Search

While numerous studies explored the response of walnut plants to drought stress (DS), there remains a significant gap in the knowledge regarding the impact of heat stress (HS) and the combined effects of DS and HS on the recovery capacity of walnut trees. This study aimed to investigate the mechanism of Persian walnut (cv. Chandler) response to the combined DS and HS, focusing on various aspects including photosynthesis, water relations, and osmotic regulation. The treatments involved subjecting plants to DS (through a withholding method for 24 d), HS (gradually up to 40 °C for 8 d), and a combined DS and HS, which were compared to a control group (no stress) during the stress and recovery phases. The results showed that DS had significantly more negative effects on chlorophyll content, relative water content (RWC), leaf water potential (WP), osmotic potential (OP) compared to HS. Involvement of osmoregulation mechanism was detected more in DS and HS plants through the accumulation of proline, glycine Betaine and total soluble carbohydrates. The functionality of photosynthesis was significantly impacted by both HS and DS, respectively. While the HS accelerated the change of the abovementioned physiological processes in drought-stressed seedlings. Consistently, more pronounced damage was found in leaves under the combined stress, alongside the decrease RWC, chlorophyll content and fluorescence ratios. Based on the analysis of the linear mixed-effect model, the effects of combined stress and HS on photosynthesis parameters were detected in the early stages of stress compared to DS. Within a range of stresses, the abovementioned physiological processes of individual and combined-stressed plants recovered to levels comparable to those of the control. Our results also showed a substantial reduction in the expression of the photosynthetic genes (Fd, Cyt b6f, and PsbB) in Persian walnut saplings under abiotic stress conditions indicating significant damage to their photosynthetic apparatus. This study highlights that, under scenarios of aggravating drought occurring with heat, walnut seedlings could face a high risk of damage to physiological structures in relation to the synergistically increased hydraulic and thermal impairments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

During the seasons with limited light intensity, reductions in growth, yield, and quality are challenging for commercial cut rose production in greenhouses. Using artificial supplemental light is recommended for maintaining commercial production in regions with limited light intensity. Nowadays, replacing traditional lighting sources with LEDs attracted lots of attention. Since red (R) and blue (B) light spectra present the important wavelengths for photosynthesis and growth, in the present study, different ratios of supplemental R and B lights, including 90% R: B 10% (R90B10), 80% R: 20% B (R80B20), 70% R: 30% B (R70B30) with an intensity of 150 µmol m -2 s -1 together with natural light and without supplemental light (control) were applied on two commercial rose cultivars. According to the obtained results, supplemental light improved growth, carbohydrate levels, photosynthesis capacity, and yield compared to the control. R90B10 in both cultivars reduced the time required for flowering compared to the control treatment. R90B10 and R80B20 obtained the highest number of harvested flower stems in both cultivars. Chlorophyll and carotenoid levels were the highest under control. They had a higher ratio of B light, while carbohydrate and anthocyanin contents increased by having a high ratio of R light in the supplemental light. Analysis of chlorophyll fluorescence was indicative of better photosynthetic performance under a high ratio of R light in the supplemental light. In conclusion, the R90B10 light regime is recommended as a suitable supplemental light recipe to improve growth and photosynthesis, accelerate flowering, and improve the yield and quality of cut roses., (© 2023. The Author(s).)

The production and consumption of nuts are increasing in the world due to strong economic returns and the nutritional value of their products. With the increasing role and importance given to nuts (i.e., walnuts, hazelnut, pistachio, pecan, almond) in a balanced and healthy diet and their benefits to human health, breeding of the nuts species has also been stepped up. Most recent fruit breeding programs have focused on scion genetic improvement. However, the use of locally adapted grafted rootstocks also enhanced the productivity and quality of tree fruit crops. Grafting is an ancient horticultural practice used in nut crops to manipulate scion phenotype and productivity and overcome biotic and abiotic stresses. There are complex rootstock breeding objectives and physiological and molecular aspects of rootstock-scion interactions in nut crops. In this review, we provide an overview of these, considering the mechanisms involved in nutrient and water uptake, regulation of phytohormones, and rootstock influences on the scion molecular processes, including long-distance gene silencing and trans-grafting. Understanding the mechanisms resulting from rootstock × scion × environmental interactions will contribute to developing new rootstocks with resilience in the face of climate change, but also of the multitude of diseases and pests.

Walnut (Juglans spp.) trees hold immense significance in both economic and ecological contexts within agri-horticultural ecosystems. The comprehension of the intricate mechanisms underpinning walnut growth and development stands as a pivotal endeavor, essential for advancing sustainable yield practices. This comprehensive review delves into the multifaceted factors that contribute to the growth and development of walnuts, encompassing hormonal, biochemical, and genetic dimensions. Notably, hormones such as gibberellic acids (GAs) and sugars assume pivotal roles in the initiation and maturation of walnut flowers, with specific investigations demonstrating that the application of GAs has the capacity to augment male flower counts. The levels of endogenous auxins and gibberellins exhibit variations across distinct phases of walnut development, with the highest concentrations observed in young tissues. The molecular underpinnings of walnut growth and development involve a complex interplay of genetic regulation, hormonal dynamics, and environmental factors. Distinct sets of genes exhibit activation at discrete developmental stages, thereby influencing fundamental processes such as cell division, differentiation, and food reserve metabolism. Several key regulatory genes, including ACC, ASMT, SAD, FAD, SOC, and TFL1, emerge as pivotal orchestrators, steering essential processes encompassing cell division, differentiation, flowering, and fruit development. Conclusively, this article provides a detailed exploration of the diverse aspects of walnut growth and development, from genetic regulation to hormonal and biochemical processes. This will provide a valuable resource for researchers, horticulturalists, and biotechnologists aiming to improve walnut productivity and resilience in the face of changing environmental conditions. [ABSTRACT FROM AUTHOR]

Background: Root plays an important role in the growth and development of fruit trees; however, the molecular mechanisms behind the differences among rootstock varie-ties remain unclear. Methods: This study examined the effects of different rootstocks on root structure and the endogenous hormone content of 1-year old apple seedlings in combinations of Tianhong 2 (T2)/Malus robusta (HT), T2/G935, and T2/Jizhen 2 (J2). Results: The results showed that the T2/HT treatment had greater root length, surface area, volume, average diameter, tips and forks, followed by G935 and J2. In T2/HT leaves and roots, the indole-3-acetic acid (IAA) and gibberellins (GA3) levels were highest, and the abscisic acid (ABA) levels were the lowest. A root transcriptome analysis detected 10,064, 10,511, and 8,719 differentially expressed genes in T2/HT vs. T2/G935, T2/HT vs. T2/J2, and T2/J2 vs. T2/G935, respectively. The analysis of Gene Ontology (GO) terms indicated a significant enrichment in biological processes, cellular components, and molecular functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that plant hormone signaling, MAPK signaling pathway–plant, and plant–pathogen interaction played important roles in differences in the rooting ability of different rootstocks. In addition, some key differential genes were associated with root growth and development and were involved in these metabolic pathways. This study is important for enriching theoretical studies of fruit tree roots. [ABSTRACT FROM AUTHOR]

Identifying and selecting superior genotypes in different countries and regions is a valuable breeding method in walnuts. The present study evaluated 31 quantitative and qualitative traits of seven superior walnut genotypes comparable to 'Jamal', 'Lara', and 'Serr' cultivars. The comparisons followed IPGRI descriptions. We evaluated pomological traits in the superior genotypes for four consecutive years (2019, 2020, 2021, and 2022), observing high variations among the genotypes. The thickness of husk, fruit weight, nut weight, and nut length ranged between 2.47–4.08 mm, 42.26–58.38 g, 10.43–14.60 g, and 29.59–37.61 mm, respectively. Also, kernel weight, percentage, color, plumpness, and fillness ranged between 5.22–6.97 g, 40.18–54.75%, 1.33–2.67 (approximately light), 2.33 (medium)—3.00 (plump), and 4.78 (medium)—7.00 (good), respectively. Biochemical features in the kernels varied significantly among the genotypes, particularly in the case of oil content (62.26–70.08%), SFA (10.10–13.03%), MUFA (13.38–36.40%), and PUFA (52.05–74.40%). Furthermore, kernel protein content, total polyphenols, and antioxidant activity ranged between 16.79–21.61%, 58.78–95.06 mg GAE/g, and 0.15–0.22 EC50, respectively. The kernel percentage correlated significantly and negatively with the flowering type (r = −0.414) and nut weight (r = −0.467) but positively with DFO (r = 0.545), fruitfulness percentage (r = 0.471), kernel weight (r = 0.412), saturated fatty acid (r = 0.375), oil percentage (r = 0.472), and protein percentage (r = 0.422). These genotypes were superior due to closed-shell seal, light kernel color, ease of kernel removal from nuts, lateral bearing, high kernel percentage, and high nutritional value. The selected genotypes are the bearers of desirable genes for future walnut breeding programs. [ABSTRACT FROM AUTHOR]

Background: The presence of oxygen in the growth medium is absolutely essential for root development and the overall metabolic processes of plants. When plants do not have an adequate oxygen supply for respiration, they can experience a condition known as hypoxia. In order to investigate the impact of different nitrogen forms and varying oxygen levels in nutrient solutions on the growth, photosynthesis, and chlorophyll fluorescence parameters of bell pepper plants, a comprehensive study was conducted. The experiment was designed as a factorial experiment, considering two main factors: nitrogen forms (calcium nitrate and ammonium sulfate) with a fixed nitrogen concentration of 5 mM, and the oxygen levels of the nutrient solutions (ranging from 1.8 ± 0.2 to 5.3 ± 0.2 mg. L-1). Results: The study examined the effects of nitrogen (NH4+ and NO3−) application on various parameters of vegetative growth. The results demonstrated that the use of ammonium (NH4+) led to a reduction in the most measured parameters, including the fresh and dry mass of both the root and shoot, at low O2 concentrations of 1.8 ± 0.2; 2.6 ± 0.2 and 3.8 ± 0.2 mg. L-1. However, an interesting observation was made regarding the impact of oxygen levels on root growth in plants grown with nitrate (NO3−). Specifically, the highest levels of oxygen significantly increased root growth in NO3−-fed plants. Additionally, the application of NH4+ resulted in an increase in chlorophyll concentration in the leaves, particularly when combined with high oxygen levels in the nutrient solution. On the other hand, leaves of plants fed with NO3− exhibited higher photosynthetic rate (A), intrinsic water use efficiency (iWUE), and instantaneous carboxylation efficiency (A/Ci) compared to those fed with NH4+. Furthermore, it was found that NO3−-fed plants displayed the highest instantaneous carboxylation efficiency at oxygen levels of 3.8 and 5.3 mg. L-1, while the lowest efficiency was observed at oxygen levels of 1.8 and 2.6 mg. L-1. In contrast, NH4+-grown plants exhibited a higher maximal quantum yield of PSII photochemistry (Fv/Fm), as well as increased variable fluorescence (Fv) and maximum fluorescence (Fm), compared to NO3−-grown plants. Interestingly, the NO3−-fed plants showed an increase in Fv/Fm, Fv, and Fm with the elevation of oxygen concentration in the nutrient solution up to 5.3 mg. L-1. Conclusion: This study showed that, the growth and photosynthesis parameters in bell pepper plants are sensitive to oxygen stress in floating hydroponic culture. Therefore, the oxygen level in the nutrient solution must not be lower than 3.8 and 5.3 mg. L-1 in NH4+ and NO3− –supplied culture media or nutrient solutions, respectively. [ABSTRACT FROM AUTHOR]

This research aimed at in vitro propagations of bananas originating from India. Banana (Musa spp.) is a nutritious fruit but shows susceptibility to specific diseases. A traditional method of its propagation is through the separation of suckers, although it may culminate in the transmission of nematodes, parasitic organisms, and viral diseases. In the past two decades, plant tissue culture techniques have facilitated the production of disease-free plantlets. Tissue culturing bananas can involve different explants, including shoot tips, suckers, leaves, and flower buds. Each responds differently to the presence and absence of light. In the current research, explant cultures were placed in light or dark incubation for identical durations, i.e., one to six months, to monitor their growth and development. The color intensity of the explants changed in response to different photoperiods. Young flower buds, mature flower buds, and suckers developed a higher color intensity when placed in light than in dark conditions. However, the opposite occurred in leaf explants that grew optimally in the dark. The results indicated that banana growth occurred productively from sucker explants in different light conditions and variable durations. The results were optimal when employing sucker explants, which exhibited the fastest growth. [ABSTRACT FROM AUTHOR]

The photosynthetic phenotype of trees undergoes changes and interactions that reflect their abilities to exploit light energy. Environmental disturbances and genetic factors have been recognized as influencing these changes and interactions, yet our understanding of the underlying biological mechanisms remains limited, particularly in stochastic environments. Here, we developed a high-dimensional stochastic differential framework (HDSD) for the genome-wide mapping of quantitative trait loci (QTLs) that regulate competition or cooperation in environment-dependent phenotypes. The framework incorporates random disturbances into system mapping, a dynamic model that views multiple traits as a system. Not only does this framework describe how QTLs regulate a single phenotype, but also how they regulate multiple phenotypes and how they interact with each other to influence phenotypic variations. To validate the proposed model, we conducted mapping experiments using chlorophyll fluorescence phenotype data from Populus simonii. Through this analysis, we identified several significant QTLs that may play a crucial role in photosynthesis in stochastic environments, in which 76 significant QTLs have already been reported to encode proteins or enzymes involved in photosynthesis through functional annotation. The constructed genetic regulatory network allows for a more comprehensive analysis of the internal genetic interactions of the photosynthesis process by visualizing the relationships between SNPs. This study shows a new way to understand the genetic mechanisms that govern the photosynthetic phenotype of trees, focusing on how environmental stochasticity and genetic variation interact to shape their light energy utilization strategies., Competing Interests: Declarations. Conflict of interest: The authors have no relevant financial or nonfinancial interests to disclose., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The present study was conducted in the Laboratory of Tissue Culture, Horticulture Department, Faculty of Agriculture, Damietta University, Egypt. The objective of this study was to establish a micropropagation protocol suitable for three imported peach rootstocks: Okinawa (P. persica), Nemared (P. persica × P. davidiana) × P. persica), and Garnem (P. dulcis × P. persica) in vitro. The results showed that soaking the explants in sodium hypochlorite (NaOCl) at 20% for 15 min produced the highest responsiveness (82.81%), survival (96.61%), with the lowest mortality (3.14%) and contamination (0.24%). Explants of the Garnem genotype had the best response (89.12%), survival (90.62%), lowest mortality (0.00%), and highest contamination (9.37%) when compared to the other genotypes. In comparison with axillary buds, the shoot tip displayed the highest responsiveness, survival, and death (100, 87.40, and 12.59%, respectively), as well as the least significant contamination (0.00%). Additionally, the percentages of responsive, survived, dead, and contaminated explants at the various collection dates varied significantly. The 6-benzylaminopurine (BAP) concentrations used (3 to 5.0 mg/L) demonstrated similar behavior in terms of in vitro proliferation, with rates of 3.77 to 6.11, 4.33 to 8.88, and 3.33 to 7.44 shoot numbers per explant for the Okinawa, Nemared, and Garnem peach rootstocks, respectively, indicating that the number of shoot proliferations is genotype-dependent. Additionally, using 5.0 mg/L BAP in combination with 0.2 mg/L IBA significantly increased average shoot proliferation (96.29%), number of shoots per explant (7.48), and average leaf number/explant (16.33) compared to the other treatments. Based on these results, adventitious bud development was enhanced during in vitro multiplication of the Okinawa, Nemared, and Garnem peach rootstocks by the synergistic interaction of indole-butyric acid (IBA) and 6-benzylaminopurine (BAP). [ABSTRACT FROM AUTHOR]

Avocado is an important tree crop grown in the tropics, including Ghana. Avocados are primarily propagated by seed into trees, which grow to provide shade for young cocoa trees and, subsequently, food and income. Cultivation of this crop as a monocrop is limited in Ghana; hence, there is a considerable risk of losing desirable genetic materials. There has been an effort by scientists at the University of Ghana to collect and curate available avocado germplasm to preserve, multiply, and disseminate to growers. Nurserymen have been tasked with germplasm multiplication through grafting. Unfortunately, the outcome of this grafting practice has been inefficient due to the high incidence of grafting failure. This study assessed the effects of the grafting experiences of four nurserymen under no shade, traditional, and adjusted shade conditions on the graft success of two avocado scions (Fuerte and Hass). The results of this study indicated that the absence of shade led to complete graft failure. Nevertheless, modifying the conventional shade to 70% using shade net resulted in a 10-20% enhancement in graft success. The success of grafting was found to be more associated with the skill of the grafters rather than their age or years of grafting experience. In general, the low graft success rate in avocados was most probably attributed to variations in the skills of individual grafters. Grafter A achieved a graft success rate of 23-29% higher than the other grafters, suggesting variations in the skill levels employed. Significantly (p = 0.05), graft success was higher in the Fuerte cultivar than in the Hass cultivar. [ABSTRACT FROM AUTHOR]

Soil salinization is a global problem limiting growth and economical yield in fruit species including walnut. Knowledge of the response of varieties and cultivars to salinity can represent an important contribution to future walnut plantation in areas affected by soil salinization. Juglans regia 'Sorrento' is a commercially important Italian variety. The present work aimed to explore the morpho-physiological response to NaCl-induced stress in 'Sorrento' plants using clonally propagated ex vitro plantlets to reduce the impact of genetic variation. Ex vitro acclimatized plants were exposed to salinity conditions by irrigating pot soil with half-strength Hoagland solution containing 100 mM NaCl for 20 days. Salt-induced effects on plant growth, chlorophyll and carotenoid content, osmolality, membrane injury and on activities of antioxidant enzymes catalase and guaiacol peroxidase (G-POD) in leaves were evaluated. Morphological and growth parameters were not significantly altered by salt stress with respect to the control. Slight differences in leaf necrosis and absence of injury in the membranes, stable content of photosynthetic pigments, and an increase in G-POD activity were also found in salt-treated plants. These results collectively suggest that 'Sorrento' has potential for the cultivation in salinized environments. [ABSTRACT FROM AUTHOR]

Key Message: Boron is essential for plants, but excess can induce toxicity. Boron (B) is a vital micronutrient for plants, but excess B can induce toxicity symptoms and reduce crop yields. B bioavailability depends on soil properties, including clay type, pH, and organic matter content. Symptoms of B toxicity include reduced shoot and root growth, leaf chlorosis and necrosis, impaired photosynthesis, and disrupted pollen development. This review paper examines the current knowledge on B toxicity mechanisms, tolerance strategies, and management approaches in plants. This review covers (1) factors affecting B bioavailability; (2) toxicity symptoms in plants; (3) uptake, transport, and detoxification mechanisms; and (4) strategies. To mitigate toxicity, plants reduce B uptake, activate efflux transporters, compartmentalize B, and enhance antioxidant systems. On the basis of this review, future research should focus on identifying novel tolerance mechanisms, exploring genetic strategies for improved B management, and developing innovative agronomic interventions. These insights will facilitate the breeding and management of crops for enhanced productivity under B toxicity stress., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Teak (Tectona grandis L.) is a forest tree having 2n = 2x = 36 diploid chromosomes. Plants are continually subjected to variety of abiotic stresses due to climate change, which alter their physiological processes and gene expression. Methods and results: The current study sought to examine the physiological and differential gene expression of teak seedlings exposed to abiotic stresses (150 mM NaCl and 15% PEG-6000). Chlorophyll content, membrane stability index and relative water content were measured at 0, 2, 7 and 12 days after treatment. These parameters were initially numerically reduced, but they were significantly reduced during a longer period of treatment. Seedlings treated with 150 mM NaCl displayed more harmful effect on the plant than other treatments. The results showed that variety of stresses significantly affect the physiology of seedlings because they cause membrane damage, ROS generation, chlorophyll degradation, and reduction in water absorption. The gene expression of treated and control seedlings was also evaluated at 12 days after treatment. Ten stress-related genes were examined for their differential expression using RT-PCR under applied stress. The stress-treated seedlings' leaves showed an up-regulated expression of the genes MYB-3, HSP-1, BI-1 and CS-2. Conclusion: Up-regulation of the genes confirmed the protective function of these genes in plants under abiotic stress. However, gene expression was affected by treatments, the extent of stress and the species of plant. This study came to the conclusion that physiological parameters could be utilized as marker indices to assess a tree's capability to withstand stress at seedling stage. The up-regulated genes will be further investigated and utilized to validate stress tolerance and susceptible teak seedlings. [ABSTRACT FROM AUTHOR]

Lignin deficiency in the endocarp of walnuts causes kernel bare, leads to inconvenient processing and transportation of walnuts, and easily produces insect damage and mildew, thereby affecting the quality of walnuts. Cinnamyl alcohol dehydrogenase (CAD) is one of the key rate-limiting enzymes in lignin synthesis and plays an important role in the synthesis of lignin in the endocarp of walnut. However, knowledge about CAD gene family members and their evolutionary and functional characteristics in walnuts is limited. In this study, all 18 JrCADs were identified, and phylogenetic relationships, gene structure, protein motifs, collinearity analysis, and expression patterns of the JrCADs were also analyzed. All JrCADs could be divided into three groups based on the phylogenetic tree, gene structure, and motif analysis also support this grouping. Transcriptome data demonstrated that JrCADs have different expression patterns in walnut endocarps at different developmental stages. Combined with qRT–PCR data, we finally identified several candidate JrCADs involved in the process of endocarp sclerosis. This study showed that the JrCAD family members are highly conservative in evolutionary characteristics and they might participate in a variety of hormone responses. JrCAD17 and JrCAD18 are highly expressed in all periods of walnut endocarp harding, they are closely related to lignin accumulation. [ABSTRACT FROM AUTHOR]

Biochar-supported metal oxide nanocomposites as functional materials could help to improve the production and stress tolerance of plants by enhancing the physicochemical properties of biochar. This experiment was carried out to assess the effects of unmodified biochar (30 g kg−1 soil) and biochar-based nanocomposites (BNCs) of iron (30 g BNC-FeO kg−1 soil), zinc (30 g BNC-ZnO kg−1 soil), and a combined form (15 g BNC-FeO + 15 g BNC-ZnO kg−1 soil) on dill (Anethum graveolens L.) plants under various salinity levels (non-saline, 6 and 12 dS m−1). The biochar-related treatments reduced sodium content of the plants, leading to a decline in osmolytes, antioxidant enzymes activities, reactive oxygen species (ROS), lipid peroxidation, NADP reduction, abscisic acid, jasmonic acid, and salicylic acid in dill leaf tissues. The combined form of BNCs reduced sodium content of leaf tissue by about 22% and 26% under 6 and 12 dS m−1 salinities, respectively. In contrast, addition of biochar, particularly biochar-based nanocomposites to the saline soil, enhanced potassium, iron, and zinc contents of leaf tissue, photosynthetic pigments, leaf water content, oxygen evolution rate, hill reaction and ATPase activities, endogenous indole-3-acetic acid, plant organs biomass, and consequently essential oil yield of plant organs. The combined form of BNCs in comparison with unmodified biochar improved vegetative, inflorescence, and seed biomass under 12 dS m−1 salinity by about 33%, 25%, and 6%, respectively. These findings revealed that BNCs with novel structure can potentially enhance salt tolerance, plant biomass, and essential oil yield of different organs in salt-stressed dill plants through decreasing leaf sodium content and ROS generation and increasing nutrient availability, water status, and photosynthetic pigments. [ABSTRACT FROM AUTHOR]

The massive establishment of new plantations supported by the basic needs of a crop are technical approaches for an increased crop productivity. Water and decreased light levels by shade (i.e. intercropping) are considered basic needs of cacao plants, especially during the early vegetative growth stage. Thus, this study aimed to evaluate the influences of irrigation, intercropping, and intercrops on the performance of 39 cacao plantations at the establishment phase. The performance of each cacao plantation, after establishment, was evaluated and rated from 1 to 7 (1- poor; 3- satisfactory; 5- very good; and 7- outstanding) as a rating scale. In general, the results revealed that cacao plantations supplied with irrigation or under decreased light levels by intercrops (regardless of their nature), as well as a combination of these, made the plants perform better than those in plantations without irrigation and when plants were highly exposed to sunlight. The results suggested the importance of irrigation and decreased light levels by intercropping as prerequisites for a successful establishment of cacao plantations. [ABSTRACT FROM AUTHOR]

Objective Lily is known as the third main bulbous flower in the world that used for cut flowers and pots. Bulblet as a staple procedure is known for propagation of this plant. Due to the high performance of in vitro bulblets regeneration, the use of this method can reduce the costs production of this plant and also reduction of water and soil pollution due to minimizing the field area for ex vitro propagation. The size of lily bulblets produced in vitro is smaller than ex vitro propagated bulblets. For this purpose, several concentrations of phosphorus, potassium and calcium were used to investigate their role on lily bulblet growth under in vitro condition. Materials and methods In this experiment, 'Santander' cultivar was used for bulblet growth of lily. For this purpose, the effect of five strength (0, 0.5, 1, 2, 3) of macro elements (phosphorus, potassium and calcium) based on MS medium on bulblet regeneration percentage, bulblet number, bulblet fresh weight, scale explant fresh weight, and fresh weight of leaf and root was surveyed. Results The results of the experiment clearly showed the effect of all three elements on the growth of bulblet, so that the limitation of any of the elements (0 strength) caused serious disorders in all explants. With increasing the concentration of the studied elements, the bulblet regeneration percentage increased significantly. The maximum in vitro bulblet regeneration percentage (95.3 %) was found in explants grown on medium supplemented with double-strength of phosphorous. All three macroelementsnotably phosphorus played a major role on lily bulblets growth. According to results, application of double-strength of phosphorus caused the highest number of bulblet compared to test with 11.6. A considerable decrement in the fresh weight of leaves (16 g) and roots (10 g) was observed in the absence of calcium in the culture medium. Conclusions In general, phosphorus and calcium play a vital role in the regeneration of lily bulblets in vitro, so that on the one hand, double-strength of phosphorus had the highest amount of bulblet regeneration and fresh weight of the bulblets and on the other hand, shortage of calcium had the lowest amount in all parameters. So it is recommended to increase the concentrations of above mentioned macroelementsfor obtaining bigger bulblets. [ABSTRACT FROM AUTHOR]