi-chemical and yield characteristics of pepper Capsicum annuum L. under greenhouse conditions

A field experiment was carried out under the conditions of protected agriculture in the agricultural season 2020-2021 to study the effects of three factors: The first is the addition of vermicompost, with three levels: 0, 10 and 20 tons ha-1, the second factor is the addition of Mycorrhiza to the soil with two levels: without and with vaccination of 10 g per plant; and the third factor is spraying humic acid in three concentrations: 0, 2.5 and 5 ml l-1 on some biochemical properties and yield characteristics of pepper, according to randomized complete block design (RCBD). Results showed a significant effect on chlorophyll a, b, nitrogen, phosphorus and potassium in leaves, ascorbic acid content in fruit, and yield per plant. The best interaction was when adding the third level of vermicompost (20 tons ha-1) with vaccination of Mycorrhiza and spraying the third level of humic acid (5 ml l-1) on most of the studied characteristics of the plant. Keywords: vermicompost, humic acid, Mycorrhiza, Capsicum annuum L.

Identification of the GDP-L-Galactose Phosphorylase Gene as a Candidate for the Regulation of Ascorbic Acid Content in Fruits of Capsicum annuum L.

Ascorbic acid (AsA) is an antioxidant with significant functions in both plants and animals. Despite its importance, there has been limited research on the molecular basis of AsA production in the fruits of Capsicum annuum L. In this study, we used Illumina transcriptome sequencing (RNA-seq) technology to explore the candidate genes involved in AsA biosynthesis in Capsicum annuum L. A total of 8272 differentially expressed genes (DEGs) were identified by the comparative transcriptome analysis. Weighted gene co-expression network analysis identified two co-expressed modules related to the AsA content (purple and light-cyan modules), and eight interested DEGs related to AsA biosynthesis were selected according to gene annotations in the purple and light-cyan modules. Moreover, we found that the gene GDP-L-galactose phosphorylase (GGP) was related to AsA content, and silencing GGP led to a reduction in the AsA content in fruit. These results demonstrated that GGP is an important gene controlling AsA biosynthesis in the fruit of Capsicum annuum L. In addition, we developed capsanthin/capsorubin synthase as the reporter gene for visual analysis of gene function in mature fruit, enabling us to accurately select silenced tissues and analyze the results of silencing. The findings of this study provide the theoretical basis for future research to elucidate AsA biosynthesis in Capsicum annuum L.

Assessment of Genetic Variability for Fruit Nutritional Composition in the Ex-Situ Collection of Jujube (Ziziphus spp.) Genotypes of Arid Regions of India

Jujube or ber (Ziziphus spp.) is one of the most important fruit crops of India’s arid and semi-arid regions because of its high adaptability to resource constraints hot (semi)arid region. Jujube is a rich source of minerals, vitamins and dietary antioxidants to arid zone dwellers, where it is known as poor man’s apple. Given the present rising trends in discovering and exploiting plant-based health-promoting compounds, it is imperative to know the extent of variability with respect to fruit nutritional compositions present in the jujube germplasms. In this study, we assessed genetic variability for fruit nutritional and functional quality traits in eighteen jujube accessions belonging to three species (Z. mauritiana, Z. rotundifolia and Z. oenoplia) from an ex-situ collection from Indian arid and semi-arid regions in two consecutive fruiting seasons (2020-21 and 2021-22). Results revealed significant variability among eighteen jujube genotypes for important fruits physico-biochemical parameters. The IC 625864 (Z. oenoplia) identified as a superior accession for fruit antioxidant potential with having high levels of total phenols (256.2 mg/100 g dry weight) and total antioxidants (423 mg/100 g in FRAP). Moreover, IC 625849 (Z. mauritiana) and IC 625848 (Z. rotundifolia) were other genotypes containing high levels of phenols and total antioxidant (FRAP). Thus, while aiming for simultaneous improvement for total antioxidants with phenols, IC 625848, IC 625849 and IC 625864 genotypes can be considered as valuable resource for jujube fruit quality improvement program. Further, the high levels of phenotypic variance with high genotypic variance coupled with high heritability and genetic advance particularly for total antioxidants, total phenols, and ascorbic acid contents in fruits, indicating them to be considered as reliable biochemical markers to identify the productive genotypes having higher amounts of dietary antioxidants. Depending on the identified genotypes for their richness in the particular phytonutrients, these can be exploited either for table purpose or biofortification of other products, or using in jujube breeding program for quality improvement.

Irradiation with green light at night has great effects on the management of Conopomorpha sinensis and maintains favorable litchi fruit quality

The photophobia of Conopomorpha sinensis was explored using eight kinds of LED lights, including those with single wavelengths as follows: 400, 460, 520, 600, 660 and 740 nm, and mixed wavelengths: MixW and MixY. The results showed that 460 nm (blue light), 520 nm (green light) and MixW (white light) were the most effective wavelengths for controlling C. sinensis, effectively reducing pest activity by 98.2%, 99.2% and 99.3%, respectively. Egg production decreased by 99.3%, 93.0% and 98.6% under these treatments with a light intensity of 0.5 μmol m−2 s−1, respectively. The C. sinensis damage rate was 72% in the dark control group and 10%, 6%, and 16% under continuous light at night with 460, 520 nm and MixW light, respectively. To further investigate the effect of different wavelengths of light applied to the whole plant at night on Yu-Her-Pao litchi fruit quality, the fruits under 460, 520 nm and MixW light at night were 23.4, 29.8 and 26.6 g in weight and 17.5, 19.3 and 17.8°Brix in total soluble solids, respectively. There was no significant difference in fruit weight or total soluble solids under 520 nm or bagging with no light at night. Thus, 520 nm green light at night had the least effect on fruit quality. HPLC results showed that the sucrose, glucose, fructose, citric acid, L-malic acid, and shikimic acid contents in fruits under 520 nm green light illumination at night were significantly higher than those under other light treatments. Only the fumaric acid content was significantly less than that under the other light treatments. There is no known previous research on the effects of continuous application of light to whole fruit trees and different light wavelengths on fruit quality. The results of this study showed that 520 nm green light at night could prevent and control C. sinensis and maintain fruit quality. These experimental results represent important progress in reducing the use of pesticides in the litchi industry.

Evaluation of F1 Crosses of Brinjal (Solanum melongena L.) Landraces for Fruit Yield, Quality and Tolerance to Bacterial Wilt

Field experiment was carried out at All India Coordinated Research Project on Vegetable Crops, OUAT, Bhubaneswar, Odisha, India in order to identify the superior F1 crosses for marketable fruit yield quality and resistance to bacterial wilt. All total 21 F1 crosses evolved from seven distinctly diverse local landraces of brinjal along with a hybrid check, Mahy Green were evaluated by adopting Randomized Block Design and replicated twice in rabi 2021-2022. Results revealed significant variations among various fruit quality attributes (TSS: 4.32 oBrix to 6.00 oBrix and ascorbic acid content of fruit: 5.10 mg100g-1 to 7.10 mg100g-1), incidence of bacterial wilt (30 DAT: 0.00% to 4.17%, 60 DAT: 0.00% to 12.50% and 90 DAT: 0.00% to 20.83%). Out of 21 crosses, nine cross showed immune reaction to bacterial wilt at 90 DAT. The marketable fruit yield plant-1 varied significantly from 1.00 kg to 1.99 kg. The F1 cross viz. BBSR-08-2 × Selection from BBSR-145-1(1.99 kg) recorded significantly highest fruit yield plant-1 followed by BBSR-08-2 × BBSR-10-25(1.87 kg) and BBSR-08-2 × BBSR-10-26 (1.81 kg). Thus, it may be concluded that, F1 crosses obtained from local landraces of brinjal viz., BBSR-08-2 × Selection from BBSR-145-1, BBSR-08-2 × BBSR-10-25 and BBSR-08-2 × BBSR-10-26 may be recommended for higher marketable fruit yield, fruit quality and over all resistance to bacterial wilt for higher profit. These local landraces may also be used for future brinjal improvement programme towards development varieties with higher fruit yield quality and resistance to bacterial wilt.

Ascorbic acid content and the antioxidant activity of common fruits commercially available in Addis Ababa, Ethiopia

ABSTRACT. The present work was aimed to determine the contents of ascorbic acid and the antioxidant activity of eight types of common fruits commercially available in Addis Ababa, Ethiopia using iodometric titration and UV-Vis spectrophotometric methods, respectively. The contents of ascorbic acid were found in the range 15.41 mg/100 g in grapes to 78.01 mg/100 g in papaya. The antioxidant activity was found highest in papaya (89.41) and lowest in water melon (31.28) in mg of ascorbic acid equivalent per 100 g of the edible part of fruit juice. The calibration curve of ascorbic acid was in the range 50 - 3.125 mg/L with R2 = 0.9994. The results also revealed the strong correlation (r = 0.863) between ascorbic acid contents in fruits and their antioxidant activity. Using the optimized conditions, UV-Vis spectrophotometric method with the 2,2-diphenyl-1-picrylhydrazil assay allows determination of antioxidant activity of fruits with limit of detection 0.32 mg/L and limit of quantification 0.96 mg/L. The precision was in the acceptable range (relative standard deviation, RSD < 20%) for determination of ascorbic acid and < 10% for antioxidant activity determination. The recovery of ascorbic acid was between 85% and 113% for selected fruits showing good accuracy of the results.
 
 KEY WORDS: Fruits, Ascorbic acid contents, Antioxidant activity, Free radical scavengers, Iodometric titration, UV-Vis spectrophotometry
 
 Bull. Chem. Soc. Ethiop. 2023, 37(2), 277-288. 
 DOI: https://dx.doi.org/10.4314/bcse.v37i2.3

Changes and response mechanism of sugar and organic acids in fruits under water deficit stress.

The content and the ratio of soluble sugars and organic acids in fruits are significant indicators for fruit quality. They are affected by multiple environmental factors, in which water-deficient is the most concern. Previous studies found that the content of soluble sugars and organic acids in fruit displayed great differences under varied water stress. It is important to clarify the mechanism of such difference and to provide researchers with systematic knowledge about the response to drought stress and the mechanism of sugar and acid changes in fruits, so that they can better carry out the study of fruit quality under drought stress. Therefore, the researchers studied dozens of research articles about the content of soluble sugar and organic acid, the activity of related metabolic enzymes, and the expression of related metabolic genes in fruits under water stress, and the stress response of plants to water stress. We found that after plants perceived and transmitted the signal of water deficit, the expression of genes related to the metabolism of soluble sugars and organic acids changed. It was then affected the synthesis of metabolic enzymes and changed their metabolic rate, ultimately leading to changes in soluble sugar and organic acid content. Based on the literature review, we described the pathway diagrams of sugar metabolism, organic acid metabolism, mainly malic acid, tartaric acid, and citric acid metabolism, and of the response to drought stress. From many aspects including plants’ perception of water stress signal, signal conversion and transmission, induced gene expression, the changes in soluble sugar and the enzyme activities of organic acids, as well as the final sugar and acid content in fruits, this thesis summarized previous studies on the influence of water stress on soluble sugars and the metabolism of organic acids in fruits.

Potassium Fertigation Improved Growth, Yield and Quality of Kinnow Mandarin in Potassium Rich Soils

ABSTRACT Effects of potassium fertigation on the productivity of Kinnow were investigated in potassium rich soils of South-Western Punjab, India during 2018–2020. Three application rates of potassium i.e. 1000, 750 and 500 g Muriate of Potash (MoP; 60% K as K2O) per tree were applied at fortnightly intervals in two, three and four splits during February, May, July and September. The results were compared with standard recommendation for the region (three foliar sprays of 1% potassium nitrate) and no K application (control). The experiment was laid out in randomized block design, replicated thrice. The data showed that K fertigation significantly (p < .05) improved the growth, yield and quality of fruits over both standard recommendation and control. A comparison among different K split applications (fertigation) revealed higher growth, yield and quality of fruits in trees which received MoP in four splits. However, the differences among 1000 g, 750 g and 500 g K application rates were statistically comparable especially in terms of tree vigor, yield, percent juice, TSS–acid ratio and ascorbic acid content of fruits. These results suggest the fertigation of 500 g MoP per tree in four split applications to achieve higher growth and productivity of Kinnow in K rich soils of South-Western Punjab.

Multi-omics approaches identify a key gene, PpTST1, for organic acid accumulation in peach.

Organic acid content in fruit is an important determinant of peach organoleptic quality, and undergoes considerable variations during development and maturation. However, its molecular mechanism remains largely unclear. In this study, an integrative approach of genome-wide association studies and comparative transcriptome analysis was applied to identify candidate genes involved in organic acid accumulation in peach. A key gene, PpTST1, encoding tonoplast sugar transporter, was identified and the genotype of PpTST1 with a single-base transversion (G1584T) in the third exon that leads to a single amino acid substitution (Q528H) was associated with a low level of organic acid content in peach. Overexpression of PpTST1His resulted in reduced organic acid content along with increased sugar content both in peach and tomato fruits, suggesting its dual function in sugar accumulation and organic acid content reduction. Two V-type proton ATPases interacted with PpTST1 in a yeast two-hybrid assay. In addition, the G1584T transversion appeared and gradually accumulated during domestication and improvement, which indicated that PpTST1 was under selection. The identification and characterization of PpTST1 would facilitate the improvement of peach fruit quality.

INFLUENCE OF ROOTSTOCKS ON THE PHYSICAL AND CHEMICAL CHARACTERISTICS OF THE FRUITS AT SOME PLUM CULTIVARS

This paper investigated physical and chemical characteristics of five cultivars (‘Andreea’, ‘Piteștean’, ‘Romanța’, ‘Čačanska Lepotiča’ and ‘Jojo’) influenced by seven rootstocks (‘Mirobolan dwarf’, ‘Mirodad 1’, ‘Mirodad 2’, ‘Adaptabil’, ‘Redutabil’, ‘BN4Kr’ and ’B83-8’. The trees were planted in 2015 at 4 x 3 m and comprised 3 trees / 3 replications. Physical (weight, colour and firmness) and chemical attributes (soluble solids, acid content and pH) were evaluated and calculated. The influence of rootstocks on the fruit’s quality was very variable due to complex interactions: rootstock x cultivar, rootstock x year, cultivar x rootstock, cultivar x year. As results of the investigations, we found that some traits such as fruit weight, firmness, soluble solids and acid content of fruits have been influenced by rootstocks. ‘Adaptabil’ and ‘Mirodad 1’ rootstocks had a positive effect on some fruit attributes of all plum cultivars studied and can be recommended for extended in commercial orchards.

Calcium lactate and salicylic acid foliar application influence eggplant growth and postharvest quality parameters

Eggplant is one of the most popular and vital vegetable crops in the world. Various plant bio-regulators have been used in different crops to increase uptake of nutrients thereby leading to improvement in growth, flowering, fruit quality, storability and yield. The scope of this study was to evaluate the effects of calcium lactate and salicylic acid foliar application on growth parameters, physiological characteristics and shelf-life of eggplant fruit. Obtained results showed that the highest applied concentrations of calcium lactate (4 mM or 0.8 g l-1) and salicylic acid (1.5 mM or 0.2 g l-1) foliar application led to the highest values of measured growth parameters and yield. Applying of calcium lactate and salicylic acid foliar treatments could increase tissue firmness and ascorbic acid content of fruits. Foliar application of calcium lactate 4 mM (0.8 g l-1) and salicylic acid 1 mM (0.13 g l-1) was the best treatment to decrease percentage of fruit decay. In conclusion, our results showed that foliar application of calcium lactate and salicylic acid can be useful and inexpensive treatment to improve growth parameters, physiological characteristics and post-harvest properties of eggplant fruit

Evaluation of biochemical changes and quality in peach fruit: Effect of putrescine treatments and storage

The effects of putrescine (0.4, 0.8, 1.2 and 1.6 mM) on quality and bioactive compounds of peach fruit (cv. Monley) are the focus of this study. Fruits were stored at 0 ± 0.5 °C and 90 ± 5% relative humidity for 40 days. In the controls, increases in weight loss, decay and soluble solids concentration, and decreases in fruit density, firmness, titratable acidity, pH, respiration rate and L*, a*, b*, C* and H° detected higly throughout storage period. All these properties examined were delayed importantly after putrescine treatments. It was observed that the phenolics, vitamin C and organic acid contents of fruits in general decreased during storage. All doses of putrescine prevented the breakdown of phenolic compounds more than the control group. The least changes in chlorogenic acid (9.26 mg 100g-1) and rutin (5.74 mg 100g-1) contents on the 40th day were obtained in 1.6 mM. Malic acid, which is the dominant organic acid of fruits, was determined as 6.73 and 8.61 g kg-1 in the treatments of 1.2-1.6 mM putrescine on the 40th day, respectively. It was noted that 1.6 mM (12.90 mg 100g-1) application prevented the breakdown of vitamin C more than the control group (6.10 mg 100g-1).