Flower Opening Research Articles

Harvest stage and storage effects on postharvest quality and vase life of Queen Anne’s lace (Daucus carota L.)

ABSTRACT Market sales of specialty cut flowers (SCF) have increased in recent years. SCF increase the variety of floricultural products to help establish new trends for the floriculture industry. The longevity of Daucus carota L. ranged between 13.2 and 13.8 days when harvested at 40–70% open flowers (i.e. Stage III) or full maturity of 70-100% open flowers (i.e. Stage IV), respectively. Respiration rates (RR) followed a gradual decline from 30.3 mL CO2/100 g FW/h on day-0 to 12.5 mL CO2/100 g FW/h on day-9. Colour changes at different harvest stages were associated with flower opening and flower senescence. Colour difference of Stage I inflorescences, was significantly (P < 0.05) lower (e.g. 8.4) compared to Stages II, III and IV (e.g. 19.8, 25.7 and 28.7, respectively). Short-term storage at 1, 3 or 6°C for 7 days did not affect VL of the inflorescences, which maintained their fresh weight (FW) above initial values for almost 14 days. However, long-term storage for 14 or 21 days at 1, 3 or 6°C resulted in sharp FW reduction and abrupt decreases in Fv/Fm values, which may justify chilling injury and quality loss.

Why flowers close at noon? A case study of an alpine species Gentianopsis paludosa (Gentianaceae).

Repeatable floral closure with diurnal rhythms, that is, flower opening in the morning and closing in the evening, was widely reported. However, the rhythm of flower opening in the morning but closing in the midday received much less attention. Gentianopsis paludosa, Gentianaceae, has an obvious petal movement rhythm opening in the morning and closing at noon at northeast of the Qinghai‐Tibetan Plateau. In this study, we examined the effects of temperature (T), relative humidity (RH), and illumination intensity (II) on G. paludosa's flower closure. Furthermore, we monitored the environmental changes inside and outside of the flowers, aiming to test the effect of floral closure on the stability of microenvironment inside the flower. Finally, we artificially interrupted temporal petal closure and investigated its effects on reproductive fitness. The results showed that high/low temperature contributed more to the flower closure than low RH, while illumination intensity had no significant effect on it. The medium temperature, relative humidity and illumination intensity (environmental conditions at 10:00) did not delay flower closure when flowers at pre‐closing period or stimulate reopen when flowers full closed. Floral closure provided a stable temperature condition and a higher RH condition inside the flower. Meanwhile, compulsive opening and delayed closure of flowers decreased the seed‐set ratio while no effect was found when flowers were forced to close. We conclude that endogenous rhythm regulates floral closure. The rhythm of petal movement providing a stable microenvironment for G. paludosa, increasing the seed production and saving energy from flower opening maintenance, which might be an adaptive strategy to against unfavorable environmental conditions.

Viability of pollen grains and stigma receptivity in Desert Rose

Abstract Adenium obesum (Forssk.) Roem. &amp; Schult., popularly known as desert rose, has become a valuable ornamental plant. In floriculture, the production of hybrids is prioritized. Hence, knowledge on floral biology and sexual reproduction of the target species is fundamental. The objectives of this study were: (1) to test sucrose concentrations and temperatures for in vitro germination of A. obesum pollen grains; (2) to identify the effect of temperature on the viability of A. obesum pollen grains; and (3) to evaluate the viability of pollen grains and stigma receptivity in pre-anthesis, at flower opening, and 72 h post-flower opening in three accessions of A. obesum. A significant relationship between temperatures and sucrose concentrations was observed in the in vitro germination test. The highest percentage of in vitro germination of pollen grains, 39.81%, was observed at an estimated temperature of 26.05 °C. Desert rose accessions maintained in biochemical oxygen demand (BOD) chambers at 30 °C during a 16-h light photoperiod showed faster flowering, and temperatures ≥ 25 °C induced pollen grain viability percentages above 69%. Temperature is one of the most important abiotic factors, influencing mainly in pollen germination, pollen tube growing and in efficiency fertilization. The ICA-wd accession stood out and can be considered a pollen donor in artificial pollination. The stigmas of flowers were receptive from a day before flower opening until three days after. The two parameters presented above, stigma receptivity and pollen viability, allow inferences about the appropriate time for successful pollination and subsequent fertilization in desert roses.

Developmental Pattern and Reproductive Biology of Nymphaea micrantha Guill. &amp; Perr. and Nymphaea nouchali Burm. f. in Kerala

Water lily (Genus Nymphaea L.) has got immense ornamental, medicinal and cultural significance. The study was carried out to understand developmental pattern and reproductive biology of two species in Genus Nymphaea, which is fundamental for any crop improvement programme. Flowers were found to be solitary, pedicellate, and complete with various floral whorls in a spiral fashion on the floral axis. Significant variability was observed for various floral characters among the two species evaluated. The flowers were found opened in the morning and closed in the evening hours and the process was repeated on the subsequent days. Blossom life lasted for three days in Nymphaea micrantha and four days in Nymphaea nouchali. The peak flower production was observed during September to November period. The dehiscence of pollen occurred by the longitudinal splitting of the anthers in both the species and proceeded from the outer whorl to the inner whorl. The pollen grains retained viability only for 30 to 40 minutes. The stigma became receptive 17 hours before flower opening and receptivity was retained up to 32 hours after flower opening. Very low fertility of pollen was observed in both the species used for the study. No fruit or seed development was observed in both the species under study.

Accumulation of 2-&lt;i&gt;C&lt;/i&gt;-Methyl-d-erythritol as a Major Osmoticum in Petals During Flower Opening in &lt;i&gt;Phlox drummondii&lt;/i&gt;

Accumulation of 2-&lt;i&gt;C&lt;/i&gt;-Methyl-d-erythritol as a Major Osmoticum in Petals During Flower Opening in &lt;i&gt;Phlox drummondii&lt;/i&gt;

Who are the pollinators of Petunia interior (Solanaceae) and how are they attracted to flowers?

Many features of flowers comprise the key elements of the pollinating strategies of flowering plants. Our aims were to describe features that attract pollinators and to identify the pollination system of Petunia interior, a species for which bees have been suggested as the probable pollinators. Therefore, we described the morphology and floral biology, assessed nectar production, concentration, and composition, examined reproductive mode and identified pollinators. P. interior has a purple, infundibuliform, zygomorphic corolla with a short and wide tube and blue pollen. Flower opening and pollen release were asynchronous throughout the day. The pollen grains have pollenkitt on the surface. The nectar sugar composition has a proportion of sucrose lower than the proportion of glucose + fructose, and the nectar supply was constant, in small amounts, at a concentration between 16.6-23.1 %. The reproductive system is xenogamous and bees were the exclusive pollinators. P. interior exhibits a set of floral traits that prevent self-pollination and maintains attractiveness to the bees. The greater reproductive success under natural conditions highlights the importance of bees for the reproductive success of P. interior. As far as floral traits are concerned, only the sugar concentration in the nectar does not correspond to melittophily.

Regulation of Diurnal Rhythms by Direct Light Stimulation in Flower Opening and Closing in Eustoma Grandiflorum

Regulation of Diurnal Rhythms by Direct Light Stimulation in Flower Opening and Closing in Eustoma Grandiflorum

Phytofabricated Silver Nanoparticles (AgNPs) Applied in Vase Solution as a Novel Anti-Microbial Agent for Enhancing the Vase-life of Cut-Rose Flower

Plant extract has been exploited for biogenic synthesis of metallic nanoparticles. This is considered as the promising alternative routes of chemical and physical synthesis methods owing to their abundancy in nature and ecofriendly friendly synthesis protocol. Rose is the top-ranked and universally favorite cut flower. Poor post-harvest management deteriorates the quality and reduces the vase life. Microbial proliferation of the stem base in the vase solution is a concern for these cut flowers that shortens their vase-life. To overcome this problem, a smart solution i.e. phytofabricated silver nanoparticles have been shown to act as anti-microbial agent. In this study, leaf extracts of Camellia sinensis were exploited to fabricate biogenic silver nanoparticles which showing UV-peak absorption ranging from 412-500 nm. This biogenic silver nanoparticles were applied @ 0.01, 0.05 and 0.1mM and compared with a control (without AgNPs) and silver nitrate (AgNO3). Interestingly, AgNPs showed a strong antimicrobial activity in vase solution and cut roses extended their vase life up to 13 days compared to 8 days in control and 9 days in AgNO3. Statistical differences in flower opening, bacterial growth (CFUmL−1) in vase solutions, water uptake, relative fresh weight and vase life of cut roses were found among treatments. In vitro microbial analysis and microscopic investigation of vessels showed that the development of microorganisms was reduced by a high concentration of AgNPs (0.1mM) at the cut end of flower and improving water uptake that followed by extended flowers vase life. The unique phytofabricated AgNPs technology can serve as a promising preservative to increase the ornamental value of cut rose flowers. Taken all together, applied phytofabricated AgNPs in vase solution significantly enhance vase life of cut rose flowers over control.

Anatomy of the floral nectaries of selected species of Gardenieae (Rubiaceae)

Abstract Rubiaceae is one of the five most species-rich families of Angiosperm, its flowers are characterized by a nectariferous disc surrounding the base of the style; however, there are almost no studies on anatomy of these structures in the family. The aim of this study was to describe for the first time the anatomy of the floral nectaries in the tribe Gardenieae (Rubiaceae). Flowers from Cordiera concolor, Genipa americana, Randia calycina, Randia ferox, Randia heteromera, Randia micracantha, and Tocoyena formosawere collected, photographed, and processed using conventional techniques for observation with optical and scanning electron microscopies. In all species the nectary is differentiated histologically into epidermis, nectary and sub-nectary parenchyma, and vascular bundles. Nectar is exuded via nectarostomata. The nectaries have reproductive function, and are structural and mesenchymal during the floral stage. Whereas after corolla has fallen they are persistent nectaries, with post-floral secretion and extranuptial function. In addition, floral visitors that appeared on open flowers and after corolla fall were recorded.

Phosphorus fertilisation may induce Zn deficiency in cotton (Gossypium hirsutum) on calcareous Mediterranean soils.

On a P-poor, calcareous soil, three upland cotton (Gossypium hirsutum L.) cultivars (ST 402, ST 405, Zeta 2) were tested for 2years under three P rates (0, 13.1, 26.2kgPha-1 ). Leaf traits (SPAD values; specific leaf area, SLA; carbon isotope discrimination, Δ; 15 N natural abundance, δ15 N) and elements (N, P, K, C, Na, Zn) along with arbuscular mycorrhizal (AM) colonisation were measured at first open flower, full bloom and first open boll stages. Phosphorus addition decreased yield, but had no effect on fibre quality, a response attributed to P-induced Zn deficiency, previously reported for cereals. The best-performing cv., ST 405, had high SPAD and SLA, but the lowest P, N and Zn concentrations, an indication of cultivar's high use efficiency for these nutrients. At full bloom, SPAD was lowest, while SLA was highest. AM increased gradually with growth stages, while N, P, K and Zn concentrations showed an opposite trend, possibly due to a dilution effect. On Mediterranean calcareous soils, P fertilisation should take into account soil Zn levels in order to avoid P-Zn antagonistic relationships, which could impact negatively on yield.

Comparative Analysis of the Complete Chloroplast Genome Sequences of Four Origin Plants of Lonicerae Flos (Lonicera; Caprifoliaceae)

Lonicerae Flos (LF) derived from the dried flower buds or opening flowers of four Lonicera plants (Lonicera macranthoides, L. hypoglauca, L. confusa, and L. fulvotnetosa), is a popular traditional Chinese medicine. Because the four origin plants are very similar in morphology, it is difficult to control the quality of LF in actual production. Over the past decade, many reports have pointed out the differences among them, including the botanical characteristics and active ingredients. However, there is still a lack of rapid methods that can be applied to the identification of the four origins. In this study, comparative analysis of the four chloroplast genomes was performed, and they showed low diversity (Pi = 0.00267), three variation hotspots regions (rbcL-accD, rps12-ndhF and rps12-trnN-trnG) were identified as potentially molecular marker of highly informative. Meanwhile, the most obvious difference in SSR comparative analysis is reverse and complement repeats were only identified in L. confusa and L. hypoglauca, respectively. Lastly, the phylogenetic tree showed that L. confusa is more closely related to L. fulvotnetosa, while L. macranthoides is closer to L. hypoglauca. This study systematically revealed the differences among the four chloroplast genomes, and it provides valuable genetic information for identifying the origin of LF.

Application of naphthalene acetic acid and gibberellic acid favours fruit induction and development in oil palm hybrid (Elaeis oleiferaxElaeis guineensis)

SummaryThe OxG hybrid bunches contain more parthenocarpic fruits (PF) than normal fruits (NF) and present problems of development and ripening due to either an asynchronous opening of flowers or insufficient pollination. The objective of this study was to compare the effect of α-naphthaleneacetic acid (NAA) and gibberellic acid (GA3) in the induction and development of PF and NF, the fatty acid profile (FAP), and the oil potential in the ‘Coari x La Mé’ oil palm hybrid. NAA and GA3induced parthenocarpy in the fruits and did not alter the FAP of the mesocarp oil. The commercial dose of pollen (0.9 g talc + 0.1 g pollen) resulted in increased bunch weight (BW) (20.8 kg) and lower percentage of PF in the bunch (65.4%). The most effective hormonal doses to induce the formation of PF in the bunch were NAA 300 and 600 mg L-1. GA3alone or in mixture with NAA increased the percentage of PF but did not increase the BW, indicating that GA3had no synergistic effect on BW. The NAA applications represent alternatives to complement assisted pollination of OxG hybrids to increase bunch production and oil yield.

Effect of organic manure on growth and flowering attributes of dog flower (Antirrhinum majus)

A field experiment was undertaken in Phek, Nagaland, to investigate the effects of organic manure on the growth and flowering attributes of dog flower (Antirrhinum majus). The trial was statistically designed as a Randomized block design with seven treatments and three replications. In this experiment, three locally available organic manure viz., pig manure, poultry manure and forest debris were used. The results showed that, all vegetative parameters (plant height, no. of leaves per plant, no. of shoots per plant, leaf length and width) and flowering parameters (minimum days to first bud initiation, 1st flower opening, 50% flowering, 100% flowering, maximum spike length, no. of buds per spike, and no. of spikes per plant) was found to be statistically superior in the treatment where the soil was enriched with a combination of pig manure @1kg/m2 + forest debris @1kg/m2

Potential of Gynoecious Line in Generating Superior Heterotic Hybrids in Bitter Gourd (Momordica charantia L.)

An experiment was designed to find out the extent of heterosis in bitter gourd using gynoecious line, KAU- MCGy-101 and three monoecious lines viz., Preethi, Priyanka, and MC133. Hybrids were generated by both direct and reciprocal crosses. All the hybrids exhibited earliness in terms of days to first female flower opening, node bearing first female flower, and days to first harvest. The hybrid KAU-MCGy-101 × Priyanka exhibited significantly higher heterosis with regard to heterobeltiosis (-16.03 %) and standard heterosis (-18.63 %) for days to first female flower opening. All the six hybrids manifested significant standard heterosis for sex ratio in the desirable negative direction, ranged from 44.25 to -55.52 %. The highest yield was recorded in the hybrid KAU-MCGy-101 × Priyanka (22.88 t/ha) and was followed by KAU-MCGy-101 × Preethi (20.42 t/ha) and KAU-MCGy-101 × MC 133 (20.05 t/ha). Heterobeltiosis for yield (t/ha) varied from 14.72 to 57.85 % and the standard heterosis ranged between 37.59 to 89.31 %. The best performing hybrids were KAU-MCGy-101 × Preethi, KAU-MCGy-101 × Priyanka, and KAU-MCGy-101 × MC 133 with respect toearliness, number of fruits per plant, and yield. Thus, the superiority of hybrids having gynoecious line as a maternal parent is prominent in the present study.

EFFECTS OF DIFFERENT TREATMENTS ON VASE LIFE OF GLADIOLUS CUT SPIKES: A REVIEW

Gladiolus is a commercial cut flower whose demand is 6000-8000 spikes/day and increasing day by day because of its majestic spikes. Long vase life is one of the important attributes of cut flowers but due to lack of proper aftermath effects and management flower does not remain consumable for long. This review focuses on different approaches to increase the vase life of the gladiolus cut flower. Cultivation practices, nutrients applied and maturity judgment during cultivation were found as responsible factors to determine the vase life. However, vase solutions containing different concentrations of 8-HQC, salicylic acid, Humic acid, silver nanoparticles, and sucrose (energy source) influence the vase life considerably. The number of Gamma rays and light also determines the vase life of gladiolus cut spikes by diminishing chromosomal aberration was seen higher responsible for improving flower opening and vase life. Gladiolus is extremely sensitive to Fluoride, so it is better not to use water from contaminated sources during the preparation of the preservative solution.

Pollination of Turnera subulata: exotic or native bees?

ABSTRACT This work analyzed floral visitors of Turnera subulata Sm. (Turneraceae) within an anthropized area in Bahia (UEFS Campus), focusing on potential pollinators, fruit and seed production and the influence of climatic factors on this interaction. The study was carried during six months in 2018 and 2019. Aspects of floral biology and visitor behavior were observed. Turnera subulata flowers lasted approximately six hours and during this period they were exposed to visitors at different intervals to assess the peak time of fruit formation. The most frequent visitors were the bees Apis mellifera Linnaeus, 1758, Trigona sp., Augochlora sp. and Protomeliturga turnerae (Ducke, 1907). The foraging peak occurred in the morning, coinciding with the time of greatest formation of fruits and seeds, and with the time of greatest number of open flowers. Both exotic and native bees acted as potential pollinators, being considered complementary in the flower pollination process.

From canopy to single flowers: a downscale approach to flowering of the invasive species

Context Acacia longifolia is a native legume of south-eastern Australia and Tasmania and is invasive in many parts of the world. A key feature to its success is the production of a high quantity of flowers every season, resulting in a massive seedbank that remains dormant in the soil for decades. Many studies have been performed on this species’ reproductive biology, but none has focused on flowering in detail. Aims Our main objective was to understand this species’ resource allocation strategy that ensures its successful reproduction in the invasive range. Methods We developed an integrative approach, assessing flowering at different levels, namely, canopy and branch flowering (macro scale), downscaling to individual flower functional stages and their duration, pollen longevity and stigma receptivity (micro scale). We performed this study in three different locations in sand dunes along the Portuguese coast with different environmental conditions. Key results Canopy flowering shows no difference among sites. Pollen and stigma assessment showed that this species is protogynous, with the stigma being highly receptive long before pollen is released. Once released, pollen lasts roughly 72 h. Individual flowers are relatively short-lived, with a rapid progression from closed flower buds to fully open flowers. Implications Our results indicated that A. longifolia has a resource trade-off strategy of investing in flowers and pollen that are relatively short-lived, which are counterbalanced by their massive quantities.

Bee Diversity Associated with Canavalia rosea (Sw.) DC. (Fabaceae, Papilionoideae) in an Peri-Urban Patch of “Restinga”

The Restinga is one of the physiognomies of the Atlantic Forest biome with the highest degree of anthropic impact, mainly due to disordered urbanization. The impacts generate habitat loss and threaten the animals and plants that inhabit this ecosystem. In the Restinga, the psammophilous vegetation have an important role in stabilizing the sandy substrate and maintaining the pollinator community. In this study, we analyzed the floral resources offered by Canavalia rosea to floral visitors between October 2019 and September 2020, in the Municipal Natural Park of Barreto’s Restinga, in Macaé, Rio de Janeiro, Brazil. Sampling was carried out from 8:00 am to 4:00 pm, covering a 250-meter transect in the sandy cord, counting the total number of open flowers and collecting visiting bees. The morphology of C. rosea flowers was described to relate to the functional traits of visitors, related to pollen and nectar collection. The pollen load of visitors was analyzed to estimate the degree of specialization in relation to C. rosea. A total of 192 individuals of 14 bee species were captured. There was a significant relationship between the availability of floral resources, measured by the number of open flowers and the richness and abundance of bees. The greatest richness of bees was observed between January and March and the greatest abundance in January. The most frequent visiting genera in C. rosea were Eufriesea, Centris and Xylocopa. The greatest richness of pollen types was observed in Eufriesea species. Most Xylocopa individuals showed C. rosea pollen. In this study, the importance of C. rosea as a source of floral resources for fourteen species of solitary bees was demonstrated. The data generated increases the knowledge about the ecological patterns of C. rosea and its floral visitors and may contribute to the maintenance and expansion of Restinga areas in urban environments.

Diversidad alfa y beta de thrips (Thysanoptera) y agentes de control biológico en flores de crisantemo (Chrysanthemum sp.) de dos ecoregiones en la provincia de Jujuy, Argentina

The objectives of this study are to identify thrips and their biological controllers, to analyze their abundance in three flower opening stages stages of chrysanthemum crops, and to determine alpha and beta diversity in two ecoregions of Jujuy province (Argentina). The study was carried out in the Chaco ecoregion (ECH) in October and November 2016, and in the Prepuna ecoregion (EP) in February and March 2018. On each date, six replicates of five flowers were excised in the stages: flower bud , semi-open flower and open flower. Diversity profiles and rank-abundance curves were built, and Jaccard's coefficient of similarity was applied. The diversity profiles showed significant differences in thrips communities. In the ECH, 15 thrips species were identified; the dominant and permanent species were Microcephalothrips abdominalis (Crawford) and Frankliniella occidentalis (Pergande). Five species were recorded in the EP, although Frankliniella gemina Bagnall and Thrips tabaci Lindeman on their own represented 78% of the total abundance. In the ECH, 20 entomophagous species/morphospecies were recognized, and 19 in the EP; antocorids were dominant in both ecoregions. The thrips and the entomophagous communities of chrysanthemum flowers were different (34%) between the ecoregions studied.

Deionized water as vase solution prolongs flower bud opening and vase life in carnation and rose through sustaining an improved water balance

Deionized water as vase solution prolongs flower bud opening and vase life in carnation and rose through sustaining an improved water balance