Fruiting Stage Research Articles

Host genotype and age shape the microbial community in the rhizosphere soils of Camellia forests.

Microbiota living in the rhizosphere influences plant growth and fitness, from the opposite perspective; whether host genotypes control its root microbiota is of great interest to forest breeders and microbiologists. To improve low-yield plantations and promote sustainable management of Camellia oleifera, high-throughput sequencing was used to study the chemical properties and microbiome in rhizosphere soil of Camellia forests under three genotypes (common C. oleifera, local C. gauchowensis, and C. chekiangoleosa) and three growth stages (sapling stage at 4-year-old, primary fruit stage at 7-year-old, and full fruiting stage at 11-year-old). The results showed that the rhizosphere soil organic matter (OM), nutrient concentrations, diversity, and community composition of the microbiome were significantly varied among different Camellia genotypes. The relative abundance of symbiotic and pathotrophic fungi in the rhizosphere soil of C. chekiangoleosa was significantly higher than that of C. gauchowensis. Concentrations of OM, available phosphorus (AP), and bacterial alpha diversity increased with tree age. Fungi of Saitozyma, Mortierella, and Glomeromycota and bacteria of Burkholderia-Caballeronia-Paraburkholderia and Vicinamibacterales had potential for fertilizer development for Camellia plantation. Camellia genotypes and growth stages were significantly correlated with the rhizosphere soil pH, OM, and available potassium (AK). Soil pH and OM were key factors that affected the microbiome in the Camellia rhizosphere soils. In conclusion, tree genotypes and growth stages shaped microbial communities in Camellia rhizosphere soils, and some plant growth-promoting rhizobacteria were identified as preliminary candidates for improving Camellia plantation growth.

Reduced Fertilization and Magnesium Supplementation: Modulating Fruit Quality in Honey Pomelo (Citrus maxima (Burm.) Merr.)

The excessive use of chemical fertilizers in the Guanxi honey pomelo production area has led to severe soil acidification and magnesium (Mg) deficiency, adversely affecting pomelo fruit quality. To address this issue, an integrated nutrient optimization model crucial for ensuring the sustainable and environmentally friendly development of the Guanxi honey pomelo industry has been explored. In a three-year experiment, two fertilizer treatments were implemented: a farmer fertilizer practice (FP) and an NPK reduction plus foliar Mg fertilizer (OPT + fMg). We investigated the impact of this integrated optimized fertilization measure on pomelo fruit quality from three aspects: flavor (sugars and organic acids), nutrition (vitamin C and mineral elements), and antioxidant properties (phenolics, flavonoids, and phytic acid). The results revealed that the OPT + fMg treatment improved fruit flavor by reducing acidity (titratable acid, citric acid, and quinine), while having a minimal impact on sugar components (sucrose, fructose, and glucose). Additionally, the OPT + fMg treatment increased the total phenolics, total flavonoids, and phytic acid in the fruit peel, enhancing its potential antioxidant quality. However, the OPT + fMg treatment reduced the mineral nutrient quality (excluding calcium) in the fruit. As for the fruit developmental period, the OPT + fMg treatment significantly increased the total flavonoid concentration in the peel from the mid-expansion fruit stage, followed by notable increases in phytic acid in the peel during the mid-to-late expansion fruit stage. The total phenolic concentration in the peel significantly rose only during the late fruit development stage. The most pronounced effect was observed on phytic acid in both peel and pulp. The influence of the OPT + fMg treatment on the mineral nutrients (excluding calcium) primarily occurred during the mid-to-late expansion fruit stage. Overall, the OPT + fMg treatment significantly improved the comprehensive nutritional quality of pomelo fruit, providing valuable insights for scientifically reducing fertilizer application while enhancing fruit quality.

An in-depth study of anthocyanin synthesis in the exocarp of virescens and nigrescens oil palm: metabolomic and transcriptomic analysis.

Oil palm (Elaeis guineensis Jacq.) is a very important tropical woody oil plant with high commercial and ornamental value. The exocarp of the oil palm fruit is rich in anthocyanosides and proanthocyanidins, which not only give it a bright colour, but also mark the maturity of the fruit. The study of the dynamic change pattern of anthocyanoside content and important anthocyanoside metabolism-related regulatory genes during oil palm ripening is conducive to the improvement of the ornamental value of oil palm and the determination of the optimal harvesting period of the fruits. We analyzed the virescens oil palm (AS) and nigrescens oil palm (AT) at 95 days (AS1, AT1), 125 days (AS2, AT2) and 185 days (AS3, AT3) after pollination were used as experimental materials for determining the changes in the total amount of anthocyanins as well as their metabolomics and transcriptomics studies by using the LC-MS/MS technique and RNA-Seq technique. The results showed that the total anthocyanin content decreased significantly from AS1 (119µg/g) to AS3 (23µg/g), and from AT1 (1302µg/g) to AT3 (170µg/g), indicating a clear decreasing trend during fruit development. Among them, the higher flavonoids in AS and AT included anthocyanins such as peonidin-3-O-rutinoside (H35), pelargonidin-3-O-rutinoside (H21), and cyanidin-3-O-glucoside (H7), as well as condensed tannins such as procyanidin B2 (H47), procyanidin C1 (H49), and procyanidin B3 (H48). Notably, nine genes involved in the anthocyanin biosynthetic pathway exhibited up-regulated expression during the pre-development stage of oil palm fruits, particularly during the AS1 and AT1 periods. These genes include: Chalcone synthase (CHS; LOC105036364); Flavanone 3-hydroxylase (F3H; LOC105054663); Dihydroflavonol 4-reductase (DFR; LOC105040724, LOC105048473); Anthocyanidin synthase (ANS; LOC105035842), UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT; LOC105039612); Flavonoid 3',5'-hydroxylase (F3'5'H; LOC105036086, LOC105044124, LOC105045493). In contrast, five genes demonstrated up-regulated expression as the fruits developed, specifically during the AS3 and AT3 periods. These genes include: Chalcone synthase (CHS; LOC105036921, LOC105035716); Chalcone isomerase (CHI; LOC105045978); UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT; LOC105046326); Flavonoid 3'-hydroxylase (F3'H; LOC105036086). Most of differentially expressed genes exhibited up-regulation during the early stages of fruit development, which may contribute to the elevated anthocyanin content observed in oil palm fruits of both types during the pre-developmental period. Furthermore, the expression levels of most genes were found to be higher in the AT fruit type compared to the AS fruit type, suggesting that the differential expression of these genes may be a key factor underlying the differences in anthocyanoside production in the exocarp of oil palm fruits from these two fruit types. The findings of this study provide a theoretical foundation for the identification and characterization of genes involved in anthocyanin synthesis in oil palm fruits, as well as the development of novel variations using molecular biology approaches.

Genome-wide investigation of glycoside hydrolase 9 (GH9) gene family unveils implications in orchestrating the mastication trait of Citrus sinensis fruits

Mastication trait of citrus significantly influences the fruit’s overall quality and consumer preference. The accumulation of cellulose in fruits significantly impacts the mastication trait of citrus fruits, and the glycoside hydrolase 9 (GH9) family plays a crucial role in cellulose metabolism. In this study, we successfully identified 32 GH9 genes from the Citrus sinensis genome and subsequently conducted detailed bioinformatics analyses of the GH9 family. Additionally, we profiled the spatiotemporal expression patterns of CsGH9 genes across four distinct fruit tissue types and six crucial developmental stages of citrus fruits, leveraging transcriptome data. Parallel to this, we undertook a comparative analysis of transcriptome profiles and cellulose content among diverse fruit tissues spanning six developmental stages. Furthermore, to identify the pivotal genes involved in cellulose metabolism within the GH9 family during fruit maturity, we employed correlation analysis between cellulose content and gene expression in varying tissues across diverse citrus varieties. This analysis highlighted key genes such as CsGH9A2/6 and CsGH9B12/13/14/22. Collectively, this study provides an in-depth analysis of the GH9 gene family in citrus and offers novel molecular insights into the underlying mechanisms governing the mastication trait formation in citrus fruits.

Plasticity response of desert shrubs to intense drought events at different phenophases under the context of climate change

Global climate change has led to the frequent occurrence of intense drought events in mid-latitude desert ecosystems, coupled with uneven rainfall distribution across phenophases within the year. However, the impact of intense drought events at different phenophases on plant growth and drought resistance strategies still lacks clear conclusions. We selected the typical desert semi-shrubs Artemisia ordosica as our research object, and constructed a rain shelter to simulate intense drought events (without rainfall for 30 consecutive days) during the sprouting, vegetative growth, flowering and fruiting stages. Based on this, we analyzed the differential impacts of intense drought events at different phenophases on the phenotypic characteristics (e.g. shrub height, cover, volume, specific leaf area) and functional traits (ANPP accumulation and allocation) of A. ordosica. The experiment employed a randomized complete block design with three replicates for each treatment. The results indicate that: (1) Under intense drought events at different phenophases, all phenotypic characteristic indicators of A. ordosica significantly decreased. (2) Contrary to the significant negative correlation between twig number and twig size in response to rainfall variations, under intense drought conditions, there is a significant positive correlation between the two, indicating a synergistic effect. (3) The impact of intense drought events at different phenophases on the ANPP (aboveground net primary production) accumulation of A. ordosica varied significantly. The degree of impact is as follows: the flowering and fruiting stage > the sprouting stage > the vegetative growth stage. (4) A. ordosica adapted to intense drought by increasing the proportion of reproductive growth and decreasing the proportion of vegetative growth. Our results reveal the phenotypic and functional trait plasticity response mechanisms of A. ordosica to intense droughts at different phenophases, laying a foundation for predicting the impacts of climate change on desert ecosystems.

Response of blueberry photosynthetic physiology to light intensity during different stages of fruit development.

To investigate the response of blueberry photosynthetic physiology to different light intensities during different stages of fruit development. In this study, four light intensity treatments (25%, 50%, 75% and 100% of full light) were set up to study the change rule of photosynthetic pigment content and photosynthetic characteristics of 'O'Neal' southern highbush blueberry leaves during the white fruiting stage (S1), purple fruiting stage (S2) and blue fruiting stage (S3) under different light intensity environments, and to explore the light demand and light adaptability of blueberry during different developmental stages of the fruit. The results showed that the chlorophyll and carotenoid contents of blueberry leaves showed an increasing trend with decreasing light intensity at all three stages of fruit development. The total chlorophyll content of blueberry leaves at 25% light intensity increased by 76.4% compared with CK during the blue fruiting stage; the maximum net photosynthetic rate (Pmax), light compensation point (LCP), light saturation point (LSP), rate of dark respirations (Rd), inter-cellular CO2 concentration (Ci), stomatal conductance (Gs), transpiration rate (Tr), net photosynthesis rate (Pn), and chlorophyll a/b showed a decreasing trend with decreasing light intensity. The Pn of blueberry leaves was highest under full light conditions at all three stages, and the Pn at 25% light intensity decreased by 68.5% compared with CK during the white fruiting stage Reflecting the fact that blueberries can adapt to low-light environments through increases in chlorophyll and carotenoids, but reduced light intensity significantly inhibited their photosynthesis. The photosynthetic physiology of blueberry showed a consistent pattern at all three stages, but there were some differences in the changes of photosynthetic parameters at different stages. The results of the study can provide theoretical references for the selection of sites and density regulation in blueberry production.

Genome-wide identification and expression analyses of SWEET gene family reveal potential roles in plant development, fruit ripening and abiotic stress responses in cranberry (Vaccinium macrocarpon Ait).

The sugars will eventually be exported transporter (SWEET) family is a novel class of sugar transporters that play a crucial role in plant growth, development, and responses to stress. Cranberry (Vaccinium macrocarpon Ait.) is a nutritious berry with economic importance, but little is known about SWEET gene family functions in this small fruit. In this research, 13 VmSWEET genes belonging to four clades were identified in the cranberry genome for the first time. In the conserved domains, we observed seven phosphorylation sites and four amino acid residues that might be crucial for the binding function. The majority of VmSWEET genes in each clade shared similar gene structures and conserved motifs, showing that the VmSWEET genes were highly conserved during evolution. Chromosomal localization and duplication analyses showed that VmSWEET genes were unevenly distributed in eight chromosomes and two pairs of them displayed synteny. A total of 79 cis-acting elements were predicted in the promoter regions of VmSWEETs including elements responsive to plant hormones, light, growth and development and stress responses. qRT-PCR analysis showed that VmSWEET10.1 was highly expressed in flowers, VmSWEET16 was highly expressed in upright and runner stems, and VmSWEET3 was highly expressed in the leaves of both types of stems. In fruit, the expression of VmSWEET14 and VmSWEET16 was highest of all members during the young fruit stage and were downregulated as fruit matured. The expression of VmSWEET4 was higher during later developmental stages than earlier developmental stages. Furthermore, qRT-PCR results revealed a significant up-regulation of VmSWEET10.2, under osmotic, saline, salt-alkali, and aluminum stress conditions, suggesting it has a crucial role in mediating plant responses to various environmental stresses. Overall, these results provide new insights into the characteristics and evolution of VmSWEET genes. Moreover, the candidate VmSWEET genes involved in the growth, development and abiotic stress responses can be used for molecular breeding to improve cranberry fruit quality and abiotic stress resistance.

Changes in the fruits and seeds morphometric, germination, phytochemicals content, and antioxidant capacity in seed ripening of Echinocereus stramineus

Within the cacti family, most studies have focused on the physicochemical characterization of the stems, fruits, and seeds from Mammillaria, Opuntia, Hylocereus, and Stenocereus genera. However, few information is focused on the morphological and physicochemical characterization of the stems, fruits, and seeds of other genera widely distributed in the arid and semiarid zones of the Chihuahuan desert, such as the genus Echinocereus. The objective of this study was to analyze the fruit morphology, morphometry, germination process, and phytochemical content in four stages of seed in fruit ripening from E. stramineus. Morphometric parameters were measured by picking ten fruits and sixty seeds for each ripening stage. The characterization of the germination process included the germination percentage, mean germination time, germination speed, and mean germination speed which were computed 21 days after germination. The quantification of total phenols, flavonoids, tannins, reducing sugars, protein, and antioxidant activity of seeds was determined using colorimetric approaches under basal conditions. The morphometric results revealed a negative correlation between the fruit ripening stage and total mass (r= -0.980, p = 0.020), shell mass (r= -0.986, p = 0.014), pulp mass (r = -0.979, p = 0.021), fruit length (r = -0.978, p = 0.022), fruit width (r = -0.968, p = 0.032) and fruit area (r = -0.960, p = 0.04). The germination characterization process showed a negative association between the fruit ripening stage and the seed germination percentage (r = -0.979, p = 0.021) and between the seed mean germination time and the mean germination speed (r= -0.986, p = 0.014). The content of flavonoids, reducing sugars, proteins, and antioxidant capacity showed significant differences among the four stages of fruit ripening; however, no association was found between seed phytochemical content and the ripening stage. This study provides the first data on seed phytochemicals and information on the germination process of E. stramineus seeds.

Mapping and transcriptomic profiling reveal that the KNAT6 gene is involved in the dark green peel colour of mature pumpkin fruit (Cucurbita maxima L.).

We identified a 580bp deletion of CmaKNAT6 coding region influences peel colour of mature Cucurbita maxima fruit. Peel colour is an important agronomic characteristic affecting commodity quality in Cucurbit plants. Genetic mapping of fruit peel colour promotes molecular breeding and provides an important basis for understanding the regulatory mechanism in Cucurbit plants. In the present study, the Cucurbita maxima inbred line '9-6' which has a grey peel colour and 'U3-3-44' which has a dark green peel colour in the mature fruit stage, were used as plant materials. At 5-40days after pollination (DAP), the contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids in the 'U3-3-44' peels were significantly greater than those in the '9-6' peels. In the epicarp of the '9-6' mature fruit, the presence of nonpigmented cell layers and few chloroplasts in each cell in the pigmented layers were observed. Six generations derived by crossing '9-6' and 'U3-3-44' were constructed, and the dark green peel was found to be controlled by a single dominant locus, which was named CmaMg (mature green peel). Through bulked-segregant analysis sequencing (BSA-seq) and insertion-deletion (InDel) markers, CmaMg was mapped to a region of approximately 449.51kb on chromosome 11 using 177 F2 individuals. Additionally, 1703 F2 plants were used for fine mapping to compress the candidate interval to a region of 32.34kb. Five coding genes were in this region, and CmaCh11G000900 was identified as a promising candidate gene according to the reported function, sequence alignment, and expression analyses. CmaCh11G000900 (CmaKNAT6) encodes the homeobox protein knotted-1-like 6 and contains 4 conserved domains. CmaKNAT6 of '9-6' had a 580bp deletion, leading to premature transcriptional termination. The expression of CmaKNAT6 tended to increase sharply during the early fruit development stage but decrease gradually during the late period of fruit development. Allelic diversity analysis of pumpkin germplasm resources indicated that the 580bp deletion in the of CmaKNAT6 coding region was associated with peel colour. Subcellular localization analysis indicated that CmaKNAT6 is a nuclear protein. Transcriptomic analysis of the inbred lines '9-6' and 'U3-3-44' indicated that genes involved in chlorophyll biosynthesis were more enriched in 'U3-3-44' than in '9-6'. Additionally, the expression of transcription factor genes that positively regulate chlorophyll synthesis and light signal transduction pathways was upregulated in 'U3-3-44'. These results lay a foundation for further studies on the genetic mechanism underlying peel colour and for optimizing peel colour-based breeding strategies for C. maxima.

Loss-of-function mutation in anthocyanidin reductase activates the anthocyanin synthesis pathway in strawberry

Fruit color substantially affects consumer preferences, with darker red strawberries being economically more valuable due to their higher anthocyanin content. However, the molecular basis for the dark red coloration remains unclear. Through screening of an ethyl methanesulfonate mutant library, we identified a rg418 mutant, that demonstrated anthocyanin accumulation during early fruit development stages. Furthermore, the ripening fruits of this mutant had higher anthocyanin content than wild-type (WT) fruits. An analysis of flavonoid content in WT and rg418 mutant fruits revealed substantial changes in metabolic fluxes, with the mutant exhibiting increased levels of anthocyanins and flavonols and decreased levels of proanthocyanidins. Bulked sergeant analysis sequencing indicated that the mutant gene was anthocyanidin reductase (ANR), a key gene in the proanthocyanidin synthesis pathway. Furthermore, transcriptome sequencing revealed the increased expression of MYB105 during the early development stage of mutant fruits, which promoted the expression of UFGT (UDP-glucose flavonoid 3-O-glucosyltransferase), a key gene involved in anthocyanin synthesis, thus substantially enhancing the anthocyanin content in the mutant fruits. Additionally, mutating ANR in a white-fruited strawberry variant (myb10 mutant) resulted in appealing pink-colored fruits, suggesting the diverse roles of ANR in fruit color regulation. Our study provides valuable theoretical insights for improving strawberry fruit color.

Deep learning for image-based detection of weeds from emergence to maturity in wheat fields

Effective weed control in wheat (Triticum aestivum L.) fields is crucial for optimizing production and ensuring food security in semi-arid regions. The implementation of deep learning for weed detection could enable precise weed management, leading to enhanced wheat yield, increased income for growers through targeted herbicide use, and a reduced environmental footprint associated with herbicide application. Charlock mustard (Sinapis arvensis L.) [CM], creeping thistle (Cirsium arvense (L.) Scop) [CT], and forking larkspur (Consolida regalis Gray) [FL]) are among the most invasive weed species in wheat fields. Effective management of these weeds is essential to ensure optimal wheat productivity in the semi-arid regions. To detect weeds, an unmanned arial vehicle was used to collect images and videos from 185 wheat fields in Tokat, Turkey. The images were collected from five phenological periods of each species including seedling, rosette, vegetative, flowering, and fruiting (in total 15 classification process). These stages are either important for timely weed control or essential for understanding weed pressure threshold, the potential for increasing weed seedbank increase, and identifying herbicide resistant weeds. A total of 145,792 objects were labeled in the images to create the dataset, divided into 80 % for training + validation and 20 % for testing. The dataset was used with the YOLOv5 (You Only Look Once) deep learning architecture. The YOLOv5 was the newest YOLO model during this study carried out. All neural networks provided by YOLOv5 (nano, small, medium, large, and xlarge) were trained and the Precision, Recall, F-1 Score, and AUC (Area under the Curve) performances of the neural networks were evaluated. The YOLOv5s (small) was the most precise neural network in detecting weeds regardless of the species. In contrast, nano was the least precise neural network in detecting each weed species. For CT, when small neural network was used, precision of detection ranged from 0.87 (fruit stage) to 0.96 (rosette and vegetative stages). For, forking larkspur, the best neural network was achieved with YOLOv5 small and the precision ranged from 0.45 (fruit stage) to 0.93 (vegetative stage). Using YOLOv5 small in Charlock mustard, the most precise detection occurred at seedling, rosette, and vegetative stages (with precision of 0.96) and the least precise detection was recorded at the fruit stage (0.81). Other performance evaluations (Recall, F-1 Score, and AUC) were in agreement with those of Precision. Our results indicated that by using YOLOv5 small neural network, all three weed species could be detected at all growth stages with the precision of 0.86 with the exception of fruit stage. Future research should (1) focus on assessing YOLOv5 small neural network with the newest versions of YOLO and also (2) evaluate this neural network for detecting weed species in wheat fields to allow for improved weed control and future recommendations.

Enhancing fruit quality and yield in tomato through cyanobacterium mediated nutri-fertigation

Protected cultivation of high-value crops such as tomato, with several health benefits, is gaining global significance. This study explored the influence of aqueous formulations of cyanobacteria-Anabaena laxa (C11), Nostoc carneum (BF2), and Anabaena doliolum (BF4), applied as soil drench at pre-flowering and fruiting stages, on the dynamics of soil and plant attributes important for growth, productivity, and quality of fruits in an indeterminate tomato variety (NS4266) under protected cultivation. Drenching with the BF2 formulation resulted in a significant fold-increase in soil dehydrogenase activity and an increase of 40–45% in soil nitrogen availability; positively impacted glutamine synthetase activity, fruit weight, lycopene content, skin elasticity, in comparison to control. C11 drenching led to a 17% elevation in soil microbial biomass carbon, besides bringing about a 24 and 54% enhancement in available phosphorus and iron content. Additionally, it also enhanced chlorophyll a, b and total pigments by 54–65% over control. Principal Component Analysis (PCA) and Multivariate analysis showcased the distinct effects of cyanobacterial formulations on crop growth and soil fertility, as well as the significant and positive correlations among quality, plant, soil, and yield attributes contributed through cyanobacterial drenching. This investigation highlighted cyanobacterial drench as a promising organic option to augment soil nutrient availability, bolster overall productivity, and enhance fruit quality in tomato grown under protected cultivation.

β values obtained by linear regression models of morpho-physiological and biochemical variables as novel drought stress estimators in Capsicum annuum varieties

Capsicum annuum varieties are highly sensitive to drought. Under water stress conditions, these can show yield losses of up to 70 %. Due to the above, this work proposes a novel approach to obtain estimators of drought stress based on linear regression models for morpho-physiological and biochemical variables in jalapeño pepper (C. annuum cv. jalapeno M), bell pepper (C. annuum cv. california wonder), and serrano pepper (C. annnuum cv. serrano tampiqueno). Jalapeno pepper plants were grown for 69 days under permanent water deficit conditions at 40, 60, 80 % and 100 % of field capacity (FC) (100 % FC as control). Throughout the crop cycle, we monitored the plant's height and weight, basal stem diameter, transpiration, photosynthesis, stomatal conductance, NDVI, and proline. This monitoring allowed us to obtain linear regression models from the accumulated values for these variables, from which the slope values (β) were used as estimators of drought stress using the interval estimation method, in the same way, this method was used to estimate water status in bell pepper and serrano pepper. For bell pepper, drought levels of 40, 60, 80 and 100 % FC were imposed for 12 days and serrano pepper 60 and 100 % FC for 63 days. The results showed that this method can be used to estimate drought stress in jalapeno pepper for all the irrigation levels through photosynthesis and NDVI and can be applied for bell pepper and serrano pepper using stem diameter and plant height, and in the case of serrano pepper, NDVI showed adequate results. Also, this work establishes the relationship between the jalapeno pepper responses (morpho-physiological and biochemical) to drought stress during vegetative, flowering, and fruiting stages through a Principal Component Analysis (PCA). The PCA found that interaction among morphological, physiological, and biochemical responses change concerning the phenological stage of the plant. The results suggested several direct and inverse relationships between the variables and showed that drought can be described by stomatal conductance during any phenological stage of the crop. In parallel, the proline content, NDVI and plant height can also describe drought stress during the vegetative and flowering stages. This research is the first to apply this methodology to drought stress estimation in jalapeno, bell pepper, and serrano pepper cultivation. The results could significantly contribute to precision agriculture, sensor development, and water management.

Population Dynamics and Environmental Correlates of Insect Pests in Watermelon, Citrullus lanatus (T.)

The study was conducted in Kandavara village, Chikkaballapur district, during 2021, investigated the insect pest complex affecting watermelon, Citrullus lanatus (T) following standard crop management practices but without any insecticidal interventions to assess the natural occurrence of insect pests. Weekly observations were made from February to April (2021) employing various sampling methods to monitor key pests, including leaf miners, thrips, whiteflies, fruit flies, leaf-eating caterpillars, and pumpkin beetles. The study revealed that leaf miners, Liriomyza trifolii (Frick) were the first to appear, peaking in the 11th Standard Meteorological Week (SMW) with 6.45 leaf mines per five leaves. Thrips, Thrips palmi Karny and whiteflies, Bemisia tabaci (Gennadius) emerged during the vegetative stage, showing a significant positive correlation with maximum temperature. Fruit flies, Zeugodacus cucurbitae (Coquillett) caused the most significant damage during the fruiting stage, with a peak incidence of 14.92 per cent in the 15th SMW. The study highlighted that higher temperature had a positive correlation with pest populations, while rainfall had a negative correlation reducing the pest activity. These findings emphasize the importance of precise timing in pest management interventions to minimize crop losses and enhance the sustainability and productivity of watermelon cultivation in India.

Exogenous Melatonin Enhances Moisture Stress Tolerance in Mango (Mangifera indica L.) through Alleviating Oxidative Damages.

In subtropical regions, April to June represents a temporary moisture stress for mango trees, leading to huge economic loss. Although water is available in the deep root zone, the upper soil surface, which has fibrous roots, is dry, and the tree transpiration rate is high. Moisture stress causes an increased oxidation state, which is detrimental to fruit growth and development. Finding substitutes for moisture stress management is important for sustainable mango production. To manage this moisture stress in mango, we tested if foliar application of 20, 50, 100 and 150 μM melatonin helped to maintain a reduced oxidation state in the cells. Applications were made at three phenological stages of fruit development (marble, egg and mature fruit stages) in 16-year-old trees and the same plants for each treatment were followed over three years. Melatonin application indeed improved the fruit yield of mango. Moisture stress decreased yield by 55.94% compared to irrigated trees but only by 7.5% in melatonin treatment. Also, more 'A' grade fruits were harvested in irrigated and melatonin-treated conditions than in non-irrigated and non-treated conditions. Indeed, the total chlorophyll content in the leaves of moisture-stressed melatonin-treated trees (12.58 mg.g-1 fresh weight) was well above non-treated trees (6.77 mg.g-1) and similar to irrigated trees (12.50 mg.g-1). A dose-dependent increase in the chlorophyll content of melatonin-treated plants was found. Similarly, the activities of catalase, peroxidase, superoxidase dismutase enzymes in leaves of irrigated and melatonin-treated trees were lower than in non-irrigated condition, and superoxide free radial formation was lower in moisture-stressed melatonin-treated trees (0.77 nmol H2O2.mg-1 protein) and irrigated trees (0.65) than moisture-stressed non-treated trees (4.27). Significant variations was found in antioxidants (total, reduced and oxidized glutathione and ascorbate) content and antioxidant enzymes' activities (i.e., glutathione reductase and ascorbate peroxidase) in irrigated, melatonin-treated and non-irrigated conditions. Overall, 150 μM exogenous melatonin applied three times at different fruit development stages may be a sustainable and useful approach to manage transient moisture stress in mango trees thanks to its positive action on the antioxidant system.

Combining with E-nose, GC-MS, GC-IMS and chemometrics to explore volatile characteristics during the different stages of Zanthoxylum bungeanum maxim fruits

To explore the volatile characteristics of Z. bungeanum fruits during different developmental stages, the dynamical changes of volatile organic compounds (VOCs) were detected by E-nose, GC-MS and GC-IMS, respectively. The results showed that terpenes, alcohols, esters and aldehydes played the important roles in the aroma formation of Z. bungeanum. Meanwhile, these VOCs also exhibited the high abundance levels among five growth stages of Z. bungeanum. According to the analysis of odor activity value (OAV) and relative odor activity value (ROAV), 37 VOCs can be recognized as the important aroma compounds. Thereinto, β-myrcene and linalool were the most key aroma compounds. Multi-factor analysis exhibited that the combination of GC-MS and GC-IMS was a better strategy to clarify the volatile characteristics comprehensively. Using the above combined VOC datasets, six positively correlated modules and 32 hub VOCs were finally identified by weighted correlation network analysis among five growth stages of Z. bungeanum.

Research Progress and Biosynthetic Mechanisms of Nutritional Compounds Obtained from Various Organs During the Developmental Stages of a Medicinal Plant (Chinese Jujube).

The fruit of the jujube tree is high in nutrients and has various health benefits. China is a major producer of jujube, and it is now cultivated all around the world. Numerous studies have demonstrated the nutritional value and potential health advantages of bioactive compounds found in the jujube tree. Furthermore, the jujube tree has a remarkable 7000-year agricultural history. The jujube plant has developed a rich gene pool, making it a valuable resource for germplasm. Different studies have focused on the developmental stages of jujube fruits to identify the optimal time for harvest and to assess the changes in their bioactive natural compounds or products during the process of development but the molecular mechanism underlying the production of bioactive natural products in Z. jujuba is still poorly understood. Moreover, the potential differential expressed genes (DEGs) identified as responsible for the synthesis of these compounds should be further functionally verified. It has been noticed that the contents of total flavonoids, total phenolic, and vitamin C increase significantly during the ripening process, while the contents of soluble sugars and organic acids decrease gradually. In this review, we have also scrutinized the challenges that hinder the utilization of jujube fruit resources and suggested potential areas for further research. As such, our review serves as a valuable resource for the future development of jujube-based nutritional compounds and the incorporation of their nutritional elements into the functional foods industry.

Effect of different timing of water deficit combined with foliar application of ascorbic acid on physiological variables of sour passion fruit

The objective of this study was to evaluate the effects of deficit irrigation treatments during different phenological stages and foliar application of ascorbic acid on gas exchange, photosynthetic pigments, chlorophyll fluorescence, electrolyte leakage, relative water content and yield of ‘BRS GA1’ sour passion fruit. Treatments were distributed in randomized blocks, in a split-plot scheme, with plots consisting of six deficit irrigation treatments, based on crop evapotranspiration – ETc (irrigation with 100% ETc - FULL; irrigation with 50% ETc in the vegetative stage - VEG; flowering stage - FLO; fruiting stage - FRU; successively in the vegetative/flowering stages - VEG + FLO and vegetative/fruiting stages - VEG + FRU) and subplots represented by three concentrations of ascorbic acid - AsA (0, 0.5 and 1.0 mM). Water deficit induces changes in photosynthetic activity across all developmental stages of sour passion fruit, resulting in reduced yield in the period of 160 and 200 days after transplanting. Notably, flowering exhibits the greatest physiological acclimatization to water deficit conditions, albeit with more pronounced losses in the yield. When water deficit occurs during the vegetative and fruiting stages and is coupled with foliar application of ascorbic acid at 0.5 mM, there is an enhancement in the synthesis of photosynthetic pigments in ‘BRS GA1’ sour passion fruit. Overall, foliar application of ascorbic acid at concentrations of 0.5 and 1.0 mM emerges as a viable strategy to mitigate the adverse effects of water deficit on the physiology and yield of sour passion fruit at 200 days after transplanting.

Full-length RNA sequencing and single-nucleus sequencing deciphers programmed cell death and developmental trajectories in laticiferous canals of Decaisnea insignis fruits.

Programmed cell death (PCD) is a fundamental biological process crucial for plant development. Despite recent advancements in our understanding of PCD's molecular mechanisms, the intricate orchestration of this process within plant cells remains enigmatic. To address this knowledge gap, the present study focuses on Decaisnea insignis, a plant species renowned for its unique fruit anatomy, including laticiferous canals that secrete latex. While extensive anatomical studies have elucidated the structural features of these canals,molecular insights into their developmental regulation, particularly the involvement of PCD, are lacking. In this study, we sequenced the single-cell transcriptomes at two developmental stage of Decaisnea insignis fruit using the technology known as 10x Genomics (S1, S2). Using sequencing technology combining full- length RNA sequencing and single-nucleus RNA sequencing (snRNA-seq) in combination with ultrastructural analyses, our study revealed a cellular map of Decaisnea insignis fruit at the single-cell level and identified different cell types. In particular, we identified a possible PCD-mediated cluster of Decaisnea insignis fruit lactiferous canals in epidermal cells and clarified the expression patterns of DiRD21A (a hydrolase) and DiLSD1 (a transcription factor), which may be closely related to the development of laticiferous canals in Decaisnea insignis fruits. By integrating high-resolution gene expression profiling with visual insights into cellular transformations, we sought to more precisely characterize the regulatory role of PCD during the developmental formation of lactiferous canals in Decaisnea insignis fruit.

Effects of different water stresses under subsurface infiltration irrigation on eggplant growth and water productivity

Soil moisture deficiency limits eggplant growth and affects the yield and quality. Identifying an appropriate deficit irrigation strategy to enhance irrigation water productivity is an urgent task. Additionally, the dynamic response of eggplants to water stress at various phenological stages needs further clarification. In this study, eggplants were used as experimental materials, with field capacity (FC) (Senyigit et al.) serving as the irrigation standard. Two levels of deficit irrigation treatments (60 % FC and 50 % FC) were applied at three key phenological stages of eggplant (seedling stage, flowering and fruiting, and prime fruit stage). A randomized block design was used with non-deficit irrigation (80 % FC) during the phenological stages as the control (W1), resulting in seven treatments, each with three replicates. The results showed that at the same phenological stage, plant height, stem diameter, leaf area index (LAI), dry matter accumulation, total fresh root weight, total root length, total root surface area, and total root volume decreased as the irrigation threshold was lowered. The content of vitamin C, soluble sugars, souble proteins, and crude fiber increased as the irrigation threshold decreased. Leaf photosynthetic parameters (photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), and intercellular CO2 concentration (Ci)) were positively correlated with the irrigation threshold. The W1 treatment had the highest yield (89.1 t·ha−1 in 2018; 88.8 t·ha−1 in 2019), followed by the W2 treatment (86.1 t·ha−1 in 2018; 85.6 t·ha−1 in 2019). Water deficit during the prime fruit stage (W6, W7) had the most significant impact on yield. W1 had the highest water productivity (19.4 kg·m−3 in 2018; 19.2 kg·m−3 in 2019), with no significant difference from W2 (19.4 kg·m−3 in 2018; 19.0 kg·m−3 in 2019). Using the Jensen function, the water sensitivity of eggplants at different phenological stages was ranked as follows:prime fruit stage > flowering and fruiting stage > seedling stage. Path analysis indicated that dry matter accumulation, single fruit weight, and single plant yield were important indicators affecting yield. Considering irrigation amount, eggplant growth, fruit yield and quality, and water productivity, the optimal deficit irrigation thresholds for eggplants in arid regions are determined to be 60 % FC during the seedling stage, 60 % FC during the flowering and fruiting stage, and 80 % FC during the prime fruit stage. The findings of this study offer valuable insights for precision agricultural irrigation practices.