Mature Green Stage Research Articles

The dynamic N1-methyladenosine RNA methylation provides insights into the tomato fruit ripening.

N1-methyladenosine (m1A) methylation is an essential mechanism of gene regulation known to impact several biological processes in living organisms. However, little is known about the abundance, distribution, and functional significance of mRNA m1A modification during fruit ripening of tomato the main model species for fleshy fruits. Our study shows that m1A modifications are prevalent in tomato mRNA and are detected in lncRNA and circRNA. The distribution of m1A peaks in mRNA segments indicates that m1A is mainly enriched at the start codon and CDS regions. Assessing changes in global RNA methylation during fruit ripening in wild-type tomatoes and in the ripening-impaired Nr mutant affected in the ethylene receptor gene (SlETR3) revealed a decrease in the overall methylation levels from mature green (MG) stage to 6 days postbreaker (Br + 6). Nr mutant fruits show significantly lower methylation levels than Ailsa Craig (AC) fruits. Notably, differences in m1A methylation are well correlated to the expression levels of a number of key ripening-related genes. The integration of RNA-seq and MeRIP-seq data suggests a potential positive impact of m1A modifications on gene expression. In comparison to the AC fruits, the hypomethylation and reduced expression of ethylene-related genes, ACO3, EBF1, and ERF.D6, in the Nr mutants likely underpin the distinct phenotypic traits observed between the two fruit genotypes at the Br6 stage. Overall, our study brings further arguments supporting the potential significance of m1A methylation modifications in fruit ripening, a developmental process that is instrumental to plant reproduction and to fruit sensory and nutritional qualities.

Study on the Changes in the Microbial Community in Rhizosphere Soil of Blueberry Plants at Different Growth Stages

In order to clarify the relationship between mineral nutrients and rhizosphere microorganisms at different growth and development stages of blueberry (Vaccinium spp.), this work studied the dynamic changes in element content and microbial quantity in different parts of blueberry plants. The test material was a 12-year-old half-highbush blueberry variety (‘Beilu’). The changes in the mineral nutrient elements in leaves, branches and the soil of blueberry plants were studied at the full bloom stage (T1), green fruit stage (T2), mature stage (T3) and late mature stage (T4), and the correlations of the average contents of mineral elements in the four periods were studied. The bacterial community in the rhizosphere soil was determined and analyzed using 16S rRNA high-throughput sequencing technology. The results showed that the changes in other mineral elements in various parts of blueberry plants varied in different periods. Nitrogen (N) showed a downward trend in branches, leaves and soil, especially in leaves (p < 0.05). The N contents in T2, T3 and T4 decreased by 9.9%, 26.4% and 29.9%, respectively. The N contents in the leaves and branches showed a downward trend at different growth stages, especially in leaves. The phosphorus (P) content in leaves showed a trend of increasing first and then decreasing, while it continued to increase in branches. The content of potassium (K) in leaves changed significantly, where it increased first and then decreased. The content of calcium (Ca) in leaves decreased first and then increased, while the content of magnesium (Mg) in branches and leaves decreased first and then increased, and the relative change was significant. The contents of iron (Fe) and zinc (Zn) in leaves decreased first and then increased, while the contents of manganese (Mn) and copper (Cu) were relatively stable. Cu decreased first and then increased in leaves and soil, and it increased first and then decreased in branches. The mineral nutrients in different growth stages of blueberry showed significant correlation in leaves, branches and soil. Mn in leaves was significantly positively correlated with P, Ca, Mg, Mn, Cu and Zn in soil (p < 0.01). Nitrogen and calcium in leaves were significantly correlated with manganese and phosphorus in soil, respectively. Ca in branches was significantly positively correlated with N and K in soil and was significantly positively correlated with Zn in soil (p < 0.01). Magnesium was significantly negatively correlated with iron in soil. The bacterial community structure of the blueberry rhizosphere soil changed significantly over time (p < 0.05), and the relative abundance showed the following trend: T4 > T2 > T3 > T1. At the phylum level, Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi and Verrucomicrobia were the dominant bacteria in different periods. Candidatus solibacter and Bryobacter were significantly higher in T1 and T3 than in T1 and T4. Bradyrhizobium flora increased significantly at T3. Sphingomonas increased significantly at T1 (p < 0.05).

Identification and characterization of a key LcTPS in the biosynthesis of volatile monoterpenes and sesquiterpenes in Litchi fruit.

Litchi (Litchi chinensis Sonn.) has a desirable sweet taste and exotic aroma, making it popular in the markets. However, the biosynthesis of aroma volatiles in litchi fruit has rarely been investigated. In this study, the content and composition of volatile compounds were determined during litchi fruit ripening. In the mature green and mature red stages of litchi, 49 and 45 volatile compounds were detected, respectively. Monoterpenes were found to be the most abundant volatile compounds in mature red fruit, and their contents significantly increased compared to green fruit, mainly including citronellol, geraniol, myrcene, and D-limonene, which contributed to the aroma in litchi fruit. By comparing the expression profiles of the genes involved in the terpene synthesis pathway during fruit development, a terpene synthesis gene (LcTPS1-2) was identified and characterized as a major player in the synthesis of monoterpenes and sesquiterpenes. A subcellular localization analysis found LcTPS1-2 to be present in the plastid and cytoplasm. The recombinant LcTPS1-2 enzyme was able to catalyze the formation of three monoterpenes, myrcene, geraniol and citral, from geranyl pyrophosphate (GPP) and to convert farnesyl diphosphate (FPP) to a sesquiterpene, caryophyllene in vitro. Transgenic Arabidopsis thaliana plants overexpressing LcTPS1-2 exclusively released one monoterpene D-limonene, and three sesquiterpenes cis-thujopsene, (E)-β-famesene and trans-β-ionone. These results indicate that LcTPS1-2 plays an important role in the production of major volatile terpenes in litchi fruit and provides a basis for future investigations of terpenoid biosynthesis in litchi and other horticultural crops.

Response of postharvest treatments on shelf life, biochemical and microbial quality of banana variety Red Banana.

The popular Red Banana variety faces transportation challenges and has a limited postharvest shelf life due to its ripe fruits being less resistant and being a climacteric fruit. This study aims to prolong the shelf life of Red Banana fruits through different postharvest treatments. Fruit bunches of Red Banana were harvested at the mature green stage, separated into hands, precooled, subjected to 12 treatments and stored in corrugated fibre board boxes till the end of shelf life under ambient conditions. Fruits coated with 10% bee wax + 0.5% clove oil (T4), fruits subjected to coating with 10% bee wax and packaging with potassium permanganate (T9) and fruits dipped in hot water at 50 °C for 10 min. and packaging with potassium permanganate (T11) registered highest shelf life of 18.67 days. The highest TSS of 26.33°Brix was noticed in fruits stored with potassium permanganate (T8) after 12.67 days of storage and lowest titratable acidity of 0.19% and the highest sugar-acid ratio of 79.76 was noticed in control (T12) after 11.33 days of storage. Moreover, the highest vitamin C content (7.74 mg 100 g?¹), total sugar content (18.47%), reducing sugar content (15.49%), total carotenoid content (24.13 µg 100 g-1) was noticed in treatment T7 (hot water dipping at 50 °C for 10 min.) after 17.67 days, T10 (coating with 40% aloe vera extract and packaged with potassium permanganate) after 13.33 days, T4 (coating with 10% bee wax + 0.5% clove oil) after 18.67 days and T9 (coating with 10% bee wax + potassium permanganate) after 18.67 days of storage respectively. Furthermore, the lowest fungal and bacterial count was observed in treatments T2 (dipping in 30ppm sodium hypochlorite solution), T7 (hot water dipping at 50 °C for 10 min.), T9 (coating with 10% bee wax + potassium permanganate) and T10 (coating with 40% aloe vera extract + potassium permanganate) .

SlZIP11 mediates zinc accumulation and sugar storage in tomato fruits.

Zinc (Zn) is a vital micronutrient essential for plant growth and development. Transporter proteins of the ZRT/IRT-like protein (ZIP) family play crucial roles in maintaining Zn homeostasis. Although the acquisition, translocation, and intracellular transport of Zn are well understood in plant roots and leaves, the genes that regulate these pathways in fruits remain largely unexplored. In this study, we aimed to investigate the function of SlZIP11 in regulating tomato fruit development. We used Solanum lycopersicum L. 'Micro-Tom' SlZIP11 (Solanum lycopersicum) is highly expressed in tomato fruit, particularly in mature green (MG) stages. For obtaining results, we employed reverse transcription-quantitative polymerase chain reaction (RT-qPCR), yeast two-hybrid assay, bimolecular fluorescent complementation, subcellular localization assay, virus-induced gene silencing (VIGS), SlZIP11 overexpression, determination of Zn content, sugar extraction and content determination, and statistical analysis. RT-qPCR analysis showed elevated SlZIP11 expression in MG tomato fruits. SlZIP11 expression was inhibited and induced by Zn deficiency and toxicity treatments, respectively. Silencing SlZIP11 via the VIGS technology resulted in a significant increase in the Zn content of tomato fruits. In contrast, overexpression of SlZIP11 led to reduced Zn content in MG fruits. Moreover, both silencing and overexpression of SlZIP11 caused alterations in the fructose and glucose contents of tomato fruits. Additionally, SlSWEEET7a interacted with SlZIP11. The heterodimerization between SlSWEET7a and SlZIP11 affected subcellular targeting, thereby increasing the amount of intracellularly localized oligomeric complexes. Overall, this study elucidates the role of SlZIP11 in mediating Zn accumulation and sugar transport during tomato fruit ripening. These findings underscore the significance of SlZIP11 in regulating Zn levels and sugar content, providing insights into its potential implications for plant physiology and agricultural practices.

Imaging Hyperspectral Feature Fusion for Estimation of Rapeseed Pod’s Water Content and Recognition of Pod’s Maturity Level

Imaging hyperspectral technology is becoming popular in agriculture to provide detailed information on crop growth. In this work, we propose an estimation of rapeseed pod’s water content model and identification of maturity levels (green, yellow, and full) model by using this technology. Four types of hyperspectral features are extracted—color, texture, spectral three-edge parameters, and spectral indices. By integrating these features, satisfactory results are achieved: the optimal feature combination is from spectral indices and three-edge parameters, with low RRMSE and RE for yellow maturity. Incorporating spectral indices significantly improved the pod’s water content estimation, reducing RRMSE by up to 43.30% and 30.11% in the green and full maturity stages. Random forest and support vector machine with kernel method (SVM-KM) algorithms outperformed other statistical models, with SVM-KM achieving up to 96.90% accuracy in identifying maturity levels. These findings provide valuable insights for managing rapeseed production during the pod stage.

Integrative analysis of the metabolome and transcriptome provides insights into the mechanisms of lignan biosynthesis in Herpetospermum pedunculosum (Cucurbitaceae).

Herpetospermum pedunculosum (Ser.) C. B. Clarke is a traditional Chinese herbal medicine that heavily relies on the lignans found in its dried ripe seeds (Herpetospermum caudigerum), which have antioxidant and hepatoprotective functions. However, little is known regarding the lignan biosynthesis in H. pedunculosum. In this study, we used metabolomic (non-targeted UHPLC-MS/MS) and transcriptome (RNA-Seq) analyses to identify key metabolites and genes (both structural and regulatory) associated with lignan production during the green mature (GM) and yellow mature (YM) stages of H. pedunculosum. The contents of 26 lignan-related metabolites and the expression of 30 genes involved in the lignan pathway differed considerably between the GM and YM stages; most of them were more highly expressed in YM than in GM. UPLC-Q-TOF/MS confirmed that three Herpetospermum-specific lignans (including herpetrione, herpetotriol, and herpetin) were found in YM, but were not detected in GM. In addition, we proposed a lignan biosynthesis pathway for H. pedunculosum based on the fundamental principles of chemistry and biosynthesis. An integrated study of the transcriptome and metabolome identified several transcription factors, including HpGAF1, HpHSFB3, and HpWOX1, that were highly correlated with the metabolism of lignan compounds during seed ripening. Furthermore, functional validation assays revealed that the enzyme 4-Coumarate: CoA ligase (4CL) catalyzes the synthesis of hydroxycinnamate CoA esters. These results will deepen our understanding of seed lignan biosynthesis and establish a theoretical basis for molecular breeding of H. pedunculosum.

Sustainable Approaches to Prolonging Shelf Life in Green Mature Tomato Fruit

Green mature tomato fruits demonstrate better transportability compared to fully matured ones. This approach has the potential to play a significant role in diminishing postharvest losses and enhancing the accessibility of nutritionally rich fruit in developing countries. The instability of electricity and insufficient cold storage facilities is recognized for fading the shelf life of various fruits and vegetables. However, post-harvest interventions, including tomatoes, can extend perishable products' shelf life. Firstly, tomato fruits were harvested at the green mature stage and stored at 33℃ for 0, 10, 20, and 30 days, followed by a shift to 25℃. Subsequently, ten fruits were subjected to various treatments: A - control (25℃), B - 33℃ with 30-40% RH, C - 33℃ with 50-60% RH, and D - 33℃ with 80-90% RH. Different relative humidity (RH) levels were achieved using saturated salts, specifically MgCl2.6H2O, Mg (NO3)2.6H2O, and KCl+KNO3 for treatments B, C, and D, respectively. The evaluation encompassed parameters such as ethylene production, CO2 release, fruit firmness, weight loss, and color development. A higher temperature, such as 33℃, may be considered advantageous for the storage of green mature tomato fruit. Evidently, tomatoes were successfully stored for over 55 days at this temperature. Across all relative humidity (RH) conditions, there was more noticeable color development in fruits stored at 25°C compared to those stored at 33°C. Among the various RH conditions, fruits stored at 33°C with 80-90% RH experienced the least weight loss, although fruit firmness gradually declined over time. Storing green mature tomato fruit at 33°C with 30-40% RH resulted in the lowest ethylene production compared to 25°C and other RH conditions. Consequently, certain practical benefits of green mature tomato fruit under elevated temperatures and diverse relative humidity (RH) conditions are suggested. However, further detailed research may be necessary to explore potential metabolic changes.

A mixed genetic analysis of major gene plus polygene for purplish-black pericarp at mature-green stage in pepper

A mixed genetic analysis of major gene plus polygene for purplish-black pericarp at mature-green stage in pepper

Reassessing the contribution of TOMATO AGAMOUS-LIKE1 to fruit ripening byCRISPR/Cas9 mutagenesis.

CRISPR/Cas9-edited TOMATO AGAMOUS-LIKE1 (TAGL1) provided new insights into fruit ripening. TOMATO AGAMOUS LIKE 1 (TAGL1) has been identified as playing a key role in the process of tomato fruit development and ripening. We have re-evaluated the functions of TAGL1 using CRISPR/Cas9 mutagenesis. Three KO mutants contained frameshift mutations resulting in premature termination codons due to a 1 bp insertion. TAGL1-KO mutants exhibited dark immature fruits and orange ripening fruits. The fruit shape was characterized by a prominent pointed tip at the end and the pericarp thickness was significantly thinner. TAGL1-KO mutants showed reduced ethylene biosynthesis, increased firmness, and delayed onset of ripening. The chlorophyll content of TAGL1-KO mutants was higher in the mature green stage and the lycopene content of TAGL1-KO mutants in the ripening stage was lower compared to the WT. ACS2, ACS4, ACO1, ACO3, PG2a, PL, PME, EXP1, and PSY1 in the mutants were significantly down-regulated during ripening. Ripening fruits in the double mutant of rin and tagl1 showed a more extreme phenotype than the rin mutant suggesting that the double mutation acts synergistically during ripening. TAGL1-targeted mutagenesis by CRISPR/Cas9 strengthens its regulatory functions controlling ripening parameters and provides new insights into fruit ripening.

Evaluation of microbiome and physico-chemical profiles of fresh fruits of Musa paradisiaca, Citrus sinensis and Carica papaya at different ripening stages: Implication to quality and safety management.

The ripening of fleshy fruits is a developmental process that involves changes in color, texture, aroma, nutrients, and diversity of microbiomes. Some microorganisms, specially, bacteria and molds are responsible for postharvest spoilage of fruits. Thus, this study is aimed at evaluating the alterations in microbiome and physico-chemical properties of selected fruits at different ripening stages. Totally, 108 fresh fruit samples of Musa paradisiaca, Citrus sinensis and Carica papaya at three ripening stages were collected and processed in this study. The biochemical methods and MALD-TOF MS were used in identification. The physico-chemical properties of all samples were analyzed using standard methods. The minimum counts (6.74± 0.48-6.76± 0.42 log CFU/mL) and the maximum count (7.51± 0.43-7.96± 0.34 log CFU/mL) of AMB in all fruit samples was observed at mature green and overripe stages of the fruits, respectively. The ripening stage has significantly affected the microbial counts (P < 0.05) in all fruits, except counts of Enterobacteriaceae in banana and orange, and fungal counts in orange. The bacterial community of all fruits was predominated by B. cereus (33.7%), A. faecalis (17.3%), P. putida (15.2%), M. morganii (11.1%), S. sciuri (6.6%) and S. epidermidis (4.9%); while the fungal microbiome was constituted by Candida spp. (33.9%) followed by Saccharomyces spp. (18.1%) and Aspergillus spp. (16.3%). The ripening stages have also significantly affected the physico-chemical property in all samples. Accordingly, the lowest pH (3.53) and highest content of ascorbic acid (69.87 mg/100g) were observed in mature green oranges and overripe papaya, respectively, while the maximum concentration of total sugar (17.87%) and reducing sugar (14.20%) were recorded in overripe bananas. The presence of some potential human pathogens and spoilage microorganisms in fruit samples could contribute to post-harvest product losses besides the potential health risk associated with consumption of the tainted fruits. Hence, proper safety management practices and preservation mechanisms should be developed and put in place to ensure consumers safety against pathogens besides minimizing product losses through microbial spoilage.

Localized foliar application of iodine on tomato: An effective approach for targeted agronomic biofortification

Iodine is an essential mineral for the human body and inadequate intake causes iodine deficiency disorders (IDDs) worldwide. Agronomic biofortification is a promising complementary approach to other strategies to avoid IDDs. It consists of the enrichment of fruit and vegetables with nutritional elements through preharvest techniques. Tomato is an important, nutritious, and widely consumed crop. Despite a poor iodine accumulation in the fruit, tomato is an iodine accumulator. Our research focused on iodine enrichment of two table tomato types (cherry and mini-plum) in a commercial mediterranean greenhouse. Potassium iodate (KIO3) was applied four times through foliar spray at three concentrations (0, 1, 5 mM) at two localized sites of application (at plant apex and at the three leaves above the target truss, “target leaves”) until the mature green stage of a target truss (untreated and the same for each treatment). The application of 1 mM KIO3 solution at the target leaves was the most suitable approach for adequate fruit enrichment. The accumulation of 110 μg∙100 g−1 of fresh weight (FW) in cherry and 130 μg∙100 g−1 FW for mini-plum tomato largely satisfy the iodine recommended dietary allowance for adults, pregnant and lactating women. Plant health, yield and commercial quality of fruit (color, size, dry matter content, total soluble solids, titratable acidity, pH) were not affected, while some carotenoids and total phenolics were slightly incremented, indicating a possible positive influence on the nutritional quality. In conclusion, foliar application of iodine for the preharvest enrichment of tomato was a successful approach to biofortification in a commercial greenhouse. That suggests further research is needed to investigate and improve the iodine biofortification techniques in different crops and systems.

Effect of Postharvest Treatments on Physiological, Chemical, Microbial and Sensory Qualities of Fruits of Papaya Variety Surya

Background: Papaya is a climacteric fruit which is highly perishable due to rapid ripening and softening and susceptibility to biotic or abiotic stresses, resulting in large losses during storage. Traditionally, people resort to the application of synthetic chemical fungicides on to the crop plant and to the fruits during storage, to control the anthracnose caused by the fungus Colletotrichum gloeosporioides on fruits. But their repeated use has caused resistance in microorganisms and toxicity for humans. Hence, nowadays there has been increasing interest in using natural alternatives instead of chemical treatment. Methods: Fruits of papaya variety Surya collected at fully mature green stage were subjected to different postharvest management practices namely precooling, surface sanitization, treatment with chitosan and were packaged in corrugated fibre board boxes and stored till the end of shelf life under ambient condition. Untreated fruits (control) were also used in the study. Result: Fruits coated with chitosan (1%) registered an improved shelf life of 6.33 days as against 4.33 days in control in ambient storage and it further improved the sensory score for all the organoleptic parameters, after six days of storage. 1% chitosan coating also reported significantly lowest physiological loss in weight (3.51 %), ion leakage (60.47%), total soluble solids (12.13 °Brix), total carotenoids (2.34 mg 100g-1), total sugar (7.26%) and reducing sugar (6.34%) and least disease index (16.67%), bacterial count (22.33 cfu/ml × 106) and fungal count (7.33 cfu/ml × 103) after three days of storage when compared with control.

Effect of Pre-Storage Edible Coating on Post Harvest Quality of Guava Fruits cv. Lalit Under Ambient Condition

A significant fruit crop, the guava (Psidium guajava L.), is grown around the world in a wide range of tropical and subtropical climates. The shelf life of guavas is short, and they ripen quickly after being harvested. This limited shelf life necessitates effective management techniques to ensure a consistent market supply through post-harvest treatments to extend the storage life. In this study, we aimed to assess the impact of different treatments on the quality attributes of guava fruit cv. Lalit at 3-day intervals during storage. The experiment was carried out in the Postharvest Laboratory, Department of Horticulture, Banaras Hindu University, Varanasi. The findings from our investigation revealed that guava fruits harvested at the mature green stage and treated with Carboxy methylcellulose (CMC) and sodium alginate, maintained their desirable chemical and functional qualities for an extended period, up to 12 days of storage. Specifically, the post-harvest treatment using CMC (1.5%) proved to be exceptionally effective in reducing physiological weight loss and decay loss and retarding the increase in total carotenoids and lycopene content. Additionally, it delayed the decline in total soluble solids, ascorbic acid content, chlorophyll content, total antioxidant capacity and phenolic content throughout the storage period. Therefore, this treatment showed excellent results in extending the shelf life of guava fruits and maintaining their post-harvest quality by delaying the processes of ripening and senescence, lowering spoilage, and improving marketability and appearance.

Estimation of Response to Selection in Chilli (Capsicum annuum L.)

&#x0D; This experiment was conducted at Main Experiment Station of Department of Vegetable Science, Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya (U.P.) during Rabi 2019-20. The objective of the experiment was to estimate the correlation coefficient among yield and yield attributing traits in available genotypes of chilli. There were 35 genotypes and one check (KA-2) used in study as an experimental material.&#x0D; The investigation was carried out in Randomized Completely Block Design with 3 replications. Observations were noted on 10 traits viz. days to 50% flowering, number of primary branches per plant, plant height (cm), and days to maturity (Red Ripe Stage), average fruit weight (g), fruit length (cm), days to maturity (Mature Green Stage), fruit diameter (mm), and fruit yield per plant. Fruit yield/plant was significantly and positively associated with average fruit weight and number of fruits per plant while primary branch per plant, fruit length and plant height showed negative and significant correlation with fruit yield per plant. Thus, selection for these parameters with positive correlation would be effective for yield improvement in chilli.

Transcriptome and Metabolome Provide Insights into Fruit Ripening of Cherry Tomato (Solanum lycopersicum var. cerasiforme).

Insights into flavor formation during fruit ripening can guide the development of breeding strategies that balance consumer and producer needs. Cherry tomatoes possess a distinctive taste, yet research on quality formation is limited. Here, metabolomic and transcriptomic analyses were conducted on different ripening stages. The results revealed differentially accumulated metabolites during fruit ripening, providing candidate metabolites related to flavor. Interestingly, several key flavor-related metabolites already reached a steady level at the mature green stage. Transcriptomic analysis revealed that the expression levels of the majority of genes tended to stabilize after the pink stage. Enrichment analysis demonstrated that changes in metabolic and biosynthetic pathways were evident throughout the entire process of fruit ripening. Compared to disease resistance and fruit color genes, genes related to flavor and firmness may have a broader impact on the accumulation of metabolites. Furthermore, we discovered the interconversion patterns between glutamic acid and glutamine, as well as the biosynthesis patterns of flavonoids. These findings contribute to our understanding of fruit quality formation mechanisms and support breeding programs aimed at improving fruit quality traits.

Influence of Maturity Stage on Post-harvest Quality of Guava Cultivars

The guava (Psidium guajava L.), a member of the Myrtaceae family and a native of tropical America, was brought to India by the Portuguese in the 17th century. The primary focus lies in comprehending the physiological and biochemical alterations within the fruit, which play a crucial role in understanding metabolic phenomena such as fruit ripening, softening, and overall aging. Additionally, these changes hold significance for shaping commercial procedures and meeting post-harvest demands. It is imperative for the post-harvest management system to strive to deliver the fruit to the market in the desired condition sought by consumers or importers. Guavas are highly perishable fruits, with fresh supplies to markets often lasting only a few days. In the Postharvest Laboratory of the Department of Horticulture, Banaras Hindu University, Varanasi, an experiment was carried out to investigate the influence of maturity stage on the post-harvest quality of guava cultivars under ambient conditions at 3-day intervals of storage. The guava cultivars, namely Lalit, Allahabad Safeda, and Shweta, were chosen at distinct stages of maturity, encompassing mature green, color break and ripe. The findings showed that the ripeness or stage of maturity at harvest had a substantial impact on the quality and storage life of guava fruits. In comparison to the colour-turning stage and the ripe stage of fruits, the mature green stage demonstrated promising results in maintaining post-harvest quality. Considering all the parameters, the best guava cultivars in terms of superior post-harvest quality, including total soluble solids, lycopene content, ascorbic acid content, and minimal acidity content, were found to be the Lalit cultivar.

Biophysical and biochemical changes in tomato (Solanum lycopersicum) genotypes at different fruit developmental stages under protected cultivation

An experiment was conducted during 2020–21 and 2021–22 to evaluate the biophysical and biochemical characteristics of tomato [Solanum lycopersicum (L.)] genotypes (Pusa Rohini, Pusa Cherry-1, S-22, PKM-1 and Pusa Protected-1) grown at Centre for Protected Cultivation Technology (CPCT), ICAR-Indian Agricultural Research Institute, New Delhi. Tomato fruits were harvested at 14 different fruit developmental stages (DS01-DS14) starting from 4 days after post anthesis to the final red riped stage. Fruit size (length and width), biomass, firmness, total soluble solids (TSS), titratable acids (T.A), β-carotene, ascorbic acid and lycopene content were analysed for all the developmental stages. The highest value of fruit length, breadth, biomass, TSS, β-carotene and lycopene content was observed at full ripe tomatoes and the lowest in the early immature green stage. However, parameters like fruit firmness,T.A and ascorbic acid content were higher in early immature to mature green stage and decreased once the fruit entered the ripening stage. Thus, irrespective of the genotypes considered in this study, all the above parameters except fruit firmness, ascorbic acid and T.A were found to increase gradually with the advancement of ripening process. This clearly showed a significant relationship between the biochemical and biophysical parameters of the tomatoes with their fruit developmental stages, hence could be used as an indicator to characterize the fruit developmental stages.

Effect of Red Visible Lighting on Postharvest Ripening of Bananas via the Regulation of Energy Metabolism

The mechanism by which LED red light irradiation regulates postharvest banana ripening was evaluated in this study by the continuous irradiation of banana fruits at the mature-green stage. In this study, a self-developed LED banana fresh-keeping container lid was used to continuously irradiate the immature banana fruit. The light wavelength was 655.0 ± 1.0 nm, the light intensity was 800.0 ± 10.0 LX, and the height between the LED lamp and the fruit was 15.0 ± 0.5 cm. Bananas stored under dark conditions were used as the negative control group, and bananas stored under dark conditions after spraying with 500.0 mg/L ethephon diluent were used as the positive control group. Changes in physiological parameters related to postharvest banana ripening, such as the respiration rate, ethylene release, texture, color, carotenoid content, chlorophyll content, adenosine triphosphate content, and energy metabolism-related enzyme activities, were measured during 8 days of storage at 20.0 ± 0.1 °C to analyze the key factors determining postharvest banana ripening in response to red light. The red light-irradiated bananas had higher total color differences and higher rates of chlorophyll degradation and carotenoid synthesis than those of the ethephon-treated group during the storage period. Red light irradiation promoted banana fruit ripening and senescence mainly by promoting carotenoid synthesis, capturing absorbed light energy, accelerating energy metabolism, effectively enhancing the activities of the respiratory and energy metabolism-related enzymes H+ adenosine triphosphatase, Ca2+ adenosine triphosphatase, succinate dehydrogenase, cytochrome C oxidase, and malic enzyme, and promoting organic acid degradation. In conclusion, LED red light can be used as a new physical ripening technology for bananas, with a similar effect to that of traditional ethephon treatment.

Ripening Process of Tomato Fruits Postharvest: Impact of Environmental Conditions on Quality and Chlorophyll a Fluorescence Characteristics

This study aimed to investigate the combined effects of temperature and light conditions on tomato maturation. Tomato fruits that had completed volumetric growth at the mature green stage were harvested and matured in growth chambers composed of two temperature conditions (daytime–nighttime: 30–20 °C or 20–15 °C) and two light conditions (0 µmol·m−2·s−1 or 400 µmol·m−2·s−1), which were set for 12 h each day and night. Our findings indicate that tomato ripening was significantly influenced by both light and temperature. Tomatoes that matured under low-temperature conditions in the absence of light took more than three times longer to transition from the green stage to the breaker stage compared to those matured under high-temperature conditions with light exposure. Notably, tomato fruit maturation occurred at a faster rate under low-temperature and light conditions than under high-temperature and dark conditions. Changes in chlorophyll a fluorescence parameters were observed throughout the ripening process of tomato fruits. Tomato fruits ripened under low-temperature and dark conditions exhibited significantly lower NPQ (non-photochemical quenching) and RFD (relative fluorescence decrease) values compared to other treatments, while their FO (initial fluorescence) and FM (maximum fluorescence) values were higher. The accumulation of sugar in tomato fruits was observed to be more influenced by light than temperature. On the other hand, the highest levels of phenolic content and lycopene were observed in tomato fruits matured under high-temperature and light conditions. Antioxidant activities, as measured by ABTS and DPPH assays, were highest in mature tomato fruits under high-temperature and light conditions, while they were lowest in fruits under low-temperature and dark conditions. In conclusion, this study highlights the critical role of temperature and light as crucial environmental factors influencing tomato maturation. Understanding these factors can contribute to optimizing postharvest conditions and enhancing fruit quality in the tomato industry.