Flowering Period Research Articles

Structural changes in Nelumbo flower petals during opening and closing.

Nelumbo nucifera is one of several plant species with flowers that typically open in the early morning and close by noon. This movement normally repeats for 3 days, with all petals falling off on day 4. However, detailed observations of flower movement in Nelumbo species are limited. Movement of flowers on plants in growth chambers were observed using time-lapse photography. Petals were examined with scanning electron microscopy or fixed and sectioned for light microscopy to determine whether changes in cell size contribute to petal elongation during flowering. This study is the first to microscopically observe petal cells of a Nelumbo species during flowering in controlled conditions. Petals elongated during the 4-day flowering period. Inner petals were more elongated than the outer petals. Among the basal, central, and tip regions of a single petal, the cells in the basal region enlarged the most. Outer and inner epidermal cells in the basal region of the inner petals, on both adaxial and abaxial sides, gradually enlarged during the flowering period through cycles of repeated increases as the petals opened and decreases as they closed. Petals opened and closed repeatedly as they elongated, primarily in their basal region. Cells in the basal region of the petal on the adaxial and abaxial sides periodically fluctuated in size, increased during flower opening and decreased during closing, but differences in these patterns were observed between the two sides, suggesting that one of the driving forces behind the opening and closing of flowers of Nelumbo species is the increase and decrease in the size of the petal cells.

Floral Developmental Morphology and Biochemical Characteristics of Male Sterile Mutants of Lagerstroemia indica

Male sterility is a common phenomenon in higher plants and often plays an important role in the selection of superior offspring. ‘Xiang Yun’ is a mutant of Lagerstroemia indica that does not bear fruit after flowering, and its flowering period is significantly longer than that of normal L. indica. To explore the timing and molecular mechanisms of sterility in ‘Xiang Yun’, this study determined the period of sterility through anatomical observation and compared the content of nutrients and the activity of antioxidative enzymes at different stages of flower development. Finally, sequence alignment and qPCR were used to analyze the differences in pollen development genes between ‘Xiang Yun’ and ‘Hong Ye’. The results showed that the anthers of ‘Xiang Yun’ dispersed pollen normally, but the pollen grains could not germinate normally. Observations with scanning electron microscopy revealed that the pollen grains were uneven in size and shriveled in shape. Further observation of anther sections found that abnormal development of the microspores began at the S2 stage, with the callose wall between microspores of ‘Xiang Yun’ being thicker than that of ‘Hong Ye’. In addition, during the flower development of ‘Xiang Yun’, the contents of soluble sugar, soluble protein, free proline, and triglycerides were deficient to varying degrees, and the activities of POD, SOD, and MDA were lower. Sequence alignment and qPCR showed that there were several mutations in EFD1, TPD1, and DEX1 of ‘Xiang Yun’ compared with ‘Hong Ye’, and the expression levels of these genes were abnormally elevated in the later stages of development. Our results clarified the timing and phenotype of male sterility in ‘Xiang Yun’. This provides solid and valuable information for further research on the molecular mechanism of sterility in ‘Xiang Yun’ and the genetic breeding of crape myrtle.

First Report of Leaf Spot on Lonicera japonica Caused by Aspergillus niger in China.

Honeysuckle (Lonicera japonica Thunb, LJ) is a common medicinal and edible plant (He et al. 2022). It has been utilized in various industries such as biomedicine, animal husbandry, and food production (Li et al. 2014; Su et al. 2020). In June 2023, a significant leaf lesion was observed on approximately 20% of honeysuckle "Juhua No.1" leaves in a 3.33-ha field at the base of Julu County, Hebei province, China. Almost all leaves were infected. Leaf spot disease occurred in the field honeysuckle throughout the flowering period, especially after picking. The disease mainly infected the leaves of honeysuckle, forming irregular spots on the edge of the leaf surface with black-brown edges, the midrib and lateral veins were affected (Figure S1A). In advanced stages, the entire leaf would become necrotic. For pathogen isolation, small pieces (4×4 mm) of the infected tissue from diseased leaves were surface sterilized with 75% ethanol and 5% sodium hypochlorite, rinsed with the sterile water, incubated on PDA. Finally, six isolated pathogens were obtained. Hyphae were white. The mycelium was multicellular, had diaphragm. Conidiophores protruded from the stroma, started as spherical structures and gradually developed into radial, black-brown formations. Spore acrosome was subglobose, bilayered pedicels covering acrosome, 40-60 µm in diameter, yellowish brown (Figures S1B, S1C). Based on morphological and cultural characteristics, the leaf spot disease fungus was tentatively identified as Aspergillus spp. (Wei 1979). To test the pathogenicity of pathogen, leaves of three healthy potted honeysuckle "Juhua No.1" plants were inoculated by sprayed with conidial suspensions (106 spores/ml) (Figure S1D). Negative controls were established by inoculating leaf with sterile distilled water. All plants were incubated in a greenhouse at 28 ± 2℃. The experiment was replicated three times. After 10 days, typical leaf spot symptoms were observed on inoculated leaves, whereas no symptoms were found on the control groups. The re-isolated fungus from the inoculated leaves displayed the same morphological traits (Figures S1E-S1H), again identified as Aspergillus spp., confirming Koch's postulates, designated as H2. To confirm the pathogen's identity, genomic DNA was extracted from the pathogenicity isolate H2. The 18S rDNA and the ITS genes were amplified and sequenced using primer pairs S1/S2 (Zhang et al. 2018) and ITS1/ITS4 (Zhang et al. 2023), respectively. Results of BLAST searches showed that the 18s rDNA and ITS sequences of H2 were highly homologous (>99%) with Aspergillus niger. The close genetic relationship indicated that H2 belonged to the genus Aspergillus (Figure S2a). We further sequenced the whole genome of H2. The sequence data were available in the NCBI GenBank (Accession number: PRJNA1117256). We also analyzed the ANI (Yoon et al. 2017) and digital DNA-DNA blotting (dDDH) (Figures S2b, S2c). The ANI values of H2 compared to Aspergillus niger CBS 554.65 and Aspergillus niger KJC3 were higher than 95%. The dDDH values of H2 compared to Aspergillus niger CBS 554.65 and Aspergillus niger KJC3 were higher than 70%. Above all results, honeysuckle leaf spot disease was identified as Aspergillus niger. This is the first report of leaf spot on Lonicera japonica caused by Aspergillus niger in China. Our findings expand the geographical range of A.niger-infected plants, also provide reference for scientific prevention and control of honeysuckle leaf spot disease.

Assessment of conservation status of Ferula huber‐morathii: association with population genetic structure and regional climate

Ferula huber‐morathii is an endemic and medicinally important plant. This species is distributed in eight Turkish localities, including three newly identified ones. Its extent of occurrence and area of occupancy is determined to be 3963 km2 and 32 km2 respectively. All localities are characterized by East Mediterranean and sub‐Mediterranean precipitation regimes; however, temperatures increase excessively and precipitation decreases during the flowering period of the species. The population sizes are quite small, and the number of reproducing individuals in some populations is below ten. Analyses of ISSR markers showed the percentage of polymorphic loci to be 94% at the species level and 56% at the population level. The level of genetic differentiation (measured by GST) was 0.37 and the estimated level of gene flow among populations (NM) was 0.84. The percentage of variance occurring within and among populations, determined by AMOVA, was 75% and 25%, respectively. STRUCTURE analysis revealed two genetic clusters of individuals with a geographic structure, similar to that found in UPGMA and an ordination analysis. Some populations turned out to have both low numbers of individuals and low genetic diversity. Since many of the populations are subject to anthropogenic disturbance, the species should remain in the EN category. At the same time, it is suggested that a new in‐situ conservation area should be created around nearby dams, situated in the same climate area as the currently known populations.

Floral Elegance Meets Medicinal Marvels: Traditional Uses, Phytochemistry, and Pharmacology of the Genus Lagerstroemia L.

The genus Lagerstroemia L. (Lythraceae), known for its exquisite flowers and prolonged flowering period, is commonly employed in traditional medicinal systems across Asian countries, where it has always been consumed as tea or employed to address ailments such as diabetes, urinary disorders, coughs, fevers, inflammation, pain, and anesthesia. Its diverse uses may be attributed to its rich active ingredients. Currently, at least 364 biological compounds have been identified from Lagerstroemia extracts, encompassing various types such as terpenes, flavonoids, phenolic acids, alkaloids, and phenylpropanoids. Extensive in vitro and in vivo experiments have examined the pharmacological activities of different extracts, revealing their potential in various domains, including but not limited to antidiabetic, anti-obesity, antitumor, antimicrobial, antioxidant, anti-inflammatory, analgesic, and hepatoprotective effects. Additionally, 20 core components have been proven to be associated with antidiabetic and hypoglycemic effects of Lagerstroemia. Overall, Lagerstroemia exhibit substantial medicinal potential, and the alignment between its traditional applications and contemporary pharmacological findings present promising opportunities for further investigation, particularly in food and health products, drug development, herbal teas, and cosmetics. However, evidence-based pharmacological research has largely been confined to in vitro screening and animal model, lacking clinical trials and bioactive compound isolations. Consequently, future endeavors should adopt a more holistic approach.

Creation of a collection fund and study of cultivars of daylilies in the M. M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine

Purpose. Analysis and comparative study of daylily cultivars from the collection fund of the M. M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine (NBG), selection of assortment for decorative horticulture and landscaping. Methods. Cultivars from the NBG daylily collection were studied. The cultivars were evaluated in terms of their aesthetic and economic attributes, and were classified according to their coloration and the timing of their flowering. The author of the cultivar, country of origin, year of creation and introduction into the NBG were also identified. The cultivars were also grouped according to these parameters. Results. The NBG daylily collection is the result of 40 years of introduction and 20 years of breeding work with this crop at the NBG. It includes 174 world cultivars, 26 cultivars of Ukrainian breeding and more than 1000 hybrid seedlings. Most of the cultivars (79) were introduced in 2000–2009. The main part of the current structure of the daylily collection consists of cultivars bred in the 1960–1970s. Most of these are hybrids from American breeders: David F. Hall (20 cultivars) and Allen Wild (46 cultivars). A total of 15 new cultivars were developed based on the original collection. These new cultivars feature double flowers, a valuable trait for hybrids in Ukraine. For effective use in ornamental horticulture and landscaping, the cultivars were grouped according to flower colour and flowering time. The yellow­flowered group is the most widely represented. A large number of cultivars with red flowers are inherent in hybrids bred between 1980 and 1999. Cultivars from modern breeding are mostly represented by the purple and pink colour group. Most of the cultivars in the collection are early and medium early. The smallest part is made up of medium­late and late hybrids. Conclusions. The modern daylily collection is representative. The cultivars introduced into the NBG illustrate the main stages of breeding work with the crop and the achievements of breeders from different countries of the world. The collection includes early and medium early, medium, medium late and late flowering cultivars. Varying in colour and flowering time, the collection can be effectively used to extend the flowering period of daylilies by three months (from the second decade of May to the second decade of August) in ornamental gardening in Ukraine and in various landscape compositions.

Effects of green seaweed (<i>Ulva onhoi</i>) on the reproductive development of tomato (<i>Solanum lycopersicum)</i> plants

Algae-derived products have great potential as crop biostimulants due to their multiple beneficial effects at different stages of plant development. Green seaweeds of the genus <i>Ulva</i> are well suited for this purpose because they are widely distributed and grow rapidly in a wide range of conditions. In this study, a greenhouse experiment was conducted to evaluate the effects of dry seaweed powder (DSP) and liquid seaweed extract (LSE) of <i>Ulva ohnoi</i> on the reproductive development of tomato plants. The experiment included three treatments: 1) plants treated with 5 g of DSP, 2) plants treated with 250 mL of LSE, and (3) control plants (without algae). The reproductive parameters, chlorophyll content, and mineral composition were measured during the flowering and early fruiting periods. The application of DSP was the most effective treatment in promoting early flowering and significantly increased the number of buds (103%), flower clusters (55%), flowers (61%), and fruits (45%) per plant. Furthermore, the DSP-treated plants exhibited an enhancement in the levels of chlorophyll and nutrients in the plants and fruits. The results of the current work show that the application of <i>U. ohnoi</i> in its natural form (dry powder) stimulates the reproductive development of crop tomato. This represents a sustainable and natural alternative to synthetic inputs that growers can incorporate into horticultural production to improve yield attributes.

Effects of NH4 +-N: NO3 --N ratio on growth, nutrient uptake and production of blueberry (Vaccinium spp.) under soilless culture.

Blueberry (Vaccinium corymbosum) is a small pulp shrub, which prefers to grow on a soilless culture. For soilless culture, nutritional management remains typically vital for blueberry production. However, the effect of different nutritional treatments on blueberry growth and production is largely unknown. This study was designed to investigate to formulate a specific nutritional treatment for blueberry. The results showed that NH4 +-N: NO3 --N ratios significantly affected the growth, nutrient uptake, physiological characteristics, and flowering, as well as the fruiting characteristics of blueberry plants. The number of shoots and top projection area was increased considerably by 25:75 treatment. In contrast, 50:50 treatment promotes plant height, shoot length, and stem thickness, increasing chlorophyll contents, photosynthetic capacity, and P, Ca, and Mg in leaves. In contrast, 50:50 treatment promotes the flowering fruiting rate and prolongs the blueberry flowering period. The maximum soluble sugar contents were noted in 25:75, while maximum starch contents were reported in the 50:50 treatment. The treatments 100:0 and 75:25 promote early flowering and accelerate fruit set. Notably, NH4 +-N: NO3 --N ratios; 50:50 treatment significantly encourages plant growth, nutrient uptake, chlorophyll contents, photosynthetic capacity, and fruit setting rate in blueberry plants. These findings suggested that NH4 +-N: NO3 --N ratios 50:50 is the most appropriate treatment that significantly promotes vegetative growth and enhances production in blueberry plants. This study provides valuable information for improved blueberry production under a controlled environment.

Фенологические особенности развития сортов вишни в меняющихся погодно-климатических условиях

Annotation. Cherry is a stone fruit crop cultivated in almost all regions of Russia. Currently, there is a significant change in weather and climatic conditions, their impact leads to a shift in the phenological phases of plant development and to disruption of the stages of organogenesis. In this regard, there is a need to study the passage of phenological phases of cherry development in the changing weather and climatic conditions of the southern region. The research was carried out on the basis of the collective use center (CUC) “Genetic collection of fruit crops” in the period 2020-2023 in the Kuban horticulture zone of Krasnodar region. The objects of research were 11 varieties of sour cherries of various ecological and geographical origins. Planting scheme is 5x3 m, rootstock is antipka seedlings. During the research, the sum of active temperatures during the cherry growing season was determined, which determines the occurrence of the main phenological phases of development of cherry varieties in the annual development cycle. It was established that over the years of research, on average, the sum of active temperatures exceeded the long-term average by 551,7 °C. It was determined that during the research period the phenological phase “beginning of growing season” of cherries took place at a sum of temperatures of 32.8-54.2 °C. The phenological phase of “beginning of flowering” for most varieties in 2020 and 2023 occurred earlier than the long-term average date by 2-8 days, in 2023 – by 2-6 days, and in 2021-2022 – later by 2-14 days. It was revealed that at the phenophase "beginning of flowering", early cherry varieties (Krasnodarskaya sladkaya, Chudo vishnya), medium (Timati, Feya, Assol’, Svatlaya) are strongly affected by stress. Tamaris and Hodosa cherry varieties of late ripening showed relatively high resistance to stress during the flowering period. Key words: cherry, variety, phenological characteristics, flowering, climate.

Genome-wide identification, expression analysis of the R2R3-MYB gene family and their potential roles under cold stress in Prunus sibirica

BackgroundThe R2R3-MYB transcription factors in plants participate in various physiological and biochemical processes and responds to various external stimuli. Prunus sibirica (known as Siberian apricot) is a drupe tree species that produces extremely high nutritional value kernels. However, it is susceptiblility to frost damage during the flowering period, results in a marked reduction in kernel yield.ResultsIn this study, the MYB gene family of P. sibirica (PsMYB) was systematically analyzed, and 116 R2R3-MYB genes that were distributed unevenly over eight chromosomes were ultimately screened. Phylogenetic analysis divided these 116 genes into 30 subgroups. We discovered that 37 PsMYBs had cold stress-responsive promoters, and six PsMYBs were annotated to be associated with cold response. Intraspecific homology analysis identified segmental duplication as the primary gene amplification mechanism, and homology analysis of the PsMYB genes with those of five other species revealed phylogenetic relationships with Rosaceae species. Protein interaction studies revealed collaborative regulation of the PsMYB proteins with Arabidopsis protein, and transcriptome analysis identified PsMYB genes that were highly expressed at low temperatures. Additionally, the expression levels of 22 PsMYBs in different tissue parts of P. sibirica and under different low-temperature stress conditions were evaluated using quantitative real-time PCR, with the results verifying that PsMYBs are specifically expressed in different plant parts and may be involved in the growth and development of P. sibirica species. Genes upregulated after exposure to low-temperature stress and likely involved in cold response were identified.ConclusionThis study lays a foundation for understanding the molecular biology of PsMYBs in P. sibirica and provides a theoretical basis for the future study of transgenic lines with cold resistance during the flowering period of this tree.

Pollination‐related plant traits under environmental changes: Seasonal and daily mismatches produce temporal constraints

Abstract Pollination is a key tenet of ecosystem sustainability and food security, but it is threatened by climate change. While many studies investigated the response of plant‐pollination traits to temperature, few attempted multifactorial and integrative approaches with multiple floral traits. We determined which plant‐pollination traits were disrupted by environmental changes and the consequence for plant fitness. We focused on the thermogenic plant, Arum italicum, which relies on floral scent and heat production to attract its pollinators with a deceptive strategy. In a field mesocosm, we measured the response of floral phenology, thermogenesis traits, scent and plant fitness to experimental changes in shade level, water supply and soil temperature. In the laboratory, we exposed plants to extreme heat to determine the thermoregulation ability at high temperatures. Plant fitness decreased dramatically in response to soil warming and the level of shade. While both factors caused a lower number of inflorescences, soil warming was mostly responsible for the crash in number of fruits. The plant traits related to thermogenesis and scent were relatively resilient to the environmental changes in the mesocosm and were unlikely to produce the observed decrease in plant fitness. First, environmental changes only weakly modified the scent composition. Second, the appendix regulated its maximal temperature almost perfectly, while stamen regulated imperfectly. In the laboratory experiment, the appendix maintained a thermal gradient supposedly to improve scent emission while stamen became cooler than ambient air, possibly preventing the pollinators from overheating within the floral chamber. By contrast, the phenology of flowering was drastically modified. Flowers appeared earlier in the season in response to soil warming (by 39 days) or absence of shade (by 19 days). At the daily scale, flowering hour did not change across the season resulting in plants flowering before sunset late in the season and before the pollinator activity window (mostly nocturnal). The strong shift observed in the flowering period may induce a temporal mismatch with this pollinator both early and late in the season when the insects may not be active so early in the spring and during daytime, respectively, thereby altering plant fitness. Read the free Plain Language Summary for this article on the Journal blog.

Sex-Dependent Rhizosphere Microbial Dynamics and Function in Idesia polycarpa through Floral and Fruit Development

Male Idesia polycarpa, which display distinct morphological and physiological traits, exhibit greater adaptability to stressful environments than females. However, the connection between this adaptability and rhizosphere processes remains unclear. Here, we investigate the differences in root bacterial community structures between male and female plants at different developmental stages, identifying bacterial strains associated with plant sex through functional predictions. This study aims to inform the optimal allocation of male and female plants during cultivation and provide a theoretical basis for sex identification and breeding. Samples from seven-year-old male and female plants were collected during the flowering (May) and fruit ripening (October) stages. Rhizosphere nutrient content and bacterial diversity were analyzed using Illumina high-throughput sequencing technology. The results demonstrate that total nitrogen (TN), total carbon (TC), and available potassium (AK) varied between sexes at different times. No significant differences between male and female plants were observed in the Shannon, Simpson, and Chao1 indexes during the flowering period. However, the Chao1 and Shannon indexes were significantly higher at fruit maturity in male rather than female plants. The predominant phyla of rhizosphere bacteria were Pseudomonadota, Acidobacteriota, and Actinomycetes. Interestingly, from flowering to fruit ripening, the dominant phyla in both male and female plants shifted from Actinomycetes to Pseudomonadota. A significant correlation was observed between pH and AK and rhizosphere bacteria (p < 0.05), with metabolism being the main functional difference. This study provides preliminary insights into the functional predictions and analyses of bacteria associated with Idesia polycarpa. The above findings lay the groundwork for further investigation into the sex-specific differences in microbial flora across different developmental stages, elucidating the mechanisms underlying flora changes and offering theoretical support for the high-quality management of Idesia polycarpa.

European pollen reanalysis, 1980–2022, for alder, birch, and olive

The dataset presents a 43 year-long reanalysis of pollen seasons for three major allergenic genera of trees in Europe: alder (Alnus), birch (Betula), and olive (Olea). Driven by the meteorological reanalysis ERA5, the atmospheric composition model SILAM predicted the flowering period and calculated the Europe-wide dispersion pattern of pollen for the years 1980–2022. The model applied an extended 4-dimensional variational data assimilation of in-situ observations of aerobiological networks in 34 European countries to reproduce the inter-annual variability and trends of pollen production and distribution. The control variable of the assimilation procedure was the total pollen release during each flowering season, implemented as an annual correction factor to the mean pollen production. The dataset was designed as an input to studies on climate-induced and anthropogenically driven changes in the European vegetation, biodiversity monitoring, bioaerosol modelling and assessment, as well as, in combination with intra-seasonal observations, for health-related applications.

The Influence of Planting Density on the Flowering Pattern and Seed Yield in Peanut (Arachis hypogea L.) Grown in the Northern Region of Japan

In peanut cultivation in the Tokachi region of Hokkaido, Japan, it is essential to complete the harvest by early October to prevent frost damage. Therefore, cultivation methods that can accelerate the flowering period are necessary. It is understood that planting density can influence the timing of flowering, with crops often flowering earlier at higher densities. This study aimed to investigate whether growing peanuts at higher densities could advance the flowering period and, consequently, enhance yield. The Japanese peanut variety, Tachimasari, was cultivated in 2022 and 2023 at a conventional planting density of 5.8 plant m−2 (D5.8) and at density conditions of 8.7 plant m−2 (D8.7) and 11.6 plant m−2 (D11.6). The D8.7 and D11.6 plants reached the peak of flowering 2.8 and 5.1 days earlier, respectively, and the end of flowering 3.7 and 8.0 days earlier than the D5.8 plants. Although the total number of flowers was higher in D5.8, pod fertility was greater in D8.7 and D11.6, where plants were able to reduce the occurrence of ineffective flowers and immature pods. Consequently, higher seed yields were observed in D8.7 (2709 kg ha−1) and D11.6 (2754 kg ha−1), where lower individual productivity was offset by higher planting densities, compared to the conventional density condition of D5.8 (2169 kg ha−1).

Mitigating the impact of Erysiphe Lonicerae on honeysuckle through preventive use of potassium dihydrogen phosphate and a comparative analysis of floral composition across three developmental stages

Honeysuckle, a key traditional Chinese medicinal herb, holds significant economic and therapeutic value. However, its three flowering stages lack clarity in component differentiation, leading to resource waste. Furthermore, the plant is consistently challenged by powdery mildew caused by Erysiphe lonicerae during cultivation. This study demonstrates that E. lonicerae reduces the flowering period from 12.4 to 8.6 days and alters the expression of two key flowering genes. However, foliar application of 0.1 % KH₂PO₄ three times weekly effectively mitigates the reduction in flowering duration. Initiating treatment at least one month prior to E. lonicerae inoculation significantly reduces the disease's impact, with earlier treatments proving more effective. Further, A comprehensive analysis of the three floral stages revealed significant metabolite and enzyme activity differences. We identified 175 differentially expressed metabolites (DEMs) between gold flowers and buds, 60 between gold and silver flowers, and 162 between buds and silver flowers, particularly in lipids, phenylpropanoids, and polyketides. Enzyme activities of PPD, SOD, PPO, and PAL, along with flavonoid content and antioxidant capacity, varied significantly across these stages. Notably, a total of 13 medicinal compounds were uniquely distributed across the floral stages, indicating that these compounds are not concentrated solely in the buds.In summary, The prophylactic use of KH₂PO₄ can effectively reduce the damage caused by E. lonicerae.The distinct metabolic profiles of the buds, silver flowers, and gold flowers highlight the need for further research into their optimal medicinal applications.

Specific Weather Factors Affecting the Incidence of Fire Blight in Korea from 2020 to 2023

Since its initial outbreak in Korea in 2015, fire blight has consistently emerged annually. Fire blight outbreaks usually begin in May, peak in June, and decline in July in Korea. In this study, we analyzed cases that exhibit a distinct pattern of disease occurrence based on yearly weather conditions from 2020 to 2023. In 2020, fire bight disease occurrence began in late May. Although the disease incidence started late by the low temperatures in April, which caused flowering period delayed, the incidence increased significantly due to the high risk of blossom infection. In 2021, the first outbreak began in late April because the flower infection started in early April. In 2022, despite the high blossom infection risk during the flowering period in April and the high incidence of fire blight in May, the incidence decreased sharply from June due to the low rainfall in May. In 2023, due to torrential rains and hail in late June, the incidence of fire blight increased even in July. Considering the weather factors that affect the increase of fire blight disease, it is suggested that control measures to prevent the fire blight infection should be carried out before and after wind-driven rains.

Gene pyramiding improved cell membrane stability under heat stress in cotton (Gossypium hirsutum L.)

Climate change has been drastically affecting cotton not only in Pakistan but also all over the world. Normally cotton is known as heat tolerant when compared with other crops, but if the high temperature occurs during flowering period the yield decreases significantly. Marker assisted gene pyramiding provides a sustainable solution to improve heat tolerance. A total of seven genotypes were developed by a series of crossing seven tolerant genotypes over the period of three years. Tolerant genotypes were selected by screening for important transcription factors (GHSP26, HSP3, HSFA2, DREB1A, HSP101, DREB2A, GhNAC2, HSPCB, GhWRKY41, TPS, GbMYB5, ANNAT8, GhMPK17, GhMKK1, GhMKK3, GhMPK2, HSC70, APX1 and GhPP2A1). The seven genotypes were evaluated under normal and heat stress in a multi-year trial. The traits related to heat tolerance, such as cell membrane stability, relative water content, excised leaf water loss, plant height, number of nodes, internodal length, number of buds, number of bolls and leaf area was observed under normal and heat stress conditions. The developed genotypes showed improvement in cell membrane stability and relative water content under heat stress. The genotypes [(VH-305×MNH-886)×MNH-1035)×NIAB-78)], [(MNH-1035×MNH-886)×MNH-886)×SM-431] and [(MNH-1035×MNH-886)×MNH-886)×SS-32] depicted heat tolerance and could be used as heat tolerant material for variety development in breeding programs.

Insect Pollinivores of Sorghum bicolor and Plant Traits that Influence Visitation1

Abstract Grasses such as sorghum, (Sorghum bicolor (L.) Moench), are rarely considered as an important food resource for pollinators. Here, we report insects collecting or consuming pollen of sorghum over the 8-wk flowering period of a mapping population in Tifton, GA. We also examine the response of insects to plant morphological traits and disease damage and the ability of bumble bees (Bombus impatiens) to cross-pollinate sorghum. The most numerous insect observed collecting/consuming sorghum pollen was the hover fly Toxomerus politus Say (i.e., the maize calligrapher) followed by honey bees (Apis mellifera L.), lined earwigs (Doru taeniatum Dorhn), lovebugs (Plecia nearctica Hardy), southern carpenter bees (Xylocopa micans Lepeletier), common eastern bumble bees (Bombus impatiens Cresson), exotic stripetails (Allograpta exotica Wiedemann), margined soldier beetles (Chauliognathus marginatus F.), a signal fly (Rivellia sp. Robineau-Desvoidy), and a dusky-winged hover fly (Ocyptamus fuscipennis Say). Maximum flowering occurred at Week 3, which coincided with the maximum number of maize calligraphers, bumble bees, and honey bees observed. A positive linear relationship was seen between the number of flowering plots and the number of maize calligraphers and honey bees. The probability of observing a bee on a panicle increased as plant height increased, whereas the probability of observing a bee or hover fly decreased as plant disease percentage increased. These results suggest that inflorescence abundance, plant height, and plant disease impact bee visitation in sorghum. Furthermore, field-captured bumble bees successfully fertilized sorghum in a greenhouse study, suggesting that bumblebees can pollinate sorghum flowers in field conditions.

A new nothospecies of Prosthechea (Orchidaceae: Laeliinae) from the Diamantina Plateau, Minas Gerais, Brazil

Based on morphological evidence found in some specimens recently collected in the Diamantina Plateau region, Minas Gerais State, Brazil, a new natural hybrid between Prosthechea calamaria and P. faresiana is described and illustrated as P. ×riopretensis. Both putative parental species are known for the region and their flowering period overlaps. The new nothospecies carries most of the morphological features of P. calamaria, such as short plants (≤ 19 cm height) and inflorescences (≤ 7 cm long), and flowers with a small ovate lip (≤ 1 cm long), but the floral color pattern are remarkably like P. faresiana – sepals and petals covered by longitudinal vinaceous stripes. In addition to a digital composite plate of the taxonomic novelty, further images and a distribution map of the new nothospecies and its putative parents are provided, as well as notes on morphology, phenology, and ecology.

Analysis of Yield Indicators of Eastern Persimmon (Diospyros kaki L. f.) Varieties Grown in the Territory of the Sheki-Zagatala Region of the Republic of Azerbaijan

The article analyzes phenological observations and yield indicators of eastern persimmon varieties cultivated in the Sheki-Zagatala region of the Azerbaijan Republic. The existing 10 varieties of eastern persimmon (Diospyros kaki L. f.) were studied: Hiakume, Guyboshi, Tanenashi, Tamopan, Sidles, Amon-kaki, Geili, Tranta-kaki, Khachia and Kaki-mela. The beginning of the growing season for persimmon depends on the weather conditions of the year, the swelling of shoots is in early April (04/10) at an average air temperature of 8.3–9.3°C, and the opening of shoots is at the end of April (04/21) at an average daily temperature of 12.6–13°C. Flowering by variety began earliest on May 15 for the Hiakume variety and ended on May 30 for the Sidles variety; the flowering period lasted approximately 15 days. The earliest start of fruit ripening was observed in the Hiakume variety on October 12, and the latest in the Khachia variety - on October 20. The fruit ripening period lasted from October 12 to October 30. The earliest leaf fall began at the beginning of May for the variety Tamopan (05.11) and ended at the end of November for the variety Amon-khaki (28.11). The duration of the growing season ranged from 216-227 days. The highest yield was 268.5 kg per tree for the Tamopan variety, and the lowest was 71.0 kg for the Khachia variety. The weight of 1 persimmon fruit for the Tamopan variety was 350 g, for the Geili variety — 110 g. The number of fruits on the tree for the Geili variety was 2730 pcs., for the Sidles variety — 140 pcs. In the Sheki-Zagatala region, the main part of the areas for growing and producing eastern persimmons is in the Belokan and Zagatala regions, and over the years there has been an increase in these areas.