Flower Initiation Research Articles

Local climate and vernalization sensitivity predict the latitudinal patterns of flowering onset in the crop wild relative Linum bienne Mill.

The timing of flowering onset often correlates with latitude, indicative of climatic gradients. Flowering onset in temperate species commonly requires exposure to cold temperatures, known as vernalization. Hence, population differentiation of flowering onset with latitude might reflect adaptation to the local climatic conditions experienced by populations. Within its Western range, seeds from Linum bienne populations (the wild relative of cultivated L. usitatissimum) were used to describe the latitudinal differentiation of flowering onset to determine its association with the population´s local climate. A vernalization experiment, including different crop cultivars, was used to determine how vernalization accelerates flowering onset, and the vernalization sensitivity response among populations and cultivars. Additionally, genetic differentiation of L. bienne populations along the latitudinal range was scrutinized using microsatellite markers. Flowering onset varied with latitude of origin, with southern populations flowering earlier than their northern counterparts. Vernalization reduced the number of days to flowering onset, but vernalization sensitivity was greater in northern populations compared to southern ones. Conversely, vernalization delayed flowering onset in the crop, exhibiting less variation in sensitivity. In L. bienne, both flowering onset and vernalization sensitivity were better predicted by the population´s local climate than latitude itself. Microsatellite data unveiled genetic differentiation of populations, forming two groups geographically partitioned along latitude. The consistent finding of latitudinal variation across experiments suggests that both flowering onset and vernalization sensitivity in L. bienne populations are under genetic regulation and might depend on climatic cues at the place of origin. The association with climatic gradients along latitude suggests that the climate experienced locally drives population differentiation of the flowering onset and vernalization sensitivity patterns. The genetic population structure suggests that past population history could have influenced the flowering initiation patterns detected, which deserves further work.

Optimizing crop water productivity and delineating root architecture and water balance in cotton–wheat cropping system through sub-surface drip irrigation and foliar fertilization strategy in an alluvial soil

Water-intensive agricultural practices in tandem with conventional irrigation methods such as flood irrigation, has caused severe water scarcity in south-Asian Indo-Gangetic Plains (IGPs). The adoption of micro-irrigation systems (sprinker, surface drip and sub-surface drip) instead of flooding offers a great promise in water saving and enhanced fertilizer-use efficiency, and thus, improved productivity. The change in irrigation and fertilization methodology may affect the behavior of plant root growth, root architecture and, crop and water productivity. Hence, current study aimed at evaluating the influence of sub-surface drip-irrigation and fertigation strategy on crop and water productivity besides delineating root architecture and soil water balance in cotton–wheat cropping system (CWCS). Results showed that sub-surface drip irrigation (SSDI) enhanced the root system by stimulating the development of new secondary roots which actively participated in physiological responses. Root length at boll opening stage of cotton increased significantly under SSDI at 60% ETc (60% of evapo-transpiration) over other treatments. Root mass density in wheat was also significantly higher under SSDI particularly at 15–30 cm depth over surface drip and flood irrigation during 2020–21. SSDI at 100% ETc (100% of evapo-transpiration) produced statistically similar seed cotton yield, wheat grain yield and the system productivity (wheat equivalent yield) to 80% ETc. SSDI at 80% ETc (80% of evapo-transpiration), resulted in water-saving of ∼43.2% over flood irrigation in CWCS. Further, fertigation through SSDI resulted in ∼20% reduction in fertilizer needs, while achieving the yield equivalent to that of conventional fertilization. Irrigation water productivity and bio-physical water productivity of this system were ∼46.1 and 5.7% higher under 80% ETc along with F80 (80% recommended dose of nitrogen, RDN) and Mfoliar (foliar application of KNO3 & MgSO4 at flower initiation and boll development stages of cotton) over flood irrigation. Overall, SSDI at 80% of evapo-transpiration along with 80% RDN and foliar application of KNO3 & MgSO4 may prove highly beneficial to enhance the crop and water productivity in CWCS, besides saving irrigation water-use by ∼43.2% over flood irrigation in water-scarce agro-ecologies of south-Asia.

Genotypic variations of phenological and growth parameters in rapeseed (Brassica rapa, var. Toria)

Rapeseed is a short duration, self-pollinated and long day crop. It is an important and widely used oil seed crops among the people of Assam and North-East India. However, there is still lack of sufficient rapeseed genotypes for the local farmers. Only a few improved genotypes are recommended in the region. To increase the production and productivity, more numbers of improved genotypes have to be identified. Therefore, a field experiment was conducted at the Instructional-cum-Research (ICR) Farm, Assam Agricultural University, Jorhat, Assam, during rabi 2021-22 and 2022-23 to study the genotypic variations of phenological and growth parameters in rapeseed genotypes. The experiment was laid out in randomized block design with three replications comprising of 22 different genotypes of rapeseed including TS-38 (Check), TS-46, TS-67, TS-36, TS-29, TS-75-1, TS-75-1TL, TS-75-2ME, TS-75-2-MM, TS-76-1, TS-76-2, JT-90-1, Panchali, Bhawani, CG Toria-4, TKM-20-1, TKM-20-2, JT-14-5, PT-2018-09, CG Toria-3, Tapeshwari and PT-303. The crops were grown following the recommended package of practice. All the phenological and growth parameters were taken following the standard methodologies. The result of the experiment indicated significant difference in reaching phenological and growth parameters among the genotypes. The genotype JT-14-5 and TKM-20-2 took the longest duration for 50% flowering and siliqua initiation. However, JT-14-5 and JT-90-1 took the longest duration for physiological maturity. On the other hand, TS-67 and TS-75-1TL took the shortest duration for physiological maturity. The genotype TS-75-2ME showed highest dry weight followed by the genotype TS-38 at harvest. There was gradual increase in Absolute Growth Rate and Crop Growth Rate with the advancement of growth. However, in case of Relative Growth Rate, a decline was noticed in the values from 30-60 DAS to 60 DAS-harvest. The genotype TS-75-2ME and TS-38 were recorded highest yield and highest Crop Growth Rate during 30-60 DAS indicating that the parameter at that particular stage of growth, has positive impact on seed yield.

Transcriptome-Based Identification of Candidate Flowering-Associated Genes of Blueberry in a Plant Factory with Artificial Lighting (PFAL) under Short-Day-Length Conditions.

In blueberry (Vaccinium corymbosum L.), a perennial shrub, flower bud initiation is mediated by a short-day (SD) photoperiod and buds bloom once the chilling requirement is satisfied. A plant factory with artificial lighting (PFAL) is a planting system that can provide a stable and highly efficient growing environment for blueberry production. However, the characteristics of bud differentiation of blueberry plants inside PFAL systems are poorly understood. To better understand flower bud initiation and the flowering mechanism of blueberry in PFAL systems, the anatomical structure of apical buds under SD conditions in a PFAL system was observed using the southern highbush cultivar 'Misty' and a transcriptomic analysis was performed to identify the candidate flowering genes. The results indicated that the apical bud of 'Misty' differentiated gradually along with SD time course and swelled obviously when chilling was introduced. A total of 39.28 Gb clean data were generated, and about 20.31-24.11 Mb high-quality clean reads were assembled, yielding a total of 17370 differentially expressed genes (DEGs), of which 9637 were up-regulated and 7733 were down-regulated. Based on the functional annotation, 26 DEGs were identified including 20 flowering-related and 6 low-temperature DEGs, out of which the expressive level of four flowering-related DEGs (VcFT2, VcFPA, VcFMADS1, and VcCOP1) and two low-temperature-induced DEGs (VcTIL-1 and VcLTI 65-like) were confirmed by qRT-PCR with a good consistency with the pattern of transcriptome. Functional analysis indicated that VcFT2 was highly conserved with nuclear and cytoplasmic subcellular localization and was expressed mainly in blueberry leaf tissue. In Arabidopsis, ectopic overexpression of VcFT2 results in an early flowering phenotype, indicating that VcFT2 is a vital regulator of the SD-mediated flowering pathway in blueberry. These results contribute to the investigation of photoperiod-mediated flowering mechanisms of blueberry in PFAL systems.

Highly stable and antifungal properties on the oilseed rape of Cu3(MoO4)2(OH)2 nanoflakes prepared by simple aqueous precipitation

In the last few decades, nanoparticles have been a prominent topic in various fields, particularly in agriculture, due to their unique physicochemical properties. Herein, molybdenum copper lindgrenite Cu3(MoO4)2(OH)2 (CM) nanoflakes (NFs) are synthesized by a one-step reaction involving α-MoO3 and CuCO3⋅Cu(OH)2⋅xH2O solution at low temperature for large scale industrial production and developed as an effective antifungal agent for the oilseed rape. This synthetic method demonstrates great potential for industrial applications. Infrared spectroscopy and X-ray diffraction (XRD) results reveal that CM samples exhibit a pure monoclinic structure. TG and DSC results show the thermal stable properties. It can undergo a phase transition form copper molybdate (Cu3Mo2O9) at about 300 °C. Then Cu3Mo2O9 nanoparticles decompose into at CuO and MoO3 at 791 °C. The morphology of CM powder is mainly composed of uniformly distributed parallelogram-shaped nanoflakes with an average thickness of about 30 nm. Moreover, the binding energy of CM NFs is measured to be 2.8 eV. To assess the antifungal properties of these materials, both laboratory and outdoor experiments are conducted. In the pour plate test, the minimum inhibitory concentration (MIC) of CM NFs against Sclerotinia sclerotiorum (S. sclerotiorum) is determined to be 100 ppm, and the zone of inhibiting S. sclerotiorum is 14 mm. When the concentration is above 100 nm, the change rate of the hyphae circle slows down a little and begins to decrease until to 200 ppm. According to the aforementioned findings, the antifungal effects of a nano CM NFs solution are assessed at different concentrations (0 ppm (clear water), 40 ppm, and 80 ppm) on the growth of oilseed rape in an outdoor setting. The results indicate that the application of CM NFs led to significant inhibition of S. sclerotiorum. Specifically, when the nano CM solution was sprayed once at the initial flowering stage at a concentration of 80 ppm, S. sclerotiorum growth was inhibited by approximately 34%. Similarly, when the solution was sprayed once at the initial flowering stage and once at the rape pod stage, using a concentration of 40 ppm, a similar level of inhibition was achieved. These outcomes show that CM NFs possess the ability to bind with more metal ions due to their larger specific surface area. Additionally, their semiconductor physical properties enable the generation of reactive oxygen species (ROS). Therefore, CM NFs hold great potential for widespread application in antifungal products.

Influence of Growth Regulators Application on Seed Development and Maturation in Pigeonpea (Cajanus cajan (L.)

The experiment was carried out at National Pulses Research Centre (NPRC), Vamban, Tamil Nadu Agricultural University to assess the effect of growth regulators foliar sprayon seed development and maturation in Pigeonpea VBN (Rg) 3. Plant growth regulators viz., GA3 (200 ppm) and chlormequat chloride(CCC) 200 ppm were sprayed at vegetative (65 DAS) and flowering stage (80 DAS). The plants without any foliar spraying treatment considered as control. When 50 percent of the plants in a population have reached bud initiation stage, the buds were tagged and collected at five days interval from 5th day upto45th days after initiation (DAI). The variation in pod colour, changes in pod length and weight, seed fresh and dry weight, moisture content, germination and seedling vigour were recorded at regular intervals of five days up to 45 days after flower initiation. The results revealed that the maximum pod length, fresh and dry weight of pod and seed, seed germination and seedling vigour was observed in pigeonpea at 30 days after floral initiation (DAI) in chlormequat chloride (CCC) 200 ppm foliar treatment. The control i.e. without any foliar treatment had attained the physiological maturity at 35 DAI by recording all the physiological parameters viz. maximum pod length, fresh and dry weight, seed germination and seedling vigour. In pigeonpea, application of CCC @ 200 ppm as foliar treatmentleadsto attain physiological maturity at 30 days after initiation of flowering (DAI) by recording the highest seed weight, germination and seedling dry weight over control.

Inducing the Growth and Yield of Mungbeans Applied with Different Level of Concentrations of Bio-Stimulant Solutions

The study sought to determine the effects of different levels of concentrations of bio-stimulant solution (BSS) in inducing the growth, flower, and yield of mung bean. The study was conducted at UNO-R School of Agriculture, Philippines last February to April 2022. Pag-asa 3 variety was used as planting material. The study was laid out in RCBD) with four treatments and replicated 4 times. The BSS was diluted in water and applied 6 inches from the base of the plant as per research protocol. Statistical analysis revealed highly significant differences among treatments in growth parameters such as plant height and leaf area index (LAI) at 35DAS. Likewise, there was high significant difference among treatments on the days to 50% flowering of the plant. Furthermore, results showed highly significant differences among treatments in the number of pods per plant, pod weight per plant, number of seeds per pod, 100 seed weight, and yield of mung bean. For the highest plant height, LAI, and period of flowering they were obtained from plants applied with 150ml BSS, followed by 100ml BSS, and 50ml BSS. On the other hand, untreated plants have the shortest height, narrower leaves, and late in flower initiation. Mung bean pods per plant were great in number, heavier in weight from plants treated with 150ml BSS among the other treatments, the most number of seeds per pod, and the heaviest per 100-seed weight as well as the highest seed yield per hectare. This study recommends the use of 150ml BSS in inducing the growth and higher yield of mung bean plant production.

Screening cotton genotypes for their drought tolerance ability based on the expression level of dehydration-responsive element-binding protein and proline biosynthesis-related genes and morpho-physio-biochemical responses.

Drought stress adversely affects growth, development, productivity, and fiber quality of cotton (Gossypium hirsutum L). Breeding strategies to enhance drought tolerance require an improved knowledge of plant drought responses necessitating proper identification of drought-tolerant genotypes of crops, including cotton. The objective of this study was to classify the selected cotton genotypes for their drought tolerance ability based on morpho-physio-biochemical traits using Hierarchical Ward's cluster analysis. Five genotypes of cotton (Takfa 3, Takfa 6, Takfa 7, Takfa 84-4, and Takfa 86-5) were selected as plant materials, and were grown under well-watered (WW; 98 ± 2% field capacity) and water-deficit (WD; 50 ± 2% field capacity) conditions for 16days during the flower initiation stage. Data on morpho-physio-biochemical parameters and gene expression levels for these parameters were collected, and subsequently genotypes were classified either as a drought tolerant or drought susceptible one. Upregulation of GhPRP (proline-rich protein), GhP5CS (Δ1-pyrroline-5-carboxylate synthetase), and GhP5CR (Δ1-pyrroline-5-carboxylate reductase) in relation to free proline enrichment was observed in Takfa 3 genotype under WD condition. An accumulation of free proline, total soluble sugar, and potassium in plants under WD conditions was detected, which played a key role as major osmolytes controlling cellular osmotic potential. Magnesium and calcium concentrations were also enriched in leaves under WD conditions, functioning as essential elements and regulating photosynthetic abilities. Leaf greenness, net photosynthetic rate, stomatal conductance, and transpiration rate were also declined under WD conditions, leading to growth retardation, especially aboveground traits of Takfa 6, Takfa 7, Takfa 84-4, and Takfa 86-5 genotypes. An increase in leaf temperature (1.1 - 4.0°C) and crop water stress index (CWSI > 0.75) in relation to stomatal closure and reduced transpiration rate was recorded in cotton genotypes under WD conditions compared with WW conditions. Based on the increase of free proline, soluble sugar, leaf temperature, and CWSI, as well as the decrease of aboveground growth traits and physiological attributes, five genotypes were categorized into two cluster groups: drought tolerant (Takfa 3) and drought susceptible (Takfa 6, Takfa 7, Takfa 84-4, and Takfa 86-5). The identified drought-tolerant cotton genotype, namely, Takfa 3, may be grown in areas experiencing drought conditions. It is recommended to further validate the yield traits of Takfa 3 under rainfed field conditions in drought-prone environments.

Genome-Wide Characterization of Differentially Expressed Scent Genes in the MEP Control Network of the Flower of Lilium 'Sorbonne'.

Fragrance is an important feature of ornamental lilies. Components of volatile substances and important genes for monoterpene synthesis in the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway were examined in this study. Twenty volatile compounds (2 in the budding stage, 3 in the initial flowering stage, 7 in the semi-flowering stage, 17 in the full-flowering stage, and 5 in withering stage) were detected in the Oriental lily 'Sorbonne' using gas chromatography-mass spectrometry. The semi- and full-flowering stages were key periods for volatile substance production and enzyme function. Sequence assembly from samples collected during all flowering stages resulted in the detection of 274,849 genes and 129,017 transcripts. RNA sequencing and heatmapping led to the detection of genes in the MEP monoterpene metabolism pathway. Through gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis, we extracted key genes (LiDXS2, LiLIS, and LiMYS) and transcription factors (in the bHLH, MYB, HD-ZIP, and NAC families) associated with the MEP pathway. Tissue localization revealed that LiDXS2, LiLIS, and LiMYS were expressed in Lilium 'Sorbonne' petals in the full-flowering stage. Genes regulating the 1-deoxy-D-X-lignone-5-phosphate synthase family of rate-limiting enzymes, involved in the first step of monoterpene synthesis, showed high expression in the semi- and full-flowering stages. LiDXS2 was cloned and localized in chloroplast subcells. The relative expression of terpene-related genes in the MEP and mevalonic acid pathways of wild-type and LiLIS/LiMYS transgenic Arabidopsis thaliana, and changes in chemical composition, confirmed that LiLIS/LiMYS regulates the monoterpene synthesis pathway. The results of this study provide a theoretical basis for the synthesis of lily aromatic substances and the cultivation of new garden flower varieties.

Prohexadione-calcium improves grape quality by regulating endogenous hormones, sugar and acid metabolism and related enzyme activities in grape berries.

Prohexadione-Calcium (Pro-Ca) plays key roles in improving fruit quality and yield by regulating various aspects of plant growth. However, the effects of how Pro-Ca regulates the regulation of sugar and acid balance and its impact on the production of volatile aroma substances during fruit growth and development are poorly understood. In this study, the Pro-Ca solutions developed at concentrations of 200, 400, 600 and 800 mg·L-1 were sprayed on the entire "Chardonnay" grape tree 22, 42, 62 and 82 days after initial flowering. The values of endogenous hormones, sugar and acid content, enzyme activities and flavor content were then measured in grapes 45, 65, 85 and 105 days (ripeness stage) after the initial flowering. The results showed that Pro-Ca had significant effects on fruits during development, including reducing ABA content, increasing ZT, GA3 and IAA levels, promoting fruit ripening and enhancing enzymes, which are involved in sugar and acid synthesis. Consequently, these effects led to an increase in sugar and acid content in the berries. Particularly during the ripening phase, the application of 600 mg L-1 Pro-Ca resulted in an increase in soluble sugar content of 11.28% and a significant increase in citric acid and malic acid content of 97.80% and 68.86%, respectively. Additionally, Pro-Ca treatment enhanced both the variety and quantity of aroma compounds present in the berries, with the 600 mg·L-1 Pro-Ca treatment showcasing the most favorable impact on volatile aroma compounds in 'Chardonnay' grapes. The levels of aldehydes, esters, alcohols, phenols, acids, ketones, and terpenes were significantly higher under the 600 mg·L-1 Pro-Ca treatment compared to those of control with 51.46 - 423.85% increase. In conclusion, Pro-Ca can regulate the content of endogenous hormones and the activities of enzymes related to sugar and acid metabolism in fruit, thereby increasing the content of soluble sugar and organic acid in fruit and the diversity and concentration of fruit aroma substances. Among them, foliar spraying 600mg · L-1 Pro-Ca has the best effect. In the future, we need to further understand the molecular mechanism of Pro-Ca in grape fruit to lay a solid foundation for quality improvement breeding.

FLOWERING LOCUS T1 and TERMINAL FLOWER1 regulatory networks mediate flowering initiation in apple.

Flower bud formation is a critical process that directly determines yield and fruit quality in fruit crops. Floral induction is modulated by the balance between 2 flowering-related proteins, FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1); however, the mechanisms underlying the establishment and maintenance of this dynamic balance remain largely elusive. Here, we showed that in apple (Malus × domestica Borkh.), MdFT1 is predominantly expressed in spur buds and exhibits an increase in expression coinciding with flower induction; in contrast, MdTFL1 exhibited downregulation in apices during flower induction, suggesting that MdTFL1 has a role in floral repression. Interestingly, both the MdFT1 and MdTFL1 transcripts are directly regulated by transcription factor basic HELIX-LOOP-HELIX48 (MdbHLH48), and overexpression of MdbHLH48 in Arabidopsis (Arabidopsis thaliana) and tomato (Solanum lycopersicum) results in accelerated flowering. Binding and activation analyses revealed that MdbHLH48 functions as a positive regulator of MdFT1 and a negative regulator of MdTFL1. Further studies established that both MdFT1 and MdTFL1 interact competitively with MdWRKY6 protein to facilitate and inhibit, respectively, MdWRKY6-mediated transcriptional activation of target gene APPLE FLORICAULA/LFY (AFL1, an apple LEAFY-like gene), ultimately regulating apple flower bud formation. These findings illustrate the fine-tuned regulation of flowering by the MdbHLH48-MdFT1/MdTFL1-MdWRKY6 module and provide insights into flower bud formation in apples.

Effect of Micro Climate on Flowering Characteristics in Grapes (Vitis vinifera L.)

The study aimed to find out the effect of micro climate on flowering characteristics in grapes varieties viz. Perlette, Flame Seedless, Superior Seedless and Punjab Purple. The experiment was conducted in Punjab-Ludhiana during 2018-19 fruiting seasons. Grape varieties were grown in both protective covering (Greenhouse) and open field. The data recorded showed that temperature and relative humidity was higher in protective covering with comparison to open field. The result of the experiment showed advancement in flowering characteristics viz. time of bud-burst, flowering initiation and fruit set in grape varieties grown under protective covering as compared to those grown in open field condition. Maximum advancement in bud burst was observed in Perlette variety (9 and 5 days earlier). Flower initiation was advanced by 4 days in Flame Seedless and Superior Seedless varieties and fruit set by 3-10 days in Punjab Purple variety grown in protective covering.

Biostimulants for Promoting Growth, Yield and Flower Quality in Anthurium andreanum Lind

The present study was carried out at the Department of Floriculture and Landscaping, College of Agriculture, Vellayani, Kerala Agricultural University, during 2022-23 with an aim to evaluate the effect of foliar application of different biostimulants on growth, yield, and flowering attributes of Anthurium under naturally ventilated polyhouse condition. The experiment was laid out in CRD with ten replications. There were fifteen treatments including the control. Fertilizers and manures were applied as per the Package of Practices Recommendations of Kerala Agricultural University (i.e., application of cow dung supernatant + 2 g L-119:19:19 weekly once) to all the treatments including the control (T1). In addition, for treatments T2 to T15, different biostimulants were applied as foliar sprays either alone or in combination fortnightly or monthly as per the treatment specifications. Being a popular cut flower, improvement in floral attributes is very much valued in Anthurium. The study concluded that the treatment T8 i.e., application of cow dung supernatant and 2 g L-119:19:19 weekly once as foliar spray along with foliar application of 2% humic acid - fulvic acid mixture and 100 mg L-1 salicylic acid at fortnightly intervals exhibited superior values for stalk length, spathe length, spathe width, number of flowers, flower longevity and vase life and it also recorded earliest flower bud initiation. The results revealed that growth and floral attributes of Anthurium can be improved through the foliar application of treatment T8.

Hormonal Regulation and Transcriptomic Insights into Flower Development in Hydrangea paniculata 'Vanilla Strawberry'.

Understanding the molecular mechanisms that regulate flower growth, development, and opening is of paramount importance, yet these processes remain less explored at the genetic level. Flower development in Hydrangea paniculata 'Vanilla Strawberry' is finely tuned through hormonal signals, yet the genetic underpinnings are not well defined. This study addresses the gap by examining the influence of gibberellic acid (GA3), salicylic acid (SA), and ethylene (ETH) on the flowering traits and underlying molecular responses. Treatment with 100 mg/L SA significantly improved chlorophyll content and bolstered the accumulation of soluble sugars and proteins, advancing the flowering onset by 6 days and lengthening the flowering period by 11 days. Concurrently, this treatment enhanced inflorescence dimensions, increasing length, width, and petal area by 22.76%, 26.74%, and 27.45%, respectively. Contrastingly, 100 mg/L GA3 expanded inflorescence size but postponed flowering initiation and decreased inflorescence count. Higher concentrations of SA and GA3, as well as any concentration of ETH, resulted in delayed flowering and inferior inflorescence attributes. A physiological analysis over 50 days revealed that these regulators variably affected sugar and protein levels and modified antioxidant enzyme activities. An RNA-seq analysis during floral development highlighted significant transcriptomic reprogramming, with SA treatment downregulating Myb transcription factors, implicating them in the modulation of flowering timing and stress adaptation. These findings illuminate the complex interplay between hormonal treatments, gene expression, and flowering phenotypes in Hydrangea paniculata, offering valuable perspectives for ornamental horticulture optimization.

Extensive post-transcriptional regulation revealed by integrative transcriptome and proteome analyses in salicylic acid-induced flowering in duckweed (Lemna gibba).

Duckweed is an aquatic model plant with tremendous potential in industrial and agricultural applications. Duckweed rarely flowers which significantly hinders the resource collection and heterosis utilization. Salicylic acid (SA) can significantly induce duckweed to flower; however, the underlying regulatory mechanisms remain largely unknown. In this work, transcriptome and proteome were conducted in parallel to examine the expression change of genes and proteins in Lemna gibba under SA treatment. A high-quality reference transcriptome was generated using Iso-Seq strategy, yielding 42,281 full-length transcripts. A total of 422, 423, and 417 differentially expressed genes (DEGs), as well as 213, 51, and 92 differentially expressed proteins (DEPs), were identified at flower induction, flower initiation, and flowering stages by ssRNA-seq and iTRAQ methods. Most DEGs and DEPs were only regulated at either the transcriptomic or proteomic level. Additionally, DEPs exhibited low expression correlations with the corresponding mRNAs, suggesting that post-transcriptional regulation plays a pivotal role in SA-induced flowering in L. gibba. Specifically, the genes related to photosynthesis, stress, and hormone metabolism were mainly regulated at the mRNA level, those associated with mitochondrial electron transport / ATP synthesis, nucleotide synthesis, and secondary metabolism were regulated at the protein level, while those related to redox metabolism were regulated at the mRNA and/or protein levels. The post-transcriptional regulation of genes relevant to hormone synthesis, transcription factors, and flowering was also extensively analyzed and discussed. This is the first study of integrative transcriptomic and proteomic analyses in duckweed, providing novel insights of post-transcriptional regulation in SA-induced flowering of L. gibba.

Effect of Poultry Manure and Ethephon on Growth, Yield, and Quality of Cayenne Pepper (Capsicum frutescens L.) ‘Ratuni UNPAD’

<p><span lang="IN">The production of 'Ratuni UNPAD' cayenne pepper can be increased using organic chicken manure. However, the application of ethephon is needed during fertilization due to the significantly slow flower initiation. Therefore, this study aim</span><span>s</span><span> <span lang="IN">to determine the interaction between chicken manure and ethephon on the growth, yield, and quality of the 'Ratuni UNPAD' cayenne pepper. Planting </span></span><span>is </span><span lang="IN">carried out 829 meters above sea level (masl), and a factorial randomized block experimental design comprises 2 factors with 3 replications. The first factor </span><span>i</span><span lang="IN">s the dose of chicken manure (10, 20, 30, and 40 t/ha), while the second is the ethephon concentration (0, 500, 1000, and 1500 ppm). The results showed no interaction between poultry manure and ethephon on the growth, yield, and quality of the 'Ratuni UNPAD' cayenne pepper. According to the doses of chicken manure, 40 t/ha significantly affect</span><span>s</span><span lang="IN"> the flower initiation, fruit number, weight, length, and diameter, as well as capsaicin and dihydrocapsaicin. The 30 t/ha shows the highest value for the number of leaves and productive branches, while 20 tons dose/ha influences flavonoids, phenolics, and total carotenoids. The ethephon concentration of 1500 ppm significantly affects the flower initiation, fruit length, diameter, capsaicin, and dihydrocapsaicin.</span></p>

Earlier Flowering Phenology and Pollinator Visitation on Urban Green Roofs Compared to Ground-Level Gardens

Urban green space, green infrastructure, and horticultural installations are gaining recognition for their potential to foster biodiversity. Green roofs are challenging growing environments for plants, characterized by extreme substrate temperatures, high light intensity, limited moisture availability, and limited substrate depth. Plants have a variety of physiological responses to these unique conditions, but little is known about how green roof growing conditions affect ecological characteristics like plant flowering phenology. Meanwhile, studies are only just uncovering the degree to which green roofs can provide habitat and support urban pollinator biodiversity. We evaluated the flowering phenology and made in situ pollinator observations of 15 plant taxa growing both on green roof systems and at ground level in Denver, Colorado, over two growing seasons. We found that flowering phenology occurs substantially earlier on green roofs compared to ground level among the observed plant taxa and observed a greater number of pollinators on green roofs early in the season, compared to ground level, presumably due to the availability of floral resources among the observed plant taxa. We observed significantly higher substrate temperatures along with wider diurnal temperature amplitude during the growing season that may contribute to the observed phenological patterns. Divergence in flowering phenology between individual plants of the same species on green roofs and plants at ground-level may have implications for organisms that rely on floral resources in urban environments. Earlier flower initiation on green roofs may provide pollinators with unique foraging opportunities and aid targeted conservation where early-season floral resources are limited.

Phenological Variation in Chickpea (Cicer arietinum L.) Varieties through Foliar Application of Cytokinin Analogs and Nutrients under Water Deficit Stress

Chickpea (Cicer arietinum L.), a rainfed crop predominantly grown in temperate and subtropical climates, faces significant challenges in production due to terminal drought stress impacting various phenological stages. This study addresses the challenges posed by terminal drought stress on the phenological stage of chickpea varieties viz., JG 36 and JG 14. The experiment was conducted during the Rabi seasons of 2021-2022 and 2022-2023 at the Experimental Research Farm, Seed Technology Research Unit, JNKVV, Jabalpur (M.P), using a split-split plot design with three replications. This research also investigates the impact of foliar applications of cytokinin analogs viz., Thiourea, Thidiazuron, and Benzyladenine and nutrients viz., ZnSO4 and KCl on chickpea under water deficit stress conditions. The results revealed significant differences in days to pod formation, seed formation, physiological maturity, and harvest maturity among the irrigation levels, varieties, and foliar spray of plant growth regulators and nutrients. Under different irrigation levels, D1 (Irrigation at 30 DAS and flower initiation) exhibited delayed phenological stages of the crop, while D2 (Drought stress at flowering up to physiological maturity) showed an early onset of all the phenological stages. Under water deficit conditions, JG 14 exhibited accelerated maturity beyond its typical early maturation in comparison to well-watered conditions, highlighting the impact of environmental stress on varietal responses. With respect to the application of plant growth regulators and nutrients, treatment T12 (TDZ @ 10 ppm + 1% KCl) significantly delayed pod and seed formation, as well as physiological and harvest maturity as compared to untreated control (T1). Foliar application of TDZ @ 10 ppm + 1% KCl (T12) enhanced seed filling duration by 2.59 days compared to the untreated control. Further investigations are needed to identify the impact of Thidiazuron and KCl in enhancing seed yield and seed weight of chickpea under optimal and sub-optimal soil water conditions, to provide recommendations for chickpea growers.

Flower Initiation Pattern, Developmental Stages, and Seed Morphology of Paraphalaenopsis Labukensis P.S. Shim, A. Lamb & C.L. Chan, An Endangered Orchid in Sabah

Background Paraphalaenopsis labukensis P.S. Shim, A. Lamb & C.L. Chan is a monopodial epiphytic species that can only be found in Sabah. P. labukensis orchids have unique characteristics in that it has a long floral lifespan as compared to other orchid species. The flower developmental pattern of P. labukensis greatly influenced capsule formation and seed maturation. Objective The present research was conducted to record the initiation of flower initiation, and floral morphology, and to observe the flowering and capsule development, as well as the effect of different capsule ages on asymbiotic seed germination. Methods A total of three individual plants of P. labukensis were observed. The flowering stages were characterized by quantitative parameters such as length of inflorescence, diameter, and length of buds, the number of flowers produced, and the length of the capsule formed. All the data were recorded through direct observation. Results Overall, twelve morphological landmark that define each stage of floral development was recorded. Based on the observation, P. labukensis inflorescence was asymmetric and in the shape of a panicle. The number of flowers varied among inflorescences, ranging from 3–5, that blossomed at different times. Furthermore, early capsules appeared 40–90 days after pollination (DAP). Then, 120 DAP of the capsule was selected as the most suitable capsule age for germination as it had reached its maturation period. Conclusion Identifying the duration of the whole flowering developmental process will aid in the production of capsules to attain a reliable and adequate seed source for in vitro seed germination.

Co-relation studies in desi cotton genotypes (Gossypium arboreum L.)

The present investigation entitled “Correlation studies indesi cotton genotypes (Gossypium arboreum L.)” was carried out to evaluate promising cotton genotypes yield and yield contributing traits at Cotton Research Station, Mahboob baugh farm, VNMKV, Parbhani, during Kharif season-2022. The present experiment conducted on fifteen promising genotypes of cotton (Gossypium arboreum L.) including two checks. The genotypes tested were PA-904, PA-906, PA- 907, PA-927, PA-929, PA-932, PA-936, PA-941, PA-942, PA-945, PA-947, PA-948, PA-950 along with two checks PA-742 (C) and NH-615 (C). The results revealed that the characters vizsympodia per plant, number of bolls per plant, 10-boll weight, seed index, and ginning out turn were significantly and positively correlated with the seed cotton yield. Whereas, days to first flower initiation, days to 50% flowering and days to first boll development had negative and significant correlation with the seed cotton yield.