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Effect of hypothermia (5°С; 1 and 7 days) on growth processes and accumulation of phenolic compounds in above-ground organs was investigated in buckwheat (Fagopyrum esculentum Moench) seedlings of di- and tertaploid genotypes. It was found that changes in all the examined parameters in the seedlings of the diploid genotype were more pronounced than in the tertaploid genotype. Under hypothermia, a reduction in the height of seedlings and the length of the root system as compared with control material, an elevation of the content of malonic dialdehyde, and a decrease in the content of total phenolics in the above-ground organs of diploid genotype in contrast to tertaploid were observed. Exposure to low temperature caused a reduction in the content of phenylpropanoids in buckwheat hypocotyls of both genotypes, whereas accumulation of anthocyans in most cases rose depending on the duration of chilling and genotype. At the same time, hypothermia did not cause changes in the content of phenylpropanoids and flavonoids in cotyledonary leaves of either genotypes, which remained on the level of control material. The activity of a key enzyme of phenolic metabolism L-phenylalanine ammonia lyase in above-ground organs of the seedlings exposed to hypothermia either did not change or decreased. Thus, investigation of the composition of phenolic compounds in buckwheat seedlings of two genotypes for the first time showed its dependence on the ploidy of cells and temperature conditions of plant growing.

The wound inflicted during grafting of watermelon seedlings requires rapid and sufficient vascular development which is affected by light quality. Our objective was to investigate the effect of light spectra emitted by light-emitting diodes (LEDs) during healing of grafted watermelon (Citrullus lanatus) seedlings on their vascular development, physiological and phytohormonal profile, and root architecture. Three LEDs emitting red (R), blue (B), and RB with 12% blue (12B) were tested in a healing chamber. During the first three days, the photosynthetic apparatus portrayed by PIABS, φP0, ψE0, and ΔVIP was less damaged and faster repaired in B-treated seedlings. B and 12B promoted vascular reconnection and root development (length, surface area and volume). This was the result of signaling cascade between phytohormones such as indole-3-acetic acid and others. After vascular reconnection the seedlings switched lights for 3 more days and the picture was reversed. Seedlings treated with B for the first 3 days and R for days 4 to 6 had better photosynthetic characteristics, root system development, morphological, shoot and root biomass, and quality (i.e. Dickson’s quality index) characteristics. We concluded that blue light is important during the first 3 days of healing, while the presence of red is necessary after vascular reconnection.

Treating plants with elevated carbon dioxide (eCO2) can increase their drought tolerance. Increased atmospheric CO2, a fundamental factor in climate change, may compensate for the drought-induced reduction in crop growth and yield. Basil, being moderately sensitive to drought stress, experiences several morphological changes under drought conditions. Thus, we designed an experiment that addresses how drought stress and different levels of CO2 affect the overall morphological growth patterns during basil’s early and late-season growth. The experiment was conducted under four different growth conditions: two water treatments, (1) a full-strength Hoagland’s solution was added to the basil plants at 120% of the evapotranspiration each day, and (2) 50% of the full-strength Hoagland’s solution was added to basil plants for the drought treatment, alongside two levels of CO2 application [ambient 420 ppm (aCO2) and elevated 720 ppm (eCO2)]. The drought had a severe impact on the morphological traits of the shoot and root systems. Compared to control, the drought stress reduced the marketable fresh mass (FM) by 31.6% and 55.2% in the early and late stages of growth. FM was highest under control + eCO2 (94.4–613.7 g) and lowest under drought + aCO2 (67.9–275.5 g). Plant height under drought + aCO2 and drought + eCO2 reduced by 16.8 % and 10.6 % during the late season. On the other hand, dry mass (DM%) increased by 31.6% and 55.2% under DS + eCO2 compared to control in the early and late stages of growth, respectively. This study suggested that eCO2 during drought stress significantly impacts basil morphological traits compared to aCO2. Besides, anthocyanin (Antho) decreased by 10% in DS + aCO2 and increased by 12.6% in DS + aCO2 compared to control. Similarly, NBI, a ratio of chlorophyll (Lchl) and flavonoids (Flav), was recorded to be the highest in DS + aCO2 (40.8) compared to any other treatments. Overall, this study indicates that the suppression of basil’s morphophysiological traits by drought is more prominent in its later growth stage than in the earlier stages and eCO2 played an important role in alleviating the negative effect of drought by increasing the DM% by 55%.

The comparison of the influence of foliar fertilization with four preparations on the growth of ‘Conference’ maiden pear trees growing on MA quince rootstock was conducted in a nursery in a three-year period. The evaluation was conducted on the basis of maidens growth parameters and the state of their leaf minerals content as well as on photosynthetic activity of the maiden trees. The preparations used in the experiment affected the improvement of some growth parameters studied, especially the stem diameter and fresh mass of the maidens. Biopuls Original turned out to be the best preparation as it improved significantly three out of five studied growth parameters. A varied impact of the preparations used on the content of micro and macro-elements in leaves was detected. All tested preparations positively influenced the leaves area index of maiden trees except for Blackjak preparation. Photosynthetic intensity of maiden pear trees nourished through leaves was significantly smaller in comparison with the control. Only plants treated with Biopulus Original were characterized by a higher concentration of CO2 and its level in intercellular space. The aim of the second experiment was to check the influence of the application of Trifender WP preparation with hydrogel on the growth of ‘Champion’ maiden quince trees at the stage of planting the rootstocks into a nursery. A better branching of the rootstocks was obtained after the use of the preparation with hydrogel and the hydrogel alone. The trees in these combinations were also characterized by bigger fresh and dry mass of the leaves. The influence of Trifinder WP applied in connection with hydrogel was the best.

BACKGROUND Tomato is widely consumed throughout the world for its flavor and nutritional value. This functional food largely depends on the implementation of new strategies to maintain the nutraceutical value, e.g. lycopene concentration, and overcome the challenges of sustainable production and food security. The use of arbuscular mycorrhizal fungi (AMF)-based biostimulants represents one of the most promising tools for sustainable management of agricultural soils, being fundamental for organic food production, reducing fertilizers and pesticides use, and decreasing environmental damage. This study aimed at elucidating whether native arbuscular mycorrhizal fungi (AMF) could positively affect tomato yield and lycopene concentration. RESULTS Native AMF inoculum consisted of two inoculum types: the single species Claroideoglomus claroideum, and a mix of Scutellospora calospora, Acaulospora laevis, Claroideoglomus claroideum, and Claroideoglomus etunicatum. At the end of the study up to 78% of the root system was colonized by single inoculum. Tomato diameters in single and mix mycorrhizal plants showed increases of 80% and 35% respectively. Fresh weights were 84% and 38% higher with single and mix inocula compared with the controls, respectively. The lycopene concentration in tomato fruits of plants with single and mix inoculum was higher than controls. The lycopene concentration was 124.5% and 113.9% greater in single and mix than non-inoculated plants. CONCLUSION Tomato diameters, fresh weight and lycopene concentration was significantly higher in plants colonized by AMF compared with uninoculated plants. Results suggest that the role of single species Claroideoglomus claroideum could generate better plant performance due to its high production of extraradical mycelium. © 2021 Society of Chemical Industry.

Tissue loss of plants caused by herbivores is very common in nature. As the storage and first photosynthetic organ, the loss of cotyledon severely impacts dicot seedling establishment and the subsequent growth. However, it is still not clear how plants adjust their metabolic strategy in response to cotyledon loss. In this study, we employed ICP-OES, GC and LC-MS to examine the effects of cotyledon removal (RC1: remove one cotyledon, RC2: remove two cotyledon) on mineral element distribution and metabolite changes in a traditional Chinese herbal plant, Astragalus membranaceus. The results showed that cotyledon removal had a greater effect on shoot than root growth. Specifically, RC2 revealed a more serious impact on shoot growth than RC1. Microelement Mn and Na in shoot increased more in RC2 than RC1. Macroelement K and microelement B in root increased in RC2. The metabolite results in shoot showed that sugars related to galactose metabolism reduced while amino acids significantly increased in RC2. In root, sugars related to fructose and mannose metabolism decreased in both RC1 and RC2 while most flavonoids increased in RC2. It can be concluded that cotyledon removal triggered different metabolic strategies in both root and shoot. In shoot, more Mn was absorbed to improve the lowered photosynthetic efficiency. Meanwhile, increased Na may have promoted carbohydrate consumption and amino acid synthesis, thereby maintaining shoot growth. In root, K and B participation in cell division and expansion increased, as well as the delivery and metabolism of carbohydrates, to maintain root system growth.

Objetivou-se com esta pesquisa avaliar o crescimento de mudas do cafeeiro com utilização do inseticida Thiametoxan em diferentes dosagens em mudas de Coffea arábica L. Foram utilizadas duas formulações do inseticida Thiametoxan, o granulado dispersível (WG A), e o granulado (GR B), ambos diluídos em água sendo os tratamentos constituídos por doses: 0% (controle), 50%, 100% e 150% para ambas as versões do inseticida. O delineamento experimental utilizado foi em blocos casualizados, em esquema fatorial 2 x 4, com três repetições. Após 180 dias, foram avaliados os seguintes parâmetros: altura, comprimento da raiz e da parte aérea, a biomassa fresca e seca do sistema radicular e da parte aérea. O uso do Thiametoxan, em duas aplicações, influenciou no desenvolvimento do sistema radicular, altura das plantas, comprimento e massa da parte aérea das mudas de café em comparação com controle não sendo observado o efeito de diferentes dosagens do Thiametoxan no desenvolvimento do sistema radicular.

Background Inoculation of arbuscular mycorrhizal (AM) fungi has the potential to alleviate salt stress in host plants through the mitigation of ionic imbalance. However, inoculation effects vary, and the underlying mechanisms remain unclear. Two maize genotypes (JD52, salt-tolerant with large root system, and FSY1, salt-sensitive with small root system) inoculated with or without AM fungus Funneliformis mosseae were grown in pots containing soil amended with 0 or 100 mM NaCl (incrementally added 32 days after sowing, DAS) in a greenhouse. Plants were assessed 59 DAS for plant growth, tissue Na+ and K+ contents, the expression of plant transporter genes responsible for Na+ and/or K+ uptake, translocation or compartmentation, and chloroplast ultrastructure alterations. Results Under 100 mM NaCl, AM plants of both genotypes grew better with denser root systems than non-AM plants. Relative to non-AM plants, the accumulation of Na+ and K+ was decreased in AM plant shoots but increased in AM roots with a decrease in the shoot: root Na+ ratio particularly in FSY1, accompanied by differential regulation of ion transporter genes (i.e., ZmSOS1, ZmHKT1, and ZmNHX). This induced a relatively higher Na+ efflux (recirculating) rate than K+ in AM shoots while the converse outcoming (higher Na+ influx rate than K+) in AM roots. The higher K+: Na+ ratio in AM shoots contributed to the maintenance of structural and functional integrity of chloroplasts in mesophyll cells. Conclusion AM symbiosis improved maize salt tolerance by accelerating Na+ shoot-to-root translocation rate and mediating Na+/K+ distribution between shoots and roots.

In this study we tested the hypotheses that root classes would exhibit distinctive anatomical and architectural responses to drought stress, and that those responses would vary along the root axes. The root systems of four maize (Zea mays L.) sweet corn genotypes designated SC1, SC2, SC3 and SC4 were phenotyped under well-watered and drought treatments in greenhouse mesocosms, permitting increasing stratification of moisture availability as the drought progressed. Anatomical and architectural responses to drought were evaluated for each root class. Lignin distribution was assessed by image processing of UV-illuminated root cross-sections acquired by laser ablation tomography. The two cultivars with less biomass reduction under drought, SC3 and SC4, substantially enhanced lateral root development along the apical segments of axial roots when plants were grown with drought stress. These segments grew into the deeper part of the mesocosm where more moisture was available. Apical segments of the axial and large lateral roots from drought-stressed plants were thicker and had greater theoretical axial water conductance than basal segments, especially in SC3 and SC4. Basal segments of crown roots of SC3 and SC4 showed increased lignification of the stele under drought. Root anatomical and architectural responses to drought are complex and vary among cultivars and root classes, and along root axes. Drought-induced proliferation of lateral roots on apical segments of axial roots would be expected to enhance deep water acquisition, while lignification of axial roots could help preserve axial water transport.

Para un adecuado y exitoso establecimiento del cultivo de aguacate se necesitan plantas con un sistema radicular desarrollado y sano. Sin embargo, en los viveros comerciales de aguacate no se realizan manejos orientados a la mejora radicular. El objetivo del presente trabajo fue evaluar el efecto de bioestimulantes radiculares a base de microorganismos y ácidos orgánicos sobre el crecimiento, contenido de clorofila y micorrización en plantas de aguacate. Se tuvieron siete tratamientos, incluido un testigo. El diseño experimental fue completamente al azar, con ocho repeticiones. Las variables evaluadas fueron número de hojas, altura de la planta, longitud de la raíz principal, unidades SPAD, peso seco de la raíz y porcentaje de micorrización. En cada una de las variables, el mejor tratamiento fue la combinación Nutrisorb® L+ Biofit® RTU, lo cual confirma que el uso de microorganismos y ácidos orgánicos favorece el crecimiento vegetativo y radicular, así como promueve una mayor micorrización.

В статье представлены результаты исследований состояния насаждений шести сортов груши (Изумрудная, Изюминка Крыма, Мария, Мрия, Отечественная, Таврическая), привитых на три подвоя крымской селекции (КА 53, КА 86, КА 92) в сравнении с контролем (Бере Арданпон /ВА 29) в зависимости от архитектоники корневой системы. Анализ полученных данных дает возможность классифицировать деревья по силе роста в зависимости от подвоя и сорта. Наиболее рослыми являются комбинации сортов Изумрудная, Бере Арданпон, Отечественная на подвоях ВА 29, КА 53 и КА 86. Сорта Изюминка Крыма и Мария, а также подвой КА 92, относятся к группе слаборослых, что подтверждается биометрическими показателями. Площадь сечения штамба 11-летних деревьев в группе сильнорослых сорто-подвойных комбинаций составляет 79,2-81,1 см, у слаборослых - 64,2-68.8 см. На силу роста, помимо указанных факторов, влияет также развитие корневой системы. Цель исследований - установление зависимости роста и развития деревьев груши на разных подвоях от состояния корневой системы. Основным отличием подвоев крымской селекции является хорошо развитая корневая система. Результаты раскопки корней всех сортов на ВА 29 показывают, что основная их масса расположена на глубине 10-40см. Отдельные корни уходят вглубь до 1,7-2,0 м. Основная корневая система подвоев серии КА занимает почвенные горизонты 20-65 см, проникая в глубину до 2,5 м. Более развитая корневая система деревьев груши повышает также засухо- и хлорозоустойчивость деревьев, увеличивает их якорность и повышает продуктивность. Следовательно, при закладке интенсивного сада груши необходимо подбирать сорто-подвойные комбинации, устойчивые к био- и абиотическим условиям произрастания и обладающие умеренной силой роста. Выбор перспективных подвоев для интенсивного садоводства предусматривает необходимость изучения структурно-морфологических особенностей корневой системы. The article presents the study results of stand condition of plantings of six pear varieties (‘Izumrudnaya’, ‘Izyuminka Kryma’, ‘Maria’, ‘Mriya’, ‘Otechestvennaya’, ‘Tavricheskaya’), grafted on three rootstocks of Crimean selection (KA 53, KA 86, KA 92) in comparison with the control (‘Bere Ardanpon’ / BA 29) depending on the root system architectonics. Analysis of the data obtained makes it possible to classify trees according to the growth power depending on the rootstock and variety. The most strongly-grown are combinations of varieties ‘Izumrudnaya’, ‘Bere Ardanpon’, ‘Otechestvennaya’ on rootstocks BA 29, KA 53 and KA 86. The varieties ‘Izyuminka Kryma’ and ‘Maria’, as well as KA 92, belong to the group of weakly-grown, as confirmed by biometric indicators. Basal area of the trunk of 11-year-old trees in the group of strongly-grown variety-rootstock combinations is 79.2-81.1 cm, in the weakly-grown group - 64.2-68.8 cm. The strength of growth, in addition to above mentioned factors, is also influenced by the root system development. The aim of the research is to establish the dependence of growth and development of pear trees using different rootstocks on the root system condition. The main difference of Crimean rootstocks is a well-developed root system. The results of digging up the roots of all varieties on BA 29 show that their basic weight is located at a depth of 10-40 cm. Separate roots go down to 1.7-2.0 m. Basic root system of KA-series rootstocks occupies soil layer of 20-65 cm, penetrating to a depth of 2.5 m. A more developed root system of pear trees also increases the drought and chlorosis resistance of trees, improves their anchoring and productivity. Consequently, when starting an intensive pear garden, it is necessary to select variety-rootstock combinations, resistant to biotic and abiotic growing conditions and having a moderate growth power. The choice of promising rootstocks for intensive gardening involves the necessity to study structural and morphological features of the root system.

The research about the Effect of Sargassum crassifolium Extract Formula as Biostimulant to Increase Growth and Yield of Glycine max L. Merill was conducted from February until June 2020 at the warehouse of Plant Physiology Laboratory, Department of Biology, Faculty of Mathematics and Natural Sciences, Andalas University, Padang. The research aims to evaluate the effectiveness of liquid and powder extract formula of S. crassifolium as biostimulant on the growth and yield of soybean (Glycine max L. Merill). The research was conducted by an experimental method arrange in a Completely Randomized Design (CRD). The experiment consisted of 3 treatments. Each treatment was laid out with nine replications. The treatments tested were control, liquid extract (0.4%), powder extract (1.6 g/L). The results showed that the application of liquid extract gave a higher tendency towards the improvement of the root system, fresh and dry weight, chlorophyll content, and 100 seeds weight of soybean plant. While the powder extracts shown the best result on the total seed weight. Both of extract formula had the potential to be used to increase growth and yield of soybean.

This study aimed at understanding the uptake pathway of combined copper, zinc, and molybdenum applied to soybean (Glycine max (L.) Merrill) and maize (Zea mays (L.) seeds and their effect on seedling development. Two doses—2 and 4 mL kg−1 seeds—of a mixed copper, zinc, and molybdenum formulation were applied on both seed species, and process efficiency, i.e., how much of the applied solutions were transferred to the seeds, was determined. The spatial distribution of these nutrients was examined through microprobe X-ray fluorescence spectroscopy, and the effects on seed germination and seedling’s root and shoot development were recorded. Besides, the fraction of applied nutrients transferred from the seeds up to the seedlings tissues and the efficiency of the coating process were quantified. The results showed that seed treatments presented an overall efficiency of 70%. Most of the nutrients applied remained attached to the seed surface, i.e., seed coat or pericarp tissues in both species, being transferred to the soil afterwards. Only a tiny fraction of zinc, copper, and molybdenum was found in root and shoot tissues germinated from the coated seeds. The treatments did not impair seed germination or affected the content of the other mineral elements in the root and shoot tissues, although it had promoted a slight increase on maize’s root tissue length and dry mass. These results bring to light that the current seed treatment transfers part of the nutrients directly to the early developing seedling, while the remaining is precisely deposited in the soil volume where the root system will develop.

A micropropagação em comparação ao método de propagação via estacas herbáceas apresenta maior taxa de multiplicação em menor espaço e tempo; melhor controle fitossanitário, porém os custos elevados. A indução do sistema radicular durante a fase de aclimatização é uma alternativa para redução dos custos no sistema de propagação in vitro. Com o objetivo de induzir raízes nos brotos na fase de aclimatização, avaliou-se o efeito de diferentes concentrações do regulador vegetal, ANA, no enraizamento ex vitro e aclimatização para produção de mudas de pimenteira-do-reino. O delineamento experimental foi em blocos ao acaso, em esquema fatorial 3x4, sendo três cultivares: ‘Apra’, ‘Bragantina’ e ‘Kuthiravally’ e quatro concentrações de ANA: 26,85, 53,70; 80,56; 134,26 μmol/L, seis repetições com duas plantas por parcela. As variáveis avaliadas foram: taxa de sobrevivência e enraizamento; número de raízes por broto (NR); comprimento da maior raiz (CR); número de folhas (NF), massa seca da raiz (MSR) e da massa seca da parte área (MSPA). Os dados obtidos, para cada variável, foram submetidos à análise de variância, considerando o modelo fatorial 3 x 4, sendo três cultivares e quatro doses de ANA e quando significativa pelo teste F, foi aplicado o teste de comparação de médias, tukey (p

The results of a field experiment to study the effect of seed treatment with the biological product Rhizoactive (сompany BioNorma, Ukraine) on the formation and functioning of the symbiotic apparatus of common bean (grain) plants are presented. The experiment examined six varieties of common beans (grain), included in the State Register of plant varieties suitable for distribution in Ukraine: Bukovynka, Halaktyka, Slaviia, Ros, Otrada, Nata. The influence of bacterial fertilizer based on nodule bacteria " Rhizoactive " on the indicators of symbiotic and grain productivity of these varieties of common beans was studied. It was found, that the maximum number and raw weight of active nodules in the studied varieties of common beans were formed in the flowering phase. A larger number of nodules, compared to the variety Bukovynka (control), was formed on the root system of bean varieties Ros, Otrada and Nata. The maximum raw weight of rhizobia in the plots without the use of Rhizoactive was formed by the common bean variety Otrada – 0.297 g/plant of active nodules. Inoculation of the seeds of the studied common bean varieties with Rhizoactive increased the raw weight of active nodules in the flowering phase by 0.016–0.042 g/plant. A larger mass of nodules, compared to the Bukovynka variety, was formed on the root system of Ros, Otrada and Nata beans. The maximum raw weight of rhizobia in areas without the use of Rhizoactive was formed by the variety of beans Otrada – 0.297 g/plant of active nodules. Inoculation of seeds of the studied varieties of beans with Rhizoactive increased the raw weight of active nodules in the flowering phase by 0.016–0.042 g/plant. The highest increase in grain yield from seed inoculation was obtained in 2018, which was more favorable in terms of moisture. Thus, the largest increase in grain yield from the use of Rhizoactive was provided by the varieties Halaktyka (0.14 t/ha or 5.7 %), Ros (0.15 t/ha or 5.5 %) and Otrada (0.22 t/ha or 7.7 %). On average, in 2018–2020, inoculation of bean seeds with Rhizoactive, depending on the variety, provided an increase in grain yield from 2.4 to 6.7 %. And the highest level of bean grain yield on average in 2018–2020 was provided by the varieties Otrada (2.60 t/ha), Nata (2.50 t/ha) and Ros (2.40 t/ha) for inoculation of seeds with Rhizoactive

Previous studies found that non-uniform salt stress could alleviate salt damage to plants compared to uniform salt treatment. The root system of tomato was divided into two parts, including salt-fr...

Electrical capacitance (EC) is widely used to measure root traits especially in hydroponic and wet soil environments, but its feasibility was recently questioned due to the possible leakage of electrical current before entering the root system. To investigate whether the current can travel deeper in woody roots, EC was evaluated in cotton (Gossypium hirsutum L.) grown under different soil moisture conditions (two rounds of pot experiments, one PVC tube experiment and one field experiment). In these experiments, electrical capacitance of the root (ECroot) was recorded before and after severing roots, and immediately afterward, the roots were collected to measure root dry weight, surface area, length, and volume. The results showed that ECroot was significantly reduced after root cutting especially under dry conditions in the three experiments. The PVC tube experiment further demonstrated that root cutting did not significantly affect the changes in ECroot measured at different soil layers under dry conditions possibly suggesting that the current could flow into the deep roots under these conditions. Moreover, incorporating root tissue density and soil moisture into the prediction model can improve the predictive accuracy of ECroot. In contrast, ECroot was less affected by root cutting under wet soil conditions, indicating that it may not directly measure roots under these conditions. ECroot shows the potential to directly quantify root traits under dry conditions rather than wet conditions.

A produção de girassol na região Nordeste ainda é incipiente. Seria um importante desafio para o Piauí produzir girassol, em quantidade e qualidade, pois certamente somaria ao PIB agropecuário do Estado, principalmente no que tange à produção de óleo comestível, extraído dos aquênios. Analisou-se os efeitos de um biofertilizante bovino líquido, sobre o crescimento e a biomassa do girassol, sob cultivo agroecológico. O experimento foi realizado em DIC, com cinco tratamentos e seis repetições, totalizando 30 unidades experimentais. Os quatro tratamentos com o biofertilizante foram 50, 75, 100 e 125% da recomendação ótima, e o controle (sem aplicação). Analisou-se: altura das plantas (AP), diâmetro do caule (DC), diâmetro do capítulo (DCAP), produção de matéria seca da parte aérea (MSPA) e do sistema radicular (MSSR). Os resultados foram submetidos à análise de variância e posteriormente foram realizadas as regressões. Apesar dos resultados não significativos, as plantas de girassol que receberam o biofertilizante demonstraram melhor desempenho, quando comparadas às plantas que não receberam o insumo orgânico líquido; ademais, nas variáveis AP e MSSR, os melhores resultados foram verificados nas plantas que receberam as maiores concentrações de biofertilizante. Já quanto às demais variáveis os pontos de máxima (concentração de biofertilizante) encontraram-se entre 79 a 167%, com sugestão de efeito tóxico em doses mais concentradas do insumo orgânico.

Success in production of any perennial tree depends on the use of high-quality seedlings. This study aimed to evaluate cultivation benches with reflective material and protected environments for production of rubber tree rootstock seedlings. The experiments were conducted in two types of protected environments: 35% shading aluminized screen and 30% shading black screen. Cultivation benches with and without reflective material were tested inside the protected environments. A completely randomized design with 7 replications and 5 seedlings per plot was adopted for each environment, and the environments were compared by joint analysis. Solar radiation (global and photosynthetically active) was the most influencing micrometeorological factor on plant environment and plant growth differentiation. Regardless of the environment, the use of reflective material in cultivation bench had a positive effect on production of rubber rootstock seedling (clone GT1), providing seedlings with a robust root system and better quality. The use of reflective material also improved rubber tree rootstock seedlings (clone GT1) grown in the black screen environment.

– O processamento do coco gera resíduos com volumes bastante significativos, cujo descarte no ambiente provoca sérios problemas. Uma solução seria utilizá-lo após o desfibramento, na produção de substrato para produção de mudas. Com base nisso, o objetivo desse trabalho foi identificar a proporção de fibra de coco associada a esterco bovino para a formação de mudas de mamão. O experimento foi conduzido em delineamento experimental de blocos ao acaso, com 5 repetições, sendo os substratos produzidos em cinco proporções de fibra de coco para esterco bovino (0:1; 1:3; 1:1; 3:1; 1:0), semeados com mamão formosa. Cinquenta dias após a semeadura foram realizadas avaliações de comprimento da parte aérea e do sistema radicular, diâmetro do caule, número de folhas, massa seca da parte aérea e do sistema radicular, massa seca total e capacidade de retenção de água no substrato. Os dados foram submetidos a análise de variância e regressão polinomial a 5% de probabilidade. Houve significância apenas para os parâmetros da parte aérea das mudas. A associação de fibra de coco e esterco bovino forma um substrato que garante a produção de mudas de mamão, sendo recomendado utilizar a proporção de 44,38% de fibra de coco e 55,62% de esterco bovino nessa cultura.

Key message Root-specific expression of a cytokinin-degrading CKX gene in maize roots causes formation of a larger root system leading to higher element content in shoot organs. Abstract The size and architecture of the root system is functionally relevant for the access to water and soil nutrients. A great number of mostly unknown genes are involved in regulating root architecture complicating targeted breeding of plants with a larger root system. Here, we have explored whether root-specific degradation of the hormone cytokinin, which is a negative regulator of root growth, can be used to genetically engineer maize (Zea mays L.) plants with a larger root system. Root-specific expression of a CYTOKININ OXIDASE/DEHYDROGENASE (CKX) gene of Arabidopsis caused the formation of up to 46% more root dry weight while shoot growth of these transgenic lines was similar as in non-transgenic control plants. The concentration of several elements, in particular of those with low soil mobility (K, P, Mo, Zn), was increased in leaves of transgenic lines. In kernels, the changes in concentration of most elements were less pronounced, but the concentrations of Cu, Mn and Zn were significantly increased in at least one of the three independent lines. Our data illustrate the potential of an increased root system as part of efforts towards achieving biofortification. Taken together, this work has shown that root-specific expression of a CKX gene can be used to engineer the root system of maize and alter shoot element composition.

Morpho-physiological characteristics in Eucalyptus species can determine N (NUE) and P (PUE) use efficiency and, consequently, the plant's responses to fertilization. The study aimed to evaluate whether morphological and physiological characteristics of seedlings from Eucalyptus species affect the N and P use efficiency. For this, in a greenhouse, Eucalyptus grandis (GPC 23) and Eucalyptus saligna (32864) clones were grown in Hoagland nutrient solution for 21 days, followed by N and P restriction in CaSO4 solution 0.1 mol L−1 during 15 days. Morphological parameters from shoot and root system, dry mass of organs, photosynthetic pigments concentration, and chlorophyll a fluorescence of Eucalyptus species were evaluated, and NUE and PUE were calculated. Eucalyptus grandis presented the highest NUE and PUE values. The highest surface area, volume, and roots length values contributed to these results, justifying the highest dry mass production from leaves, stem, roots, and plant. Eucalyptus saligna presented the lowest NUE and PUE values, which negatively influenced photosynthesis (higher F0 values and lower concentrations of photosynthetic pigments). Root morphological parameters had a strong relationship with NUE and PUE and can be used to select Eucalyptus species, and breeding programs, as they can predict the ability of development of Eucalyptus species under low N and P availability.

Cytokinin is a plant hormone and an important regulator of root growth. Reduced cytokinin levels increase root systems, which can be beneficial for crops grown on nutrient poor and/or dry soils. Our study analyzed the effects of increased cytokinin oxidase 5 (OsCKX5) expression in rice roots on root morphology, architecture, and nutrient uptake. We fused the OsCKX5 gene to the strong, root-specific RCc3 rice promoter and overexpressed it in rice plants. The root-specific expression of OsCKX5 in the transgenic plants resulted in positive effects on root development without compromising shoot growth. The root system of the transgenic plants exhibited greater volume, length, projection area, a higher number of tips, and enhanced surface area. OsCKX5 overexpression also resulted in an increased uptake ability of certain macro- and micronutrients, a greater root biomass, deeper root system, and a higher root:shoot ratio, when cultivated on low-fertility soils. We conclude that the enhanced root growth and development by root-specific expression of OsCKX5 could be advantageous for crops grown on oxidic soils in the tropical regions, with a low availability of certain nutrients, especially P and Zn.

The bromeliads are desirable vase plants because of the flowering bract and the usually large, bold, colored and exotic format of the leaves that forms a cistern. The main function of epiphytic bromeliads roots is the fixation on the substrate, while water and nutrients uptake are performed mainly by leaves. However, recent studies have shown that the roots of epiphytic bromeliads can also help in the absorption of water and nutrients, contributing to plant growth and development. The present study aimed to evaluate the importance of the root system in the mineral nutrition of an epiphytic ornamental bromeliad silver vase bromeliad (Aechmea fasciata) that occurs in Brazil. 80 plants were cultivated for 240 days in plastic pots (900 mL) containing composted pine bark and were subjected to 5 treatments with 50 mL of 0% (control), 25%, 50%, 75% and 100% Hoagland & Arnon (HA) nutrient solution, applied twice a week only onto the substrate. Biometric and biomass variables of root and shoots, as well as macro- and micronutrients content in silver vase bromeliad leaves were evaluated. Results showed that all biometric and biomass parameters increased with the application of increasing HA solution concentrations, while the nutritional content in leaves showed different responses, with increase in nitrogen and potassium, decrease in calcium, phosphorus, magnesium, manganese, copper, sulfur, iron and zinc. We conclude that silver vase bromeliad grows better when fertilized with 75% or 100% HA solution on the substrate. We emphasize that the roots of the epiphytic silver vase bromeliad are functional and plays important roles in its nutrition and growth. Resumo As bromélias são desejáveis como plantas de vaso devido as brácteas floridas e formato geralmente grande, colorido e exótico das folhas que formam uma cisterna. A principal função das raízes de bromélias epifíticas é a fixação no substrato, enquanto a captação de água e nutrientes é realizada principalmente pelas folhas. Porém, estudos recentes têm demonstrado que as raízes das bromélias epífitas também podem auxiliar na absorção de água e nutrientes, contribuindo para o crescimento e desenvolvimento das plantas. O presente estudo teve como objetivo avaliar a importância do sistema radicular na nutrição mineral da bromélia ornamental epifítica Aechmea fasciata que ocorre no Brasil. Oitenta plantas foram cultivadas por 240 dias em vasos plásticos (900 mL) contendo casca de pinus compostada e foram submetidas a 5 tratamentos com 50 mL de 0% (controle), 25%, 50%, 75% e 100% da solução nutritiva de Hoagland & Arnon (HA ), aplicada duas vezes por semana somente sobre o substrato. Foram avaliadas as variáveis biométricas e de biomassa da raiz e da parte aérea, bem como o teor de macro e micronutrientes nas folhas de A. fasciata. Os resultados mostraram que todos os parâmetros biométricos e de biomassa aumentaram com a aplicação de concentrações crescentes da solução de HA, enquanto o conteúdo nutricional nas folhas apresentou diferentes respostas, com aumento de nitrogênio e potássio, diminuição de cálcio, fósforo, magnésio, manganês, cobre, enxofre, ferro e zinco. Concluímos que A. fasciata cresce melhor quando fertilizada com solução de AH 75% ou 100% no substrato. Ressaltamos que as raízes da bromélia epifítica A. fasciata são funcionais e desempenham importante papel na sua nutrição e crescimento.

Agapanthus praecox has become a burgeoning variety in the flower market due to its high ornamental value with unique large blue-purple inflorescence. For rapid entering into the market, tissue culture technology or organogenesis has an attractive application over the conventional reproduction approach. In this study, a highly efficient protocol based on indirect organogenesis has been successfully established for A. praecox subsp. orientalis ‘Big Blue’. Two types of explants, root tips versus root segments, were compared for callus induction frequency in response to the induction culture media. The induction media contain Murashige and Skoog’s (MS) Basal Salt supplemented with various concentrations of picloram (PIC), 2,4-Dichlorophenoxyacetic acid (2,4-D), thidiazuron (TDZ), kinetin (KT) and naphthalene acetic acid (NAA). Of the two types of explants, root tips were found to be more effective for callus induction than root segments. Among the induction media tested, the highest callus induction rate (100.00%) was achieved when cultured on MS supplemented with 2.0 mg/L PIC, 1.5 mg/L KT and 0.1 mg/L NAA, which was probably accredited to higher endogenous phytohormone contents, especially of 3-indoleacetic (IAA). The optimal medium for callus proliferation was MS + 1.0 mg/L PIC + 1.0 mg/L 6-BA + 0.4 mg/L NAA, and the fresh weight increased by 72.74%. After being transferred onto the adventitious bud induction medium for 25 days, shoots were dedifferentiated from the surface of the flourishing callus, which then developed to the plantlet with roots in 90 days. The plantlets were transplanted in a greenhouse with a survival rate of 92.86%. This study innovatively established an indirect organogenesis tissue culture system of A. praecox with roots as explants, which provided a practical reference in its application.

Kiwifruit Vine Decline Syndrome (KVDS) is currently affecting Italian kiwifruit cultivation, causing dramatic yield and economic losses. The syndrome’s aetiology is due to soil-borne pathogens and waterlogging, leading to the decay of roots and then the canopy. Current knowledge about the disease is limited, and the techniques to control the syndrome are ineffective. The use of tolerant rootstocks is one of the most promising tools. Six genotypes of Actinidia were tested for two years at four infected experimental sites in Friuli Venezia Giulia (NE Italy). Plant evaluation and analysis were carried out on the root system and the vegetative parts. At all experimental sites, three genotypes, all belonging to the A. macrosperma group, grew normally. In contrast, plants of A. polygama died earlier and those of A. chinensis var. deliciosa ‘Hayward’ declined during the first year. A. arguta ‘Miss Green’ survived the first year but started to decline during the second year. After two years of study, we were able to identify three putative resistant genotypes: A. macrosperma accession numbers 176 and 183, and ‘Bounty71’, which will be a useful resource as rootstocks or as parents for breeding owing to their potential genetic resistance traits.

Bromeliads with water-impounding tanks uptake water and nutrients by the leaf-absorbing trichomes present on the leaf surface while the compact root system functions as for plant anchorage on other plants. However, recent studies showed a clear role of the bromeliad roots in nutrient absorption and subsequently improving plant growth. Accordingly, the present study aimed to compare the uptake and assimilation of inorganic and organic nitrogen by roots and leaf-absorbing trichomes of silver vase bromeliad (Aechmea fasciata). As treatments, plants were fertilized with 0, 15 or 30 mM nitrogen (N) as either urea or ammonium nitrate applied into the tank or on the substrate (roots). Dry biomass, number of leaves, macro and micronutrient contents in leaves, chlorophylls a, b, and total carotenoids were determined. In addition, gas exchange, chlorophyll fluorescence, and nitrogen efficiency indexes were analyzed. The results showed that ammonium nitrate is taken up either by leaf-absorbing trichomes and or by roots of silver vase bromeliad. Plants fertilized with ammonium nitrate had an increase in leaf nitrogen content with the increase of nitrogen concentrations on tank. However, these increases did not result in biomass accumulation or changes in the photosynthetic apparatus. Our results showed that the roots of silver vase bromeliad are more efficient for inorganic nitrogen.

The knowledge of fertilization in ornamental plant production is essential to improve productivity and longevity of plants and their flowers. In the case of Hemerocallis x hybrida Hort. there is only few studies showing this relation. The lack of research in the field led the execution of this study, which aimed to evaluate the effect of different doses of NPK on the growth of daylily cultivar Regina. The study was conducted in an experimental area at Pontifícia Universidade Católica do Paraná, located in Toledo, PR, Brazil. Seedlings were obtained from dividing the parent plants’ clumps which were cultivated in a clonal garden. Subsequently, standardization was carried out regarding the length of the aerial part of 10 cm and root system of approximately 5 cm. The experimental design used was randomized blocks with five treatments, containing four replications with five plants each. The treatments consisted of five doses (0; 4.5; 9.0; 13.5 and 18.0 g pl-1) using NPK (4-14-8). The parameters evaluated were number of shoots per plant, number of leaves per shoot, number of stems per plant, length of stems per plant and number of flower buds per stems. We observed the flowering timing was influenced by the different doses of NPK. There was linear fit for the parameters and the dose of 18 g pl-1 promoted the best results, except for the number of stems per plant. The results indicate that increasing doses of NPK positively influence the flowering period, and promote an increase in the number of shoots, stem length and number of flower buds.

En huertos de manzana de alta densidad, los portainjertos enanizantes juegan un papel clave, puesto que ellos promueven o estimulan la producción temprana, incrementan el rendimiento y calidad del fruto por unidad de superficie. Sin embargo, su desempeño hortícola depende de la capacidad del suelo para suministrar agua y nutrientes para el sistema radical. Bajo condiciones limitantes de suelos someros algunos portainjertos enanizantes no son capaces de satisfacer los requerimientos de agua y nutrientes para la variedad. En Aquixtla, Puebla, el crecimiento y desarrollo en árboles de manzano ‘Brookfield Gala’/Bud.9 son débiles, con sintomatología de deficiencias minerales, en contraste a los árboles injertados en Emla7, los cuales están produciendo frutos normalmente. En este trabajo se reporta el estatus nutrimental de árboles ‘Brookfield Gala’/Bud.9, apoyados por el portainjerto Emla7. El análisis foliar en 2018 demostró una concentración más alta de Mn y B en arboles ‘Brookfield Gala’/Bud.9 con injerto de aproximación realizado en 2016 y 2017 respectivamente. En 2019 la concentración de Cu y B fue más alta en los ‘arboles con injerto de aproximación realizado en 2017. En todos los árboles la concentración de Zn y K fue baja y la concentración de Ca y B fue alta. El efecto del injerto de aproximación con el portainjerto Emla7 fue incipiente en el desarrollo y crecimiento del manzano ‘Brookfield Gala’/Bud.9.

The structure of seasonal dynamics of daily growth of shoots of basket willow (Salix viminalis) is described and analyzed. Object: model inbred-clone population of S. viminalis. Material: developing shoots on annual saplings from cuttings. Methods: comparative morphological, chronobiological, numerical analysis of time series. The formation of dimorphic root systems of one-year saplings from cuttings is described. It is established that the seasonal dynamics of daily increment of shoots is determined by the interaction of linear and nonlinear components. Linear components are approximated by regression equations, and nonlinear components are approximated by harmonic oscillation equations. The rhythmicity of seasonal dynamics of shoot growth is described. Four groups of biorhythms were identified: annual with a period of about 96 days, subannual with a period of 4064 days, and infradian with a period of 1924 days and infradian with a period of 1016 days. The alternation of peaks and dips in the seasonal dynamics of shoot increment is determined by infradian biorhythms with a period of 19...24 days. Infradian biorhythms with different periods are synchronized with each other. The probable reason is the existence of a pulse synchronizer of biorhythms. Interclonal differences in the seasonal dynamics of the daily growth of shoots were not revealed. The probable cause of intraclonal differences is the ontogenetic heterogeneity of vegetative buds, from which annual shoots have developed. To verify this hypothesis, we plan to observe the development of seedlings grown from cuttings harvested from different parts of the uterine shoots. The results obtained are recommended to be taken into account when planning agroforestry measures for crop of S. viminalis.

The purpose of research was the study of vegetative organs reaction in strawberry seedling to the components of organic substrate and phytoregulation. Seedlings of 6 strawberry varietiess, organic substrate (fluffed peat, peat, sand) and growth phytoregulators (Radifarm and Atlante plus) were studied. Analysis of the results of experiments in 2019–2020 showed that the use of a substrate based on dissolved peat with perlite significantly affected the increase in root length by 15.1–27.6 % compared to the control (a mixture of peat and sand) on average for the studied varieties. The root saturation indice with plug volume of (40 cm 3 ) differed significantly compared to the control namely by 27.9–26.8 % for the studied variants. We have established the biological affectiveness of using the studied phytoregulators on root system in low volume plugs (cassettes) on all studied varieties. The root saturation did not differ in the variants with Radifarm and Atlante plus and averaged 5.2-5.4 cm/cm 3 which was significantly higher compared to the control on 28.3–46.0 %.

Aim. To determine water deficiency tolerance of genetically modified common wheat plants (Triticum aestivum L., cv Zymoyarka), containing the heterologous ornithine-δ-aminotransferase gene, based on the analysis of grain productivity and physiological and biochemical characteristics in transgenic and non-transgenic genotypes. Methods. Biochemical spectrophotometric assays: the enzyme ornithine-δ-aminotransferase activity, the free L-proline content, and the photosynthetic pigments content; biotechnological: Agrobacterium-mediated transformation in planta; physiological: morphometric traits and elements of grain productivity; mathematical statistics. Results. It was established that the presence of an additional copy of the ornithine-δ-aminotransferase gene in transgenic plants leads to higher activity of the ornithine-δ- aminotransferase enzyme: by 1.6 times higher on average for all lines as compared to the non-transgenic plants at 70 % of fi eld capacity and by 1.5 – at 30 % fi eld capacity. However, transgenic plants did not differ significantly from the original variety in the free L-proline content either under optimal water conditions or under soil drought. The increase in the total chlorophyll (a + b) content in flag leaves of transgenic plants was established under conditions of both optimal water supply and drought, as compared with the original genotype (increase by 5–7 % and 8–11 %, respectively). The enhanced expression of the orni- thine-δ-aminotransferase gene in the transgenic plants stimulated root growth both under optimal and stressful conditions: the root length of the transformed plants exceeded that of the original variety by 3.4–3.9 cm in the variant with optimal water supply, and by 4.2–4.6 cm – under drought. They were also characterized by a more developed root system. Dry root weight of the transgenic plants exceeded the original variety both in the control (by 23–27 %), and under drought (by 37– 44 %). Under drought, the root dry weight decreased by 29 % in the plants of the original variety, compared 70 % fi eld capacity, and by 11–15 % in the lines. Under 30 % field capacity, the transgenic lines also exceeded non-transformed plants in the number of grains from the whole plant (on average for 3 lines by 26 %) and in the grain weight (by 22 %). Transgenic plants are characterized by the formation of a higher productive shoots number: from 3.2 to 3.4 compared with 2.5 in non-transgenic plants at 70 % fi eld capacity and 2.7–3.1 vs 2.2 at 30 % field capacity it was found. Conclusions. Thus, the analysis of genetically modified common wheat plants cv. Zymoyarka, containing the heterologous alfalfa ornithine-δ- aminotransferase gene, by yield structure elements, morphometric parameters and photosynthetic pigment content showed their better tolerance to soil drought as compared to non-transgenic plants. We explain the improvement of grain productivity of the whole plant in transgenic wheat lines with an additional copy of ornithine-δ-aminotransferase gene by the fact that they have a better developed root system (dry root weight of the transgenic plants exceeded the original variety both in the control by 23–27 %, and under drought by 37–44 %) and a higher (on average for 3 lines – 3.3 compared to 2.5 in non- transgenic plants at 70 % fi eld capacity and 2.9 vs 2.2 at 30 % fi eld capacity) number of productive shoots than in the origi- nal variety both under optimal and insuffi cient water supply.

Baru (Dipteryx alata Vogel) is a native tree plant, widely distributed in Brazil, and has a growth and development in acidic soils like Cerrado, indicating a probable tolerance to adverse soil conditions, such as the high concentration of metals and the acidic pH. Due to the lack of information about the tolerance of this species to metals and the possibility of being used in the recovery of degraded areas and/or in phytoremediation, this work was developed with the objective of evaluating the in vitro germination and growth capacity of baru in medium supplemented with different concentrations of aluminum, iron, and manganese, as well as through chemical analysis, to determine the concentration of metals accumulated in cultivated plants in these conditions. The treatments consisted in different concentrations of metals: aluminum, Al3+ (0, 3.5, 7.0, 10.5, 21.0, or 42.0 mg L−1); iron, Fe3+ (0, 2.5, 4.9, 7.4, 14.7, or 29.4 mg L−1); and manganese, Mn2+ (0, 0.4, 0.8, 1.2, 2.4, or 4.8 mg L−1) added to the medium WPM. The tested values were based on using the lower concentration as the limit value, calculated based on risk to human health in accordance with CONAMA resolution 420/2009 for groundwater. At 60 days of cultivation, the percentage of germination, the average number of leaves, the length of the main root and the aerial part, the fresh and dry mass of the aerial part and the root system and the cations concentration Al3+, Fe3+ and Mn2+ in the plant biomass, were evaluated. The results showed that under the conditions in which the experiment was conducted, germination and in vitro growth of baru were not affected by the presence in high concentrations of any of the evaluated metals, with no differences in the percentage of germination and plant growth, as well as typical toxicity characteristics were not observed, such as changes in root morphology, chlorosis, or tissue oxidation. The absence of toxicity symptoms in baru plants, in the presence of Al3+, Fe3+, and Mn2+, indicate that the species is tolerant to these metals. The accumulation of Al3+ and Fe3+ in the plant biomass at the beginning of growth, simultaneously with the increase in the concentrations of these elements in the culture medium, indicates that this species can be used for phytoremediation, because it is a probable accumulator of these elements throughout its development, given the presence in significant concentrations of these elements also in the seeds.

Improvement in rainfed finger millet productivity is close to stagnation from the last decade due to insufficient above-ground biomass which includes vegetative shoot mass, grain-bearing ear-heads and their size. As the partitioning of biomass to sink traits has reached reasonably high, an increase in shoot mass is expected to improve the yields further. The shoot mass is primarily dependent on the root system, hence, the root growth pattern at different crop growth stages and their relationship to shoot mass was studied under well-watered (WW) and drought stress (DS) conditions. Results revealed that, the mean root length increased by twofold from 15 to 30 DAS followed by a marginal increase up to 75 DAS under WW condition. While the root dry weight had a slow increase up to 45 DAS and rapid growth afterwards under WW condition. The DS during tillering (15 to 30 DAS) and later vegetative stage (35 to 55 DAS) increased the root length marginally, whereas, the root dry weight and shoot dry weight were decreased substantially and; recovered to > 80 and nearly 70% respectively after the alleviation of DS. The root dry weight was positively and significantly related with shoot mass at all stages up to 55 DAS in WW and up to 45 DAS in DS, whereas the root length at 45 DAS only under WW and DS conditions. Therefore, rapid deep root and particularly the root mass at tillering have relevance in shoot mass production, especially under DS conditions.

To meet the high demand of the consumer market for ornamental plants, various techniques are used to increase production and flowers quality, through growth regulators. Despite all the benefits arising from the use of regulators, it is essential to establish concentrations that meet the purpose of their use. The aim of the study was to evaluate the growing and flowering characteristics of Impatiens hawkeri, after the exogenous application of different dosages of spermine, spermidine and gibberellic acid. Two pulverizations were made separated by 15 days, with polyamines (500/2,000 and 1,000 μM), or gibberellic acid (50 and 100 μM), and for the control, water was used. The evaluated parameters were the number of leaves, plant height, number of flower buds, dry and fresh weights of the root system and the aerial parts, and also volume of the root system and the chlorophyll content (SPAD). The treatments with gibberellin caused higher averages in all measurements, except for SPAD. Based on the results obtained, the use of gibberellin with the dosage of 100 µM as a regulator is the most appropriate to meet the needs of the Impatiens hawkeri market with more vigorous plants and with a greater number of flowers. Resumo Para atender a alta demanda do mercado consumidor de plantas ornamentais, variadas técnicas são empregadas para incremento produtivo e na qualidade das flores, por meio de reguladores de crescimento. Apesar de todos os benefícios oriundos do uso dos reguladores, é imprescindível estabelecer dosagens e concentrações que atendam a finalidade do seu uso. O objetivo do presente trabalho foi avaliar crescimento e o florescimento de Impatiens hawkeri, após a aplicação de diferentes dosagens de espermina, espermidina e ácido giberélico. Foram feitas duas pulverizações, com poliaminas (500/2000 e 1000 μM), ou ácido giberélico (50 e 100 μM), e para o controle foi utilizado a água. Os parâmetros avaliados foram o número de folhas, altura da planta, número de botões florais, massa seca e fresca do sistema radicular e da parte aérea, e ainda volume do sistema radicular e o teor de clorofila (SPAD). A análise dos dados foi por meio de modelos mistos com as principais matrizes de covariância e estudo qualitativo por médias. Os tratamentos com giberelina obtiveram maiores médias em todas as medições, com exceção do SPAD. Com base nos resultados obtidos, o uso da giberelina como regulador a 100 µM é o mais adequado para atender as necessidades do mercado de Impatiens hawkeri com plantas mais vigorosas e com maior número de flores.

Phedimus aizoon L. is a drought-resistant Chinese herbal medicine and vegetable. However, its drought tolerant limit and the mechanism of drought tolerance are unknown, which restricts the promotion of water-saving cultivation of Phedimus aizoon L. in arid areas. To solve the above problem, we carried out a 30-day-long drought stress experiment in pots that presented different soil water contents and were divided into four groups: control check, 75–80% of the maximum water-holding capacity (MWHC); mild drought, 55–60%; moderate drought, 40–45%; and severe drought, 20–25%. The dynamic changes in both plant physiological indexes from 10 to 30 days and leaf anatomical structure on the 30th day of stress were recorded. The results show that Phedimus aizoon L. grew normally under mild drought stress for 30 days, but the growth of the plants became inhibited after 20 days of severe drought and after 30 days of moderate drought. At the same time, Phedimus aizoon L. physiologically responded to cope with drought stress: the growth of the root system accelerated, the waxy layer of the leaves thickened, and the dark reactions of the plants transformed from those of the C3 cycle to CAM. The activity of antioxidant enzymes (SOD, POD and CAT) continuously increased to alleviate the damage caused by drought stress. To ensure the relative stability of the osmotic potential, the contents of osmoregulatory substances such as proline, soluble sugars, soluble protein and trehalose increased correspondingly. Although Phedimus aizoon L. has strong drought stress resistance, our experimental results show that the soil available water content should not be less than 27% during cultivation.

In this study, pepper (Capsicum annuum L.) inbred lines were grafted onto different rootstock genotypes and tested under saline conditions. A hydroponic experiment was conducted in nutrient solution growth system in a growth chamber of Erciyes University, Agricultural Faculty in Kayseri, Turkey. The experiment was conducted in spring 2017 growth season. Two pepper inbred lines (ERu-462 and ERu-1227) were grafted onto three different pepper rootstocks/genotypes (Scarface F1, 11B14, and Yaocali F1) and grown in 8 L pots filled with continuously aerated nutrient solution under saline conditions (8 dS m(-1)) with three replications. The growth chamber experiment was carried out to determine the effects of salt stress on plant growth, shoot and root dry weights, leaf area, photosynthesis, leaf total chlorophyll (a + b) and carotenoid content, proline content, glycine betaine content, leaf electrolyte leakage, leaf and root macro element concentration in grafted and non-grafted pepper plants. The results indicated that ERu-462 grafted on to Scarface and 11B14 rootstock genotypes were more tolerant to salinity than ERu-1227 in term of leaf chlorophyll (a + b) content and leaf carotenoid content, photosynthesis, and proline content. Though, higher shoot and root biomass, leaf area formation, root K+, Na+, Cl- contents were observed when ERu-1227 grafted on to Scarface and 11B14 rootstock genotypes. Strong rootstock promoted plant growth in pepper plant both under control and saline conditions and significant depression of plant biomass production under saline conditions was observed in both grafted and non-grafted plants. However, grafting onto vigorous rootstocks alleviated negative effects of salinity stress on pepper plants. Scarface and 11B14 were found more tolerant to salinity than non-grafted pepper plants and the other genotypes used as regard to investigated parameters.

Salix viminalis is a typical dioecious shrub willow, which has been widely used in the heavy metal polluted soil phytoremediation due to its fast growth rate, deep root system, and metal-resistance...

This work presents the research results of artificial infection of garden strawberry plants of the Elsanta variety with the phytopathogenic fungus Colletotrichum nymphaeae from the Colletotrichum acutatum complex. Three different ways of infecting strawberry plants were analysed: by injecting the plant rosette, spraying with a spore suspension, and infecting the soil. The study showed that the plants of this variety are susceptible to the C. nymphaeae species. The most susceptible parts of plants were identified: leaf blades, petioles and strawberry rosettes. The most obvious symptoms of infection, caused by C. nymphaeae, were found in case of injecting into the rosette. In this work, the most sensitive and valid laboratory methods for isolating and identifying the causative agent of strawberries anthracnose on the planting material were determined: isolation of the pathogen using the deposit method on the 2 % PGA nutrient medium with the addition of 4 % citric acid and identification by the real-time PCR method using the “Fitoscreen set. C. acutatum complex-PB” (CJSC Syntol, Moscow). The C. nymphaeae species from the C. acutatum complex is a pathogen harmful to strawberry plants, causing rapid damage to leaf blades, petioles and rosettes. In the conducted experiment, the root system of strawberry plants was not affected, and there was no infection in the soil.

The dependence of the action of lactone-structure brassinosteroids in composition with a growth-inhibiting dose of glyphosate on the root system and the aerial part of fiber flax (Linum usitatissimum L.) and spring barley (Hordeum vulgare L.) seedlings was determined. The species specificity of growth responses to seed incrustation by such mixtures was identified. The concentration ranges of brassinosteroids, in which their interaction with the herbicide is most pronounced, were detected. In this case, there is an increase (on spring barley seedlings) or weakening (on fiber flax seedlings) of the inhibitory effect of glyphosate on the root system.

Root systems play a major role in supplying the canopy with water, enabling photosynthesis and growth. Yet, much of the dynamic response of root hydraulics and its influence on gas exchange during soil drying and recovery remains uncertain. We examined the decline and recovery of the whole root hydraulic conductance (Kr) and canopy diffusive conductance (gc) during exposure to moderate water stress in two species with contrasting root systems: Tanacetum cinerariifolium (herbaceous Asteraceae) and Callitris rhomboidea (woody conifer). Optical dendrometers were used to record stem water potential at high temporal resolution and enabled non-invasive measurements of Kr calculated from the rapid relaxation kinetics of water potential in hydrating roots. We observed parallel declines in Kr and gc to

To assess whether grafting could improve the nitrogen (N) efficiency of potato cultivars and to determine which physiological and morphological characteristics are predominantly contributing to N efficiency, a hydroponic experiment was conducted. Two contrasting potato cultivars (Agria: N-efficient and Van Gogh: N-inefficient) were grafted reciprocally onto each other. Grafted and non-grafted control plants were grown in a growth chamber for 42 days in 8 L pots filled with continuously aerated nutrient solution under two N rates (Low-N : 0.5 mM N and High-N : 3.0 mM N) by using a deep water culture (DWC) technique. The shoot and root fresh (FW) and dry (DW) weights, main stem length, number of leaves, total leaf area, photosynthetic activity of leaves, shoot and root N concentration, total N uptake, total root length and root volume of potato plants were significantly increased with increased N rate. The grafted plants produced significantly higher above ground biomass than non-grafted ones, indicating that N efficiency was significantly improved by the reciprocally grafting under low and high N rates. Non-grafted cv. Agria showed higher numbers of shoot and root FW and DW, total leaf area, intensity of photosynthesis net measurements, compared to non-grafted cv. Van Gogh under both N rates. In reciprocal grafting, the growth performance of cv. Agria slightly increased when it was grafted onto cv. Van Gogh, whereas a significant increase in crop growth performance was recorded when cv. Van Gogh was grafted onto cv. Agria. The N efficiency of non-grafted cv. Agria was closely associated with its vigorous root growth and active root system under both N conditions. Same root morphological characteristic could not be exhibited by the N-inefficient cv. Van Gogh. Our study suggested that root morphological characteristics are contributing more than shoot characteristics to N efficiency of potatoes. These traits could be useful characters to breed/select N-efficient potato rootstocks for sustainable agriculture in the future.

Plant nitrogen assimilation and use efficiency in the seedling's root system are beneficial for adult plants in field condition for yield enhancement. Identification of the genetic basis between root traits and N uptake plays a crucial role in wheat breeding. In the present study, 198 doubled haploid lines from the cross of Yangmai 16/Zhongmai 895 were used to identify quantitative trait loci (QTLs) underpinning four seedling biomass traits and five root system architecture (RSA) related traits. The plants were grown under hydroponic conditions with control, low and high N treatments (Ca(NO3)2·4H2O at 0, 0.05 and 2.0 mmol L−1, respectively). Significant variations among the treatments and genotypes, and positive correlations between seedling biomass and RSA traits (r=0.20 to 0.98) were observed. Inclusive composite interval mapping based on a high-density map from the Wheat 660K single nucleotide polymorphisms (SNP) array identified 51 QTLs from the three N treatments. Twelve new QTLs detected on chromosomes 1AL (1) in the control, 1DS (2) in high N treatment, 4BL (5) in low and high N treatments, and 7DS (3) and 7DL (1) in low N treatments, are first reported in influencing the root and biomass related traits for N uptake. The most stable QTLs (RRS.caas-4DS) on chromosome 4DS, which were related to ratio of root to shoot dry weight trait, was in close proximity of the Rht-D1 gene, and it showed high phenotypic effects, explaining 13.1% of the phenotypic variance. Twenty-eight QTLs were clustered in 12 genetic regions. SNP markers tightly linked to two important QTLs clusters C10 and C11 on chromosomes 6BL and 7BL were converted to kompetitive allele-specific PCR (KASP) assays that underpin important traits in root development, including root dry weight, root surface area and shoot dry weight. These QTLs, clusters and KASP assays can greatly improve the efficiency of selection for root traits in wheat breeding programmes.

The type of the root system development of different species and cultivars gives valuable information for choosing of proper rootstock/scion combinations in different soils and soil horizons, the establishment of active rhizosphere where the input nutrition can give maximum results. Researches showed that cherry grafted on a vigorous rootstock in molic eutricambosoil develops a root system which is mainly horizontally spread (88-90°), in some rare cases with angles of 45°, with 5-7 strong V order roots (>80 mm) which provides good anchorage for trees. To the periphery the roots reached up to 6.5-8.5 m in the old trees and 3.5 m in the young trees. The depth of the root system achieved 2.0-2.5 m in the old trees and 1.0-1.5 m in the young trees. The highest quantity of roots were observed between 18-60 cm depth in both young and old trees.

The nano-carbon graphene has unique structural and physicochemical properties, which are conducive to various biomedical applications. We assessed the effect of graphene oxide (GO) on tomato plants at the seedling and mature stages in terms of morphological and biochemical indices. GO treatment significantly improved the shoot/stem growth of tomato in a dose-dependent manner by increasing the cortical cells number, cross-sectional area, diameter and vascular-column area. In addition, GO also promoted the morphological development of the root system and increased biomass accumulation. The surface area of root tips and hairs of tomato plants treated with 50 mg/L and 100 mg/L GO were significantly greater compared to the untreated control. At the molecular level, GO induced the expression of root development-related genes (SlExt1 and LeCTR1) and inhibited the auxin-responsive gene (SlIAA3). However, 50 mg/L and 100 mg/L GO significantly increased the root auxin content, which in turn increased the number of fruits and hastened fruit ripening compared to the control plants. Taken together, GO can improve the tomato growth when used at the appropriate concentration, and is a promising nano-carbon material for agricultural use.

Models of cultivars of agricultural crops are created for certain agro-climatic conditions. The aim of the research is to supplement the existing models of two- and multirow spring barley cultivars adaptive to the soil-climatic conditions of the Volga-Vyatka region with new features and properties for their more effective implementation. Studies were carried out using extensive, statistically processed data from collection nurseries and competitive variety tests for 2003–2019. Cultivars having longer growing periods were characterized by high yields. Under the conditions of the region, barley cultivars formed yields due to a different combination of elements of the yield structure. Thus, a significant contribution to yields was made by the spike productivity and the thousand kernel weight; however, in multirow barley, the dependence of productivity on these traits was more significant (r = 0.61 and 0.78, respectively) than in two-row barley (r = 0.40 and 0.42). In all cultivars, the density of plants per unit area for harvesting should not exceed 350–400 pieces per m2. The optimal ratio of the count of grains per spike and the thousand kernel weight in two-row cultivars is 1.0 : 2.3 and that in multirow cultivars 1 : 1. Lodging-resistant cultivars of both the subspecies were characterized by a large number of nodular roots and a ratio of grain mass to straw of 1.0 : 1.0 or 1.1 : 1.0, depending on the growing conditions. To select forms with high adaptive properties, it is necessary to use the root length index (RLI), which characterizes the growth of the root system under stress, and the RSR index, which reflects the distribution of plastic substances whose values should approach 100%, and changes in physiological processes in plants under stress should be minimal (the integral index of resistance). The statistically significant association (at p ≤ 0.05) of chlorophyll a (r = 0.64), chlorophyll b (r = 0.58), and carotenoids (r = 0.60) in the second last leaf with the yield capacity also makes these indicators promising for use in barley breeding.

The presence of mycorrhiza is the reason for the efficient process of carbon deposition in the ecosystem. Different methods of mycorrhization contribute to the effective growth and productivity of plants. The effect of Tuber melanosporum IMB F-100106 in Mikovital composition on the growth, development and productivity of Masterpiece hazelnuts was studied. The influence of different methods of mycorrhizal preparation such as root soaking, drip irrigation and fertilization on the growth and development of hazelnuts has been studied. The results of the research have revealed that the diameter of the root neck increased by 10.2 %, the number of main roots increased by 12.2 % and the length of the root system increased by 13.9 %. There was also an increase in the total number of leaves by 14.0 %, the length of annual growth – by 14.4 % and the height of seedlings – by 12.9 %. Root fertilization with 2-5 % solutions of the drug provided an increase in yield levels of hazelnuts to 21.7-22.4 c/ha with a yield increase of 10.2-13.7 %. Important indicators for nut plants are the chemical composition of the fruit and their tasting evaluation. Root feeding with 2-5 % solution of the drug did not increase their fat content by 1.5-2.7 %, and also led to an increase in kernel yield by 6.0-6.9 %. Tasting evaluation of fruits increased by 0.3-0.4 points. Mycological analysis of 150 soil samples of hazelnut rhizosphere and virgin land soil was performed. 475 isolates of micromycetes belonging to 124 species of microscopic fungi were isolated. 48 species of microscopic fungi of different taxonomic groups, which were most often found in the studied soils, are presented. The mycoflora of the rhizosphere of mycorrhizal and non-mycorrhizal hazelnuts was found to differ sharply in species composition. Indices of species diversity of micromycetes indicate that the most diverse species composition of mycobiota is characteristic of the rhizosphere of mycorrhizal hazelnuts. A characteristic feature of the micromycetic composition of the rhizosphere of mycorrhizal hazelnuts is a decrease in the number and species diversity of pathogens. The capacity of the hazelnut garden ecosystem, the ability to create living conditions for populations of different species, in particular soil micromycetes, is analyzed. The role of regenerative land use technology, which we successfully implement in Ukraine at the level of forests, small and medium farms, and holdings, has been determined as well. It can become the basis of the Food Sovereignty of our country and will allow Ukraine to develop according to its unique plan, i.e. to preserve a healthy environment for future generations and to provide the population with quality organic food.