Shoot Maturation Research Articles

Reducing nitrogen and deficit irrigation is a practical solution for optimal forage barley production in semi-arid cropping systems

Given the scarcity of arable land and water resources in semi-arid regions, it becomes imperative to achieve maximum yield and early maturity for winter grains. In this regard, the present research was conducted to synchronize grain and shoot maturity in high-yielding barley (cv. Behrokh) by reducing nitrogen and deficit irrigation. The experimental factors included three levels of nitrogen (50, 75, and 100% plant nitrogen requirement; PNR) and three levels of irrigation (full irrigation, cutoff irrigation in the milk stage, and dough stage). Results showed that cutoff irrigation and nitrogen fertilizer caused early ripening. The interactions of irrigation and nitrogen were significant for the number of grains/spike, grain yield, straw yield, aboveground biomass, and protein yield. Grain yield in cutoff irrigation in the dough stage plus reducing 25% PNR was similar to full irrigation plus 100% PNR. In full and cutoff irrigation in the dough stage, reducing 25% PNR did not cause a significant change in straw yield. Cutoff irrigation in the dough and milk stages did not cause a significant difference in the grain protein content. In general, it is concluded that to maintain grain, straw yield, and protein quality, it is more appropriate to use 150 kg/ha of nitrogen in the conditions of cutoff irrigation in the dough stage, which could reduce the cost of fertilizer and water in addition to early ripening of the crop and minimize the environmental consequences of consuming these inputs. Early harvesting of barley also helps to prevent summer crops from encountering late-season chilling.

Shoot Maturation Strengthens FLS2-Mediated Resistance to Pseudomonas syringae.

Temporospatial regulation of immunity components is essential for properly activating plant defense response. Flagellin-sensing 2 (FLS2) is a surface-localized receptor that recognizes bacterial flagellin. The immune function of FLS2 is compromised in early stages of shoot development. However, the underlying mechanism for the age-dependent FLS2 signaling is not clear. Here, we show that the reduced basal immunity of juvenile leaves against Pseudomonas syringae pv. tomato DC3000 is independent of FLS2. The flg22-induced marker gene expression and reactive oxygen species activation were comparable in juvenile and adult stages, but callose deposition was more evident in the adult stage than the juvenile stage. We further demonstrated that microRNA156, a master regulator of plant aging, does not influence the expression of FLS2 and FRK1 (Flg22-induced receptor-like kinase 1) but mildly suppresses callose deposition in juvenile leaves. Our experiments revealed an intrinsic mechanism that regulates the amplitude of FLS2-mediated resistance during aging. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Влияние некорневой обработки специализированным листовым удобрением на качественные показатели развития однолетнего прироста привитых виноградных саженцев

Abstract. Relevance. Currently, in grape nursery breeding, pre-plantng treatment of the seedlings (in own-root culture) and the basal part of the grafting (with grafted culture) is used to increase the yield of seedlings. There is very little data on the use of modern complex fertilizers during stratification and at nursery in the production of grafted planting material, which reflects the relevance of our research. The purpose of the study is. the exploring of the foliar application of the agrochemicals “Fertigrain Foliar Plus” on the intensity of the development of the leaf surfase of the Siberian grape variety. Methods. The methods of setting up the experience and analyzing the data obtained were used in the work, which are generally accepted in the practice of nursery breeding. Results. With additional application of “Fertigrain Foliar Plus”, a significant increase in biometric indicators was observed, namely: the total length from 84 cm (c) to 150.7–171.7 cm; shoot maturation from 25.7 % (c) to 45.4–48.0 %, shoot diameter from 5.6 mm (c) to 8.3–9.0 mm and leaf surface area with 645.1 cm2 (c) to 1995.8–3382.0 cm2. With an increase in the number of treatments, the ratio of the number of leaves by fractions changed in the direction of increasing their size, namely (< 5; 5.1–10; > 10 cm): in the control – 1 : 5 : 0; with double processing – 1 : 12 : 4; with triple treatment – 1 : 9 : 8; with quadruple treatment – 1 : 6 : 12. With an increase in the number of treatment from 2 to 4 times, there was no increase in the number of leaves, however, the average leaf size increased significantly from 8.5 to 10.5 cm. Scientific novelty. For the first time in the conditions of the Rostov region, a modern growth stimulator “Fertigrain Foliar Plus” was studied during the foliar treatment of grafted grape seedlings on nursery-garden. Practical significance. The results of the research can be used in the practice of grape nursery to improve the adaptation of seedlings on nursery-garden, stimulate the development of the leaf area and the intensity of ripening, which is especially important for growing varieties with weak ripening.

Distinct function of SPL genes in age-related resistance in Arabidopsis.

In plants, age-related resistance (ARR) refers to a gain of disease resistance during shoot or organ maturation. ARR associated with vegetative phase change, a transition from juvenile to adult stage, is a widespread agronomic trait affecting resistance against multiple pathogens. How innate immunity in a plant is differentially regulated during successive stages of shoot maturation is unclear. In this work, we found that Arabidopsis thaliana showed ARR against its bacterial pathogen Pseudomonas syringae pv. tomato DC3000 during vegetative phase change. The timing of the ARR activation was associated with a temporal drop of miR156 level. The microRNA miR156 maintains juvenile phase by inhibiting the accumulation and translation of SPL transcripts. A systematic inspection of the loss- and gain-of-function mutants of 11 SPL genes revealed that a subset of SPL genes, notably SPL2, SPL10, and SPL11, activated ARR in adult stage. The immune function of SPL10 was independent of its role in morphogenesis. Furthermore, the SPL10 mediated an age-dependent augmentation of the salicylic acid (SA) pathway partially by direct activation of PAD4. Disrupting SA biosynthesis or signaling abolished the ARR against Pto DC3000. Our work demonstrated that the miR156-SPL10 module in Arabidopsis is deployed to operate immune outputs over developmental timing.

ВЛИЯНИЕ ОРГАНО-МИНЕРАЛЬНОГО УДОБРЕНИЯ НА ПРОДУКТИВНОСТЬ ВИНОГРАДНЫХ РАСТЕНИЙ

The results of studies on the effect of organo-mineral fertilizer on agrobiological and econom-ic indicators of Cabernet Sauvignon grapevine variety are presented. To determine the biologi-cal effectiveness of the fertilizer on grapevine, foliar feeding of Cabernet Sauvignon plants was carried out during the phase of inflo-rescence advancement and 15 days after. Foliar feeding of plants with organo-mineral fertilizer had a positive effect on the formation of berries and clusters, contributing to an increase in their mass. At the drug consumption rate of 5.0 l/ha and 7.0 l/ha, both the number of berries in a bunch and the weight of one berry significantly increased compared to the control. The use of organo-mineral fertilizer also contributed to bet-ter pollination and an increase in berries in bunches, which together contributed to an in-crease in yield, depending on the applied con-sumption rates, by 8.7‒11.6 %. Estimation of quality characteristics of berry juice during har-vesting showed its compliance with standard varietal conditions in all variants of the experi-ment, despite the significant differences in the mass concentration of sugars between the con-trol and variant 3 (7.0 l/ha). The acidity of berry juice differed insignificantly between the vari-ants and the control. When feeding plants with organo-mineral fertilizer, the growth activity of shoots significantly increased in all variants of the experiment compared to the control variant. An increase in the activity of growth processes led to a decrease in shoot maturation (73.2‒74.4 %) at all drug consumption rates compared to the control (84.9 %). However, the percentage of shoot maturation in all variants is high enough for successful overwintering of plants.

ПРИМЕНЕНИЕ ГИДРОГЕЛЯ НА ЭТАПЕ АДАПТАЦИИ ОЗДОРОВЛЕННЫХ ВИНОГРАДНЫХ РАСТЕНИЙ К НЕСТЕРИЛЬНЫМ УСЛОВИЯМ

The article considers the effect of cross-linked copolymer of potassium and ammonium salts of acrylic acid "Aquasin" on grapevine plants that were freed from contamination through the cul-ture in vitro. The study was held on the basis of Ya.I. Potapenko All-Russian Research Institute for Viticulture and Winemaking on the native Don variety Krasnostop zolotovsky. The aim of the work was to study the effectiveness of the use of hydrogel for the post vitro stage. The ways of its application were investigated. Hy-drogel was added to the soil substrate in a dry form and in a gel-like form saturated with nu-trients. As a result, it was noted that the hydro-gel does not affect survival. For all variants of the experiment, it was 98‒100 %. There was a positive effect of adding the water-retaining drug Aquasin to the substrate on the growth and development of plants. This was especially reflected in such indicators as leaf surface area, maturation and diameter of shoots. The positive effect was achieved on the 80‒90 day of adap-tation. In addition, the possibility of pre-saturation of the superabsorbent with im-munostimulants or fertilizers is of interest. Plant height and leaf area were maximal in the vari-ant with the addition of hydrogel saturated with an aqueous solution of minerals

Foliar application of ethephon induces bud dormancy and affects gene expression of dormancy- and flowering-related genes in ‘Mauritius’ litchi (Litchi chinensis Sonn.)

A previous study showed that foliar application of ethephon to litchi trees with mature shoots and dormant terminal buds during autumn successfully inhibited new vegetative shoot growth prior to floral induction thereby promoting carbohydrate accumulation and flowering. However, the functional mechanisms of ethylene, the breakdown product of ethephon, in the leaves and terminal buds of litchi and its involvement in the flowering process is largely unknown. Therefore, this study aimed to investigate the phenological, physiological and molecular changes underlying ethephon application and its associations with bud dormancy and flowering in litchi. Ethephon was applied as a single full canopy spray at a concentration of 1000 mg⋅L−1 to ‘Mauritius’ litchi trees with mature vegetative shoots and dormant terminal buds during late autumn of 2018 (mid-April; Southern Hemisphere). Untreated trees served as a control. Phenological characteristics, such as bud dormancy and panicle development, leaf chlorophyll (as an indicator of shoot maturity), ethylene evolution, gene expression levels of flowering- (LcFT2, LcFLC and LcAP1), dormancy- (LcSVP1 and LcSVP2) and ethylene pathway-related (LcEIN3) genes and non-structural carbohydrates were determined in terminal buds, leaves and/or shoots. Ethephon application induced bud dormancy, significantly delayed panicle emergence and promoted pure floral panicle development under more favorable inductive conditions. Ethylene evolution increased sharply 2 h after application in both leaves and terminal buds, but decreased rapidly thereafter in the leaves, while remaining high in terminal buds for seven days before gradually declining. Ethephon application significantly increased relative expression of LcEIN3 and LcFLC in terminal buds one day after application, while LcFT2 expression in leaves and LcAP1 expression in terminal buds were significantly increased at the bud break stage. Significant treatments differences were also observed for various carbohydrate metabolites in leaves and shoots at the bud break or floral initiation stage. Our study provided evidence that ethephon application plays an important role in the physiological and molecular regulation of bud dormancy of litchi. By influencing the time of bud break, ethephon application can be a useful tool to manage panicle emergence under less inductive conditions.

The determination of pitaya shoot maturity relevant to the competence of receiving long day length induction by CPPU

For studying the flower physiology of pitaya plants (Hylocereus sp.), determining the maturity of current shoots is essential. N-(2-Chloro-4-pyridyl)-N′-phenylurea (CPPU), a synthetic cytokinin, functions as a competitive inhibitor of cytokinin oxidase and was used to amplify the function of endogenous cytokinins. Spraying 100 mg•L−1 CPPU on the current shoots of different ages 7.5 weeks after the spring equinox (WASE) may result in budding within 1 week. In our study, typical floral buds emerged on the mature shoots but not immature shoots. Furthermore, the critical shoot age for the pitaya plant to be competent for receiving long day length stimulus at spring equinox was line between 13.5 and 15.5 weeks of pre-growth. Application of CPPU to the shoot older than 1 year at 5.5 WASE resulted in precocious flowering by 2 weeks.

Chemical profiling of ancient bud black tea with a focus on the effects of shoot maturity and fermentation by UHPLC-HRMS

Chemical profiling of ancient bud black tea with a focus on the effects of shoot maturity and fermentation by UHPLC-HRMS

Extrato de algas e prolina promovem alterações fisiológicas em plantas de mangueira durante a maturação de ramos

Abstract Water stress should be adequately managed during shoot maturation to improve the floral induction of mango grown in semi-arid regions. In this scenario, proline association with algal extracts has a potential stress-mitigating effect. However, even though this practice has been reported separately for some crops, its effects on mango are still unknown. From this perspective, this study investigated the role of proline and algal extract in mitigation of water deficit effects during shoot maturation of the mango variety ‘Tommy Atkins’ grown in the tropical semi-arid region. The study consisted of five consecutive individual experiments (five foliar application treatments) in a randomized block design and a 4 x 2 factorial corresponding to i) four proline concentrations (Pro): 0.0% (without proline), 0.287, 0.575, and 1.150%, and ii) the presence of algal extract (AE) (presence and absence). The following parameters were evaluated: photosynthetic pigments, soluble carbohydrates, photochemical and non-photochemical efficiency, and flowering and production uniformity. Carotenoids were interactively affected by the factors evaluated. On the other hand, as additive effects, proline provided the highest values of gas exchange and total soluble carbohydrates, with a higher internal CO2 concentration and greater flowering uniformity. The application of proline and the algal extract of A. nodosum promoted different responses in mango physiology and can be used during shoot maturation.

Фенологическая характеристика интродуцированных растений близкородственных видов рододендронов подрода Rhodorastrum (Maxim.) Drude (серия Daurica Pojark) в Ботаническом саду ИГУ

An analysis of the seasonal development of rhododendrons of the Daurian series during introduction in the Irkutsk Botanical Garden was completed and their initial prospects for use in landscaping settlements in Baikal Siberia were assessed. For this purpose, regular phenological observations were carried out for the plants of these species since 2013. A comparative characteristic of the phenological development of four rhododendron species of the Daurian series was given. According to our observations, the processes of adaptation of introduced plants in Irkutsk conditions are primarily depending on the temperature conditions of autumn-winter-spring with a relatively favorable growing season. The most destructive factors for rhododendrons are high insolation at considerable minimum temperatures in winter, late autumn and early spring periods, also an absence of stable snow cover in late autumn and early spring, and sharp daily variations of air temperature. The hydrological regime is also not very favorable. The root layer of the soil is often subjected to severe dehydration at low air humidity during the growing season. This is very dangerous for rhododendrons with their shallow root system. The seasonal development of rhododendrons is greatly influenced by their winter hardiness, drought tolerance, thermal and hydrological regimes of the growing season, the duration of the frost-free period, and a certain value of the daily temperature amplitudes in spring and fall. The results of the analysis of long-term phenological observations of the development of introduced plants led to the following conclusion. Among the rhododendrons of Daurian series in the introduction in Irkutsk, Rhododendron ledebourii Pojark., Rhododendron dauricum L. and Rhododendron sichotense Pojark. have shown themselves promising without limitations. They are characterized by fast growth, abundant flowering, early entry into the generative phase. Also, an early and short period of growth processes and timely entry into a state of rest are characteristic of them. All this contributes to the successful maturation and hardening of shoots, due to which their winter hardiness is estimated at 1 point, less often at 2 points. Rhododendrons ledebourii and Rhododendron sichotense are the most decorative due to the regularity of flowering, the abundance of flowering and the size of the flower. Rhododendron mucronulatum Turcz. is recommended for use in landscaping settlements with milder climatic conditions or in settlements within its natural range.

Перспективи культивування рослин роду рододендрон (Rhododendron L.) в умовах північної частини Лівобережного Лісостепу України

The genus Rhododendron includes more than 1,000 species, a part of them is used in many countries for the ornamental purposes. In contrast, that plant is not widespread in Ukraine, because the peculiarities of its introduction have not been studied sufficiently. Our paper presents the results of the preliminary assessment of the promises for growing rhododendron 30 cultivars and species in the northern part of the Ukraine’s Left-Bank Lisosteppe. The evaluation was carried out on the parameters of winter hardiness, intensity of formation of viable seeds and shoots, and maturation of the latest, preservation of the bushes shape and reproductive efficiency. In the group of evergreen and semi-evergreen plants 67 % of the 15 researched taxa have appeared to belong to the first group of prospects for usage, i.e. almost without restrictions. 5 other taxa have been referred to group II due to the increased are classified to group II, due to increased sensitivity to early spring positive temperatures and subsequent frost damage. This group includes ‘Pearce’s American Beauty’ (Rhododendron catawbiense), ‘Geisha Orange’ (Rh. obtusum), hybrid varieties ‘Erato’ and ‘Rasputin’ and Rhododendron sichotense. In addition, the first two cultivars did not form seeds during the growing season. Among the 15 species and varieties of the studied deciduous plants, only 2 (Rh. mucronulatum, Rh. prinophyllum ‘White Lights’) belong to group II of prospects. A week maturation and increased sensitivity of shoots to the early spring positive temperatures were noted in the first species, whereas in the second species a lack of seeds in the boxes was fired, that is low genitive capacity. In the first species there was a weak maturation of shoots and increased sensitivity to early spring positive temperatures. In the second species there is a lack of seeds in the boxes, i.e. low generative capacity. Regardless of the prospects of rhododendron using in the investigation region, their successful vegetation requires utilizing the modified pH, which includes the sphagnum peat and light composted pine cones and needles (2:1).

Efficient regeneration protocol for callus and shoot induction from recalcitrant Phaseolus vulgaris L. explants under optimum growth conditions

Callus is the most significant morphogenic response obtained in plant tissue culture studies. It can be used for micropropagation or to create transgenic lines. Phaseolus vulgaris L. (common bean) is one of the economically important crops with a great nutritional value. However, very little effort has been made to regenerate callus from P. vulgaris explants. Six explants were used namely root tip, leaves, plumule, radicle, cotyledon and embryo to develop a callus from P. vulgaris. The minimum days for callus induction was 10 days in plumule, radicle and embryo explants, while the maximum was 15 days in cotyledon explants with the callus induction percentage of 75%. The largest callus was found to be 2.77 gm in weight and 2.5 cm in diameter in MS medium. Medium with different concentrations of plant growth regulators (PGRs) showed different growth pattern in callus induction. Culture medium with 1.50 mg/l of BAP, 0.50 mg/l of 2, 4-D and 0.10 mg/l of NAA showed the best result in callus induction. Higher concentration of BAP (2.00 mg/l), along with 0.25 mg/l of 2, 4-D was ideal for shoot regeneration and maturation. Shoot induction medium along with 2.00 mg/l of NAA concentrations were found to be best for rooting. It was found that plumule and radicle favor callus induction, however, they are also potent for shoot and root induction. Knowledge gained in this study will be useful in developing a standard protocol for plant regeneration from P. vulgaris explants and will also be useful in creating transgenic line of P. vulgaris.

In-vitro bioactivity evaluation and non-targeted metabolomic analysis of green tea processed from different tea shoot maturity

The chemical quality and biochemical properties of green tea processed from different tea shoot maturity has largely remained unexplored thus far. Total phenolic content, and total flavonoid content decreased during tea shoot maturation. Three in-vitro bioactivities, namely α-glucosidase and pancreatic lipase inhibitory and antioxidant activity showed a similar changing trend. A significant correlation between TPC and TFC, and these bioactivities was found. Non-targeted metabolomic analysis revealed that green tea processed from different tea shoot maturity had obvious differences. Variable importance analysis and S-plot gave 32 characteristic metabolites responsible for the discrimination of different green teas. Orthogonal partial least square analysis was used calculate the correlation coefficient between each characteristic metabolite and the values of three in-vitro bioactivities. Several important differential bioactive metabolites were obtained using the above analysis. This study explored the metabolic change in green tea during the process of tea shoot ripening, thus providing unique tea quality information for green tea production.

Morphological, phenological, and transcriptional analyses provide insight into the diverse flowering traits of a mutant of the relic woody plant Liriodendron chinense

Flowering is crucial to plant reproduction and controlled by multiple factors. However, the mechanisms underlying the regulation of flowering in perennial plants are still largely unknown. Here, we first report a super long blooming 1 (slb1) mutant of the relict tree Liriodendron chinense possessing a prolonged blooming period of more than 5 months, in contrast to the 1 month blooming period in the wild type (WT). Phenotypic characterization showed that earlier maturation of lateral shoots was caused by accelerated axillary bud fate, leading to the phenotype of continuous flowering in slb1 mutants. The transcriptional activity of genes related to hormone signaling (auxin, cytokinin, and strigolactone), nutrient availability, and oxidative stress relief further indicated active outgrowth of lateral buds in slb1 mutants. Interestingly, we discovered a unique FT splicing variant with intron retention specific to slb1 mutants, representing a potential causal mutation in the slb1 mutants. Surprisingly, most slb1 inbred offspring flowered precociously with shorter juvenility (~4 months) than that (usually 8–10 years) required in WT plants, indicating heritable variation underlying continuous flowering in slb1 mutants. This study reports an example of a perennial tree mutant that flowers continuously, providing a rare resource for both breeding and genetic research.

Studies of quality development and major chemical composition of green tea processed from tea with different shoot maturity

Apart from geographical difference and processing method, the maturity of fresh tea shoot is an important factor that determines tea quality. However, the quality development and chemical variation of green tea with tea shoot maturity remain unclear. This study aimed to investigate the metabolic consequences of tea shoot maturity on the taste and aroma quality of green tea by metabolite profiling. In terms of taste quality, a concentration-dependent decrease with tea shoot age was observed in gallic acid and caffeine. The levels of catechin, epicatechin, and epigallocatechin increased with tea shoot maturity, whereas those of epicatechin gallate, epigallocatechin gallate, and total catechins decreased. Furthermore, the maximum contents of most amino acids were recorded in green tea processed from one bud with two leaves. In terms of aroma quality, volatile profiles of green tea were analyzed by gas chromatography–mass spectrometry combined with chemometrics. A total of 32 differential volatile organic compounds showing significant differences were identified and divided into Groups I and II, which contribute undesirable flavor and sweet flowery aroma to tea, respectively. The relative abundance of Group I increased with tea shoot maturity whereas that of Group II decreased. These findings can be used in guiding the production of green tea.

Springtime Drought Shifts Carbon Partitioning of Recent Photosynthates in 10-Year Old Picea mariana Trees, Causing Restricted Canopy Development

Springtime bud-break and shoot development induces substantial carbon (C) costs in trees. Drought stress during shoot development can impede C uptake and translocation. This is therefore a channel through which water shortage can lead to restricted shoot expansion and physiological capacity, which in turn may impact annual canopy C uptake. We studied effects of drought and re-hydration on early season shoot development, C uptake and partitioning in five individual 10-year old Picea mariana [black spruce] trees to identify and quantify dynamics of key morphological/physiological processes. Trees were subjected to one of two treatments: (i) well-watered control or (ii) drought and rehydration. We monitored changes in morphological [shoot volume, leaf mass area (LMA)], biochemical [osmolality, non-structural carbohydrates (NSC)] and physiological [rates of respiration (Rd) and light-saturated photosynthesis (Asat)] processes during shoot development. Further, to study functional compartmentalization and use of new assimilates, we 13C-pulse labeled shoots at multiple development stages, and measured isotopic signatures of leaf respiration, NSC pools and structural biomass. Shoot water potential dropped to a minimum of −2.5 MPa in shoots on the droughted trees. Development of the photosynthetic apparatus was delayed, as shoots on well-watered trees broke-even 14 days prior to shoots from trees exposed to water deficit. Rd decreased with shoot maturation as growth respiration declined, and was lower in shoots exposed to drought. We found that shoot development was delayed by drought, and while rehydration resulted in recovery of Asat to similar levels as shoots on the well-watered trees, shoot volume remained lower. Water deficit during shoot expansion resulted in longer, yet more compact (i.e., with greater LMA) shoots with greater needle osmolality. The 12C:13C isotopic patterns indicated that internal C partitioning and use was dependent on foliar developmental and hydration status. Shoots on drought-stressed trees prioritized allocating newly fixed C to respiration over structural components. In conclusion, temporary water deficit delayed new shoot development and resulted in greater LMA in black spruce. Since evergreen species such as black spruce retain active foliage for multiple years, impacts of early season drought on net primary productivity could be carried forward into subsequent years.

Вплив краплинного зрошення та навантаження суцвіттями на ріст і розвиток маточних кущів винограду

The high yield of grafted grape seedlings and their quality depend on many factors, including the quality of graft and rootstock components, which in turn is determined by proper care of the mother plantations of grape. Their farming techniques should be aimed at better growth and maturation of shoots. On mother bushes, the technological reception of shoot fragments is mandatory, partial removal of inflorescence is not so common in the agricultural techniques of mother plantings, but has a positive effect on the overall development of plants. Mother plantings should be irrigated if possible, as insufficient moisture supply negatively affects the condition of the bushes throughout the growing season and winter. In this work, the effect of partial removal of inflorescence (load of inflorescence 100, 75 and 50% of their total number) on mother bushes and the effect of different irrigation regimes (levels of pre-irrigation soil moisture 90, 80 and 70% of the lowest moisture capacity) on the condition of mother plantations, in particular on physiological, biochemical and biometric parameters of plants. It is shown that irrigation of bushes and reduction of inflorescence load to 50 and 75% of their total number stimulated the accumulation of chlorophyll in the leaves of mother plants, improved watering of leaf tissues, increased respiration during active growth and development of grapes. There is a positive effect of irrigation and reducing the load of inflorescence bushes to 50 and 75% on the biometrical parameters of mother grape bushes. The largest values of the total length of shoots and the degree of their maturation were in the bushes of variants with 90% the lowest moisture capacity, 50% inflorescence, 80% the lowest moisture capacity 50% inflorescence, 70% the lowest moisture capacity 50 and 75% inflorescence. Thus, effective irrigation regimes and reducing the load of inflorescence contributed to the growth of medium and strong full-fledged shoots, which are more productive.

Effect of carbohydrate content on shoot maturation and yield of Palmer mango submitted to potassium fertilization and biostimulant

Mango production in the Brazilian semiarid region has gained prominence in the national scenario due to the high yield and long production period using techniques that help in the main culture stages. The aim of this work was to evaluate the use of two alternative techniques in the production of ‘Palmer’ mango in the vegetative phase. It was evaluated whether commercial potassium-based Multipotássio® fertilizer could be used as an alternative source of potassium nutrient in the maturation process of mango branches, and whether Ascophyllum nodosum algae extract MultiTurbo® biostimulant would be good alternative for fruit production. Two experiments were conducted in the same area, the first experiment with factors represented by four Multipotássio® concentrations (0; 1; 2 and 3 L ha-1) and two assessment periods in the maturation of mango branches and leaves. In the second experiment, conducted in the same area, factors Multipotássio® concentration (0; 1; 2 and 3 L ha-1) and four MultiTurbo® concentrations (0; 0.625 ml ha-1; 1. 25 ml ha-1 and 2.50 ml ha-1) were evaluated. Number and length of panicles, carbohydrate content in branches and leaves, fruiting rate, fruit mass, length and diameter and yield were evaluated. The use of potassium-based fertilizer helps to increase sugar content in 'Palmer' mango branches, which has been increasing in relation to the doses used. Biostimulants result in positive effects on the number of panicles, fruits and yield of 'Palmer' mango.

Prediction of Fruit Free Amino Acids by Foliar Nutrient Diagnosis in Longan (Dimocarpus longan Lour.)

Free amino acid (FAA) profile is an important indicator of the quality of fruit and fruit product. Foliar nutrient diagnosis has been used for crop yield prediction for decades but not for fruit quality evaluation. Concentrations of 11 leaf nutrients including N, P, K, Ca, Mg, S, Fe, Mn, Cu, Zn, and B at stages of terminal shoot maturation and fruit development and fruit FAA profile at harvest were examined in longan in South China. The relation between leaf nutrient and fruit FAA was then investigated by multiple stepwise regression analysis. Foliar N content was greatest among the nutrients among the detected elements at both stages. Twenty-nine FAAs were determined in longan flesh, with alanine (19.9%), γ-aminobutyric acid (17.5%), glutamic acid (15.2%), and asparagine (10.7%) as the main components. Flesh individual FAA, essential amino acid (AA), umami-, and sweet and bitter taste AA strongly depended on foliar nutrients. However, the relation between flesh FAAs and foliar nutrients varied with FAA species. Leaf N was the dominant indicator for most pulp FAAs at two growth stages, while other nutrients (e.g., B, Zn, P, K, Ca, Mg) also played versatile roles on flesh FAAs. This work provides a novel tool to predict fruit FAAs via foliar nutrient diagnosis, which supports the practicality of producing specific target fruit or improving fruit quality through regulation of fertilization strategies in fruit production.