Effect of Plant Growth Regulators on Rice Lodging Resistance and Grain Production of Main-crop and Ratooning Rice

Lodging is one of the major problems in rice production. In this study, we identified quantitative trait loci (QTLs) for lodging resistance traits using recombinant inbred lines (RILs) derived from a cross between two high yielding and superior lodging resistant rice cultivars, Tachisugata and Hokuriku 193. A total of 19 QTLs were detected on chromosomes (Chrs.) 2, 4, 6, 8, 9 and 10 in the F6 and F7 populations. In particular, one stable QTL for the section modulus (SM) and the outer diameter of the major axis (ODMA) was detected on Chr. 2 in both the F6 and F7 populations, and the positive allele was derived from Tachisugata. Correlation analysis showed that the SM and ODMA were positively correlated with the bending moment at breaking, the primary factor for the breaking type lodging resistance in rice. In addition, two QTLs for the spikelet number of the secondary branch and the spikelet number per panicle were also detected on Chr. 2, which overlapped with the stable QTL for the traits related to lodging resistance. These results indicated that the stable QTL might have combined effects on the traits associated with lodging resistance and grain yield. The novel QTL would be a promising target in marker-assisted selection to improve lodging resistance and grain yield in rice.

Plant growth regulators are the naturally extracted or synthesised compounds which are used in smaller quantity to modify the hormonal activity in agricultural and horticultural crops. Though there effect was not totally revealed there was some significant works carried out to know the effect of growth regulators on agronomic crops they are now using in wide range of crops to alter different parameters such as plant height, canopy development, effective branching, flower imitation and improving yield. They also play a key role in dryland farming as some of the plant growth regulators are used in stress tolerance of the crops. Few research works are carried to know the effect of major plant growth regulators on cereals and pulses. The plant growth regulators like auxins, gibberellins, cytokinins and ethephon are the majorly used plant growth regulators in cereals and pulses to obtain optimum plant growth and to improve the yields.

Navigating rice culm resilience: High-throughput quantitative trait locus mapping in indica and tropical japonica derived population.

Melia azedarach L. is a valuable source of antioxidants and secondary metabolites. This study is a first extensive report about the effect of different serialization protocols and plant growth regulators (PGRs) on explant disinfection efficiency, callus induction and secondary metabolites production and accumulation in callus cultures of M. azedarach L. In this regard, the effect of plant growth regulators on callus induction and secondary metabolites production were examined. In addition, different sterilization agents were evaluated for disinfection of chinaberry leaf explants. The results showed that the lowest percentage of explant contamination and browning with the highest percentage of callus induction and callus growth obtained with explants pretreated with benomyl (2 g/L) for 2 h and sterilized with 7% H2O2 for 10 min and NaOCl 2% (without pH adjustment) for 12 min. Although adjusting the pH of NaOCl to pH = 7 and 10 significantly reduced the microbial contamination and increased the percentage of contamination-free cultures of M. azedarach L., adversely influenced the explant viability and callus induction and growth. The highest percentage of callus induction obtained on the MS medium containing 3 mg/L NAA/2,4-D and 1 or 3 mg/L Kin/BAP, and the highest callus yield (1804.833 mg/explant) belonged to the MS medium supplemented with 5 mg/L 2,4-D and 5 mg/L Kin. The callus cultures grown on the MS medium supplemented with 3 mg/L NAA and 1 mg/L Kin produced the highest amount of Quercetin (2.06 mg/g fresh weight), Rutin (5.56 mg/g fresh weight) and Kaempferol (1.84 mg/g fresh weight).

Abiotic stresses such as unpredictable rainfall, temperature variations, drought and soil degradation reduce ginger yield and rhizome quality. Polyhouse cultivation minimizes these effects but often favors vegetative growth over rhizome development. Plant growth regulators (PGRs) help redirect assimilates to storage organs, optimize source-sink balance and improve yield and quality. Thus, the present study entitled “Effect of plant growth regulators on biochemical quality of ginger transplants grown under transplants under polyhouse cultivation” evaluated the effect of various PGRs on quality attributes in ginger transplants under polyhouse conditions. The investigation was carried out in KVK, Palakkad from August 2024 to March 2025. The pot culture was done in CRD using PGRs such as CCC, GA₃, NAA and BAP at three different concentrations (50 ppm, 100 ppm and 150 ppm) along with a control (water), which were applied at 90 and 120 DAT. The highest protein content (23.65 mg/g) was observed in naphthalene acetic acid at 150 ppm. Cycocel at 150 ppm produced the highest total sugar, volatile oil as well as oleoresin content in ginger. Gibberellin at 150 ppm maintaining the maximum chlorophyll content (3.450 mg/g), Based on the findings, foliar application of Cycocel enhanced the quality parameters of ginger by facilitating the redirection of photoassimilates from aerial parts to rhizomes. Thus, this study concluded that application of Cycocel at 150 ppm significantly improved the quality of ginger transplants under polyhouse conditions.

Biochar application elicits positive environmental and agricultural impacts owing to its physicochemical properties; however, the mechanism of biochar in regulating the lodging resistance in rice remains unclear. The present study was conducted to investigate the effects of biochar application on rice yield, lodging‐related traits, and enzymes activity and gene expression related to lignin biosynthesis in two rice (Oryza sativa L.) cultivars, that is, Shennong 265 and Akihikari. The biochar treatments were: 0 (B1), 5 (B2), 10 (B3), 20 (B4), and 40 (B5) t/ha. Results depicted that compared with B1, the B2 and B3 treatments improved the rice yield by 8.36%–27.62% and decreased the lodging index by 7.72%–24.14% for both rice cultivars, respectively. The increase in rice yield was mainly due to an increase in chlorophyll content, net photosynthesis, and dry matter at the heading stage. The reduced lodging index in B2 and B3 was mainly owing to an increase in stem lignin and silicon content by 28.55%–62.80% and 16.27%–50.09%, respectively, that was possibly linked to an increase in lignin synthase activity and its gene expression, that is, phenylalanine ammonia lyase, caffeic acid 3‐O‐methyltransferase, 4CL3 (where 4CL is 4‐coumarate: CoA ligase), and CCR20 (where CCR is cinnamyl coenzyme A reductase). Furthermore, the numbers of large and small vascular bundles were the highest in B2 and B3 treatment for both rice cultivars. However, excess biochar applications had an inhibitory effect on rice yield. Overall, biochar application at 5–10 t/ha is an appropriate dosage to improve lodging resistance and rice yield.

To investigate the effect of plant growth regulators on the growth and quality of Angelica dahurica var. formosana. Five plant growth regulators: chlormequat chloride (CCC), Mepiquat chloride (PIX), Gibberellic acid (GA3), Paclobutrazol (PP333) and Maleic Hydrazide (MH) were sprayed in rosette stage, the effects of these plant growth regulators (PGRs) on the growth, yield and quality of A. dahurica var. formosanaw were observed. The biological traits were first measured and then imperatorin and isoimperatorin contents in roots were determined by HPLC. Low concentration GA3 increased the yield while not influenced the premature bolting rate and the coumarin content. Spraying of GA3 (30 mg x L(-1)) could guarantee the growth and development of A. dahurica var. formosana to have a higher yield and maintain the active ingredients content in the root as well.

Effect of plant growth regulators on vegetative growth, sex expression,fruit setting, seed yield and quality was studied for hybrid seed production in the parental lines of bitter gourd (Momordica charantia L.) hybrids,Pusa hybrid 1 and Pusa hybrid 2 in rainy and spring-summer season. Plant growth regulators namely GA3 @ 50 ppm, NAA @ 200 ppm, maleic hydrazide @ 100 ppm, etherel @ 50 ppm were sprayed at three leaf and tendril initiation stage. The results showed that application of GA3 significantly enhanced vine length, number of branches and nodes/vine, fruiting, seed yield and quality in the parental lines in both the seasons.The plants sprayed with growth regulators showed induction of female flowers at lower nodes with 3-5 more pistillate flowers per vine and higher sex ratio as compared to unsprayed control. In manually pollinated flowers, plants sprayed with GA3@ 50 ppm had higher fruit and seed setting, fruit weight and hybrid seed yield. All the growth regulators had positive influence on vegetative, flowering and fruit traits in both the seasons but effect of growth regulators were more evident in rainy than springsummer season. GA3 @ 50 ppm, NAA @ 200 ppm, etherel @ 50 ppm were effective for enhancement in vegetative growth, fruit and seed yield and modification of sex expression but GA3 @ 50 ppm sprayed twice at three leaf and tendril initiation stage was most effective for hybrid seed production of bitter gourd.

Ginger is one of the oldest and renowned commercial spices well known for its medicinal and pharmaceutical value. Land degradation, availability of the quality rhizomes and diseases are some of the challenges faced in the ginger production. Since the productivity of a plant is influenced by a complex physiological process controlled by plant growth hormone balancing systems, the application of the growth regulators can have positive effect. Manipulating the PGR combinations and concentrations can lead to better quality and productivity in ginger. Hence, an experiment was conducted to study the effect of different plant growth regulators (PGRs) on nutrient and quality parameters in the ginger variety IISR Varada. Foliar spray of PGRs with 6-benzyl adenine purine (6-BAP), cycocel (Chlormequat chloride), gibberellic acid (GA) and paclobutrazol (PBZ) with five concentrations viz., 50ppm, 100ppm, 150ppm and 200ppm were applied 4th month after planting and water spray treated as control. Nutrients composition and biochemical components were observed on 5th month after planting and oleoresin was observed in the rhizomes after harvest. The results of pooled data over two years revealed that GA at 100 ppm recorded maximum nitrogen and chlorophyll content in leaves, potassium and protein in rhizomes. Regarding the oil content, maximum was noticed in treatment 100ppm Paclobutrazol followed by GA 100ppm.

IntroductionLodging is a critical limiting factor affecting stable rice production in the lower reaches of the Yangtze River in China.MethodsThis study aims to clarify the optimal spraying period and concentration of paclobutrazol for high-quality japonica rice by examining its effects on the mechanical, morphological, and metabolic characteristics of the stem. A clean water treatment (CK) was established alongside five spraying periods (S1: July 19; S2: July 26; S3: August 2; S4: August 9; S5: August 16) with three spraying concentrations (LP: 100 mg L-1; MP: 200 mg L-1; HP: 300 mg L-1).Results and discussionThe results indicate that the MP treatment during the S4 period resulted in a yield increase of 2.3–11.8% while reducing the lodging index by 15.8-25.5%. In the early stages of spraying (S1, S2 and S3), the lodging resistance of rice was primarily enhanced by reducing plant height, but led to a significant decrease in the spikelets per panicle and grain filling, ultimately resulting in reduced yield. In the later stages of spraying (S4 and S5), lodging resistance was mainly improved by increasing internode diameter and culm wall thickness, which concurrently resulted in a significant increase in the grain filling. Although high concentrations of paclobutrazol in each period can reduce the lodging index, they are not conducive to yield formation. Correlation analysis revealed a significant negative correlation between the lodging index and both the internode diameter and the culm wall thickness. Non-target metabolism indicated that the significant increase in mandelonitrile and sarcosine content within cyanoamino acids metabolism, and glycine, serine, and threonine metabolism during S4, might be the primary metabolic factors promoting the development and thickness of stem walls. Additionally, the increase in pheophytin-a in porphyrin and chlorophyll metabolism, along with leucine in valine, leucine, and isoleucine degradation, may be the key contributors to the enhancement of rice lodging resistance and stable yield when treated with an appropriate concentration of paclobutrazol.

Garlic (Allium sativum L.) most widely farmed bulbous crop in the world and the second most widely cultivated Allium species after onion. The aim of the study to provide input and output per hectare. of garlic to determine the potential growth regulator. Through the application of chemical fertilizers environmental pollution through nitrate poisoning and exterminating soil micro-flora thereby, the alternatives to those problem the growth regulators play important role in economic production and cost management of garlic by employing methodology of Randomized Block Design comprising of three replications with ten treatments. The present experiment conducted on various kinds of growth regulators (Gibberellic acid (GA3) @ 50 ppm, GA3@ 100ppm, GA3@ 150 ppm, Naphthalene acetic acid (NAA) @ 50 ppm, NAA@ 100 ppm, NAA@ 200ppm, Kinetin@ 10 ppm, Kinetin@ 20 ppm, Kinetin@ 40 ppm and Control (Distilled water) at the instructional and research farm of the Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, India, during the autumn and winter seasons for two consecutive years. In view of effect of different plant growth regulators on the economics of garlic under terai region of west Bengal has observed significant variation. The result obtained that the foliar application of GA3@50 ppm generated maximum net returns (812753 Rs/ ha.) and benefit cost ratio (4.44) over other treatments. The control plots treated with distilled water was produced qualitatively inferior bulbs and generated lowest net returns (461946Rs/ha.) and benefit cost ratio (2.62). Interestingly the highest harvest index obtained under the Knetin@20 ppm (71.53) and lowest HI obtained under treatment of GA3 @100 ppm. (62.59). Based on the current experimental results, it may be concluded that foliar application of GA3 @ 50 ppm proved the best over other plant growth regulators.

Oil palm (Elaeis guineensis Jacq.) has become the largest traded vegetable oil in the world due to its innumerable uses and its huge economic importance. Which increases the requirement of quality seedling but the conventional seed production limits the commercial seed production with its long germination period and low germination rate. In this context in vitro germination of zygotic embryo could be a promising alternative. Hence in this study the effect of culturing media, plant growth regulators and genotypes were assessed on in vitro regeneration and plantlet development of oil palm zygotic embryos. Zygotic embryos of four elite genotypes were cultured on MS, N6 and Y3 media, with or without plant growth regulators (NAA, BA and GA3-0.2mg/lt). There was no effect of culture media, plant growth regulators and genotypes on germination of zygotic embryos. Whereas on the growth and development of in vitro plantlets, there was a significant effect of culture media and genotypes. Where culture media N6 performs well and Y3 has shown more abnormality. In case of genotypes, genotypes G1 and G2 shown better performance when compared to genotypes G3 and G4. The effect of plant growth regulators on germination and plant growth was non significant.

A field experiment was conducted during the Rabi season of 2024–25 at the Research Farm of Mewar University, Gangrar, Chittorgarh (Rajasthan), to assess the effect of various plant growth regulators (PGRs) and organic manures on the growth, yield, and quality of onion (Allium cepa L.), variety ‘Agrifound Light Red’. The experiment followed a factorial randomized block design with 16 treatment combinations involving four PGRs (Control, GA₃ @ 100 ppm, NAA @ 100 ppm, and CCC @ 100 ppm) and four organic manure types (Control, FYM @ 12 t/ha, Vermicompost @ 4.0 t/ha, and Poultry manure @ 2.5 t/ha), replicated thrice. The results indicated that the combination treatment P2-GA₃ @ 100 ppm + O4-Poultry manure @ 2.5 t/ha significantly outperformed other treatments in enhancing plant growth parameters such as plant height (up to 48.72 cm), number of leaves (7.16 per plant), and earliness in flowering (minimum 95.17 days to 50% flowering). Yield attributes including polar and equatorial bulb diameter (5.84 cm and 7.08 cm, respectively), neck thickness (1.62 cm), bulb weight (64.07 g), and yield (26.54 t/ha) were also highest under this treatment. Additionally, the same combination produced the best quality in terms of TSS (14.34 °Brix) and sulfur content (0.65%). These findings highlight the synergistic effects of gibberellic acid and poultry manure in promoting onion productivity and quality. The integration of organic manures with plant bioregulators can improve soil health and optimize physiological responses, making it a promising strategy for sustainable onion production under semi-arid conditions.

An experiment to study the effect of plant growth regulators and chemicals on acid lime (Citrus aurantifolia Swingle) was carried out in the year 2014 in the Experimental Farm, Department of Fruit Science, College of Horticulture and Forestry, Central Agricultural University, Pasighat, Arunachal Pradesh. The experiment was laid out in Randomized Block Design with eight treatments and three replications. The treatments were T1 (control-water spray), T2 (GA 50 ppm), T3 (GA 100 ppm), T4 (Cycocel 1000 ppm), T5 (KNO3 one percent), T6 (GA3 50 ppm + Cycocel 1000ppm), T7 (GA3 100 ppm + Cycocel 1000 ppm), T8 (GA3 100 + Cycocel 1000ppm +KNO3 1 per cent. The experimental results indicate that the acid lime trees sprayed with GA3 100 ppm + Cycocel 1000ppm + KNO3 1 per cent showed better performance in delaying of flowering, increase the number of flower/shoot (6.62), number of fruits/tree (149) and average fruit yield (4.64 kg/tree) of the crop. Effect of growth regulators and chemicals on quality characters however was not found significant for most of the parameters except TSS, ascorbic acid and titrable acidity. The higher results were obtained in T8 i.e. GA3 100 ppm + Cycocel 1000ppm + KNO3 1 per cent (8.27%) for titrable acidity and ascorbic acid (41.21 mg). Control with water spray alone registered the lowest values for both quantitative and qualititative parameters.

Coffee propagation is performed by seeding. However, germination in coffee seed is slow and uneven. Indeed, the production of plants in field is affected by environmental factors, which retards the germination rates and, in consequence, the number of plants obtained. Plant tissue culture provides the possibility of applying different growing conditions, such as different types of media and using phytoregulators, to induce a response in order to shorten zygotic embryo germination times. Therefore, due to limited understanding of growing zygotic embryos of coffee, we evaluated the effect of certain plant growth regulators on zygotic embryo germination of Coffea arabica . To study germination times, we evaluated the effects of culture media with incubation either at photoperiod or darkness and with certain plant growth regulators [gibberellic acid (GA), abscisic acid (ABA), indole-3-butyric acid (IBA), naphthalene acetic acid (NAA), kinetin (KIN) and salicylic acid (SA), at concentrations of 0.1, 1, and 10 mg l -1 each]. Zygotic embryos were cultured on Murashige and Skoog (MS), and Gamborg media at different concentrations ( 1 / 1 , ½, and ¼ of its ionic strength) under conditions of darkness and photoperiod. Germination times of zygotic embryos cultured in MS medium had a mean of 5.1 days, whereas zygotic embryos cultured in B5 medium germinated with a mean of 7.5 days. Among the plant growth regulators used, gibberellic acid at 0.1 mg l -1 proved to be the most efficient in germinating zygotic embryos, with 100% germination reached by the 5th day. Germination time of zygotic embryos was 12 days when ABA at 0.1 mg l -1 was used; however, ABA inhibited germination of embryos when it was used at concentrations of 1.0 and 10 mg l -1 since only 10% germination occurred. Regarding the germination times of zygotic embryos of coffee, the priority order of efficiency was GA > KIN > SA > IBA > NAA > ABA. Also, with the exception of SA, concentrations higher than 0.1 mg l -1 increased the zygotic embryo germination rates. Key words : Zygotic embryos, coffee, germination, phytohormones.