Flower Formation Research Articles

A Fuzzy Logic Approach to Performance Evaluation of Genomics-Driven Crop Improvement

Genomics-driven crop improvement has emerged as a revolutionary approach to enhance yield, resilience, and nutritional value in agriculture. However, traditional performance evaluation methods often must catch up with agricultural systems' complex, multifaceted nature. This study proposes a fuzzy logic-based framework to assess the performance of genomics-driven crop improvement initiatives. By integrating fuzzy logic, we can effectively manage uncertainty and ambiguity inherent in agricultural data, allowing for a more nuanced evaluation of crop traits, environmental factors, and management practices. The paper begins by elucidating the fundamental principles of genomics-based agriculture and its impact on crop development. It then delves into the theoretical underpinnings of fuzzy logic and its applicability in modeling the multifaceted aspects of crop growth, encompassing genetic, environmental, and physiological factors. Through a synthesis of existing research and empirical data, the paper illustrates the effectiveness of fuzzy logic in capturing the nuances of crop development processes, including germination, flowering, and yield formation. This paper underscores the pivotal role of fuzzy logic analysis in advancing genomics-based agriculture, offering insights into the dynamic interactions shaping crop development and facilitating informed decision-making for sustainable and resilient food production systems in the face of evolving environmental challenges. Results indicate that the fuzzy logic approach enhances the accuracy of performance assessments and facilitates better decision-making in crop management.

Genome-Wide Identification and Role of the bHLH Gene Family in Dendrocalamus latiflorus Flowering Regulation.

The basic helix-loop-helix (bHLH) gene family is a crucial regulator in plants, orchestrating various developmental processes, particularly flower formation, and mediating responses to hormonal signals. The molecular mechanism of bamboo flowering regulation remains unresolved, limiting bamboo breeding efforts. In this study, we identified 309 bHLH genes and divided them into 23 subfamilies. Structural analysis revealed that proteins in specific DlbHLH subfamilies are highly conserved. Collinearity analysis indicates that the amplification of the DlbHLH gene family primarily occurs through segmental duplications. The structural diversity of these duplicated genes may account for their functional variability. Many DlbHLHs are expressed during flower development, indicating the bHLH gene's significant role in this process. In the promoter region of DlbHLHs, different homeopathic elements involved in light response and hormone response co-exist, indicating that DlbHLHs are related to the regulation of the flower development of D. latiflorus.

Assessment of land configuration techniques on in-situ soil moisture conservation and productivity of rainfed Bt. Cotton in semi-arid production systems

Rainfed agriculture is proving to be a significant contributor to cotton production. However, recent climate change characterizes a substantial threat to current rainfed agricultural production, and consequently to farmers’ livelihoods in semi-arid regions. Typical features of these areas are erratic rainfall to frequent dry spells that lead to frequent crop failure and lasting poverty. In-situ soil moisture conservation is an important climate resilience agricultural practice to enhance the productivity of crops in these regions including rainfed Bt cotton. It comprises agronomical land configuration techniques with several local modifications. The experiments were conducted in a field at Okkarai village (11o 22’ N latitude and 78o 53’ E longitudes), Thuraiyur Block, Tiruchirapallai District in the Northwestern Agro-climatic Zone of Tamil Nadu. It was undertaken during the Rabi season (North-East monsoon) of 2022 and 2023. The experiments were laid out in randomized block design (RBD) with 7 treatments with three replications. The treatments consist of different land configuration techniques viz., flat-bed, ridges and furrows, broad bed and furrows (BBF), raised bed, tied ridges, tied ridges (alternate rows) and tied broad beds (TBB). An analysis of pooled mean data of two years showed significant differences between the treatments. Among the land configuration techniques tested, tied ridges (alternate rows) registered the maximum soil moisture content during flowering and boll formation (90 DAS), boll development (120 DAS) and boll and fibre maturation (140 DAS) stages, and the increase was 34.4%, 31.8% and 15.74%, respectively over flat-bed method. Likewise, tied ridges (alternate rows) significantly enhanced the cotton growth characters viz., plant height (128.92 cm), leaf area index (4.52), dry matter production (5.19 t/ha), and yield attributes viz., number of squares (44.50/plant), number of bolls (43.73/plant), boll weight (4.76 g) and seed cotton yield (20.86 q/ha) and cost-benefit ratio (3.07). Tied ridges in alternative row served as low-cost micro catchment approach for trapping and holding water and its practice in semi-arid rainfed region has beneficial effects of reducing runoff and soil loss, increasing soil moisture and augment crop yield.

Satellite-based measurements of temporal and spatial variations in C fluxes of irrigated and rainfed cotton grown in India

The small number of carbon dioxide (CO2) observation networks and the prohibitively high equipment cost restrict the estimation of net ecosystem CO2 exchange (NEE). Satellite-based remote sensing techniques have made it possible to obtain NEE and component carbon (C) fluxes. One-third of the world's cotton area is in India, but the information on NEE is limited. We used the Level 4 Carbon (L4_C) product from the Soil Moisture Active Passive (SMAP) mission to estimate C fluxes based on satellite-derived soil moisture, weather, and vegetation data. For our study (2018-19 to 2020-21), we chose two ecosystems (rainfed central India vs. irrigated northern India). Seasonal variations were observed in C fluxes. Gross primary productivity was the highest during the boll formation phase. This phase was the strongest sink and coincided with the highest CO2 uptake, followed by the flowering and square formation phases. The cotton crop was a C source during the initial vegetative phase and after the boll opening. Overall, the cotton crop was a sink for atmospheric CO2 with an average NEE value of −189.6 g C m−2 under irrigated and −245.6 g C m−2 in rainfed cotton. Higher ecosystem respiration in irrigated cotton resulted in lower C sink strength than rainfed cotton. Our studies indicate that the SMAP L4_C product model estimates can be used to obtain information on C fluxes in real-world situations. Moreover, such satellite-based remote sensing techniques will enable large-scale environmental monitoring with different cropping systems and support policymaking.

Abundance and diversity of cotton insect pests under repeatedly cultivated cotton fields of Tanzania.

Cotton production in Tanzania is facing significant challenges due to insect pests that cause extensive damages to the crop. The most notable pests include the African bollworm (Heliothis armigera Hubner), Spiny bollworm (Earias biplaga Walker), Cotton stainers (Dysdercus sidae (Herrich-Schaeffer), Cotton Aphids (Aphis gossypii Glover), Thrips (Thrips tabaci Lindeman), Jassids (Amrasca biguttula, Bigutula), Leafhoppers (Cicadellidae jassidae), and Whiteflies (Bemisia tabaci Genn). If left uncontrolled, these pests can cause up to 60% damage to the crop. Despite the importance of cotton and the fact that most of these pests are endemic, there are scanty knowledge on the dynamics and distribution of cotton pests across the seasons of the year and crop's phenological growth stages (germination, vegetative growth, flowering and boll formation) in areas under repeated cultivation of the crop in Tanzania. Here we report on the influence of seasons and cotton's phenological stages on the abundance, diversity, distribution and richness of cotton insect pests. The study was conducted in the Misungwi district for two cotton-growing seasons, using the UKM08 cotton variety. Stick traps and handpicking methods were deployed in catching the cotton insect pests. On average, a total of 8,500 insect specimen of diverse families and species were collected every season. The four dominant species among the collected were Aphis gossypii (17.37%), Amrasca biguttula (11.42%), Nezara viridura (10.7%), and Bemisia tabacci (10.68%). Both cotton phenological growth stages and seasons significantly (p<0.05) influenced the abundance, diversity, distribution and richness of cotton insect pests. In particular, the phenological growth stage 3 exhibited greater diversity of insect pests. The pests' distribution patterns remained relatively uniform across the crop growth stages. Findings from the present study could contribute to developing sustainable pest management strategies in areas under repeated cotton production in Tanzania and elsewhere.

RhLHY-RhTPPF-Tre6P Inhibits Flowering in Rosa hybrida Under Insufficient Light by Regulating Sugar Distribution.

Light is crucial for flower bud development in plants, serving as both signal and energy source. However, the mechanisms by which daylength and light intensity regulate flowering in modern roses remain unclear. In Rosa hybrida 'Carola', insufficient light delays flowering and reduces the sugar content in terminal buds. RNA sequencing identified the Trehalose-6-phosphate phosphatase F (RhTPPF) gene as a key responder to insufficient light, modulating Tre6P metabolism. Overexpression of RhTPPF in rose calli enhanced sugar accumulation and suppressed the synthesis of RhCO/FT. In tobacco, overexpression of RhTPPF delayed the transition from vegetative growth to flowering, while silencing RhTPPF in roses accelerated flowering. Silencing RhTPPF in roses elevated trehalose-6-phosphate (Tre6P) levels and decreased trehalose. Transcriptome data showed that the expression level of RhTPPF was highly correlated with the circadian rhythm gene LATE ELONGATED HYPOCOTYL (RhLHY). Yeast one-hybrid assays, dual luciferase assays and EMSA revealed that RhLHY directly binds to the RhTPPF promoters. Overexpression of RhLHY suppressed flowering, while silencing RhLHY promoted flowering. Furthermore, altering the expression of RhLHY influenced Tre6P synthesis and the expression of sucrose-related transport genes. These findings suggest a RhLHY-RhTPPF-Tre6P regulatory module that maintains sugar balance and inhibits flower formation under reduced light conditions by modulating sugar distribution.

Study on the Effect of Foliar Fertilizers on the Growth and Yield of V108 Heat-Tolerant Cucumber Variety

This study evaluates the efficacy of various foliar fertilizers on the growth and yield of the heat-tolerant cucumber variety TV108. The experimental design included six different foliar fertilizers and a control, with applications made weekly at a concentration of 1 mL per liter of water. Results showed that all foliar treatments significantly enhanced plant height compared to the control. Among these, Treatment T4 (ATONIK foliar fertilizer) demonstrated the most pronounced effect, achieving a main stem height of 216.57 cm by the 70th day, which was significantly higher than other treatments and the control. Treatment T4 also excelled in increasing stem diameter, with a final measurement of 1.48 cm, and in promoting both male and female flower formation. The fruit set rate was highest in Treatment T4, reaching 28.67% on day 56 and maintaining at 8.67% by day 70. This treatment also proved most effective in reducing the incidence of key diseases and pests, including powdery mildew, white mold, green worms, and yellow beetles. Regarding yield, Treatment T4 produced the highest individual fruit yield (2.32 kg/plant), actual yield (33.8 tons/ha), and theoretical yield (84.91 tons/ha). Additionally, it enhanced fruit quality, as indicated by the largest fruit length (15.22 cm), diameter (4.13 cm), and the highest Brix value (3.50%). These results substantiate that Treatment T4 is the most effective foliar fertilizer for enhancing both growth and quality of heat-tolerant cucumbers under experimental conditions.

Multi-omics analysis revealed the mechanism underlying flavonol biosynthesis during petal color formation in Camellia Nitidissima

BackgroundCamellia nitidissima is a rare, prized camellia species with golden-yellow flowers. It has a high ornamental, medicinal, and economic value. Previous studies have shown substantial flavonol accumulation in C. nitidissima petals during flower formation. However, the mechanisms underlying the golden flower formation in C. nitidissima remain largely unknown.ResultsWe performed an integrative analysis of the transcriptome, proteome, and metabolome of the petals at five flower developmental stages to construct the regulatory network underlying golden flower formation in C. nitidissima. Metabolome analysis revealed the presence of 323 flavonoids, and two flavonols, quercetin glycosides and kaempferol glycosides, were highly accumulated in the golden petals. Transcriptome and proteome sequencing suggested that the flavonol biosynthesis-related genes and proteins upregulated and the anthocyanin and proanthocyanidin biosynthesis-related genes and proteins downregulated in the golden petal stage. Further investigation revealed the involvement of MYBs and bHLHs in flavonoid biosynthesis. Expression analysis showed that flavonol synthase 2 (CnFLS2) was highly expressed in the petals, and its expression positively correlated with flavonol content at all flower developmental stages. Transient overexpression of CnFLS2 in the petals increased flavonol content. Furthermore, correlation analysis showed that the jasmonate (JA) pathways positively correlated with flavonol biosynthesis, and exogenous methyl jasmonate (MeJA) treatment promoted CnFLS2 expression and flavonol accumulation.ConclusionsOur findings showed that the JA-CnFLS2 module regulates flavonol biosynthesis during golden petal formation in C. nitidissima.

Characterization of Flower’s Color based on CHS Gene Structure in &lt;i&gt;Phalaenopsis&lt;/i&gt; ‘OX Queen’ and &lt;i&gt;Dendrobium&lt;/i&gt; ‘Cheddi Jagan’ Orchids

Orchids (Orchidaceae) are ornamental plants known for their high aesthetic value attributed to the shapes, colours, and fragrances of their flowers. Two types of hybrid orchids with attractive flowers, namely the Phalaenopsis 'OX Queen' orchid and the Dendrobium 'Cheddi Jagan' boast attractive flowers were used in this research, because of the beauty of its flower colour. The objective of this research is to characterise the morphology of flower colour and CHS (Chalcone Synthase) gene content that induces flower colour. The method used in this research analyzing the flower’s colour by using the RHS (Royal Horticultural Society) colour chart and molecular analysis by DNA genomic isolation and PCR amplification of gDNA for CHS gene specific primers. The results showed that purple colour is observed through the RHS, with P. 'OX Queen' coded as Deep Purple Pink (N73A) and D. 'Cheddi Jagan' coded as Strong Reddish Purple (N72C). The CHS gene can be amplified in P. ’OX Queen’ 1,287 bp and D. ’Cheddi jagan’ 3,731 bp. In both orchids, the results of amplification showed CHS motifs with conserved domains PLN03172 and PLN03170. The research results show that there is a significant difference in the morphology of the flowers of orchids. Purple colour is observed through the RHS, with P. 'OX Queen' coded as N73A and D. 'Cheddi Jagan' coded as N73C. The results showed that gDNA can be isolated by using CTAB method according to Murray and Thomson, and the CHS gene can be amplified by using CHS primers, resulting 1200 bp of P. 'OX Queen' and 2500 bp for D. 'Cheddi Jagan'. Through this study, preliminary data is expected to be obtained for future research, which is the formation of variegated flowers through editing the CRISPR/Cas9 genome in the CHS gene. This research is intended to support further studies on the formation of variegated flower patterns in P. 'OX Queen' and D. 'Cheddi Jagan’, focusing on the CHS gene using CRISPR/Cas9 technique.

SCREENING OF COTTON (GOSSYPIUM HIRSUTUM L.) GERMPLASM AGAINST COTTON LEAF CURL VIRUS (CLCUV)

Cotton Leaf Curl Virus (CLCuV) is a devastating disease affecting cotton production worldwide, particularly in South Asia and Africa transmitted by the whitefly (Bemisia tabaci). CLCuV infection leads to severe symptoms, including leaf curling, vein thickening, stunted growth, and significant yield losses. Developing resistant cotton varieties is the most suitable strategy for managing CLCuV, given the limitations and environmental concerns associated with chemical controls. This study aimed to evaluate the resistance and susceptibility of different cotton varieties to CLCuV under natural field conditions and artificially infected condition using a disease severity scale ranging from 0 (highly resistant) to 5 (susceptible). A total of five cotton varieties, were assessed at three critical growth stages: vegetative, flowering, and boll formation. Disease severity, and yield components were recorded to determine extent of resistance of each variety. The results indicated that genotypes and treatments had significant variation in control compared to T1. According to DSI, NIAB-852 was scored as resistant with 10% infected leaves. FH-142 and CIM-496 were scored as tolerant according to DSI with 10-25% infection in leaves. NIAB Karishma and CIM-448 were scored as moderately susceptible with 50-75% infection. All genotypes had significant reduction in number of bolls, boll weight and seed cotton yield in T1 than control. These findings provide valuable insights into the effectiveness of existing cotton germplasm against CLCuV and highlight the need for continuous evaluation and development of resistant varieties. The study highlights the importance of generating resistant cultivars, thereby ensuring sustainable cotton production.

Possible Mechanism of Sucrose and Trehalose-6-Phosphate in Regulating the Secondary Flower on the Strong Upright Spring Shoots of Blueberry Planted in Greenhouse.

Secondary flowering is the phenomenon in which a tree blooms twice or more times a year. Along with the development of blueberry (Vaccinium corymbosum L.) fruits in spring, a large number of secondary flowers on the strong upright spring shoots were noticed in blueberries planted in the greenhouse. To reveal the cause and possible regulatory mechanism of the phenomenon, we clarified the phenological characteristics of flower bud differentiation and development on the spring shoots by combining phenological phenotype with anatomical observation. Furthermore, the changes in carbohydrates, trehalose-6-phosphate (Tre6P), and the relationship among the key enzyme regulatory genes for Tre6P metabolism and the key regulatory genes for flower formation during the differentiation process of apical buds and axillary buds were investigated. The results showed that the process of flower bud differentiation and flowering of apical and axillary buds was consistent, accompanied by a large amount of carbohydrate consumption. This process was positively correlated with the expression trends of VcTPS1/2, VcSnRK1, VcFT, VcLFY2, VcSPL43, VcAP1, and VcDAM in general, and negatively correlated with that of VcTPP. In addition, there is a certain difference in the differentiation progress of flower buds between the apical and axillary buds. Compared with axillary buds, apical buds had higher contents of sucrose, fructose, glucose, Tre6P, and higher expression levels of VcTPS2, VcFT, VcSPL43, and VcAP1. Moreover, VcTPS1 and VcTPS2 were more closely related to the physiological substances (sucrose and Tre6P) in axillary bud and apical bud differentiation, respectively. It was suggested that sucrose and trehalose-6-phosphate play a crucial role in promoting flower bud differentiation in strong upright spring shoots, and VcTPS1 and VcTPS2 might play a central role in these activities. Our study provided substantial sight for further study on the mechanism of multiple flowering of blueberries and laid a foundation for the regulation and utilization of the phenomenon of multiple flowering in a growing season of perennial woody plants.

Polyamine oxidase induces flower formation by promoting spermidine and ABA accumulation in cherry (Cerasus pseudocerasus Lindl.)

Polyamines are important small molecules that play a crucial in flower formation in plants. Polyamine oxidases (PAOs) have a significant function in regulating flower development by influencing polyamine homeostasis. Treatment with exogenous Spd resulted in a significant increase in the Spd content in cherry flower buds, which was accompanied by an increase in abscisic acid (ABA) levels and a decrease in gibberellin (GA) levels, as well as a notable rise in the expression of genes associated with flower formation. Polyamine oxidases are essential for maintaining endogenous polyamine homeostasis. Based on the sweet cherry genome and the ‘Manaohong’ cherry transcriptome data, four polyamine metabolism enzyme genes (CpPAO1/2/3/4) were identified. Sequence comparisons of PAO proteins revealed a high degree of sequence similarity between ‘Manaohong’ cherry and sweet cherry, with only a single amino acid variation. Phylogenetic analysis classified CpPAOs into three subclasses. The expression patterns of CpPAOs were significantly tissue-specific, exhibiting higher levels of expression in flowers and young leaves. Exogenous Spd significantly increased the expression abundance of CpPAOs, as well as ABA-related and flower-forming genes. The function of CpPAO2 was subsequently verified through genetic transformation, which demonstrated that the expression levels of ABA synthesis, signal transduction genes, and flower formation genes were substantially elevated in CpPAO2 transgenic lines. These transgenic lines exhibited earlier flowering and a greater number of inflorescences compared to wild type (WT). Yeast single-hybrid and dual-luciferase assays revealed that CpABF5 binds to the promoter of CpSOC1, promoting its expression. Collectively, these results indicated that exogenous Spd increases the content of Spd and Spm while enhancing ABA levels by promoting the transcript level of CpNCEDs in flower buds, thereby facilitating flower formation through the CpABF5-CpSOC1 pathway.

Glomus mosseae AND Pseudomonas fluorescens AGAINST Soybean mosaic virus UNDER DRIP IRRIGATION SYSTEM

ARTICLE HIGLIGHTS- Glomus mosseae and Pseudomonas fluorescens enhance soybean resistance to SMV.- Ten-day drip irrigation stop at bloom stage boosts seed yield and weight.- Treatment reduces disease severity and increases P. fluorescens population.- Water-saving irrigation method improves soybean performance in dry seasons.- Combining G. mosseae and P. fluorescens increases soybean productivity. ABSTRACTSoybeans [Glycine max (L.) Merr.] require much water, especially in the early stages of growth, flowering, and pod formation and filling. Drought stress on soybeans will increase with global climate change. The research aimed to evaluate the efficacy of Glomus mosseae and Pseudomonas fluorescens in inducing systemic resistance to control Soybean Mosaic Virus (SMV) and the performance of soybean plants with drip irrigation in the dry season. The drip irrigation was stopped for ten days at the beginning of bloom, full bloom, beginning pod, and regular drip irrigation. The application of G. mosseae inoculants used 100 g of sterile compost mixed with 30 spores. The liquid inoculum of P. fluorescens was applied on cotyledonary leaves using the watering method. The plants were inoculated with SMV 6 and 12 days after the P. fluorescens treatment. The symptoms of SMV were recorded two weeks after inoculation, and Indirect ELISA detected the virus. The results showed the combination of G. mosseae and P. fluorescens under drip irrigation stopped at the beginning of bloom for ten days on ELISA absorbance values and disease severity of 0.259 and 3.72 %, respectively. Moreover, this treatment showed the highest values for the 100-seed weight, seed yield, and fresh weight of leaves. The technique of giving water by stopping drip irrigation at the beginning of bloom for ten days will help save water and increase the P. fluorescens population optimally in Alfisols with a pH of between 4.5 and 5.1 with incredibly low fertility. The combination of G. mosseae and P. fluorescens population resulted in a significant increase in the number of G. mosseae’s spores by stopping drip irrigation at the beginning of bloom for ten days.

Over-expression of a plant-type phosphoenolpyruvate carboxylase derails Arabidopsis stamen formation

We examined whether plant-type phosphoenolpyruvate carboxylase (PEPC) is involved in flower organ formation or not by over-expression in Arabidopsis. A wheat PEPC isogene Tappc3A, belonging to the ppc3 group, was targeted due to its preferential expression pattern in pistils and stamens. Transgenic Arabidopsis over-expressing Tappc3A exhibited irregular stamen formation, i.e., a lesser number of stamens per flower and shorter filaments in T2 and T3 generations. Irregular stamens were frequently observed in homozygous T4 lines, but no morphological change was observed in other floral organs. High-degree gene co-expression of Tappc3 isogenes with wheat SEEDSTICKs but not with other homeotic transcription factor genes for flower formation implicates that Tappc3 is under control by the class D genes of the ABCDE model to flower development. In addition, the conservation of CArG box sequences on the Tappc3 promoters supported the developmentally programmed gene expression of ppc3 in wheat flowering organs. Thus, this study provides the first experimental evidence for the critical regulation of plant-type PEPC for flower formation.

HpFBH3 transactivates HpCO7 via binding to the E-boxes in the promoter and may accelerate flower formation in pitaya1

Hylocereus polyrhizus, also known as pitaya or dragon fruit, is a climbing cactus grown worldwide because of its excellent performance under drought stress and appealing red-purple fruits. In practice, accelerating flower formation and inducing more flowers usually result in higher yield. However, the genes for this purpose have not been well characterized in pitaya. Previously, FLOWERING BHLHs (FBHs) have been identified as positive regulators of flower formation. In the present work, a total of eight FBHs were identified in pitaya. This is a greater number than in beet and spinach, possibly because of the recent whole-genome duplication that occurred in the pitaya genome. The phylogenetic tree indicated that the FBHs could be divided into three groups. In TYPE II, the genes of Caryophyllales encode atypical FBHs and are generated by dispersed duplication. The Ka/Ks ratios indicated that HpFBHs are under purifying selection. Promoter and expression analysis of HpFBHs revealed that they are spatiotemporally activated in flower-related tissues and responsive to multiple abiotic stresses. These results indicated that HpFBHs are involved in the flower formation of pitaya. Therefore, typical HpFBH1/3 from TYPE III and an atypical HpFBH8 from TYPE II were selected for functional verification. HpFBH3 was found to heterodimerize with HpFBH1 in the nucleus using subcellular localization, yeast two-hybrid and luciferase complementation assays. With bioinformatic analysis, all HpFBHs were predicted to transactivate downstream genes via binding to the E-boxes, which were frequently detected in the promoters of HpCOs, HpFTs and HpSOC1s. RNA-Seq datasets showed that these flowering accelerators were expressed in coordination with HpFBH3. Yeast one-hybrid and dual-luciferase reporter assays further verified that HpFBH3 transactivated HpCO7 by selectively binding to the E-boxes in the promoter. Moreover, ectopic overexpression of HpFBH3 accelerated flower formation in Arabidopsis. In summary, this study systematically characterized the typical HpFBHs, especially HpFBH3, as positive regulators of flower formation, which could be target genes for the genetic improvement of pitaya.

ENHANCEMENT OF FLOWER INDUCTION IN HARUMANIS MANGO (Mangifera indica L.) WITH ETHEPHON APPLICATION DURING OFF-SEASON

In cultural practice of Harumanis tree, plant growth regulator such as paclobutrazol is applied at late vegetative stage to induce flowering. However, starting from 2020 to 2023, there is a sharp yield reduction due to the unexpected weather condition. Unexpected heavy rain had caused Harumanis flower to drop from the panicle before the pollination occur. Due to this problem, ethephon was identified as an alternative plant growth regulator for flower induction. Ethephon is an ethylene releasing agent that help mediate many aspects in plant growth and development such as shoot development and flower induction. Thus, the objective of this study is to observe the influence of ethephon application during off-season on vegetative growth stage and flower induction of harumanis tree. Total of 32 Harumanis trees (3 years old) in Research Plot, Unit Ladang Universiti Teknologi MARA Perlis were treated with ethephon in September 2023 by foliar spray until run-off on the plant canopy. Treatments were arranged according to Randomized Completely Block Design (RCBD) with three different concentrations of ethephon and being diluted 2 hours before application which are 400 ppm, 600 ppm, and 800 ppm and control (without application). The parameters were recorded 2 weeks interval: number of leaves, number of buds, length of bud, relative chlorophyll content, stomatal density, day to flowering, and number of flower panicles. The vegetative growth stage shows significant difference among concentrations applied where number of leaves is higher with 400 ppm. Meanwhile, the flower formation occurs after 2 months and 4 months of ethephon application at treatment of 800 ppm and 400 ppm respectively. However, there is no significant difference presented on the Harumanis physiological characteristics. As from this study, it can be concluded that the application of ethephon influences the growth of performance and flower formation of Harumanis when applied with specific concentration.

BdRCN4, a Brachypodium distachyon TFL1 homologue, is involved in regulation of apical meristem fate.

In higher plants, the shift from vegetative to reproductive development is governed by complex interplay of internal and external signals. TERMINALFLOWER1 (TFL1) plays a crucial role in the regulation of flowering time and inflorescence architecture in Arabidopsis thaliana. This study aimed to explore the function of BdRCN4, a homolog of TFL1 in Brachypodium distachyon, through functional analyses in mutant and transgenic plants. The results revealed that overexpression of BdRCN4 in B. distachyon leads to an extended vegetative phase and reduced production of spikelets. Similar results were found in A. thaliana, where constitutive expression of BdRCN4 promoted a delay in flowering time, followed by the development of hypervegetative shoots, with no flowers or siliques produced. Our results suggest that BdRCN4 acts as a flowering repressor analogous to TFL1, negatively regulating AP1, but no LFY expression. To further validate this hypothesis, a 35S::LFY-GR co-transformation approach on 35::BdRCN4 lines was performed. Remarkably, AP1 expression levels and flower formation were restored to normal in co-transformed plants when treated with dexamethasone. Although further molecular studies will be necessary, the evidence in B. distachyon support the idea that a balance between LFY and BdRCN4/TFL1 seems to be essential for activating AP1 expression and initiating floral organ identity gene expression. This study also demonstrates interesting conservation through the molecular pathways that regulate flowering meristem transition and identity across the evolution of monocot and dicot plants.

Influence of plant growth regulators on fruit set, yield and quality of mango varieties under HDP

Plant hormones are signal molecules produced within the plant, and occur in extremely low concentrations. Phytohormones determine the formation of flowers, fruit set, stems, leaves, shedding of leaves, and development and ripening of fruits. They shape the plant, affecting seed growth, time of flowering, sex of flowers, senescence of leaves and fruits. Hormones are vital for plant growth and lacking them, plants would be mostly a mass of undifferentiated cells. Plant growth regulators include salicylic acid, CPPU, tricontanol and brassinosteroid. The production of poor quality fruits is a matter of common experience. It would be therefore worth while to improve the yield and quality of fruit crops by foliar application of plant growth regulators. The use of growth regulators has become an important component of agro-technical procedures for most of the cultivated plants and especially for fruit plants. In this review, we focus on the role of plant growth regulators on fruit production.

Towards eco-friendly plant growth regulator: A robustly stable and efficient uniconazole emulsion based on onion-like lamellar liquid crystal

As a commonly water-based pesticide formulation, conventional Emulsions in Water (EWs) always suffer from demulsification in actual complex environments and burst release due to their thermodynamic instability. The ecotoxicity and phytotoxicity caused by chemosynthetic adjuvants cannot be ignored. To address these issues, herein, using a soybean lecithin-based lamellar liquid crystal emulsion (LCE) as the carrier, we construct a robustly stable and low-toxicity EW with the “onion-like” bionic structure and achieve the efficient delivery of plant growth regulator (PGR) uniconazole (UZ). The hydrophobic UZ is firmly encapsulated within the orderly assembled Oil-in-Liquid Crystal-in-Water (O/LC/W) multilayers. This confinement endows UZ-LCE with robust stability, even while encountering disturbances such as dilution, shaking, and changes in pH, ions, and temperature. Furthermore, UZ-LCE exhibits enhanced wettability and affinity to foliar surfaces, as well as specific sustained-release ability. Owing to these superiorities of UZ-LCE, during two consecutive years of efficacy evaluations in cotton field experiments, UZ-LCEs administered through drip irrigation and foliar spray demonstrate remarkable enhancements in controlling excessive plant growth, increasing chlorophyll content, and boosting flower bud formation, surpassing the effectiveness of conventional EWs. UZ-LCE even outperforms commercial preparations (WP and SC) in balancing vegetative growth and reproductive growth, resulting in an 8.3% increase in yield. This research provides an innovative pesticide formulation with eco-friendly adjuvants, less organic solvent, and synergistic functionalities, which is prospective to be extended to other pesticide EWs and contribute to sustainable agriculture.

Arctic Sea ice leads detected using sentinel-1B SAR image and their responses to atmosphere circulation and sea ice dynamics

Arctic sea ice leads are linear fractures in pack ice, which provide narrow windows for the enhanced exchange of mass, energy, and momentum between the atmosphere and ocean. However, the parameterisations of the sub-grid (< 1 km) lead distribution and its associated dynamic processes are still challenging for numerical sea ice modelling. This study explores the dynamics governing lead formation in the Arctic Ocean using multiple data sources including Sentinel-1 synthetic aperture radar (SAR) images, buoy array, and atmospheric reanalysis. Random forest (RF) models trained based on the polarisation and texture features of SAR images were compared, and an optimal RF model sensitive to narrow leads was selected with implementation of screening based on lead geometry. As a case study, the lead distribution along the trajectory of buoy array in the central Arctic Ocean during the freezing period of 2018–2019 was obtained. An enhanced lead opening was observed as the sea ice motion swerved from clockwise circulation following the Beaufort Gyre (BG) to meridional advection when assembled into the Transpolar Drift (TPD). Synoptically, active lead-opening events associated with ice divergence were driven by episodic cyclones. We noticed a dramatic change in the backscatter signal over the leads caused by the growth of thin ice and formation of frost flowers. The identification and the evolution of narrow leads during the freezing season given in this study are conducive to increasing our understanding of the response mechanism of sea ice to atmospheric dynamic processes and supporting the numerical simulation of leads.