Influence Of Plant Growth Regulators Research Articles

Influence of plant growth regulators on yield attributes and physical parameters of fruit quality in sapota under the eastern tropical region of India

The present study was conducted at Central Horticultural Experiment Station (ICAR-IIHR), Bhubaneswar, during 2022 and 2023 to evaluate the impact of the application of plant growth regulators on fruit set, yield and physical fruit quality of Sapota (Manilkara zapota L.) cv. DHS-1. The experiment was designed in a randomized completely block design with nine treatments consisting of NAA (50 and 100 ppm), CPPU (5 and 7.5 ppm), SA (150 and 300 ppm) and Homobrassinolide (10 and 15 ppm) and water as control. Treatments were imposed on 24-year-old, uniformly grown sapota trees, planted at 10m x 10m spacing, at flowering, fruit set and one month after fruit set. In general, the application of PGRs was effective in augmenting fruit sets, fruit retention, yield attributes and physical fruit quality over control. However, the application of NAA and CPPU performed better at higher doses. The treatment NAA @100 ppm resulted in the highest fruit set (34.76 %), fruit retention (57.46% at 30 DAFS, 28.48 % at 120 DAFS), yield (47.77 kg/tree) and physical fruit viz. pulp content (93.80%), dry matter (26.15%), fruit length (7.47 cm) and fruit width (6.57 cm). Pearson correlation coefficient analysis showed positive links among fruiting, yield, yield attributing traits and physical fruit quality parameters of sapota, as well as a negative correlation for peel content.

Influence of Plant Growth Regulators (PGRs), Antioxidants, HgCl2 and photoperiod on in vitro shoot proliferation of Ashwagandha (Withania somnifera)– a medicinal crop

Influence of Plant Growth Regulators (PGRs), Antioxidants, HgCl2 and photoperiod on in vitro shoot proliferation of Ashwagandha (Withania somnifera)– a medicinal crop

BIOCHEMICAL PARAMETERS, DEVELOPMENT AND SPREAD OF DISEASES IN POTATO CROPS USING PLANT GROWTH REGULATORS

Objective. To study the effect of growth regulators and planting dates on chlorophyll content, quality indicators, disease susceptibility and yield of potato tubers. Methods. Field, namely visual and measurement-weight; laboratory; statistical; calculation-comparative. Results. In 2020-2023, comprehensive studies were conducted on the influence of growth regulators Phytosubtyl, IntraCell, Kartoplex and planting dates on the content of pigments in potato leaves, biochemical parameters of potato tubers and the yield of the ultra-early Radomysl and mid-ripening Myroslava varieties. The use of plant growth regulators on potatoes contributed to an increase in the level of yield and biochemical parameters of the crop. In particular, the greatest increase in tubers in both varieties was provided by the Kartoplex, increasing the yield by 12.0–25.3 %. Plant regulators had a positive effect on the starch and dry matter content of potato tubers. Thus, in comparison with the control variant, the starch content of the Myroslava variety increased by 1.7–2.1%, dry matter by 1.4–2.97%, and the Radomysl variety by 0.7–2.0 and 1.5–2.88%, respectively. The maximum value of vitamin C content was recorded in 2023 in the Myroslava variety 23.4, in the Radomysl variety 20.3 mg/%, and the minimum in 2022 – Myroslava 21.3, Radomysl 18.1 mg/%. On average, over the years of studies, the use of growth regulators contributed to an increase in the content of vitamin C in potato tubers of Radomysl and Myroslava varieties as follows: for the Radomysl variety – Phytosubtyl by 9.1–10.9 mg/%, IntraCell: by 2.8–5.1 mg/%, Kartoplex: by 11.8–14.0 mg/%; for the Myroslava variety: Phytosubtyl – an increase of 5.2–11.0 mg/%, IntraCell 6.8–8.3 mg/%, Kartoplex 16.2–18.1 mg/%. The analysis of variance of the obtained data showed that the following factors had the greatest influence on the content of the sum of chlorophylls in potato leaves: varietal characteristics (factor A): this factor had the greatest influence on the content of chlorophylls, the share of which was 34.9 %; planting time (factor B): the influence of this factor was 25.3%, growth regulators (factor C): their influence was 10.4%, the interaction of factors of planting time and variety (AB): the share of influence of this factor was 14.8%, the interaction of factors AB, BC and ABC: their influence was as follows: AB interaction: 4.1%, BC interaction: 3.4%, ABC interaction: 4.7. The results of tuberous analysis showed that the prevalence (in total) of diseases a month after harvesting was the highest in the control varient (8.9% in the Radomysl variety and 9.8% in the Myroslava variety). When tubers were treated with Phytosubtyl, the prevalence of diseases decreased by 47.2% for the Myroslava variety and 55.1% for the Radomysl variety. Discussion. The results of studies positively correlate with the developments of domestic and foreign scientists to study the influence of plant growth regulators on various aspects of technological and biochemical indicators of potato productivity. Conclusions. The influence of growth regulators Phytosubtyl, IntraCell, and Kartoplex on the biochemical components of plants and tubers, the development and spread of diseases that determine potato yield and productivity was studied.

Anthocyanin physiology and biochemistry in fleshy fruit species: Mangosteen as a model

AbstractMangosteen (Garcinia mangostana L.) is a popular, common tropical fruit grown in Southeast Asian countries. The pericarp contains a high anthocyanin content and various other bioactive compounds that are associated with medicinal and pharmaceutical properties. In marked contrast, the white edible aril contains no anthocyanins. The anthocyanins are the major pigments in the pericarp and produce red‐to‐purple coloration, which serves as a maturity index when fruit are ripe. The major anthocyanins consist mainly of cyanidin‐sophoroside and cyanidin‐glucoside. The synthesis of anthocyanin in mangosteen involves the coordinated expression of many genes with at least eight genes encoding enzymes and three transcription factors having been identified. Ripening‐induced anthocyanin accumulation is regulated by endogenous ethylene that controls the expression of key genes. Comparisons are made between anthocyanin synthesis in mangosteen and other fruit species under various conditions including light and temperature and the influence of plant growth regulators.

Influence of plant growth regulators on fruit set, yield and quality of mango varieties under HDP

Plant hormones are signal molecules produced within the plant, and occur in extremely low concentrations. Phytohormones determine the formation of flowers, fruit set, stems, leaves, shedding of leaves, and development and ripening of fruits. They shape the plant, affecting seed growth, time of flowering, sex of flowers, senescence of leaves and fruits. Hormones are vital for plant growth and lacking them, plants would be mostly a mass of undifferentiated cells. Plant growth regulators include salicylic acid, CPPU, tricontanol and brassinosteroid. The production of poor quality fruits is a matter of common experience. It would be therefore worth while to improve the yield and quality of fruit crops by foliar application of plant growth regulators. The use of growth regulators has become an important component of agro-technical procedures for most of the cultivated plants and especially for fruit plants. In this review, we focus on the role of plant growth regulators on fruit production.

Influence of plant growth regulators on qualitative attributes of acid lime Kuliana local in Odisha

Kuliana lime is an outstanding Odisha cultivar with significant potential to be included in future crop improvement operations due to its flavor and juice content. This research was conducted at the Horticultural Research Station, Department of Fruit Science and Horticultural Technology, Orissa University of Agriculture and Technology, Bhubaneswar during 2019–2020 and 2020–2021 to determine the optimal growth regulator in terms of quality metrics. certain growth regulators 2,4-D (2,4-D @ 10 ppm and 20 ppm) and GA3 (GA3 @ 50 ppm and 100 ppm) and NAA (NAA @ 100 ppm and 200 ppm) and SA (SA @ 100 ppm and 200 ppm) and SPMD (SPMD @ 0.01 ppm and 0.5 ppm) and PUT (PUT @ 0.01 ppm and 0.5 ppm) and BR (BR @ 0.1 ppm and 0.5 ppm) quality of Acid Lime kuliana local. The biometrical observations on various quality features were recorded in the same seasons over 2 years. The best was for fruit quality, which has been determined on the basis of growth regulators performances, as growth regulator variation has a significant effect on the quality of fruit. Brassinosteroids showed the best effects for TSS (7.17 oBrix), acidity (6.05 %), total sugar content (0.61 %), reducing sugar content (0.41 %), ascorbic acid (36.35 mg per 100 mL of juice), chlorophyll content (33.03 mg/100 g), flavonoid content (119.91 mg/100 g), protein (0.82 mg/100 g) and carbohydrate content (10.29 mg/100g) with the other treatments, including the untreated fruits in both years of the study. Our results revealed that the BR gave superior results in quality attributes for Kuliana lime in the East and Southeast Coastal Plain Zones of Odisha.

Influence of Plant Growth Regulators, Urea and Micronutrient on Growth, Yield and Quality of Rangpur Lime (Citrus limonia Osbeck)

Influence of Plant Growth Regulators, Urea and Micronutrient on Growth, Yield and Quality of Rangpur Lime (Citrus limonia Osbeck)

Advancing horizons in vegetable cultivation: a journey from ageold practices to high-tech greenhouse cultivation-a review.

Vegetable cultivation stands as a pivotal element in the agricultural transformation illustrating a complex interplay between technological advancements, evolving environmental perspectives, and the growing global demand for food. This comprehensive review delves into the broad spectrum of developments in modern vegetable cultivation practices. Rooted in historical traditions, our exploration commences with conventional cultivation methods and traces the progression toward contemporary practices emphasizing the critical shifts that have refined techniques and outcomes. A significant focus is placed on the evolution of seed selection and quality assessment methods underlining the growing importance of seed treatments in enhancing both germination and plant growth. Transitioning from seeds to the soil, we investigate the transformative journey from traditional soil-based cultivation to the adoption of soilless cultures and the utilization of sustainable substrates like biochar and coir. The review also examines modern environmental controls highlighting the use of advanced greenhouse technologies and artificial intelligence in optimizing plant growth conditions. We underscore the increasing sophistication in water management strategies from advanced irrigation systems to intelligent moisture sensing. Additionally, this paper discusses the intricate aspects of precision fertilization, integrated pest management, and the expanding influence of plant growth regulators in vegetable cultivation. A special segment is dedicated to technological innovations, such as the integration of drones, robots, and state-of-the-art digital monitoring systems, in the cultivation process. While acknowledging these advancements, the review also realistically addresses the challenges and economic considerations involved in adopting cutting-edge technologies. In summary, this review not only provides a comprehensive guide to the current state of vegetable cultivation but also serves as a forward-looking reference emphasizing the critical role of continuous research and the anticipation of future developments in this field.

Optimizing callus formation in the endangered medicinal tree Hydnocarpus macrocarpa using phytohormone

Hydnocarpus macrocarpa (Flacourtiaceae) is one of the endemic and endangered medicinal tree, was selected to investigate the influence of plant growth regulators on callus formation. H. macrocarpa is majorly distributed at low and medium elevations of the Southern Western Ghats. The seeds of this plant are used for the treatment of ulcers, biliousness, leprosy and epilepsy. An experiment was carried out with two different methods. In the first method Murashige and Skoog (MS) medium supplemented with cytokinin alone or combined with auxin (2–4-Dichlorophenoxy acetic acid; Naphthalene acetic acid; Indole acetic acid; Indole butyric acid and Gibberellic acid) at different concentrations (1, 2, 3, 4 and 5 µM) were used; in the seond method, MS medium supplemented with coconut endosperm (Solid and liquid) extract (1, 2, 3, 4 and 5 %) with Aloe vera jelly extract at different concentrations (1, 2, 3, 4 and 5 %) in combination and separately were used. Among the different treatments, good callus proliferation was obtained using MS medium supplemented with Benzylaminopurine and in combination with Naphthalene acetic acid and 2–4-Dichlorophenoxyacetic acid (3 µM and 4 µM). But the best callus proliferation, shoot tip proliferation; auxiliary root and shoot formation were observed in MS medium supplemented with Aloe vera jelly extract in combination with coconut endosperm extract. The natural growth regulators supplemented with the media gave a positive response for plant growth. The results showed that the natural growth regulators, such as coconut endosperm and Aloe vera jelly extracts were found to be more efficient than the synthetic growth regulators (auxin and cytokinin). The presence of Indole acetic acid and Indole butyric acid in both Aloe vera jelly extracts and coconut endosperm were confirmed by High performance liquid chromatography and Fourier transform infrared spectroscopy analysis.

Influence of plant growth regulators on fruit drop, fruit retention and fruit yield of mango (Mangifera indica l.) cv. Amrapali under west central table land zone of Odisha

Farmers in the western region of Odisha are grappling with issues related to low fruit set, fruit drop, and erratic yield in mango cultivation. Plant growth regulators (PGRs) play a pivotal role in addressing fruit drop at different developmental stages by modulating the nutritional and hormonal status of the plant. This study aims to investigate the impact of specific PGRs on fruit drop, fruit retention, and overall yield of Mango (Mangifera indica L.) cv. Amrapali in the West Central Table Land zone of Odisha. The experimental setup was implemented at the research plot of the College of Horticulture, Chiplima, Sambalpur, following a randomized block design with ten treatments, each replicated three times. The treatments involved various concentrations of three PGRs: NAA, GA3, and 2,4-D, applied during the pea and marble stages of fruit growth. The outcomes indicated that the application of 30 ppm GA3 significantly mitigated fruit drop, with comparable efficacy observed for 30 ppm 2,4-D. GA3 positively influenced fruit retention, particularly Treatment T7 (30 ppm GA3), exhibiting the highest retention percentages at 30, 60, and 90 days post-spraying. Furthermore, GA3 at 30 ppm resulted in the maximum average fruit weight and volume. The highest number of harvested fruits per plant and maximum yield per plant were recorded in Treatment T7. These findings underscore the potential of GA3 in alleviating fruit drop, enhancing fruit retention, and improving overall yield in mango cultivation, specifically for the Amrapali variety in the West Central Table Land Zone of Odisha.

Impact of Selected Plant Growth Regulators on Rooting Response of Stem Cuttings of Psidium guajava L.

Guava can be propagated vegetatively through layering, cutting and grafting, in addition to seeds. Among the propagation techniques, cuttings have gained popularity because they produce results in a shorted span of time. Rooting is an essential step in the propagation of guava through cuttings. Nowadays, the most popular technique for growing cuttings in a misty environment is the use of plant growth regulators, especially auxins such as Indole-3-Butyric Acid (IBA) and Naphthalene Acetic Acid (NAA) that promote root growth. The present study was undertaken to assess the influence of plant growth regulators on the rooting of diverse stem cuttings from guava cv. Arka Kiran under mist chamber conditions at the Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu. Two plant growth regulators, IBA and NAA were employed at various concentrations. These regulators were applied to single-node cuttings with one leaf, double node cuttings with two leaves, and herbaceous cuttings. The highest rooting percentage (55.10%), the duration for bud sprouting (21.13 days), and number of leaves (4.83) were observed in single-node cuttings treated with IBA at a concentration of 3000 ppm concentration. Single-node cuttings treated with IBA at 3000 ppm exhibited superior rooting and sprouting performance compared to Naphthalene Acetic Acid (NAA). Among the three stem cuttings, single-node cuttings with one leaf proved to be the most effective for rapid multiplication.

Влияние регуляторов роста растений на усообразовательную способность сортов земляники в условиях южной лесостепной зоны Башкортостана

This work aims at the influence of plant growth regulators on the ability of strawberry varieties to form runners in the conditions of the southern forest-steppe zone of Bashkortostan. The plants were twice sprayed with Albit (0.6 g/l), Krezacin (1 g/l), Zircon (1 g/l), and control water. The use of foliar fertilizers increased the resistance of strawberry plants to unfavorable environmental conditions. The use of Zircon increased the number of strawberry runners by 1.1-1.4 time and the number of daughter rosettes by 1.1-1.5 time. The Asia variety turned out to be highly sensitive to the use of preparations; the proportion of rosettes increased by 27 – 54 % above the control. Under the influence of growth regulators, the Festivalnaya romashka (Festival Chamomile) variety had the largest proportion of plants with runners, up to 83.3 %.

THE ROLE OF PLANT GROWTH REGULATORS IN THE FORMATION OF SUNFLOWER HYBRIDS PRODUCTIVITY

The results of the study of the influence of plant growth regulators and basic nutrients on the productivity of sunflower hybrids of different maturity groups are presented. The research was carried out on the basis of the farm of LLC "Organic-D" in the village of Sutisky, Vinnytsia region, during 2021-2022. The soils of the experimental plot are gray forest soils with medium loamy texture and slightly acidic reaction of the soil solution. The content of the main nutrients is typical for this type of soil. The research was conducted on three sunflower hybrids: early maturing –Oskil, mid-early - NK Delphi and mid-early - NK Condi by applying the plant growth regulator (PGR) DEFENDA Vertex (0.5 l/t) and mineral fertilizer at the rate of N45P45K45 d.p. m. The technology of sunflower cultivation is generally accepted for the conditions of the Right-Bank Forest-Steppe of Ukraine, except for the factors under study. We have found that the use of seed treatment with PPP DEFENDA Vertex and the application of mineral fertilizers at the rate of N45P45K45 on the crops of the studied sunflower hybrids of different maturity groups led to an improvement in the morphological structure of plants, an increase in their productivity, which ultimately led to an increase in oil yield per unit area. The maximum value of plant height, number of flowers and seeds in the basket of the studied hybrids in the variant with the combined application of mineral fertilizers at the rate of N45P45K45 with the treatment of seeds with PPP DEFENDA Vertex: Oskil - 163.3 cm, 1129 pcs. and 923 pcs, NC Delphi - 187.1 cm 1247 and 967 pcs. and NC Condi - 171.7 cm 1335 and 995 pcs. respectively. The highest level of yield, on average for two years of research, was obtained in the variant with the use of seed treatment with PPP DEFENDA Vertex and the application of mineral fertilizers at the rate of N45P45K45 in the sunflower hybrid Oskil - 2.78 t/ha, NC Delphi - 2.95 t/ha, mid-season NC Condi - 3.09 t/ha, which is 0.48-0.59 t/ha more compared to the control variant. Seed treatment with PPP DEFENDA Vertex provided an increase in yield of 0.27-0.36 /ha, compared to the control variant (without seed treatment and fertilization). Seed treatment with PGR DEFENDA Vertex contributed to the growth of oil content in the seeds of the studied hybrids and it was 46.9%, 49.7 and 54.5%, and the combination of seed treatment with PGR DEFENDA Vertex and the introduction of mineral fertilizers in pre-sowing cultivation provided the highest value of oil content - 47.8%, 50.1 and 55.7%, respectively. The acid number of oil had an ambiguous value when using the studied factors. The highest value of huskiness was obtained when using a combination of seed treatment with PGR DEFENDA Vertex with the introduction of mineral fertilizers in pre-sowing cultivation in the hybrid Oskil - 23.7%, NC Delphi - 26.3% and NC Condi - 24.9%. The combined use of seed treatment with PGR DEFENDA Vertex and mineral fertilizers at the rate of N45P45K45 showed the highest value of oil yield per unit area - 1.47 t/ha, 1.61 and 1.72 t/ha, respectively, in hybrids Oskil, NK Delphi and NK Condi.

Influence of Growth Regulators and Different Spectra of Monochromatic Radiation on the Growth and Biosynthetic Characteristics of Callus Culture of Ipomoea batatas (L.) Lam.

The work studied the influence of plant growth regulators as well as the effect of monochromatic radiation of different spectral composition on the growth and accumulation of secondary metabolites in the callus culture of sweet potato (Ipomoea batatas L.). It was found that auxin analogues in low concentrations (0.5 mg/L) significantly stimulated the growth of cell biomass, while the effect of 4-chlorophenoxyacetic acid (4-CPA) was more pronounced (stimulation 16 times) than that of 2,4-dichlorophenoxyacetic acid (2,4-D) (13.5 times stimulation). Both the increase in the concentration of 2,4-D and 4-CPA in the medium and the addition of cytokinin, 6-benzylaminopurine (BAP), led to a significant inhibition of culture growth (up to three times). In contrast to 2,4-D, the addition of 4-CPA led to an eightfold increase in the total content of polyphenolic compounds in cultured cells. Activating effect of 4-CPA on the biosynthetic characteristics of I. batatas cell culture persisted even with the addition of BAP, while an increase in the concentration of 4‑CPA led to the leveling of the activating effect. Monochromatic radiation—white, red (660 and 630 nm), yellow, green, and blue (440 and 460 nm) light—inhibited growth (up to 1.5 times) and the total accumulation of secondary metabolites in I. batatas cells (up to 1.8 times). At the same time, the white, bright blue, and red spectra differentially activated the formation of individual compounds 3,4-dicaffeoylquinic acid and 3-feruloyl-5-caffeoylquinic acid. Thus, the authors have established that both auxin analogues and spectral radiation exhibit different effects on the growth and biosynthetic characteristics of the I. batatas calli.

Hormesis management of Moringa oleifera with exogenous application of plant growth regulators under saline conditions

The study investigated the adaptability of Moringa oleifera to saline conditions, focusing on its hormesis behavior. It also examined how various plant growth regulators affected growth, physiological parameters, and bioactive compounds of moringa. In the first phase, different NaCl stress levels (0, 50, 100, 150, 200, and 250 mM) were applied. Notably, significant stimulation was observed at 100 mM stress for growth, total phenolics, total flavonoids and total chlorophyll content while 150 mM stress had a marked inhibitory effect, with survival decreasing at 200 and 250 mM NaCl levels. A 38% reduction in root attributes and shoot length, along with a 55% decrease in leaf score, was observed at 150 mM stress. Total phenolics showed a positive correlation with growth attributes. In the second phase, moringa plants grown under 50, 100, and 150 mM NaCl stress were treated with various plant growth regulators, including cytokinin (50 mg L−1), thiourea (5 mM), bezyl amino purine (BAP @50 mg L−1), salicylic acid (50 mg L−1), hydrogen peroxide (H2O2@120 μM), or ascorbic acid (50 mg L−1) to mitigate adverse effects of salinity. Cytokinin, BAP, and salicylic acid applications improved salinity tolerance, enhancing enzymatic, and non-enzymatic antioxidants, and the abundance of kaempferol, quercetin, hydroxybenzoic, and hydroxycinnamic acids. Pearson correlation and principal component analysis manifested relationships among growth parameters, antioxidant activities, flavonoids, and phenolic acids. This study provides new insights into hormesis management for moringa plants and the influence of plant growth regulators on flavonoids and phenolic acid levels in moringa leaves under saline conditions.

Введение in vitro и регенерационная способность реликтового эндемика недзвецкия семиреченская Niedzwedzkia semiretschenskia B. Fedtsch

В статье приведены экспериментальные данные по получению асептической культуры редкого реликтового вида недзвецкия (инкарвиллея) семиреченская Niedzwedzkia semiretschenskia от исходных семян из природных популяций на юге Казахстана. Изучено влияние гормонального состава питательной среды Мурасиге и Скуга на всхожесть семян, адвентивное побегообразование и укоренение in vitro. Проведена оценка коэффициента размножения в ходе многократного микрочеренкования асептических побегов. Установлено, что in vitro всхожесть семян не превышала 25 % на среде Кнопа, максимальная всхожесть отмечалась при их посадке в почвенный субстрат. Внесение в среду цитокинина 6-бензиламинопурина (БАП) приводило к образованию каллуса из тканей семядолей, к адвентивному побегообразованию у апикальных эксплантов проростков с настоящими листьями. Выявлено, что оптимальной средой для микроклонального размножения является среда с внесением 0,5 мг/л БАП с максимальным коэффициентом размножения 7,84 на втором пассаже. Установлено, что при депонировании в условиях низкой положительной температуры в течение 6 месяцев пробирочная культура инкарвиллеи сохраняет жизнеспособность и восстаналивает рост при переносе в стационарные условия световой комнаты. В результате работы проведено введение в культуру тканей, микроклональное размножение и создана депонированная коллекция in vitro реликтового вида N. semiretschenskia.

Growth of Paulownia ssp. Interspecific Hybrid ‘Oxytree’ Micropropagated Nursery Plants under the Influence of Plant-Growth Regulators

The aim of the study was to examine the effects of application of plant-growth regulators (PGR) on the growth of paulownia plants and evaluate their usefulness in paulownia nurseries. The experiment was carried out on the paulownia interspecific hybrid (Paulownia elongata × Paulownia fortunei) ‘Oxytree’. Micropropagated plants grown in pots were sprayed with PGR solutions. Gibberellins (GA3, GA4+GA7), 6-benzyladenine (BA), triclopyr (TPA), ethephon (ETH), daminozide (DA), prohexadione-Ca (PH), and trinexapac-ethyl (TE) were used. They were included in commercial products (Florgib 245 mg dm−3, Gibb plus 11 SL 5 cm3 dm−3, Globaryll 100 SL 1.5 cm3 dm−3, Topper 10 ST 200 mg dm−3, Agrostym 480 SL 2 cm3 dm−3, B-Nine 85 SG 2 g dm−3, Regalis plus 10 WG 2.5 g dm−3, Moddus 250 EC 1 cm3 dm−3, respectively). None of the studied preparations modified positive correlations between the longitudinal vs. transverse growth of stems and growth of leaves. Not only GA3, GA4+GA7, but also BA (cytokinin) and unexpectedly TE (retardant) stimulated stem elongation and thickening. Furthermore, the effect of TE lasted longer than influence of GAx and BA. Leaves of TE-treated plants were distinguished by a higher chlorophyll a/b ratio, and a lower relative chlorophyll content and efficiency of photosystem II (Fv/Fm, Fv/F0). TPA strongly deformed the stems and leaves of liners. Other regulators (ETH, DA, PH) retarded the diameter growth of stems and leaf expansion. Some results obtained by GAx, BA, and especially by TE treatment, might be beneficial for paulownia grown as ornamental and/or timber tree.

A prospective insight into the reproduction of Sternbergia clusiana K. Gawl.: an endangered species

Sternbergia clusiana (SC) is a bulbous plant having an alluring ornamental flower, medicinal properties, and an endangered status due to climate-change ecology. However, the methods of propagation for conserving this notable species have been neglected. The main aim of this study was to evaluate the influence of plant growth regulators (PGRs) on SC regeneration by virtue of a asexual propagation method, with the intention of preserving this endangered species from extinction. In this regard, having collected the bulbs from a wild habitat, bulbs were cut in accordance with the chipping technique. Thereafter, pieces were treated with 6-benzylaminopurine (BAP) at 250, 500, and 1000 mg·L−1, 1-naphthaleneacetic acid (NAA) at 100, 250, and 500 mg·L−1, putrescine (PU) at 50, 100, and 200 mg·L−1, BAP and NAA combination, BAP and PU combination, and a control. Pieces were then transferred into primary and terminal growing media under laboratory and greenhouse conditions, respectively. Next, the number, length, width, and weight of bulbs were determined. The greatest bulb number (2.10 counts), bulb length (26.75 mm), bulb width (16.25 mm), and bulb weight (3.13 g) were observed in the PU treatments. In addition, the results showed that even though the treated bulbs with BAP and PU combinations had preferable performance generally, the results were inconsistent. Taken together, this research indicates that utilizing asexual propagation along with PGRs, in the proper dosage, can serve as a mechanism to protect the endangered geophyte from extinction in nature.

Biosynthesis, Mechanism and Potential Application of Hormones for Mitigating Stress, Conserving Bioactive Constituents in Fruits

The influence of plant growth regulators, including auxins, gibberellins, cytokinins, ethylene, abscisic acid, brassinosteroids, jasmonates, and salicylic acid, on fruit crop development and quality enhancement. Various stages of fruit crop growth, such as flowering, fruit set, ripening, and post-harvest attributes, are examined through comprehensive experimental approaches. Auxins play a crucial role in regulating fruit size, shape, and development by facilitating cell elongation. Gibberellins control fruit elongation, seed germination, and fruit set. Cytokinins influence fruit expansion, sugar metabolism, and overall quality by promoting cell division and differentiation. Ethylene affects fruit ripening processes, including color change, softening, and flavor development. Abscisic acid influences fruit maturation and dormancy. Brassinosteroids regulate fruit development, including size, ripening, and tolerance to abiotic stress. Jasmonates and salicylic acid, involved in defense responses, have an impact on fruit ripening, quality, and disease resistance. The application of these regulators shows promise in improving fruit quality, nutritional composition, and shelf life. This study aims to provide valuable insights into fruit crop physiology and develop strategies to optimize productivity and quality. It emphasizes the importance of proper regulation and responsible use of plant growth regulators to address environmental, health, and ecological concerns associated with excessive or improper application. Excessive use of PGRs can lead to various physiological issues, adversely affecting fruit crop productivity and quality. Therefore, careful control of application procedures, dosages, and timing is necessary to ensure fruit crop health and avoid negative consequences.

The Effects of Different Auxin–Cytokinin Combinations on Morphogenesis of Fritillaria meleagris Using Bulb Scale Sections In Vitro

Fritillaria meleagris is a horticulturally and medicinally valuable bulbous plant that requires a period of low temperatures for proper growth and flowering. Since conventional methods of propagation are ineffective and very slow, tissue culture techniques offer an integrated approach to mass production of this valuable geophyte. In this study, we investigated the effects of various auxin–cytokinin combinations on different morphogenetic pathways in bulb scale culture. Bulbs obtained in vitro were cut longitudinally, and bulb scales were cultured for four weeks at 7 °C on MS medium supplemented with 6-benzylaminopurine (BAP) in combination with 2,4-dichlorophenoxyacetic acid (2,4-D) or α-naphthaleneacetic acid (NAA) at different concentrations in order to investigate the influence of plant growth regulators (PGRs) on different morphogenetic responses. Regeneration percentage, number of shoots per explant, shoot length, number of bulbs and number of somatic embryos were monitored weekly. After chilling, bulb scales were transferred to 24 °C, and all parameters were recorded again. Low PGR concentrations were very effective for shoot multiplication, yielding up to 5.5 shoots per explant. 2,4-D (at 2 mg/L) in combination with low BAP (0.25 mg/L) produced the highest number of bulbs (11.00 ± 0.00), while PGR-free medium was extremely effective in somatic embryo formation (13.50 ± 2.90). Detached somatic embryos and bulblets continued to grow and develop on fresh PGR-free medium. We present data demonstrating that low auxin–cytokinin concentrations and PGR-free medium provide an effective method for a combined morphogenetic pathway in F. meleagris that is suitable for large-scale propagation.