Flower Buds Research Articles

Comparative morphoanatomic, histochemical, and phytochemical characterization of leaves of two species of the genus Cynophalla (DC.) J. Presl

Considering the morphological similarities, taxonomic complexity of the genus Cynophalla of the family Capparaceae A. Juss. an the medicinal use of its species and its potential as green energy, this study aimed to compare potential morphoanatomical diagnostic characters of the species Cynophalla flexuosa and Cynophalla hastata to determine authenticity parameters. Furthermore, it aimed to perform a histochemical study of the leaf blades due to their medicinal use. The morphological analysis was carried out using different characters, such as phyllotaxis, shape, among others. For microscopic analyzes semi-permanent slides were prepared containing cross-sections of the stems, petioles and leaf blades. We also prepared paradermal sections of the leaf blades. The analyses were carried out using light microscopy. For the histochemical analysis, we used different reagents according to the target metabolite and analyzed them using light microscopy. Phytochemical tests of the methanolic extracts of the leaves were performed using Thin Layer Chromatography. C. flexuosa has erect branches, elliptical to obtuse leaves with an obtuse to acute apex and obtuse base, globose flower buds, and fruit in a follicular, torulous capsule shape. C. hastata has gently curved branches, oblong-elliptical leaves with a rounded apex and obtuse base, corymb axillary inflorescences with quadrangular flower buds, and cylindrical foliolate capsular fruit. The anatomical characterization showed the characters of general occurrence in the Capparaceae family and those that allow the differentiation of C. flexuosa and C. hastata. The histochemical and phytochemical characterization revealed the sites of synthesis and/or storage of metabolites. Thus, the results presented comparative data on the anatomical characters and histochemical and phytochemical characterization of the species, thus increasing the taxonomic knowledge of the genus Cynophalla and contributing data for future in-depth studies on the species’ potential as renewable energy.

Development of a Micropropagation Protocol for the Ex Situ Conservation of Nuttall's Scrub Oak (Quercus dumosa).

Worldwide, oak species are threatened with extinction due to habitat loss, pathogens, and changing fire regimes. Ex situ conservation through tissue culture may protect the remaining genetic diversity of Quercus dumosa, or the coastal sage scrub oak, from further loss. We designed three basal salt formulations based on the mineral composition of shoot tips and first leaves from mature Q. dumosa and explored carbohydrate source, stress-mitigating compounds, and plant growth regulator concentrations to develop a method of cultivating many Q. dumosa culture lines in vitro. All three novel basal salt formulations led to decreased necrosis compared with commercial basal salt formulas WPM, MS, and DKW. Substitution of 30 g L-1 sucrose with glucose and adding 250 mg L-1 ascorbic acid, 5.2 mg L-1 SNP sodium nitroprusside, and 103 mg L-1 y-aminobutyric acid improved culture health overall. In an experiment involving 115 culture lines, 0.66 mg L-1 6-benzylaminopurine produced the highest average shoots per explant, but 0.33 mg L-1 produced the greatest proportion of shoots 2 cm or greater. Incubation for 24 h in 20 mg L-1 indole-3-butyric acid led to the most rooting. These methods show promise for the ex situ conservation of many genotypes of endangered Q. dumosa.

The dynamic changes in volatile metabolites provide a new understanding for the special flavor formation in z. Mioga flower buds during the growth stages

Although Z. mioga flower buds are popular among consumers for its unique spicy flavor, high nutritional and medicinal value, there are few reports on the formation and changes of the flavor during its growth and maturation process. The understanding of the profile of volatile compounds would help to unravel the flavor formation for Z. mioga flower buds during growth. The volatile changes in Z. mioga flower buds were analyzed by GC–MS and a total of 182 volatile compounds identified, and the terpenoids accounted for the most abundant volatile substances. Almost all the identified volatiles presented an intuitive upward trend throughout the growth period and reached the maximum at the later stage of development (DS3 or DS4). Regarding the PCA and HCA results, there were significant differences found among the four stages, and the DS3 was the critical node. The top 50 differential volatiles screened by OPLS-DA and PLS-DA were all up-regulated, and the correlation analysis indicated that terpenoids might synergize with other chemical types of volatiles to jointly affect the flavor formation of Z. mioga flower buds during growth. The association network for flavor omics revealed that the most important sensory flavor for Z. mioga flower buds were woody and sweet, and the main contribution compounds for the unique flavor contained β-guaiene, β-farnesene, δ-cadinene and citronellyl isobutanoate. Taken together, the results of this study provided a reference for flavor quality evaluation of flower buds and determination of the best harvest period.

Comparative proteomic analysis of papaya bud flowers reveals metabolic signatures and pathways driving hermaphrodite development

Papaya (Carica papaya) is a trioecious species with female, male, and hermaphrodite plants. Given the sex segregation, selecting hermaphroditic plants is vital for orchard establishment due to their greater commercial value. However, selecting hermaphrodite plants through sexing is laborious and costly. Moreover, environmental stressors can exacerbate the issue by potentially inducing abnormal flower development, thus affecting fruit quality. Despite these challenges, the molecular mechanisms governing sex development in papaya remain poorly understood. Thus, this study aimed to identify proteins associated with sex development in female and hermaphrodite flowers of papaya through comparative proteomic analysis. Proteins from flower buds at the early and late developmental stages of three papaya genotypes (UENF-CALIMAN 01, JS12, and Sunrise Solo 72/12) were studied via proteomic analysis via the combination of the shotgun method and nanoESI-HDMSE technology. In buds at an early stage of development, 496 (35.9%) proteins exhibited significantly different abundances between sexes for the SS72/12 genotype, 139 (10%) for the JS12 genotype, and 165 (11.9%) for the UC-01 genotype. At the final stage of development, there were 181 (13.5%) for SS72/12, 113 (8.4%) for JS12, and 125 (9.1%) for UC-01. The large group of differentially accumulated proteins (DAPs) between the sexes was related to metabolism, as shown by the observation of only the proteins that exhibited the same pattern of accumulation in the three genotypes. Specifically, carbohydrate metabolism proteins were up-regulated in hermaphrodite flower buds early in development, while those linked to monosaccharide and amino acid metabolism increased during late development. Enrichment of sporopollenin and phenylpropanoid biosynthesis pathways characterizes hermaphrodite samples across developmental stages, with predicted protein interactions highlighting the crucial role of phenylpropanoids in sporopollenin biosynthesis for pollen wall formation. Most of the DAPs played key roles in pectin, cellulose, and lignin synthesis and were essential for cell wall formation and male flower structure development, notably in the pollen coat. These findings suggest that hermaphrodite flowers require more energy for development, likely due to complex pollen wall formation. Overall, these insights illuminate the molecular mechanisms of papaya floral development, revealing complex regulatory networks and energetic demands in the formation of male reproductive structures.

Zinc Finger-Homeodomain Transcriptional Factors (ZHDs) in Cucumber (Cucumis sativus L.): Identification, Evolution, Expression Profiles, and Function under Abiotic Stresses.

Cucumber (Cucumis sativus L.) is a globally prevalent and extensively cultivated vegetable whose yield is significantly influenced by various abiotic stresses, including drought, heat, and salinity. Transcription factors, such as zinc finger-homeodomain proteins (ZHDs), a plant-specific subgroup of Homeobox, play a crucial regulatory role in stress resistance. In this study, we identified 13 CsZHDs distributed across all six cucumber chromosomes except chromosome 7. Phylogenetic analysis classified these genes into five clades (ZHDI-IV and MIF) with different gene structures but similar conserved motifs. Collinearity analysis revealed that members of clades ZHD III, IV, and MIF experienced amplification through segmental duplication events. Additionally, a closer evolutionary relationship was observed between the ZHDs in Cucumis sativus (C. sativus) and Arabidopsis thaliana (A. thaliana) compared to Oryza sativa (O. sativa). Quantitative real-time PCR (qRT-PCR) analysis demonstrated the general expression of CsZHD genes across all tissues, with notable expression in leaf and flower buds. Moreover, most of the CsZHDs, particularly CsZHD9-11, exhibited varying responses to drought, heat, and salt stresses. Virus-induced gene silencing (VIGS) experiments highlighted the potential functions of CsZHD9 and CsZHD10, suggesting their positive regulation of stomatal movement and responsiveness to drought stress. In summary, these findings provide a valuable resource for future analysis of potential mechanisms underlying CsZHD genes in response to stresses.

Constructed the metabolic compound accumulation profiles of daylily at different main producing areas using multi-omics techniques

Daylily flower buds (DFB) are widely cultivated in China. The discernible disparities exist in the nutritional composition of daylilies across different primary production areas. However, limited studies about the chemical composition and biosynthetic mechanisms of the principal constituents of DFB. This study systematically investigated daylilies from seven distinct growing regions by integrated metabolomics and transcriptomic sequencing to elucidate the environmental impact on DFB quality and metabolite biosynthesis mechanisms. In DFB, flavonoids constituting the majority, followed by phenolic acids and lipids. The total flavonoid and polyphenol content exhibited the highest levels in northern China (Ningxia, Gansu), and the lowest levels in southern regions (Hunan, Fujian). Correspondingly, antioxidant enzyme activity and free radical scavenging capacity mirrored these regional disparities. Thus, northern-producing areas demonstrated a propitious environment for the accumulation of secondary metabolites, particularly flavonoids and phenolic acids. In contrast, southern production areas exhibited a less conducive environment for the accumulation of flavonoid glycosides in daylilies. Furthermore, distinctive variations in the key metabolites were observed in FJQZ, a region characterized by diverse flower colors. Key enzymes and transcription factors were identified and validated through RT-qPCR. These results contribute valuable insights into the daylily quality formation mechanisms, offering a foundation for high-quality breeding strategies.

ANÁLISIS DEL CRECIMIENTO DE Carica papaya L. BAJO INFECCIÓN POR PRSV-P

<p><strong>Background.</strong> Papaya (<em>Carica papaya</em> L.) is cultivated in tropical and subtropical regions of the world for its nutritious and healthy fruits intended mainly for fresh consumption. Mexico was the world's leading papaya exporter in 2020 with 167,500 t. <em>C. papaya</em> is attacked by several viral diseases, the ring spot virus (PRSV-P) is the one that causes the most damage to the crop and the greatest production losses. <strong>Objective.</strong> To establish the phenology of a <em>Carica papaya</em> L. ‘Maradol Roja’ population infected with PRSV-P, to quantify its growth, and to relate its phenological steps with the accumulated degree days (DD). <strong>Methodology.</strong> The emissions of leaves, flower buds, flowers and fruits, apparent height of the plant, stem diameter and biomass were evaluated, based on the DD accumulated during the growth cycle. <strong>Results.</strong> The growth cycle is divided into nine phenological stages, where the leaf or flower bud formation requires ≈ 18 DD. In plants, the number of leaves is approximately equal to the number of flower buds. However, the number of ripe fruits is variable due to the adverse conditions that can occur throughout the growth period. To some extent, the roots typically present two growth peaks, although the available moisture in the soil could change this pattern. The apparent height of the plant and the stem diameter present a double sigmoid growth curve, with a maximum apparent height of 180 cm, and a diameter at the base of 11 cm. <strong>Implications.</strong> The infection by PRSV-P reduced the productivity and commercial quality of the fruits. <strong>Conclusions.</strong> PRSV-P infection reduced apparent height, stem diameter, number of leaves, flowers, and fruits, decrease in biomass gain, and shortened life cycle of plants.</p>

Quality Detection and Grading of Rose Tea Based on a Lightweight Model.

Rose tea is a type of flower tea in China's reprocessed tea category, which is divided into seven grades, including super flower, primary flower, flower bud, flower heart, yellow flower, scattered flower, and waste flower. Grading rose tea into distinct quality levels is a practice that is essential to boosting their competitive advantage. Manual grading is inefficient. We provide a lightweight model to advance rose tea grading automation. Firstly, four kinds of attention mechanisms were introduced into the backbone and compared. According to the experimental results, the Convolutional Block Attention Module (CBAM) was chosen in the end due to its ultimate capacity to enhance the overall detection performance of the model. Second, the lightweight module C2fGhost was utilized to change the original C2f module in the neck to lighten the network while maintaining detection performance. Finally, we used the SIoU loss in place of the CIoU loss to improve the boundary regression performance of the model. The results showed that the mAP, precision (P), recall (R), FPS, GFLOPs, and Params values of the proposed model were 86.16%, 89.77%, 83.01%, 166.58, 7.978, and 2.746 M, respectively. Compared with the original model, the mAP, P, and R values increased by 0.67%, 0.73%, and 0.64%, the GFLOPs and Params decreased by 0.88 and 0.411 M, respectively, and the speed was comparable. The model proposed in this study also performed better than other advanced detection models. It provides theoretical research and technical support for the intelligent grading of roses.

Efficacy of some botanical insecticides against <em>Aphis gossypii</em> Glover (Hemiptera: Aphididae) on chrysanthemum

An evaluation of various botanical insecticides to control Aphis gossypii and its impact on aphid population dynamics on chrysanthemum plants was investigated. In order to control A. gossypii on chrysanthemum, the effectiveness of several botanical insecticides extracted from Melia azedarach, Toona sinensis, and Chrysanthemum cinerariaefolium was investigated in the current study. The research was carried out in the experimental field of the Indonesian Ornamental Crops Research Institute under plastic house conditions. Five concentrations, i.e., 1.5, 2.0, 2.5, 3.0, and 3.5 g/L of three plant extracts, M. azedarach, T. sinensis, and C. cinerariaefolium, were sprayed on chrysanthemum cultivar White Fiji after 28 to 84 days after planting. A. gossypii had a dynamic population that changed according to the plant’s developmental stages. In vegetative growth, the alate adult and nymphal stages were dominant, and the population of nymphs increased along the plant ages. The insect colonized young leaf surfaces in the terminal apices. During the reproductive stages, the population of alate adults diminished, and the distribution of the insect extended to mature, old leaves, flower buds, and bloomed flowers. The application of several botanical insecticides revealed various responses of aphid populations. Among the tested insecticides, C. cinerariaefolium extract at 3.0 and 3.5 g/L demonstrated the highest average percentage efficacy (76 and 72%) and was the most consistent in suppressing the population. The results of this study indicate the potential efficacy of botanical insecticides against A. gossypii suggesting a different approach to efficient and environment-friendly chrysanthemum pest management.

Genome-Wide Identification and Analysis of the EIN3/EIL Transcription Factor Gene Family in Doubled Haploid (DH) Poplar.

Ethylene (ET) is an important phytohormone that regulates plant growth, development and stress responses. The ethylene-insensitive3/ethylene-insensitive3-like (EIN3/EIL) transcription factor family, as a key regulator of the ET signal transduction pathway, plays an important role in regulating the expression of ET-responsive genes. Although studies of EIN3/EIL family members have been completed in many species, their role in doubled haploid (DH) poplar derived from another culture of diploid Populus simonii × P. nigra (donor tree, DT) remains ambiguous. In this study, a total of seven EIN3/EIL gene family members in the DH poplar genome were identified. Basic physical and chemical property analyses of these genes were performed, and these proteins were predicted to be localized to the nucleus. According to the phylogenetic relationship, EIN3/EIL genes were divided into two groups, and the genes in the same group had a similar gene structure and conserved motifs. The expression patterns of EIN3/EIL genes in the apical buds of different DH poplar plants were analyzed based on transcriptome data. At the same time, the expression patterns of PsnEIL1, PsnEIN3, PsnEIL4 and PsnEIL5 genes in different tissues of different DH plants were detected via RT-qPCR, including the apical buds, young leaves, functional leaves, xylem, cambium and roots. The findings presented above indicate notable variations in the expression levels of PsnEIL genes across various tissues of distinct DH plants. Finally, the PsnEIL1 gene was overexpressed in DT, and the transgenic plants showed a dwarf phenotype, indicating that the PsnEIL1 gene was involved in regulating the growth and development of poplar. In this study, the EIN3/EIL gene family of DH poplar was analyzed and functionally characterized, which provides a theoretical basis for the future exploration of the EIN3/EIL gene function.

EuAP2a, a key gene that regulates flowering time in peach (Prunus persica) by modulating Thermo-responsive transcription programming

Abstract Frequent spring frost damage threatens temperate fruit production, and the breeding of late-flowering cultivars is an effective strategy for preventing such damage, but the lack of specific genes and markers and a lack of understanding of the mechanisms make it difficult. We examined a Late-Flowering Peach (LFP) germplasm and found that its floral buds require a longer chilling period to release from their dormancy and a longer warming period to bloom than the control cultivar, two key characteristics associated with flowering time. We discovered that a 983-bp deletion in euAP2a, an APETALA2 (AP2)-related gene with known roles in regulating floral organ identity and flowering time, was primarily responsible for late flowering in LFP. This deletion disrupts an miR172 binding site, resulting in a gain-of-function mutation in euAP2a. Transcriptomic analyses revealed that at different stages of floral development, two chilling-responsive modules and four warm-responsive modules, comprising approximately 600 genes, were sequentially activated, forming a unique transcription programming. Furthermore, we found that euAP2a was transiently downregulated during the activation of these thermal-responsive modules at various stages. However, the loss of such transient, stage-specific downregulation of euAP2a caused by the deletion of miR172 binding sites resulted in the deactivation or delay of these modules in the LFP flower buds, suggesting that euAP2a acts as a transcription repressor to control floral developmental pace in peaches by modulating the thermo-responsive transcription programming. The findings shed light on the mechanisms behind late flowering in deciduous fruit trees, which is instrumental for breeding frost-tolerant cultivars.

Seasonal Incidence of Major Insect Pests in Mungbean; Vigna radiata (L. Wilczek)

The current studies on seasonal incidence of major insect pests were carried out at Students’ Instructional Farm of Acharya Narendra Deva University of Agriculture & Technology, Kumarganj, Ayodhya (UP), India during Kharif 2022 and 2023. The current study revealed that whitefly, B. tabaci was commenced from the second fortnight of July and touched the peak at 32th (9.8 whitefly per cage) and 35th SMW (9.4 whitefly per cage) in both the year, respectively. The populations of B. tabaci had a significant negative correlation with rainfall (r= -0.699) in Kharif 2022. The jassid had the highest population in 34th SMW (4.6 jassid/cage) in Kharif 2022, while in second year, maximum jassid population of 5.1 jassid/cage was recorded during 33rd SMW. Wind speed had a significant and negative effect (r=-0.804) on the population of jassid during Kharif 2023. Seasonal abundance of thrips showed that, in first year, the thrips activity reached maximum at 33rd SMW (1.2 trips/5 flower buds). In next season, peak population of 1.4 thrips per 5 flower buds was in 32nd SMW. The correlation study during both the season revealed that the sunshine hours (r= -0.683) showed significant and negative effect on thrips population in 2023. Peak pod borer damage was observed in 36th SMW (5.3%) and 35th SMW (6.7%) during 2022 and 2023, respectively. Correlation between pod borer damage and weather parameters showed that wind speed had negative and significant (r= -0.707) effect on borer damage in first year.

Cotton plants overexpressing the Bacillus thuringiensis Cry23Aa and Cry37Aa binary-like toxins exhibit high resistance to the cotton boll weevil (Anthonomus grandis)

The cotton boll weevil (CBW, Anthonomus grandis) stands as one of the most significant threats to cotton crops (Gossypium hirsutum). Despite substantial efforts, the development of a commercially viable transgenic cotton event for effective open-field control of CBW has remained elusive. This study describes a detailed characterization of the insecticidal toxins Cry23Aa and Cry37Aa against CBW. Our findings reveal that CBW larvae fed on artificial diets supplemented exclusively with Cry23Aa decreased larval survival by roughly by 69%, while supplementation with Cry37Aa alone displayed no statistical difference compared to the control. However, the combined provision of both toxins in the artificial diet led to mortality rates approaching 100% among CBW larvae (LC50 equal to 0.26 PPM). Additionally, we engineered transgenic cotton plants by introducing cry23Aa and cry37Aa genes under control of the flower bud-specific pGhFS4 and pGhFS1 promoters, respectively. Seven transgenic cotton events expressing high levels of Cry23Aa and Cry37Aa toxins in flower buds were selected for greenhouse bioassays, and the mortality rate of CBW larvae feeding on their T0 and T1 generations ranged from 75% to 100%. Our in silico analyses unveiled that Cry23Aa displays all the hallmark characteristics of β-pore-forming toxins (β-PFTs) that bind to sugar moieties in glycoproteins. Intriguingly, we also discovered a distinctive zinc-binding site within Cry23Aa, which appears to be involved in protein-protein interactions. Finally, we discuss the major structural features of Cry23Aa that likely play a role in the toxin’s mechanism of action. In view of the low LC50 for CBW larvae and the significant accumulation of these toxins in the flower buds of both T0 and T1 plants, we anticipate that through successive generations of these transgenic lines, cotton plants engineered to overexpress cry23Aa and cry37Aa hold promise for effectively managing CBW infestations in cotton crops.

Controlled freezing storge (CFS) maintains quality of fresh edible buds of daylily (Hemerocallis citrina) by enhancing antioxidant capacity, energy charge and unsaturation of fatty acids

Fresh buds of daylily flowers (Hemerocallis citrina) have been consumed as a nutritious vegetable, but they are very perishable after harvest. In this study, the freezing point of daylily buds with different lengths was detected and compared. Then, the buds were stored at a controlled temperature higher than the freezing point but less than 0 °C. The controlled freezing storage (CFS) set at −0.95 ± 0.25 °C remarkably maintained the edible quality and extended postharvest life of daylily buds, compared to the storage at 1 ± 0.5 °C. CFS preserved vibrant color by hindering chlorophyll reduction and fostering carotenoid accumulation. CFS notably inhibited the decline in soluble protein and the accumulation of malondialdehyde content. Additionally, CFS maintained a robust level of radical scavenging ability and energy charge, and effectively delayed the reduction in unsaturation of fatty acids. Thus, CFS can effectively mitigate the senescence progression of daylily buds in practice.

Variation of Phenology of Flacourtia rukam in Two Different Habitats and Their Relation to Rainfall, Dry Days, and the Plant Water Status

Phenological shifts in the emergence of vegetative and generative parts, occur due to the response of plants to water received due to climate change. The rukam tree (Flacourtia rukam (Zoll & Moritzi)) is a local Indonesian plant with potential as an edible fruit and antioxidant agent, but its existence is increasingly rare. F. rukam can be found in Pasuruan, East Java, including Purwodadi Botanical Garden (PBG) as collected plants and Sekarmojo Village as cultivated plants. These populations show a shift in phenology, but this has never been studied. This study aimed to analyze the spatial variation of the phenology of two rukam populations and its relation to plant water status, rainfall quantity (RQ), and drought days (DD). This research was conducted on two individual trees at each location, was conducted from August 2020 to October 2022 using secondary data from BMKG, such as daily rainfall and the number of days without rain. Phenology was directly observed every week with an estimated abundance of numbers 1-4; plant water status was observed by calculating relative water content (RWC); soil physical analysis was carried out in mid-season. Data were analyzed by Mann-Whitney test and SEM WarpPLS. The results showed differences in phenology in the phases of leaf fall, flower buds, young fruit, and ripe fruit on the trees in the different locations. The decreased RQ in the past month significantly reduced the RWC value of F. rukam in both places, while the number of DD contributed to a decrease in the RWC value in PBG only, not in Sekarmojo. In both sites, decreasing the RWC of the rukam increased the abundance of fallen leaves and the chances of flowering. Rainfall and drought days affected plant phenology directly or indirectly through RWC mediation. In both places, RQ had a direct positive and significant effect on blooming flowers and new leaves but had negative effect on fallen leaves. While DD had a positive effect on leaf fall, flower formation, and fruit ripening, but had a negative effect on the appearance of young fruit (in PBG). Indirectly, RQ mainly affected several phenological parameters, while DD did not affect all phenological parameters.

Model for predicting apple bloom date based on bud response experiments in controlled environments

Climate change affects crop phenology, and this has raised interest in phenology models. Most previous studies have determined the functions and parameters of phenology models through calibrations based on observed historical bloom dates under field conditions. However, if all the functions and parameters are determined through bud response experiments in controlled environments, it becomes possible to develop a model that is independent of observation in specific regions and has a small risk of overfitting. Hence, we grew potted ‘Fuji’ apple trees under fully temperature-controlled condition to quantify the temperature response of endodormancy release, flower bud development, and their interaction to determine the functions and parameters of models. The optimum temperature to release endodormancy was between –3 °C and 6 °C, and it was not released at temperatures ≥12 °C. The developmental rate of the flower bud increased with increasing chilling treatment time at 6 °C; however, it did not change over 2000 h The relationship between the temperature and developmental rate was exponential for the ecodormancy stage. The models constructed from these experimental results were validated using a dataset of historical bloom dates observed under three different climatic field conditions in Japan. The results demonstrated that, regardless of whether the region was cold or warm, the overlap model can predict bloom dates with accuracy, whereas the sequential model can predict bloom dates with accuracy only in cold regions. The overlap model in which the functions and parameters are fixed through bud response experiments in controlled environments, is expected to be applicable for predictions spanning diverse temperature conditions in global apple-growing regions, including future temperature scenarios, without succumbing to overfitting.

Divergent reproductive responses of Caatinga dry forest plants to leaf-cutting ant herbivory

Herbivory is one of the key processes shaping life history traits linked to plant fitness and the leaf-cutting ants are amongst the most voracious and polyphagous herbivores of the Neotropics. They extensively harvest aboveground plant parts to grow their symbiotic fungus, including vegetative and reproductive tissues. Although leaf-cutting ant herbivory is expected to reduce plant reproductive success, the potentially different outputs of damage to vegetative and reproductive parts are still poorly known. This study investigates the influence of Atta opaciceps herbivory on the reproductive success of three plant species native to the Caatinga dry forest: Croton argyrophylloides (Euphorbiaceae), Cenostigma pyramidale, and Indigofera suffruticosa (Leguminosae). We selected 10 adult and active nests of A. opaciceps based on the presence of individuals of the three focal plant species in their vicinity. For each colony, we marked four individuals of each plant species (totaling 12 individuals per colony), which were then subjected to one of four herbivory treatments: (1) ant herbivory on both reproductive and vegetative parts, (2) manually simulated herbivory on the reproductive parts alone, (3) ant herbivory exclusively on vegetative parts, and (4) no herbivory. From January to April 2020, we monitored all 120 individuals, recording the number of inflorescences, flower buds, flowers, fruits, and the proportion of flowers maturing into fruits (fruit set, as a proxy of reproductive success). Results revealed variations in reproductive structure production and divergent responses to leaf-cutting ant herbivory among our focal species. In terms of inflorescence, flower bud production, and fruit set C. argyrophylloides showed reduced numbers when subjected to higher levels of total herbivory (reproductive and vegetative parts), but increased inflorescence and flower bud production when plants suffered only leaf damage. Cenostigma pyramidale individuals under partial herbivory displayed lower flower bud numbers than protected ones. In contrast, I. suffruticosa displayed conflicting results, with fully exposed plants producing more inflorescences than partially exposed counterparts and more flowers than leaf-damaged and protected individuals. Despite the varied effects on different plant parts across all three study species, the overall reproductive success (i.e. fruit set) of only one species (C. argyrophylloides) was significantly reduced by leaf-cutting ant herbivory. The resilience of the two other plant species to leaf-cutting ant pressure may be attributed to compensatory mechanisms, shedding light on the intricate interplay between herbivores and plants in the Caatinga dry forest. As leaf-cutting ants proliferate in response to anthropogenic disturbances, the patterns described in this study may become more pronounced, potentially affecting the organization of plant communities in the Caatinga dry forest.

Induction and characterization of induced tetraploid, mixoploid and control diploid teak seedlings (Tectona grandis L.f.) from shoot cultures treated with oryzalin*

Teak, known for its high-quality timber and economic value, holds significant potential as the major component of an agroforestry system to combat climate change and support sustainable development goals. The challenge of slow teak growth can be addressed by introducing fast-growing teak varieties amenable to vegetative propagation. Furthermore, the improvement of teak through somatic cell genetics, such as inducing polyploidy, can result in more vigorous, faster-growing, and drought-tolerant trees. While a report exists on a tetraploid teak accession with enhanced less water tolerance, information on the induction and characterization of tetraploid teak is lacking. In this study, we report the induction of polyploid teak by immersing 1 – 1.5 cm nodal stem segments and shoot tips obtained from teak shoot cultures in a modified MS liquid medium containing 5 − 30 µM oryzalin for one week, followed by subculture for 6 passages. The resulting shoots were acclimatized and grown in the nursery for 10 months. Based on flow cytometry for ploidy analysis of pre-selected plants having morphologies typical of polyploid followed by chromosome counting, we identified two tetraploid plants from one accession and 18 mixoploid teak plants from four accessions. Chromosome counting analysis confirmed that a diploid plant had a chromosome number of 2n = 2x = 36, tetraploid plant had a chromosome number of 2n = 4x = 72, and mixoploid plant exhibited both chromosome number of 2n = 2x = 36 and 2n = 4x = 72 in root tip cells. Morphological characterization revealed that tetraploid and mixoploid teak plants displayed typical polyploid characteristics, such as larger, thicker, and greener leaves, increased root diameter, increased cell size in root tip region, and larger stomata size but with reduced density. The development of tetraploid teak holds the potential to provide faster-growing and more drought-tolerant varieties, facilitating breeding efforts, including the development of triploid varieties.

Low Temperature Tolerance of Peach Flower Buds and Shoot Tissues Is Differentially Influenced by Freezing and High Temperature Exposure

In northern temperate zones, peach trees are vulnerable to cold temperature injury in the fall, particularly as climate change prolongs warm weather in the fall and potentially delays the onset of cold acclimation. Four experiments evaluated how cold acclimation of flower buds and shoot phloem, cambium, and xylem is affected by exposure to varying temperatures in the fall. One-year-old peach shoots from trees grown in Maine, USA, were collected from October through November, exposed to 1, 3, or 6 days of low, high, and freezing temperatures, and subjected to stepwise controlled freezing to about −30 °C. Injury was visually quantified as oxidative browning of flower buds and shoot tissues. High temperature exposure, even of a single day, decreased cold tolerance of flower buds and shoot tissues until late November, when high temperatures only minimally decreased cold hardiness. In mid-November, increasing the duration of high temperature exposure from 1 to 3 days decreased cambium and phloem hardiness, but hardiness in flower buds was not further decreased by the longer duration of 3 days. By late November, hardiness in flower buds, cambium, and phloem was less responsive to high temperature, and was increased by prior exposure to 6 days of freezing. After high temperature, xylem lost hardiness to a small degree in mid-October and late November, but in mid-November this occurred in only one experiment. In this study, deacclimation during high temperature in the fall was greater in cambium and phloem than in flower buds and at times greater than in xylem.

Floral Initiation, Organogenesis, and Flowering of Mature Paphiopedilum Clair de Lune ‘Edgard Van Belle’ Award of Merit/American Orchid Society Plants Derived from Divisions

Paphiopedilum Clair de Lune ‘Edgard Van Belle’, an excellent Maudiae-type hybrid that has been propagated by artificial division for a long time. We studied its flower bud initiation, development of floral organs, and flowering habits with a view to providing information for flowering control and efficient commercial production. According to our research, the flower bud initiation phase of this cultivar begins in February every year, and 80% of the plants completed sepal primordium differentiation in March, The flower bud differentiation lasts for 6 to 7 months, until flowering in August. Within 1 to 3 months after flower bud differentiation, all tested plants differentiated lateral buds. After 5 to 6 months, the new, aboveground vegetative shoots reached their maximum growth, with an average plant height of 20 cm, five leaves, and a shoot dry weight of more than 3 g. From February to April of the following year, a new cycle of flower development and vegetative growth began. In addition, this cultivar was notably sensitivity to high ambient temperature during the late phase of flower development, with a flower bud drop rate as high as 33.3% under average day/night temperatures of 29.0/26.5 °C.