Flower Opening Research Articles

DNA methylation analysis of floral parts revealed dynamic changes during the development of homostylous Fagopyrum tataricum and heterostylous F. esculentum flowers

BackgroundProper flower development is essential for plant reproduction, a crucial aspect of the plant life cycle. This process involves precisely coordinating transcription factors, enzymes, and epigenetic modifications. DNA methylation, a ubiquitous and heritable epigenetic mechanism, is pivotal in regulating gene expression and shaping chromatin structure. Fagopyrum esculentum demonstrates anti-hypertensive, anti-diabetic, anti-inflammatory, cardio-protective, hepato-protective, and neuroprotective properties. However, the heteromorphic heterostyly observed in F. esculentum poses a significant challenge in breeding efforts. F. tataricum has better resistance to high altitudes and harsh weather conditions such as drought, frost, UV-B radiation damage, and pests. Moreover, F. tataricum contains significantly higher levels of rutin and other phenolics, more flavonoids, and a balanced amino acid profile compared to common buckwheat, being recognised as functional food, rendering it an excellent candidate for functional food applications.ResultsThis study aimed to compare the DNA methylation profiles between the Pin and Thrum flower components of F. esculentum, with those of self-fertile species of F. tataricum, to understand the potential role of this epigenetic mechanism in Fagopyrum floral development. Notably, F. tataricum flowers are smaller than those of F. esculentum (Pin and Thrum morphs). The decline in DNA methylation levels in the developed open flower components, such as petals, stigmas and ovules, was consistent across both species, except for the ovule in the Thrum morph. Conversely, Pin and Tartary ovules exhibited a minor decrease in DNA methylation levels. The highest DNA methylation level was observed in Pin stigma from closed flowers, and the most significant decrease was in Pin stigma from open flowers. In opposition, the nectaries of open flowers exhibited higher levels of DNA methylation than those of closed flowers. The decrease in DNA methylation might correspond with the downregulation of genes encoding methyltransferases.ConclusionsReduced overall DNA methylation and the expression of genes associated with these epigenetic markers in fully opened flowers of both species may indicate that demethylation is necessary to activate the expression of genes involved in floral development.

Genome-Wide Identification and Expression Pattern Analysis of TIFY Family Genes Reveal Their Potential Roles in Phalaenopsis aphrodite Flower Opening.

The TIFY gene family (formerly known as the zinc finger proteins expressed in inflorescence meristem (ZIM) family) not only functions in plant defense responses but also are widely involved in regulating plant growth and development. However, the identification and functional analysis of TIFY proteins remain unexplored in Orchidaceae. Here, we identified 19 putative TIFY genes in the Phalaenopsis aphrodite genome. The phylogenetic tree classified them into four subfamilies: 14 members from JAZ, 3 members from ZML, and 1 each from PPD and TIFY. Sequence analysis revealed that all Phalaenopsis TIFY proteins contained a TIFY domain. Exon-intron analysis showed that the intron number and length of Phalaenopsis TIFY genes varied, whereas the same subfamily and subgroup genes had similar exon or intron numbers and distributions. The most abundant cis-elements in the promoter regions of the 19 TIFY genes were associated with light responsiveness, followed by MeJA and ABA, indicating their potential regulation by light and phytohormones. The 13 candidate TIFY genes screened from the transcriptome data exhibited two types of expression trends, suggesting their different roles in cell proliferation and cell expansion of floral organ growth during Phalaenopsis flower opening. Overall, this study serves as a background for investigating the underlying roles of TIFY genes in floral organ growth in Phalaenopsis.

Promising and Failed Breeding Techniques for Overcoming Sterility and Increasing Seed Set in Bananas (Musa spp.)

Most banana improvement programs are restricted to using a sub-set of edible landraces for sexual hybridization as the majority are female sterile. This results from an array of factors that work in tandem and lead to sterility. Use of pollination germination media (PGM) during pollination significantly increases seed set, but it is a very small fraction compared to the potential seed set. This research therefore explored early pollination (a day before anthesis), evening pollination, saline treatment, plant growth regulators (PGRs) treatment, and ovule culture as potential techniques for overcoming sterility in bananas. Early and evening pollinations did not increase seed set because of immature flowers and a mismatch of male and female flower opening, respectively (t-prob. = 0.735 and 0.884). Immersion of bunches in a saline solution before pollination and ovule culture also did not overcome pollination barriers. Auxin antagonists (TIBA and salicylic acid) increased seed set, though their respective increases were not statistically significant (t-prob. = 0.123 and 0.164, respectively). The use of auxin antagonists shows great potential for overcoming pollination barriers in bananas. However, application rates and time of application have to be optimized and used holistically with other promising techniques, such as use of PGM.

Is the time of anthesis in rice (Oryza sativa) influenced by photoperiod?

Photoperiod sensitivity in rice cultivars is defined when the cultivar begins anthesis on a relatively invariant date, varying by < 7days, regardless of the date of sowing or germination. While the date of flowering in photoperiod sensitive (PPS) rice cultivars is characteristically determined by the day length, especially during the short-day season (September-December), the response of the flower opening time (FOT) to photoperiod remains hitherto unexplored. This paper examines whether day length restrains year-to-year variation in FOT in PPS cultivars. We examined 105 PPS and 173 photoperiod insensitive (PPI) cultivars grown in different years and estimated their year-to-year FOT difference (or FOTD) and the year-to-year difference of sunrise to anthesis duration (or SADD). Wilcoxon signed rank test and bootstrap test were then performed to test whether these descriptors significantly differed between PPS and PPI groups of cultivars. The means of FOTD and SADD were detected to be significantly less in the PPS group than in the PPI group of cultivars, indicating significantly lesser variability of FOT in PPS than in PPI cultivars. This is the first report of a strong restraining influence of photoperiod on FOT variability in PPS cultivars.

Role of pore hierarchy and Mn incorporation on the electrochemical performance of bimetallic NiMn-LDHs on graphite foil for supercapattery application

In this work, nickel-manganese layered double hydroxides (NiMn-LDHs) are synthesized using hexamethylenetetramine (HMTA) and urea as precipitating agents via hydrothermal synthesis route. The materials have different flower like microstructure and porosity. The effect of microstructures, porosity and mass loading of the LDHs on the overall electrochemical performance is thoroughly studied in this work. It is observed that HMTA assisted NiMn-LDH having open flower like microstructure delivers a high specific capacity of 719 C g−1 at 1 A g–1 and excellent capacity retention of 82.6% and 86% for 10,000 CV and 5000 GCD cycles, respectively. Furthermore, a supercapattery device assembled using NiMn-LDH@HMTA as cathode and activated carbon as anode exhibit high-capacity retention of 80.1% after 5000 GCD cycles along with an energy density of 50 and 34 Wh kg–1 at power densities of 800 and 4000 W kg–1, respectively.

Two FT genes synergistically regulate the reproductive transition of loquat

Unlike annual flowering plants that exhibit a single reproductive cycle encompassing vegetative growth, flowering, and senescence within a single year, perennial woody trees undergo a transition between vegetative and reproductive growth every year after a long juvenile phase. Most woody fruit trees bloom when it turns warm in spring, and the fruit ripens in summer or autumn. However, as a member of the Maloideae subfamily, the loquat tree blooms in the cold autumn and winter, and the fruit matures in the spring. To explore the regulatory mechanism of loquat flowering, we characterized two FLOWERING LOCUS T homologous genes in loquat, EjFT1 and EjFT2. qRT-PCR results revealed that EjFT1 and EjFT2 exhibited nearly opposite expression patterns in various tissues. EjFT1 was mainly expressed in young tissues; EjFT2 was mainly expressed in mature leaves, open flowers, and fruits. EjFT2 exhibited an obvious circadian rhythm and was regulated by EjCO. After the trees were exposed to short-day conditions or sprayed with exogenous GA3, the expression of EjFT2 was strongly inhibited, and the loquat tree did not produce floral buds. Furthermore, the yeast two-hybrid, bimolecular fluorescence complementation, and Dual-luciferase assay experiments revealed that both EjFT1 and EjFT2 interacted with EjFD, with the EjFT2-EjFD protein complex enhancing the activity of EjAP1-1 and EjAP1-2 promoters, while EjFT1-EjFD inhibited the activity of the EjAP1-1 promoter. Protein structural analysis of EjFT1 and EjFT2 suggested that differences in amino acid residues at Val123/Leu123, Ser157/Ala157, and Val158/Ala158 may be the reason for their functional differences. Our results showed that EjFT1 and EjFT2 may cooperatively regulate the floral bud differentiation of loquat by competitively binding with EjFD. EjFT2 regulates the onset of loquat floral bud differentiation by responding to photoperiod and gibberellin signals, while EjFT1 is involved in the vegetative growth of loquat. These findings provide important clues for the investigation of the regulatory mechanism of loquat flowering and advance the exploration into the multiple roles of FT homologous genes in regulating the reproductive transformation and vegetative growth of flowering plants.

Adjustments of flower opening time and duration in tropical rice (Oryza sativa ssp. indica) landraces in response to heat stress

AbstractBased on our primary database of the flower opening time (FOT) and flower exposure duration (FED) of 1114 rice (Oryza sativa ssp. indica) landraces, we examined the influences of growing season, sunrise time as well as day maximum and minimum temperatures on the anthesis behaviour of indica rice landraces of South and Southeast Asia, flowering in summer and winter in 3 consecutive years (2020–2022). We also compared the FOT and FED on sunny and cloudy days of a small set of landraces, and also during summer and winter. Our data show that rice florets tend to open later in the morning and lengthen the sunrise‐to‐anthesis duration (SAD) on hotter sunny days during tropical summer than during winter and on cloudy days. These findings contradict the widely held conjecture, based on studies conducted at colder latitudes, that rice flowers open earlier in the morning to avoid heat stress. We propose that indica rice landraces are sufficiently adapted to tropical summer because they were selected and bred over millennia to withstand heat stress during tropical summer, so their FOT and SAD are weakly influenced by high day temperatures. However, the significant reduction in FED of these landraces, whose flowers open later in mid‐day, seems to be an adaptive mechanism to avoid longer exposure to rising air temperature approaching day maximum temperature.

Growth and Flowering of Lilium (Lilium longiflorum) cv. Eremo as Affected by CCC and GA3 under Naturally Ventilated Polyhouse Conditions of Prayagraj

The present investigation was carried out under naturally ventilated polyhouse conditions, Department of Horticulture, SHUATS, Prayagraj, during November, 2023 to March, 2024. The experiment was laid out in Randomized Block Design (RBD) with three replications. There were nine treatments comprising of Cycocel (CCC) and Gibberellic Acid (GA3) at different concentrations viz., GA3 (100, 200, 300 and 400 ppm) and CCC (100, 200, 300 and 400 ppm) along with Water spray. The results revealed foliar application of 300 ppm GA3 for Lilium significantly enhanced the number of leaves (71.83), plant height (76.47 cm), plant spread (15.44 cm), leaf area (9.73 cm2),number of buds (3.40),at 300 ppm of GA3 it takes lesser days taken for bud initiation(40.40),and also less days taken for first flower opening from planting (68.53), flower bud length (8.83 cm), flower stalk length (12.43 cm), stalk length (78.10 cm), self-life (12.97 days),flower yield per plant (3.40) and flower yield for 250 m2(6296.29) . Among the different treatments, the highest Gross return is 188888.7 Rs/250 m2, Net return is 120870.75 Rs/250 m2 and Benefit cost ratio is 2.77, obtained by the application of 300 ppm of GA3.Whereas in terms of only Bulb parameters, foliar application of 200 ppm of CCC for Lilium reported maximum number of bulblets per plant (4.11) and gives maximum weight of bulb per plant (74.07g).

Effect of saline water on the vase life of Narcissus poeticus L. flowers

ABSTRACT The vase life of Narcissus poeticus flowers collected at the white bud stage was investigated in 13 different concentrations of NaCl (0–5–10–15–20–30–40–…–100 mM). Every 12 hr, the opening stage of the flowers was recorded, divided into 4 main categories (bud, opening flower, full open (FO) flower and wilting flower) and 14 subcategories. The salinity did not affect the flower opening speed, diameter or weight. The duration of the full flowering stage decreased from 92 hr to 44 hr, the sum of the daily ornamental value score (OVS) decreased from 120 by 3 scores per each 10 mM concentration increase. The scape chlorophyll content increased at low salinity (10–15 mM) and then decreased significantly. The carotenoid content in the scapes of wilted flowers increased in 30–100 mM solutions compared to the values in the flowering stage and flowers grown at lower salt concentrations. The Na and Cl contents in the plant parts increased significantly with the increase in salinity (at the end of the experiment, 100 mM NaCl: scapes: 44.1 g · kg-1 and 67.2 g · kg-1 Na and Cl; flowers: 16.8 g · kg-1 and 24.8 g · kg-1 Na and Cl, respectively). There was an inverse correlation between the Na and K contents in the scapes. The EC value of the vase solutions decreased during the experiment.

Animal‐pollinated crops and cultivars—A quantitative assessment of pollinator dependence values and evaluation of methodological approaches

Abstract Crop pollinator dependence (PD) values are key when assessing a pollinator's contribution to agriculture, guiding management plans and policies for sustainable crop production. However, the available global compilations of crops PD are outdated and neglect variability between related crops and accessions (variety/cultivar), as well as pollen limitation (PL), that is the production lost due to inadequate pollen receipt. Here, we obtained quantitative PD values for animal‐pollinated crops and their accessions, using data from available pollination experiments worldwide. We also tested pollination methodologies to assess their impact on PD values and to define suitable methodological guidelines for future pollination studies. We provide a list of continuous PD values for 141 crops, including 317 accessions and 37 crops not listed in previous assessments. We found that, globally, 74% of animal‐pollinated crops are highly dependent on pollinators, and more than 40% of their production is associated with animal pollination. Pollen limitation was detected in 51% of the dataset entries, indicating that estimates calculated with open pollination studies underestimate crop pollinator dependence and, therefore, do not represent the true contribution of pollinators to food production. Synthesis and applications: Commonly applied methods for assessing PD values can lead to underestimations. Future studies evaluating pollinator dependence levels of crops and their accessions (i.e. potential pollinator contribution) should consider the possibility of pollen limitation in the study site, incorporating hand pollen supplementation (to open flower), open pollination, and pollinator exclusion treatments, preferably using the whole plant or branch as the unit of assessment. The PD values provided here, from studies that allow the incorporation of the concept of pollen limitation, enable more accurate quantifications of pollinator contribution to crop production. These PD values are an invaluable baseline and a requirement for future accurate evaluations of the value of pollinators for food security, supporting pollinator‐friendly practices in agroecosystems.

Co-hydrothermal carbonization of rape straw and industrial sewage sludge – Applications of hydrochar for N and P adsorptions and for agricultural/horticultural purposes

Reuse of agricultural and industrial wastes simultaneously to prepare hydrochars (HCs) for removal of NH4+ and PO43− in practical sewage without additional wastes produced is still a challenge. Herein, HCs were fabricated by combination of rape straw and industrial sewage sludge to remove NH4+ and PO43− from hoggery effluent. Synthesis conditions were firstly optimized and optimized HC (OPT-HC) was further applied to adsorb NH4+ and PO43−. Monolayer and Pseudo-first-order as well as Pseudo-second-orders were confirmed via adsorption kinetic and isothermal adsorption studies. Morphologies and surface areas of the OPT-HC did not show any transformations before and after adsorption of NH4+ and PO43−. The OPT-HC after adsorption of NH4+ and PO43− (OPT–HC–N/P) was further applied as fertilizer for planting Ping-pong Chrysanthemum. Results indicate that the OPT–HC–N/P can improve comprehensive qualities of the Ping-pong Chrysanthemum such as plant height, fresh, Vitamin C, Chlorophyll, soluble protein and sugar because the OPT–HC–N/P can provide extra N and P elements and also promote to release available K in soil. OPT–HC–N/P treated Ping-pong Chrysanthemum open flowers in advance. Thus, two kinds of wastes were re-utilized to remove N and P in real-life effluent.

Effect of night-break on growth and flower production in Kalanchoe

Kalanchoe blossfeldiana is a popular potted flowering plant with extended flowering periods and low demand for nutrients and water. Understanding photoperiodic response is a prerequisite for the management of the flowering period in photoperiodic crops like Kalanchoe. The night-break treatments were provided by an artificial light source (CFL bulbs) starting from 7th October 2019 for 20 (7th October - 26th October), 30 (7th October - 5th November) and 40 (7th October - 15th November) days as night interruption (NI) for 30 min. and 60 min. from 11:30 PM to 00:00 AM and 11:30 PM to 00:30 AM. Exposing the plants to a 60 min. night interruption for 20 days has proven to be crucial in achieving essential qualitative criteria for potted plants, specifically ensuring compact plant growth with minimal plant height (26.20 cm) and a controlled plant spread (19.17 cm). The maximum number of days to flower bud appearance (138.07 days), days to colour break stage (203.79 days) and days to 50% opening of flowers (232.23 days) was under 60 min. of night interruption for 40 days. Therefore, delayed flower production in Kalanchoe for up to 45 days can be achieved by 60 min. of night interruption for 40 days along with acceptable quality pot plants. A significant amount of anthocyanins and total phenols reported with photoperiodic treatment confirms that photoperiod influenced the biosynthesis of anthocyanin and phenoliccompounds in Kalanchoe.

Assessing Pollinator Assembly And Efficacy Across Species Ranges In The Genus Triodanis (Campanulaceae)

Plant-insect interactions are a key topic in evolutionary ecology, especially in the face of anthropogenic changes which threaten to disrupt these mutualisms. An in-depth pollinator survey for species in the genus Triodanis is performed here for the first time, with sampling covering four species and spanning a large portion of their geographic ranges (i.e., four U.S. states). All species in the genus exhibit dimorphic cleistogamy with variability in allocation to open (chasmogamous) flowers among populations and taxa. The genus Triodanis, therefore, provides an opportunity for understanding possible associations between pollinator assemblies and variation in species, breeding system, and geography. To assess these relationships, we sampled four species or subspecies of Triodanis at eight field sites in four states. Sampling encompassed a broad area across the Midwestern U.S. and Texas, and across a gradient of anthropogenically disturbed habitats. We found that for species of Triodanis: 1) small bee and fly generalist pollinators showed some floral constancy during feeding bouts but did not differentiate between species, 2) pollinator community was less diverse and abundant in highly degraded habitats, 3) while allocation to open flowers varied among species and populations, we found no association between breeding system (or species) on pollinator identity or abundance. This study represents the first in-depth survey of pollinator visitors of Triodanis and serves as foundational knowledge about the natural history of this group, provides resolution for members of Campanulaceae exhibiting floral traits of generalist hosts, and important documentation of plant-insect interactions in an era of ongoing anthropogenic changes.

Variations of salt stress responses and functional identification of TgPYR1-like8 in Tulipa gesneriana

Tulip cut flowers are mainly produced through hydroponic cultivation. The accumulation of nutrient substances in hydroponic solution generally resulted in ion stress and osmotic stress, which in turn affected the growth and ornamental characteristics of tulip plants. This study aimed to evaluate and compare the salt stress sensitivities of tulip cultivated varieties. The results indicated that most of tulip cultivars showed relatively high sensitivity to low concentrations of NaCl treatment, while the root growth and floral stalk elongation were significantly inhibited by 15 mM NaCl and flowering opening was completely prevented under 75 mM NaCl conditions. Salt stress caused differential accumulations of osmotic regulators including proline, soluble sugars and ions concentrations between two contrasting varieties. We further identified the function of TgPYR1-like8 which showed differential expression patterns among tulip cultivars and displayed the most expression abundance in flower petals. TgPYR1-like8 over expressed Arabidopsis lines showed hypersensitivity to salt treatment during seed germination and young seedlings growth when compared with wild-type plant. Transient silencing of endogenous TgPYR1-like8 in tulip petal discs decreased salt sensitivity and delayed salt-induced petal senescence. These findings provide evidences for revealing the function of TgPYR1-like8 in tulip salt stress responses and more clues on how to improve the hydroponic cultivation of different tulip varieties.

ABSCISIC ACID-INSENSITIVE 5-KIP-RELATED PROTEIN 1-SHOOT MERISTEMLESS modulates reproductive development of Arabidopsis.

Soil (or plant) water deficit accelerates plant reproduction. However, the underpinning molecular mechanisms remain unknown. By modulating cell division/number, ABSCISIC ACID-INSENSITIVE 5 (ABI5), a key bZIP (basic (region) leucine zippers) transcription factor, regulates both seed development and abiotic stress responses. The KIP-RELATED PROTEIN (KRP) cyclin-dependent kinases (CDKs) play an essential role in controlling cell division, and SHOOT MERISTEMLESS (STM) plays a key role in the specification of flower meristem identity. Here, our findings show that abscisic acid (ABA) signaling and/or metabolism in adjust reproductive outputs (such as rosette leaf number and open flower number) under water-deficient conditions in Arabidopsis (Arabidopsis thaliana) plants. Reproductive outputs increased under water-sufficient conditions but decreased under water-deficient conditions in the ABA signaling/metabolism mutants abscisic acid2-1 (aba2-1), aba2-11, abscisic acid insensitive3-1 (abi3-1), abi4-1, abi5-7, and abi5-8. Further, under water-deficient conditions, ABA induced-ABI5 directly bound to the promoter of KRP1, which encodes a CDK that plays an essential role in controlling cell division, and this binding subsequently activated KRP1 expression. In turn, KRP1 physically interacted with STM, which functions in the specification of flower meristem identity, promoting STM degradation. We further demonstrate that reproductive outputs are adjusted by the ABI5-KRP1-STM molecular module under water-deficient conditions. Together, our findings reveal the molecular mechanism by which ABA signaling and/or metabolism regulate reproductive development under water-deficient conditions. These findings provide insights that may help guide crop yield improvement under water deficiency.

Genome-Wide Identification of Osmanthus fragrans Histone Modification Genes and Analysis of Their Expression during the Flowering Process and under Azacytidine and Ethylene Treatments

Histone acetylation and methylation, governed by various histone modification (HM) gene families, are vital for plant biological processes. However, there are limited studies that have explored HMs in ornamental horticultural trees, including sweet osmanthus (Osmanthus fragrans). We performed genome-wide search and identified 208 OfHMs, encompassing 81 histone methyltransferases (OfHMTs), 51 histone demethylases (OfHDMs), 49 histone acetyltransferases (OfHATs) and 27 histone deacetylases (HDACs). Our comprehensive analysis covered chromosome locations, gene structures, conserved domains, cis-acting elements, phylogenetic comparisons, protein interaction networks and functional enrichment pathways for these gene families. Additionally, tandem and fragment replications were unveiled as contributors to the expansion of OfHMs, with some genes exhibiting positive selection. Furthermore, we examined OfHM expression profiles across various tissues and flowering stages, and under 5′-azacytidine (Aza) and ethylene treatments. Most OfHMs displayed heightened expression in leaves, and were downregulated during the flower opening and senescence stages, including OfPRMTs, OfHDTs, OfHDAs, OfSRTs, OfJMJs and OfHAGs; 75.86% and 80.77% of the differentially expressed OfHMs were upregulated after Aza and ethylene treatments, including OfHAGs, OfHDAs and OfSDGs. This study offers a comprehensive analysis of the OfHM gene family, which indicated their potential involvement in ethylene and Aza responses, and in the flowering process. These findings provide valuable insights into the role of OfHMs in flowering and stress responses.

Agave distribution and floral display influence foraging rates of an endangered pollinating bat and implications for conservation.

Wildlife conservation involves making management decisions with incomplete knowledge of ecological relationships. Efforts to augment foraging resources for the endangered Mexican long-nosed bat (Leptonycteris nivalis) are progressing despite limited knowledge about the species' foraging behavior and requirements. This study aimed to understand L. nivalis responses to floral resource availability, focusing on individual agave- and local-scale characteristics influencing visitation rates to flowering agaves. We observed bat visitation at 62 flowering agaves around two roosts in northeast Mexico on 46 nights in the summers of 2017 and 2018. We found visitation rate had positive relationships with two agave-scale characteristics: the number of umbels with open flowers and the lower vertical position on the stalk of those umbels (i.e., earlier phenological stages of flowering). However, these factors exhibited strong negative interaction: with few umbels with open flowers, the position of flowering umbels had little effect on visitation rate, but when umbels with open flowers were abundant, visitation rate was more strongly related to the lower flowering umbel position. We also found relationships between visitation rate and two local-scale characteristics: negative for the density of flowering conspecifics within 30 m of the focal agave and positive for the density of dead standing agave stalks within 30 m. Our findings suggest opportunities to augment foraging resources for L. nivalis in ways that are consistent with their foraging behavior, including: increasing the supply of simultaneously blooming flowers by planting agave species that tend to have more umbels with simultaneously open flowers; planting multiple species of agaves with different flowering times to increase the availability of agaves with open flowers on lower-positioned umbels throughout the period when bats are present in the region; planting agaves in clusters; and keeping dead standing agave stalks on the landscape. Our study points to useful management strategies that can be implemented and monitored as part of an adaptive management approach to aid in conservation efforts.

Evaluation of Okra Varieties under Sub-humid Plains of South-East Rajasthan for Morphological and Phenological Traits

Vegetable crop okra is well known for its Indian vegetable export and household consumption, contribution and thus should be explored for cultivation under various agro climatic zones. Enhanced production of this crop is only possible via improved and high yielding cultivars in comparison to other cultivars grown at same time or under same condition. Hadoti region of South-East Rajasthan, can serve a okra production in better way if the productive varieties can be screened for this region, which is lacking till date. Hence an experiment is made to recommend a variety, which performs better under South-East climatic conditions of Rajasthan. The present study was conducted in the summer season during 2022 and 2023 at the Instructional Farm, Department of Horticulture, School of Agricultural Sciences, Career Point University, Kota, Rajasthan. 12 varieties of okra viz. Parbhani Kranti, Parbhani Bhindi, Arka Anamika, Shahiba, Shan, No. 55, Harita, Jhilmil, No. 64, Sonal, Shakti, and Punjab Selection were evaluated in Randomized Block Design, with three replication. Analysis of variance revealed that all varieties differed significantly for all the traits. The results concluded that, variation for earliness, growth, yield and quality parameters as well. These results showed presence of significant varietal effect. However, the present study demonstrated the superiority of Arka Anamika over other varieties in terms of maximum mean plant height (89.07 cm), number of leaves per plant (25.64), number of branches per plant (13.88), leaf length (19.03 cm), leaf width (25.32 cm) and leaf area (250.04 cm2) while minimum mean days taken to flowering opening to fruit picking (5.51 DAS) and days taken to first picking (47.16 DAS) was recorded in variety Punjab Selection under soil and climatic condition of Hadoti region of Rajasthan.

Autogamy ensures reproductive success in the bromeliad Dyckia dissitiflora Schult.f., endemic to the Brazilian caatinga domain

AbstractThe genus Dyckia (Bromeliaceae) is endemic to South America, and its species show important ecological roles in xeric environments. The flowering phenology as well as floral and reproductive biology were monitored monthly in Dyckia dissitiflora at two sites (Bela Vista: 11°42′03.4″ S 39°05′21.7″ W and Barra do Vento: 11°37′58.1″ S 39°03′33.7″ W) in the municipality of Serrinha, Bahia, Brazil. Flowering occurs in the early austral summer with a peculiar time of beginning of anthesis (10:00–11:00), offering resources 18 h after the first petal movements. Pollen viability was 98%, with a high production of pollen grains. Stigma receptivity is continuous from flower opening to senescence, and nectar production initiates at 04:00 and extends until 18:00. The species is self‐compatible and autogamous, but not agamospermic. Pollen tubes developed and reached the micropyle within 24 h in all of the reproductive tests. The hummingbird Chlorostilbon lucidus was the only floral visitor and pollinator (frequency = 0.82 ± 0.02). Fruiting occurs 3 days after anthesis, and the seeds are wind‐dispersed. Self‐compatibility and autogamy are essential strategies for the reproductive success of D. dissitiflora in light of the low number and visit frequency of its pollinators, and it is favored by slow floral movements and the position of the stigmas in relation to stamens.

Floral scents, specialized metabolites and stress-response activities in Heritiera fomes and Bruguiera gymnorrhiza from Sundarban mangrove ecosystem.

Floral biochemistry and stress physiology is an underexplored aspect of mangroves, which should be investigated as part of preservation and restoration efforts. A thriving true mangrove tree (Bruguiera gymnorrhiza (L.) Lamk.) and a threatened mangrove-associate species (Heritiera fomes Buch. Ham.) were studied in the Sundarban region of India for seasonal variations in floral odours, non-volatile phytochemicals, antioxidant enzyme activities, and surface water chemistry in surrounding habitat. Both species were found to exhibit significant differences in floral volatilomes, protein contents, antioxidant enzyme activities, total flavonoids, and total phenolic contents between spring and autumn blooms. The bird-pollinated flowers of B. gymnorrhiza also showed considerable seasonal differences in floral anthocyanin and proline contents, indicating vulnerability of the post-anthesis open flowers to environmental factors. Contrarily to previous findings, B. gymnorrhiza floral bouquet appeared to be enriched in various classes of volatiles - dominated by sulphurous compounds in bud stage and terpenoids in open stage. Floral anthocyanins, contributing to the striking colouration of the calyx, were found to comprise cyanidin and delphinidin derivatives. Other glycosides of cyanidin and delphinidin were detected in H. fomes flowers, contributing to visual guides to potential food rewards for pollinating insects. Floral tissue in H. fomes was found to be protected by densely overlapping layers of stellate trichomes containing sesquiterpenoids as phytoprotectants. Comparison of the two floral species suggested that H. fomes flowering is optimized to oligohaline (but not freshwater) vernal conditions; whereas B. gymnorrhiza blooms are adapted for biologically enriched (including abundant herbivores and microbial growth), mesohaline forest habitats.