Root Dry Biomass Research Articles

Elicitor-induced phenolic acids accumulation in Salvia virgata Jacq. hairy root cultures

Phenolic acids, as the predominant secondary metabolites of Salvia plants, are largely used in pharmaceutical industries. The main aim of the study was to establish hairy root cultures of Salvia virgata Jacq. Also, the effects of methyl jasmonate (22.4 and 11.2 ppm), Ag+ ions (5 and 2.5 ppm) and yeast extract (100 and 50 ppm) were assessed on total phenol, total flavonoid, rosmarinic acid and salvianolic acid A contents in the hairy roots after 1, 3 and 5 days of exposure. Results showed that Agrobacterium rhizogenes strains (A4, ATCC15834, R1000, GM1534 and C58C1) had different potential to induce hairy roots on leaf explants. The transformed roots were molecularly confirmed using rolC gene, and the highest transformation frequency (56%) was obtained by ATCC15834 strain. Among the established hairy root lines, the highest amount of rosmarinic acid (0.45 ± 0.01 mg/g DW) and dry root biomass (2.29 ± 0.04 g) was obtained in AT3, the line which was induced by ATCC15834 strain. The maximum accumulation of total phenol (123.6 ± 0.93 mg GAE/g DW), total flavonoid (5.09 ± 0.07 mg QUE/g DW), rosmarinic acid (18.45 ± 0.8 mg/g DW) and salvianolic acid A (2.11 ± 0.04 mg/g DW) was observed in the hairy roots elicited with 22.4 ppm methyl jasmonate on day three after treatment. The results support that elicitation could be an effective procedure for the improvement of caffeic acid derivatives production in S. virgata hairy root cultures. The results of this study approved that the application of elicitors is an effective procedure for the stimulation of phenolic acids production in the hairy root cultures of Salvia virgata Jacq.

A Consortium of Rhizosphere-Competent Actinobacteria Exhibiting Multiple Plant Growth-Promoting Traits Improves the Growth of Avicennia marina in the United Arab Emirates

Gray mangrove (Avicennia marina) is the dominant vegetation distributed along the coast of the United Arab Emirates (UAE). Despite its performance as natural coastal guardians, very little is known about the reforestation projects to increase mangrove cover over the years in the UAE and in the Arabian Gulf. Plant growth-promoting actinobacteria (PGPA) were isolated from the mangrove rhizosphere sediments found in the UAE and were evaluated for their potential to produce plant growth regulators (PGRs) and to enhance mangrove growth under seawater irrigation conditions.In vitroscreening identified nine rhizosphere-competent actinobacterial isolates, in a naturally competitive environment, of whichStreptomyces coelicoflavus(Sc) showed a high phosphorus solubilizing activity. Moreover,Streptomyces polychromogenes(Sp),Streptomyces bacillaris(Sb), andStreptomyces ferrugineus(Sf) produced auxins, polyamines (PAs), and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, respectively. Although sediment inoculation with single isolates significantly improved the dry biomass of mangrove shoots (43.2–74.0%) and roots (40.8–75.9%), the consortium of isolates (Sc/Sp/Sb/Sf) caused a greater increase in the dry weight of shoots (82.1%) and roots (81.6%) compared with seawater-irrigated plants (control). In our greenhouse experiments, the levels of photosynthetic pigments,in plantaauxins, and PAs significantly increased in plant tissues inoculated withSc/Sp/Sb/Sf; whereas ACC contents were reduced. This was also evident as the maximum velocity of rubisco carboxylation (Vcmax) increased four-fold in plants treated with the mixture of isolates over control. To the best of our knowledge, this is the first study reporting culturable halotolerant, rhizosphere-competent PGPA inhabiting salty and arid ecosystems applied individually or in combination to promote mangrove growth under harsh conditions such as those found in the Arabian coastal areas.

Assessing the potential of biochar aged by humic substances to enhance plant growth and soil biological activity

BackgroundSoil carbon-rich organic amendments (biochar, humic substances) may improve the quality and fertility of arable soil. Their co-application can additively enhance the beneficial effect on soil. Hypothetically, the pre-treatment of biochar, by aging via soaking in a solution of commercially available humic substances, could result in synergism, which may exceed the benefit from simple co-application of both amendments to the soil. Therefore, the aim of this study was to investigate the impact of biochar, humic substances, the combination of both, and the impact of biochar aged by humic substances solution on soil microbial activities and plant growth in a short-term pot experiment with lettuce.ResultsThe aging of biochar decreased the C:N ratio as compared to non-activated biochar. The co-application of biochar and humic substances into the soil resulted in the highest microbial biomass carbon and respiration activity. The majority of enzyme activities (β-glucosidase, arylsulfatase, N-acetyl-β-d-glucosaminidase, phosphatase) were the highest in humic substances-amended soil. The application of humic substances and biochar with humic substances seemed to stimulate microbial growth and activity followed by the competition of microflora for nutrients with plants, whereas the aged biochar behaved differently. The plants treated by aged biochar achieved the highest values of dry aboveground and root biomass of all variants. However, the assumed rapid uptake of nutrients by plants resulted in lower nutrient availability for microflora, and a decline in microbial viability.ConclusionsBased on this study, the positive effect of co-applied humic substances and biochar on soil fertility, quality, and health can be concluded. The usability of biochar aging by humic solution requires further study.Graphic abstract

Efecto de la supresión de nutrientes sobre el crecimiento y desarrollo de plántulas de Ochroma pyramidale (Cav. ex Lam.) Urb.

Introduction: Ochroma pyramidale (Cav. ex Lam.) Urb. is a species with high potential for use in commercial reforestation. Knowledge of nutrient requirements in nursery increases the chances of success in the field by generating plants with adequate morphological and physiological characteristics. Objective: To identify the key nutrients for O. pyramidale growth in nursery and to characterize the associated visual symptoms of deficiency. Materials and methods: The design was completely randomized with 10 treatments: one treatment without fertilization, one treatment with complete fertilization (CF), and eight resulting from the CF treatment with suppression of N, P, K, Ca, Mg, S, B and cationic microelements (Mn, Fe, Cu and Zn). The effect of each treatment was determined by height, root collar diameter, aboveground dry biomass, root dry biomass, leaf area and relative growth rate. An analysis of variance and separation of means was performed using the Tukey's test (P < 0.05). Results and discussion: Nutrient suppression had significant effects (P < 0.05) on growth after six months in nursery. P was the most limiting element, followed by N. The other treatments showed no significant differences compared to the FC treatment. N suppression caused yellowing, and lack of P caused necrosis with subsequent death and detachment in leaves. B suppression showed no clear deficiency symptoms. Conclusion: O. pyramidale showed high nutrient uptake efficiency. Only N and P strongly limited its development, which represent the key nutrients for the species.

English

The objective of this study was to evaluate the residual effect of glyphosate and 2.4-D herbicides in the initial development of the soy crop in a Yellow Red Latosol. The experiment was conducted in randomized design, consisting of 4 different doses of herbicides (0, 1, 2 and 5 times the recommended dose of the glyphosate and 2.4-D mixture), applied at intervals of 0, 3, 7 and 10 days before sowing, with 4 repetitions on a soybean culture (Monsoy 8372rr cultivar) performed up to 28 days after sowing, at 7 days intervals. The variables analyzed were plant height, leaf area, phytotoxicity, aerial dry biomass, root dry biomass and chlorophylls a and b, the latter being performed from the second evaluation after sowing. For the conditions evaluated, plant height, leaf area and aerial dry biomass were lower in the plants that received the highest doses of the glyphosate mixture and 2.4-D. The higher doses of glyphosate and 2.4-D resulted in higher symptoms of phytotoxicity in transgenic soy plants. The periods of application of the glyphosate herbicide mixture plus 2.4-D closer to the date of sowing of the soybean were the ones that most harmed the development of the crop. Key words: Transgenic soy, phytotoxicity, initial development.

Effect of cadmium and ethylenediamine tetraacetic acid supplementation on cadmium accumulation by roots of Brassica species in Cd spiked soil.

Cadmium (Cd) metal extraction through efficient plant roots has attracted much attention as this methodology is environment-friendly and cost-effective. Brassica species are well known for their tolerance towards high Cd concentration in contaminated soils. The tolerance ability may vary among species; hence the assessment of this variability is mandatory for selecting Brassica species. For this purpose, a greenhouse pot experiment was carried out using three Brassica species (Brassica juncea L., Brassica campestris L., and Brassica napus L.). To evaluate the effect of chelating agent ethylenediamine tetraacetic acid (EDTA) on Cd uptake, EDTA (0, 1, and 2 g kg-1 soil) was supplemented along with Cd (0, 5, 10, 20, 40, and 80 mg kg-1 soil). Among different species, B. juncea possessed the highest root dry biomass and lowest root Cd concentration in untreated soil. Overall root dry biomass of all tested Brassica species reduced on increasing Cd and EDTA levels. The trend was appeared to be related to an increase in root Cd concentration on the supplementation of EDTA that formed a complex with the target metal contaminate and resulted in vacuolar sequestration. Roots of B. juncea showed maximum Cd accumulation and highest values at Cd and EDTA levels up to 20 mg kg-1 and 1 g kg-1 soil due to the combined effect of root biomass and Cd concentration in roots. Thus, present findings inferred that Cd and EDTA supplementation might prove as a feasible strategy to improve remediation of Cd-polluted soil using B. juncea as an efficient Cd accumulator.

Physiological, photochemical, and antioxidant responses of wild and cultivated Carthamus species exposed to nickel toxicity and evaluation of their usage potential in phytoremediation.

The impacts of Ni toxicity on growth behaviors, photochemical, and antioxidant enzymes activities of wild (Carthamus oxyacantha M. Bieb.) and cultivated (Carthamus tinctorius L.) safflower species were investigated in this study. Fourteen-day-old seedlings were treated with excessive Ni levels [control, 0.5, 0.75, and 1.0 mM NiCl2·6H2O] for 7 days. The results of chlorophyll a fluorescence indicated that toxic nickel exposure led to changes in specific, phenomenological energy fluxes and quantum yields in thylakoid membranes, and activities of donor and acceptor sides of photosystems. These changes resulted in a significant decrease in the photosynthetic activities by about 50% in both species, but these negative effects of Ni were not in a level to destroy the functionality of the photosystems. At the same time, toxic Ni affected membrane integrity and the amount of photosynthetic pigments in the antenna and active reaction centers. Additionally, the accumulation of Ni was higher in roots than in stem and leaves for both species. Depending on Ni accumulation, a significant reduction in dry biomass of root by approx. 64.8 and 45.7% and shoot by 41 and 24.7% were observed in wild and cultivated species, respectively. Two species could probably withstand deleterious Ni toxicity with better upregulating own protective defense systems such as antioxidant enzymes and phenolic compounds. Among of them, SOD and POD activities were increased with increasing Ni concentrations. The POD activities of both species were most prominent and consistently increased (approx. 2 folds in roots and 6 folds in leaves) in highly toxic Ni levels and may be protected them from damaging effect of H2O2. When all results are evaluated as a whole, Carthamus species produced similar responses to toxicity and also both species have bioconcentration (BCF) and bioaccumulation factor (BF) > 1 and translocation factor < 1 under Ni toxicity may be regarded a good indication of Ni tolerance. Furthermore, it is possible to use the Carthamus species as phytostabilizers of soils contaminated with nickel, because of their roots accumulating more nickel.

Remediation of soils co-contaminated with cadmium and dichlorodiphenyltrichloroethanes by king grass associated with Piriformospora indica: Insights into the regulation of root excretion and reshaping of rhizosphere microbial community structure

Cadmium (Cd) and dichlorodiphenyltrichloroethane (DDT) are frequently detected in agricultural soils, which poses a threat to public health. This study investigated the effects of inoculation of king grass with Piriformospora indica on the remediation of soils co-contaminated with Cd and DDTs. After treatment for 90 days, the dry shoot and root biomass of king grass inoculated with P. indica markedly increased by 13.0–15.8% and 24.1–46.4%, respectively, compared with those of uninoculated plants. Inoculation with P. indica also increased the uptake of Cd and DDTs by shoots and roots of king grass. The removal efficiency of Cd and DDTs from soils reached 4.88–17.4% and 48.4–51.0%, respectively, in the presence of king grass inoculated with P. indica. Under three Cd–DDTs contamination conditions, root secretion of organic acids, alcohol, and polyamines was distinctively stimulated by P. indica inoculation of king grass compared with planting king grass alone. After phytoremediation, changes in soil bacterial and fungal community composition occurred at different contamination levels. Overall, the results showed that king grass associated with P. indica can be adopted for phytoextraction of Cd and DDTs from moderately contaminated soils by regulating root excretion and reshaping rhizosphere microbial community structure.

Growth and root-knot nematode infection of tomato are influenced by mycorrhizal fungi and earthworms in an intercropping cultivation system with leeks

In a greenhouse experiment, we investigated the influence of leek (Allium porrum) intercropping, mycorrhizal fungi and earthworms on the root-knot nematode infection by Meloidogyne incognita (RKN) and the growth and development of tomato plants (Solanum lycopersicum). Tomato plants were grown in pots, intercropped with leeks or in monoculture, and earthworms and/or arbuscular mycorrhizal fungi (AMF) were introduced. The effects of these two treatments on root-knot nematode infection and tomato plant growth and development were assessed i) by counting the galls induced by the nematodes and the number of egg masses on their roots, and ii) by measuring their height increase, shoot and root dry biomasses and flowering time. Tomato growth was increased with leek compared to the monoculture (e.g., +82% shoot biomass), probably due to a lower plant-plant competition, although a facilitation effect cannot be excluded. The presence of leeks did not reduce the number of galls (per g of root). The presence of AMF (Rhizophagus irregularis) increased the overall infection of M. incognita (e.g., +36% egg masses) and induced more galls with multiple egg masses in the leek-tomato association (+71%) but did not increase plant biomass. On the other hand, it increased plant height in presence of the compost earthworms (Eisenia andrei) compared to earthworms alone with RKN (+2%). It also delayed the flowering compared to RKN alone (+7.6 days in average). Competition between the two tomato plants in monoculture probably strongly impacted plant growth, flowering time and thereby the RKN infection, but leek-tomato interactions should be further examined. The overall increased number of multiple egg masses per gall in presence of AMF is contrary to its protective effect reported in the litterature.

Effect of saline water and shading on dragon fruit (‘pitaya’) seedling growth

ABSTRACT ‘Pitaya’ (Hylocereus undatus) is a fruit-bearing, climbing cactus with great food potential for the semiarid region. This study aimed to evaluate the production of ‘pitaya’ seedlings irrigated with low and high salinity water and grown in different light intensities. The experiment was conducted in a completely randomized design, in a 2 × 2 factorial arrangement, with two electrical conductivities of irrigation water: S1 - 0.3 dS m-1 (low salinity) and S2 - 5.0 dS m-1 (moderate salinity) in two environments: A1 - black net with 50% shading, and A2 - full sun, with ten replicates. The variables evaluated were plant height, main cladode diameter, above-ground biomass, root biomass, total plant biomass, number of secondary cladodes, root length, and length of secondary cladodes. The 50% shading (black net) promoted higher plant height, number of secondary shoots, and root length of the ‘pitaya’ plants. The irrigation with moderate saline water (5.0 dS m-1) reduced the number of secondary cladodes, length of root, and length of secondary cladodes. The ‘pitaya’ seedlings grown under 50% shading (black net) showed greater root dry biomass when irrigated with low-salinity water. Greater values of diameter of the primary cladode, above-ground dry biomass, and total dry biomass were observed under full sunlight and elevated saline stress.

A manifold response of forage rape to combined heat wave and drought under current and elevated CO2

AbstractIntensity and frequency of heat waves (HW) accompanied by drought are increasing, however, still little is known about its effect on forage plants. A pot experiment was carried out in growth chambers in order to elucidate the multiple response of forage rape to combined HW and drought (HD) under current and elevated CO2 (HD + CO2). Forage rape was proved to be relatively HD‐resistant plant, with no significant and long‐term effects on shoot growth and photosynthetic performance, and effective stimulation of antioxidative system, especially in the case of HD + CO2 exposure. Activities of enzymes of ascorbate–glutathione cycle were further stimulated by elevated CO2 even after the termination of HD treatment. Nutritive value of forage rape was also positively affected, as was shown by elevated content of water‐soluble carbohydrates after exposure and starch after the period of recovery (up to 80% and 92%, respectively). Concentrations of most macro‐ and microelements were increased, and stabilized higher or equalized to control level after the period of recovery in a similar pattern for HD and HD + CO2 exposure. However, content of Ca was reduced and remained significantly lower (~20%). One of the most important negative and lagged HD effects was reduction of dry root biomass (~30%), most possibly induced by accumulation of non‐structural carbohydrates in shoot and was not mitigated by elevated CO2. To conclude, forage rape was proved to be a promising forage crop for the future climate with increased frequency of HWs; however, a special attention should be paid to the lagged effects, such as inhibition of root growth.

Root Application Efficacy of Plant Biostimulants in a Tunisian Portulaca Oleracea l. Cultivar Grown under Salt Stress

Plants biostimulants (PBs) have been shown to play multiple roles in plant growth and to improve crop tolerance to abiotic stresses such as salinity. The present investigation was undertaken for the first time to study the effect of PBs - a plant-derived protein hydrolysate (PH), a root activator (RA) and a root stimulator (RS) - on Portulaca oleracea L. tolerance to salt stress. For this purpose, a Tunisian P. oleracea cultivar was cultivated in pots under a greenhouse. Plants were treated with a factorial combination of three nutrient solutions (non-salt control, 50 and 100 mM NaCl) and three PBs were applied to roots. Growth and physiological parameters were then determined. Main results showed that salt stress decreased shoot and root dry biomass, chlorophyll and carotenoid contents while it increased the content in total soluble sugars, proline and relative water contents. However, root application of the three PBs induced some significant differences in the agronomical and physiological responses between PB treated and untreated plants when subjected to sodium chloride salinity from 50 and 100 mM NaCl. Overall, the present study proves that the root application of these PBs increases the performance of P. oleracea plants under salinity conditions. Therefore, PBs can be used to improve the salt-stress tolerance of vegetable crops by increasing their physiological responses to abiotic stress Portulaca oleracea L.; plant; salinity; biostimulant; growth; physiology

Green house evaluation of IAA and GA3 producing yeast isolates on growth tomato crop by root dip method

A green house experiment was conduct by use of IAA (MZL -8 and TCL -1) and GA3 (CAL – 1 and ACL- 3) producing yeast isolates on growth of tomato crop by root dip method with 8 treatments and 3 replication at Department of Agricultural Microbiology, GKVK, Bengaluru. The yeastisolate TCL -1 recorded maximum plant height, number of leaves per plant, number of branches per plant, root length, fresh shoot biomass, dry shoot biomass, fresh root biomass, dry root biomass, IAA and GA3 content, 44.73 cm, 80, 11.40, 14.70 cm, 24.00 g/plant, 11.75 g/plant, 7.98 g/plant, 3.91 g/plant, 1.205 μg/g of leaf and 0.550 μg/g of leaf respectively. The control (T1) recorded Lowest plant height, number of leaves per plant, number of branches per plant, root length, fresh shoot biomass, dry shoot biomass, fresh root biomass, dry root biomass, IAA and GA3 content, 22.20 cm, 55.70, 8.00,9.00 cm, 11.00 g/plant, 6.23 g/plant, 3.67 g/plant, 2.07 g/plant, 0.384 μg/g of leaf and 0.200 μg/g of leaf respectively at 50 DAT.

Evaluation of IAA and GA3 producing yeast isolates on growth of tomato crop by spraying under green house

A green house experiment was carried out at Department of Agricultural Microbiology, GKVK, Bengaluru by use of IAA (MZL -8 and TCL -1) and GA3 (CAL – 1 and ACL- 3) producing yeast isolates on growth of tomato crop by spraying method with 8 treatments and 3 replication. The highest plant height, number of leaves per plant, number of branches per plant, root length, fresh shoot biomass, dry shoot biomass, fresh root biomass, dry root biomass, IAA and GA3 content, 44.73 cm, 80, 11.40, 14.70 cm, 24.00 g/plant, 11.75 g/plant, 7.98 g/plant, 3.91 g/plant, 1.205 μg/g of leaf and 0.550 μg/g of leaf, respectively by the yeast isolate TCL -1.The least plant height, number of leaves per plant, number of branches per plant, root length, fresh shoot biomass, dry shoot biomass, fresh root biomass, dry root biomass, IAA and GA3 content, 22.20 cm, 55.70, 8.00,9.00 cm, 11.00 g/plant, 6.23 g/plant, 3.67 g/plant, 2.07 g/plant, 0.384 μg/g of leaf and 0.200 μg/g of leaf, respectively was recorded by control (T1) treatment at 50 DAT.

ESCALATION IN RICE (Oryza sativa L.) SEED STRENGTH AND SUCCESSIVE DEVELOPMENT THROUGH POTASSIUM HUMATE

Seed strength is an important agronomic traits and considered as an indicator of crop yield and economic value. Different concentrations of potassium humate i.e. 0, 250, 500, 750 and 100 mg per kilogram were applied on the seeds of Basmati rice and their influence was observed. After treatment with the potassium humate various vegetative (plant height; root, shoot length; fresh and dry biomass of root and shoot) and reproductive growth (number of tillers, flowers, grains, weight of 100 grains) parameters were recorded. It was observed that 500 mg/kg concentration of potassium humate has given potential results as compared to rest of the concentrations. It was also observed that an increment in the concentration from 500mg/kg has ceased a number of physiological functions of the rice plants under trial.

Assessing the Impact of Proline and Abscisic Acid on Salt Stress Grown BRASSICA NAPUS at Germination and Seedling Establishment

Abiotic stress such as Salinity causes serious challenge to plant growth and development, so it causes negative influence on plant's growth and yield. Different growth regulators and osmolytes kept attention as productive strategy and help the plant for enhancing stress tolerance and plant' growth and yield improved under stress condition. This project investigates the performance of Brassica napus at germination and seedling stage after application of abscisic acid and proline with combination of salt stress. Experiment was designed in completely randomized manner and petri plates were arranged in different sets with 10 seeds/each and applied with different concentrations of NaCl solutions. Proline (10 -20mM) and ABA (50-100mg/L) was pplied separately and in combination (proline 10 x ABA 50) and (proline 20 x 100) in these sets. After 8 days experiment was terminated and different parameters (germination percentage, seedling growth, shoot and root length, fresh and dry biomass, vigor index, Reletive water content, (RWC) Water content (WC), Root Shoot Ratio (RSR), Shoot Weight Ratio (SWR) and Root Weight Rratio (RWR). Salt stress exhibited significant decrease in shoot and root length, fresh and dry biomass, vigor index, RWC, different ratios (SWR, RWR) and different physiological indices while RSR exhibited increase in comparison to control in all sets. According to this research the application of proline and abscisic acid alone showed increased performance in all studied parameters. Interactions of proline and ABA did not support germination and seedling establishment process. This study concluded that application of proline (10mM) and ABA (100mg/L) improved germination and seedling establishment process very well as compared to other doses in Brasicca napus

Evaluation of Capsicum annum L. genotypes against salinity induced by NaCl

Soil salinity harmfully effect bell pepper production being salt sensitive crop. The aim of this study was to compare capsicum (bell-pepper) cultivars for their ability to tolerate salt stress. Electrical conductivity of different levels i.e., control (no sodium chloride), 1.5, 3.0, 4.5, and 6.0 dS m-1, was developed by using NaCl, after 30 days of seedling emergence of six cultivars (Yolo Wonder, California Wonder, Cop-amber Hybrid, F1 Pangs No. 206, Sweet Pepper F1, Kaka F1). These cultivars were evaluated based on morphological (shoot and root length, plant fresh and dry biomass), physiological (chlorophyll content) and biochemical attributes (nitrogen concentration, and protein contents). Minimum chlorophyll contents (SPAD units) in Kaka F1 (16.77 SPAD units) at 1.5 dSm-1. However, maximum value of chlorophyll contents was observed in Sweet Pepper F1 (49.23 SPAD units) at control followed by “Yolo Wonder” (41.53 SPAD units) at control. Maximum dry biomass was found in California Wonder (0.468 g) at 1.5 dSm-1, while minimum value of dry biomass (g) was observed in Kaka F1 (0.095 g) at 4.5 dSm-1. Six cultivars of capsicum were categorized into three groups. Salt tolerant cultivars included “California Wonder” followed by “Yolo Wonder”. “Kaka F1” was proved most salt sensitive and all others were moderately salt tolerant.

Effects of Nitrogen and Water Deficiency on Agronomic Properties, Root Characteristics and Expression of Related Genes in Soybean

Drought and insufficient nutrient supply are the main limiting factors for field crop production; therefore, the present study aimed to investigate the responses of four registered soybean varieties to limited nitrogen (N) supply in combination with drought stress. Plants were grown in tubes filled with silica sand, under open-air conditions. Water shortage was initiated at the three-leaf stage by providing 50% of water, and N deficiency was obtained by reducing the N content of the half-strength Hoagland solution by 50%. N deficiency did not influence the grain yield, while it significantly increased the root dry biomass in Boglár and Pannónia Kincse. Compared with nitrogen supply, the effects of the water shortage were dominant in root development. The expression levels of the investigated genes also showed genotypic variations. The expression of the Inducible nitrate reductase1 gene increased under N-deficient conditions in Boglár and decreased in Pannónia Kincse under drought conditions. The expression level of the aldehyde dehydrogenase gene and abscisic acid 8’-hydroxylase 3 increased under combined stress conditions. Summarising the agronomic and physiological characteristics, Boglár and Sinara were sensitive to drought, Bagera was sensitive to N deficiency but produced the highest yield under limited watering in each nitrogen treatment, while Pannónia Kincse was tolerant to nitrogen deficiency under well-watered conditions.

Mycorrhizal root colonization in maize fields is more affected by soil management and climate conditions than by plant genotype.

This work aims to characterize the arbuscular mycorrhizal association between maize genotypes and the effects of soil physical-chemical attributes on the symbiosis. A preliminary greenhouse assay evaluated five maize landraces and five conventional modern genotypes in non-sterile, low-P soil. Sixty days after sowing, we measured plant height, stem diameter, shoot and root dry biomass, root colonization structures, and shoot P concentration and total accumulation. In a second stage, a 2-year on-farm study evaluated how soil physical-chemical attributes in fields with three plant genotype groups affected the arbuscular mycorrhizal fungal symbiosis in a maize diversity microcenter in Southern Brazil. We collected soil and plant material in farms growing landrace, conventional modern genotypes, or genetically modified (GM) maize. There were five collection points at each group, and we measured mycorrhizal colonization, soil physicochemical attributes, and shoot phosphorus concentration. The greenhouse study showed that genotypes have different growth strategies for root production and shoot growth. No differences in mycorrhizal colonization rates occurred among landraces and modern maize genotypes in the low-P soil. The field study showed that soil and climate conditions had a more marked effect on mycorrhizal root colonization than plant genotype groups (landrace, conventional modern genotypes, or GM maize).

Effect of Potting Media on Growth and Quality parameters of &lt;i&gt;Juniperus polycarpos&lt;/I&gt; C. Koch Seedlings under Nursery Condition

A trial was conducted to study the effect of different potting media on the growth performance of Juniperus polycarpos under nursery condition. One year old seedlings of J. polycarpos raised in germination beds were transplanted in polybags filled with different combination of potting media with seven treatments comprising various combinations of soil, sand and farmyard manure and five replication in completely randomized design to study their effect on seedling growth and quality parameters. Significant differences were observed in shoot length, collar diameter, root length, number of roots, root and shoot biomass of J. polycarpos seedlings raised in different potting media. Maximum growth of various seedling parameters viz., shoot length (58.80cm), collar diameter (6.98mm), root length (55.24cm), number of roots (58.53) was recorded in treatment T 7 i. e. Soil + Sand + FYM (1:1:1) where as minimum growth of various seedling parameters was recorded in treatment T 1 i.e. nursery soil. Maximum fresh shoot biomass (32.35 g seedlings -1 ) was recorded in treatment T 4 , whereas fresh root biomass (9.08 g seedlings -1 ) and total fresh biomass (40.85g seedlings -1 ) was recorded in treatment T 7 . Maximum dry shoot biomass (17.33 g seedlings -1 ) was recorded in treatment T 5 whereas dry root biomass (4.60 g seedlings -1 ) and total dry biomass (21.86g seedlings -1 ) was recorded in treatment T 7 . Maximum value of various seedling quality parameters viz., root shoot ratio (0.27), volume index (2864.75) and Quality index (1.79) was also observed in seedling grown in treatment T 7 and whereas least value of sturdiness quotient (8.40) was observed in treatment T 1 (nursery soil) which is at par with treatment T 7 . The study recommended raising of seedlings of J. polycarpos in soil, sand and farm yard manure (1:1:1) for production of quality nursery stock.