Root Dry Matter Weight Research Articles

Assessing the impact of salinity stress on some morpho-physiological traits of two chickpea genotypes under hydroponic conditions

Evaluating the performance of crop species to salinity stress is considered an intricate task due to differences in performance, response and susceptibility at different phenological stages of chickpea crop. Assessment of the performance of chickpea genotypes in response to NaCl-induced salinity stress at the initial vegetative phase is of great importance to have a crystal idea about the threshold level of tolerance. An experiment was carried out under hydroponic conditions to evaluate the performance of two chickpea genotypes (ELMO and ORION), in response to different salinity levels (0, 25, 50 and 75 mM NaCl) as factorial arrangement under completely randomized design with three replications. The average of shoot and root dry matter weight was significantly higher for the ELMO genotype at the control treatment (1.143, 0.4133 g respectively), while it was significantly lower in the two genotypes ORION and ELMO at the highest salinity level (0.267 and 0.2700; 0.0433 and 0.0533 g respectively). The root to shoot ratio was significantly higher in both genotypes in the control and the lowest salt level (25 mM NaCl), without significant differences among them (47.98, 43.30, 37.10 and 36.25% respectively). The relative water content and stomatal conductance were significantly higher in the ORION genotype (88.01%; 335.40 mmol m-2 s-1) compared to ELMO (84.09%; 299.10 mmol m-2 s-1), and increasing salinity level caused a proportional decline in both traits, where they were significantly lower at the highest salt level (75Mm) (77.45%; 87.50 mmol m-2 s-1). Results indicate genotypic variability in response to NaCl-induced salinity stress under hydroponic conditions and the physiological traits are more expressive and reliable as selection criteria than morphological ones.

Polypeptide urea increases rice yield and nitrogen use efficiency through root growth improvement

ContextElucidating rice root growth and development characteristics is essential for improving nitrogen use efficiency (NUE) and grain yield (GY) of crops, particularly in light of innovations such as polyaspartic acid (PASP)–urea formulations. However, the effectiveness of PASP–urea on the morphological properties of rice roots is insufficiently explored. ObjectiveWe aimed to examine the effect of PASP–urea on root morphology properties, NUE, and grain yield of mid-season rice in southwest China. MethodsIn 2016 and 2017, a two-factor randomized block design experiment was conducted in Sichuan, China, during the rice planting season. Three N treatments: no N (control), conventional urea [CU], and polyaspartic acid–urea [PU] were administered to two rice varieties: Yixiangyou 2115 and Fyou 498. ResultsOur findings showed that grain yield and nitrogen recovery efficiency (NRE) of rice were closely related to the root surface area density (RSAD), root length density (RLD), and root volume density (RVD) of rice. Compared to the CU treatment, the PU application significantly boosted the root dry matter weight, RLD, RVD, and RSAD of both varieties by 12.00–16.87 %, 0.16–28.98 %, 12.41–37.06 %, and 8.14–33.66 % at the jointing, heading, and maturity stages, respectively. This contributed to a 0.37–15.63 % and 23.45–48.12 % increase in grain yield and NRE, respectively, in both years, and a 12.26–15.69 % increase in N partial productivity efficiency (NPPE) in 2017 by improving the effective panicle number per unit area, spikelets per panicle, and N uptake. ConclusionNRE and grain yield of rice were significantly increased by PU application by improving the rice root system. ImplicationsThe study findings offer insight on how PASP–urea application influences the root morphology of rice and its relationship with grain yield and NRE while offering novel strategies and concepts for optimizing N use in rice cultivation.

Irradiating roots of komatsuna (Brassica napus) with various light qualities affects growth and nutrient content in leaves, stems, and roots

Generally, plants grow without light exposure to their roots. Although the effects of light intensity and irradiation at different wavelengths on plant growth and composition in leaves and stems are becoming clearer, the effects of wavelength irradiation on roots remain largely unknown. Therefore, in this study, the effects of root irradiation with seven light wavelengths on the growth and ion and vitamin contents in hydroponically-grown komatsuna (Brassica napus) were investigated. Compared to the control treatment, the 940-nm treatment significantly increased root dry matter weight, whereas the other treatments exhibited no effect on leaves, stems, or roots. At specific irradiation wavelengths, the ion content of potassium, magnesium, calcium, boron, manganese, and zinc in the leaves and stems increased significantly compared to that in the control. The changes in ion contents in the leaves and stems were consistent with those in the roots, except for boron. Furthermore, regarding vitamins, the contents of nicotinic acid, pyridoxine, riboflavin, ascorbic acid, and phylloquinone in the leaves and stems increased significantly under irradiation compared with the control. Trends in the respective vitamin contents in leaves and stems did not coincide with those in roots. In some cases, irradiation significantly decreased the ion and vitamin contents compared to the control. These results indicate that a photoreceptor mechanism exists in roots, leaves, and stems and that irradiation of roots at different wavelengths affects the growth and nutrient content of komatsuna.

Effect of New Low-cost Polyglutamic Acid fertilizer on Cucumber Growth

Polyglutamic acid produced from the mother liquor of glutamic acid crystals was used as a test fertiliser to study its application in cucumber cultivation. The results showed that the application of polyglutamic acid fertiliser could increase cucumber plant height, plant pitch, number of leaves, root dry matter weight, promote cucumber growth, increase cucumber single melon weight and total yield, and at the same time, it could increase the content of Vc and soluble sugar in cucumber fruits and improve the quality of cucumber. Among them, the application of polyglutamic acid fertiliser increased the plant height of cucumber by 6.3%-39.5% during the flowering period, increased the plant height by 1.8%-12.1% during the melon blooming period, increased the root dry matter weight by 92.8%, increased the weight of single melon by 4.01%-37.12%, and increased the total output by 1.31%-12.87%; the application of two polyglutamic acid fertilisers increased the vitamin C of cucumber fruits by 14.36 % and 28.12 %, and the soluble sugar content by 16.91 % and 35.29 %.

Genome-wide identification and analysis of the CNGC gene family in upland cotton under multiple stress conditions

BackgroundThe cyclic nucleotide-gated channel (CNGC) gene family plays a significant role in the uptake of both essential and toxic cations, and has a role in enhancing tolerance to various forms of abiotic stresses as well as the modulation of the heavy metal toxicity to plant through the absorption of heavy metals.ResultsA complete genome-wide identification and functional characterization of the cotton CNGC genes was carried out, in which 55, 28, and 29 CNGC genes were identified in Gossypium hirsutum, G. raimondii, and G. arboreum, respectively. The protein encoded by the CNGC genes exhibited GRAVY value below zero, indicating their hydrophilic property. CNGC genes were unevenly distributed in 19 out of 26 chromosomes, in which the highest density were observed on Ah05, with 8 genes. High gene coverage was observed among the diploid cotton species, with CNGC genes mapped on all A chromosomes and on 11 out of 13 of D chromosomes. The majority of CNGC proteins were localized in the endoplasmic reticulum, nucleus, and plasma membrane. Gene expression analysis revealed the up-regulation of Gh_A01G0520 (CNGC4) and Gh_D13G1974 (CNGC5) across various forms of abiotic stresses. Moreover, down-regulation of Gh_A01G0520 (CNGC4) and Gh_D13G1974 (CNGC5) in CNGCs silenced plants caused the significantly reduced ability to tolerate drought and salt stresses. All CNGCs silenced plants were recorded to have significantly low content of antioxidants but relatively higher content of oxidant, including MDA and H2O2. Furthermore, SPAD, CMS (cell membrane stability), ELWL (excised leaf water loss), SDW (shoot dry matter weight), and RDW (root dry matter weight) were all lower in CNGCs silenced plants compared with the wild type plants.ConclusionSignificant reduction in antioxidant content and negative effects of physiological and morphological characters in CNGCs silenced plants has revealed the novel role of CNGC genes in enhancing cell integrity under abiotic stress conditions. These results provide vital information that will expand our understanding of the CNGC gene family in cotton and other plants, thus promoting the integration of these genes in the development of the environmental resilient plants.

The selection of intra-inter specific Cucurbita rootstocks for grafted melon seedlings

This study was conducted to select promising Turkish local Cucurbita rootstocks among intraspecific and interspecific hybrids for grafted melon seedling based on hybrid success rate, hypocotyl traits and graft compatibility. Rooting potentials, root system architecture and plant growth parameters of the rootstocks grafted with melon were also evaluated. Two lines of C. maxima (male parent) and eleven lines of C. moschata (female parent) at S5 generation were used. In addition, six winter squash lines were used as male parent and six pumpkin lines were used as female parent in intraspecific hybridization program. Intraspecific hybrid combinations had quite high number of seeds per fruit as compared to interspecific hybrid combinations. The highest number of seeds per fruit was obtained from HMO2 × OMO2 (359) and OMO5 × HMO8 (314) hybrid combinations. Hypocotyl lengths of all hybrid cucurbit rootstock combinations ranged from 32.96 mm (RS17) to 73.35 mm (RS8) and hypocotyl thicknesses ranged from 2.71 mm (RS2) to 3.55 mm (RS8). Graft success rates varied between 96.6 – 100% in winter squash and pumpkin intraspecific hybrids and between 87.1 – 100% in interspecific hybrids. Significant differences were seen in root architecture parameters (root length, root volume, mean root diameter, root surface area and root dry matter weight) of intraspecific and interspecies hybrid Cucurbita lines. The findings of the study indicated that the intraspecific and interspecific local cucurbit rootstock candidates developed within the rootstock breeding program showed promise as viable options for commercial use as rootstocks for grafted melon seedlings. Research about the effects of selected intraspecific and interspecific hybrid Cucurbita rootstock candidates on earliness, fruit quality and yield parameters of grafted melon will continue.
 Keywords: Cucurbita maxima; Cucurbita moschata; Rootstock breeding; Root system architecture; Melon

Selenium uptake, translocation, subcellular distribution and speciation in winter wheat in response to phosphorus application combined with three types of selenium fertilizer

BackgroundSelenium (Se) deficiency causes a series of health disorders in humans, and Se concentrations in the edible parts of crops can be improved by altering exogenous Se species. However, the uptake, transport, subcellular distribution and metabolism of selenite, selenate and SeMet (selenomethionine) under the influence of phosphorus (P) has not been well characterized.ResultsThe results showed that increasing the P application rate enhanced photosynthesis and then increased the dry matter weight of shoots with selenite and SeMet treatment, and an appropriate amount of P combined with selenite treatment increased the dry matter weight of roots by enhancing root growth. With selenite treatment, increasing the P application rate significantly decreased the concentration and accumulation of Se in roots and shoots. P1 decreased the Se migration coefficient, which could be attributed to the inhibited distribution of Se in the root cell wall, but increased distribution of Se in the root soluble fraction, as well as the promoted proportion of SeMet and MeSeCys (Se-methyl-selenocysteine) in roots. With selenate treatment, P0.1 and P1 significantly increased the Se concentration and distribution in shoots and the Se migration coefficient, which could be attributed to the enhanced proportion of Se (IV) in roots but decreased proportion of SeMet in roots. With SeMet treatment, increasing the P application rate significantly decreased the Se concentration in shoots and roots but increased the proportion of SeCys2 (selenocystine) in roots.ConclusionCompared with selenate or SeMet treatment, treatment with an appropriate amount of P combined with selenite could promote plant growth, reduce Se uptake, alter Se subcellular distribution and speciation, and affect Se bioavailability in wheat.

Low nitrogen supply inhibits root growth but prolongs lateral root lifespan in cotton

Primary and lateral roots are the main components of the root system in cotton, and their development and lifespan are critical for the uptake of water and nutrients (e.g., nitrogen). However, the responses of the daily growth dynamics and lifespan of cotton roots to low nitrogen are poorly understood. In this study of the whole growth period of cotton plants, two cotton cultivars (K836 and K837) were grown in pots in a greenhouse with 138 mg·kg-1 nitrogen fertilizer as the control (normal nitrogen) and no nitrogen fertilizer as the low nitrogen treatment. The growth of primary and lateral roots was investigated using the in situ root phenotyping platform RhizoPot. The root responses of both cultivars to low nitrogen were consistent except for the correlation between lateral root diameter and length on the 11th d after lateral root emergence. Root growth was significantly inhibited under low nitrogen, manifested as substantial reductions in root length, surface area, volume, and dry matter weight, which decreased by 23.91–26.88 %, 34.92–37.59 %, 32.71–37.94 %, and 17.92–21.62 %, respectively, in comparison with the control. Low nitrogen treatment reduced the diameter of primary roots by shortening the duration of its rapid accumulation, by 7.54–10.92 d. The smaller diameter of lateral roots was owing to low nitrogen treatment increasing the proportion of finer roots compared to the control. The effect of low nitrogen on the thickening rate of lateral roots showed stage-specific differences accompanied by elongation of lateral roots. In the early stage, the lateral root length of the low nitrogen treatment was longer than that of the control because lateral root elongation was higher, while the opposite pattern was observed in the later stage. Low nitrogen treatment significantly increased the lifespan of both the primary and secondary lateral roots, by 3.84–3.93 d and 4.95–5.46 d, respectively. Detailed studies revealed that low nitrogen treatment induced the greatest increase in the survival of lateral roots with larger diameters. Collectively, the results of this study indicate low nitrogen treatment not only reduced primary root thickness, but also resulted in shorter and thinner lateral roots with a longer lifespan relative to the normal nitrogen treatment.

Optimizing plastic mulching improves the growth and increases grain yield and water use efficiency of spring maize in dryland of the Loess Plateau in China

Transparent plastic film mulching (PFM) with flat cropping cultivation has been widely applied to grow maize (Zea mays L.) in dryland agricultural production areas of the Loess Plateau in China. However, with global warming-induced gradual increase in soil temperature, film-mulched spring maize experiences premature senescence and yield loss. In this study, a new form of mulching strategy involving dual mulching of transparent plastic film with whole maize stalks in a flat plot was established to improve growth and increase water use efficiency (WUE), precipitation use efficiency (PUE), and spring maize yield. The field experiment was conducted in 20 182 019, and 2020 on a conventional flat plot without mulching (CK), a flat plot with single transparent PFM, and a flat plot of transparent film mulching with whole maize stalks (PFM+ST) in the dryland of the Loess Plateau in China, to quantify the effects of different treatments on soil hydrothermal conditions, maize phenology, plant growth dynamics, WUE, PUE, and maize yield. Results demonstrated that soil water storage (SWS) at 0–100 cm soil layer in PFM and PFM+ST were significantly superior to those in CK, but SWS did not significantly differ between PFM and PFM+ST. Soil temperature under PFM+ST at 0–25 cm soil layer decreased by 1.2 ℃ compared with that under PFM during growth, especially in early growing seasons (20–60 days after sowing [DAS]). PFM+ST extended vegetative and reproductive growth periods by 1–2 and 6–7 days compared with those in PFM, respectively. In later growth period (80–120 DAS), PFM+ST increased the root dry matter weight, SPAD, and LAI and significantly increased the aboveground dry matter accumulation. PFM+ST significantly increased the 100-kernel dry weight, grain yield, WUE, and PUE. PFM+ST had 3-year average grain yields of 10.82% and 36.48% greater than PFM and CK, respectively. The corresponding WUE and in 0–200 cm soil layer improved by 12.55% and 39.84%, and PUE improved by 10.82% and 36.48%, respectively. With global warming, applying PFM+ST cultivation practice effectively extended growth period and increased mulching spring maize yield and WUE in the study site.

Seedling production of Coffea arabica from different cultivars in a modified hydroponic system and nursery using different containers

ABSTRACT The development of modified hydroponic cultivation has aroused interest and its use has enabled advantages in several crops, but studies for coffee are still scarce. Thus, the objective of this research was to evaluate seedling production of three Coffea arabica cultivars (Mundo Novo IAC-376-4, Catuaí IAC-62 Amarelo and MGS Paraíso 2), in a modified hydroponic system, and to compare it with the nursery production system, using plastic polyethylene tubettes and bags. Coffee seedlings in the development phase with cotyledon leaves, were cultivated in both cultivation systems. At 90 days after the implementation of the experiment, the seedlings were analyzed for growth (height, stem diameter, total number, leaf area, root area, root and shoot dry matter weight), and physiological characteristics (chlorophyll content and stomatal conductance). For the statistical analysis, a completely randomized design (CRD) was used in a factorial scheme 3 (cultivars) x 2 (containers) x 2 (cultivation systems), with four replications of ten plants per plot. The innovative production system of coffee seedlings in modified hydroponics, in combination with the use of polyethylene bags, provided greater growth of coffee seedlings with better physiological characteristics. Among the cultivars tested, MGS Paraíso 2 stood out with higher seedling growth (number of leaves, stem diameter and root and shoot dry matter weight).

Agronomic characteristics of maize after overliming

A supercalagem é uma prática econômica para se elevar a capacidade de troca de cátions (CTC) e saturação por bases do solo (V%), além de aumentar a produtividade de grãos e matéria seca. Objetivou-se com esse trabalho avaliar os efeitos da supercalagem nas características agronômicas do milho. O experimento foi realizado em delineamento de blocos casualizados (DBC), com quatro repetições, onde cinco tratamentos correspondem às dosagens (1,9; 2,5; 3,2; 3,8 e 4,4 toneladas ha-1) que simularam a elevação da saturação por bases para (60, 70, 80, 90 e 100%), respectivamente. Avaliou-se altura de plantas, altura de espigas, número de espigas por planta, número de espigas viáveis por planta, peso fresco da parte aérea, peso fresco das raízes, diâmetro de colmo, matéria seca da parte aérea, matéria seca das raízes, peso de grãos, peso de 100 grãos, peso seco da parte aérea e peso seco das raízes. Houve variação significativa para três das características avaliadas e nas condições estudadas, a supercalagem aumentou a matéria seca da parte aérea, matéria seca das raízes e peso seco da parte aérea, com destaque para as dosagens de 2,5 t ha-1 e 3,8 t ha-1 de calcário.

Bazı Sırık ve Bodur Fasulye Genotiplerinde Tuz Uygulamalarının Bitki Gelişimine Etkisi

Bu çalışmada, 20 adet farklı fasulye genotipinin (13 adet sırık, 7 adet bodur) 0 mM, 25 mM ve 50 mM tuz (NaCI) stresine gösterdikleri tepkileri incelenmiştir. Tuz uygulaması, 4 gün boyunca her gün aynı saatte sulama suyu ile birlikte verilmiştir. Tesadüf parselleri deneme desenine göre 3 tekerrürlü olarak hazırlanan çalışmada bitkiler, 2:1 oranında torf-perlit içeren saksılarda 23±2ºC sıcaklıktaki iklim odası koşullarında yetiştirilmişlerdir. Fasulye genotiplerinde tuzluluğa toleransın belirlenmesi için kök kuru madde, kök yaş ve kuru ağırlığı ile yeşil aksamda bazı besin elementi (Fosfor-P, Bakır-Cu, Çinko-Zn, Mangan-Mn, Demir-Fe ve Magnezyum-Mg) içerikleri incelenmiştir. Çalışmadan elde edilen veriler, tuz stresinin hem genotiplerde hem de uygulamalarda farklı tepkiler verdiğini ortaya koymuştur. 25 mM ve 50 mM tuz stresinde uygulamaların ortalamaları incelendiğinde, kontrol grubuna göre kök yaş ve kuru ağırlığı, kök kuru madde (%) ve Fe içeriğinin arttığı; Mn ve P içeriğinin ise azaldığı tespit edilmiştir. Tuz stresine maruz bırakılan genotipler arasında ikisi sırık (13 ve 19 no‘lu) ve ikisi bodur (8 ve 11 no‘lu) olmak üzere toplam 4 genotip tuza toleranslı; biri sırık (14 no‘lu) ve ikisi bodur (18 ve 20 no‘lu) olmak üzere toplam 3 genotip ise tuza hassas olarak değerlendirilmiştir.

Above- and Below-Ground Part Growth in Chewings and Strong Creeping Red Fescue Grown for Seed Resulting from Retardants and N Fertilization

Generative tillers are a source of assimilates necessary for the seed formation. However, their excessive elongation, especially under high doses of nitrogen, increases the susceptibility to lodging. The growth of generative shoots depends, among others on the root biomass affecting nutrient uptake, and on the ability to form rhizomes, as well as on the competitiveness of parallel developing vegetative tillers. Two-replicate field experiments were performed in Poland (53°09′ N, 17°35′ E), to determine the effect of plant growth regulators (PGRs) (single application of chloromequat chloride (CCC) at BBCH 30-31 or sequential treatment CCC at BBCH 30-31 + ethephon (ET) or CCC at BBCH 30-31 + trinexapac-ethyl (TE) at BBCH 37-39, and N fertilization (40 and 70 kg ha−1) on the length of generative tillers, the weight of generative and vegetative tillers, the canopy height, the weight of roots and rhizomes, and on N uptake in Festuca rubra L ssp. rubra (strong creeping red fescue) and F. r. L ssp. commutata (Chewings red fescue). Chewings red fescue turned to be more sensitive to the retardants. Generative tillers were shorter after single application of CCC as well as sequential treatment CCC + ET or TE. The tillers of strong creeping red fescue were shortened only after the application of CCC + TE. In every PGR treatments the canopy height at harvest was greater than in the control. Increasing the N rate from 40 to 70 kg ha−1 caused the reduction canopy height of strong creeping red fescue. Increased production of above-ground biomass, especially generative tillers, resulted in an increase in N accumulation in Chewings red fescue, as compared with strong creeping. Increasing the nitrogen rate from 40 to 70 kg ha−1, despite the reduction of root dry matter weight, stimulated generative tiller dry matter accumulation but it did not affect the biomass of vegetative tillers.

The effects of magnesium deficiency on sugar partitioning do not restrict the root growth in eucalyptus young plants

The symptoms of magnesium (Mg) deficiency have been well documented in crop plants. The relationship between sugar partitioning and Mg deficiency consists an important abiotic stress that may restrict root growth and limit the success of planting in the field. Despite of this, the primary physiological effects of low Mg availability remain largely unknown in eucalyptus. This paper aimed to investigate how the Mg deficiency affects biochemical aspects of sugar partitioning associated to dry matter accumulation in roots of young Eucalyptus urophylla plants. Experimental work was carried out at a greenhouse, arranged by completely randomized design, consisted by split plot 5x4, with five Mg concentrations (0, 25, 50, 75 and 100 % Mg levels of nutrient solution) and four times of evaluations – 15, 30, 50 and 120 days after planting (DAP). Soluble (SS) and reducing (RS) sugar contents, invertase and sucrose synthase activity and shoot and root dry matter weight were measured. Increased sugar concentrations, both SS and RS, were found in leaf tissues from 30 DAP. In root tissues, neither RS nor SS content showed differences between Mg deficiency and control. Significant differences were also not found neither in root dry matter accumulation, nor in shoot/root dry matter ratio. Mg deficiency did not affect sucrose cleaving in roots, which was predominantly catalyzed by acidic invertase, followed by susy and neutral invertase. We concluded that Eucalyptus urophylla is tolerant to Mg deficiency, since the sugar accumulation in leaf tissues is not enough to constrain dry matter accumulation in roots.

Infuences of Rice Husk Biochar (RHB) on Rice Growth Performance and Fertilizer Nitrogen Recovery up to Maximum Tillering Stage

<p>A pot study was carried out to investigate the effects of rice husk biochar addition on rice growth performance and fertilizer nitrogen recovery. The biochar effect was studied by using <sup>15</sup>N labelled fertilizer urea (10 atom% <sup>15</sup>N), as isotopic tracer, until maximum tillering stage (75 days after sowing). Rice husk biochar (RHB) was applied at rates of 0, 5, 10 and 20 Mg ha<sup>-1</sup> and laid in randomized complete block design with four replications. The result showed that biochar application significantly improved soil chemical properties (pH, total C, total N, and available P) compared to control treatment. Biochar addition increased number of tiller and root dry matter weight up to 4% and 35%, respectively, compared to un-amended pot. Likewise, application of biochar significantly increased N, P and K uptake by 3%, 19% and 33%, respectively, as compared to the nutrient uptake from the control treatment. Biochar treatment had no significant impact on fertilizer nitrogen recovery in aboveground biomass, in the range of 41% and 42%, in comparison to the control. However, nitrogen fertilizer recovery in soil significantly increased by 47% over the control at application rate of 20 Mg ha<sup>-1</sup> RHB. Increased fertilizer N recovery in soil possibly reduced N losses to the environment from volatilization and denitrification processes. Total <sup>15</sup>N fertilizer recovery also found increase at highest application of RHB biochar with an increment of 16%. In general, addition of biochar appeared to enhance crop growth performance but its effect on fertilizer N recovery in plant requires further study up to maturity of rice plant.</p>

Influence of selenium on root morphology and photosynthetic characteristics of winter wheat under cadmium stress

To explore the feasibility of reducing cadmium (Cd) concentrations and alleviating Cd toxicity via selenium (Se), this study investigated the effects of Se on the root morphology, photosynthetic parameters, and Se, and Cd concentrations in winter wheat under different Cd stress levels. Three Cd levels (0, 5 and 10 μM) and three Se levels (0, 1 and 5 μM) were applied in a hydroponics test. The results showed that increases in Cd stress significantly decreased the shoot and root dry matter weight, root length, root volume, root effective surface area, root total surface area, Se concentration, Se accumulation, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) and intercellular CO2 concentration (Ci). Increases in Cd stress significantly increased the Cd concentration and accumulation in shoots and roots, the root average diameter, and the stomatal limiting value (Ls). There were significant relationships between the root Cd concentrations and the root morphology parameters, shoot Cd concentrations and photosynthetic characteristics of winter wheat. The Se1 and Se5 treatments effectively increased the shoot dry matter weight, root length, root volume, root effective surface area and root total surface area and decreased the shoot Cd concentration, when Cd stress was at the medium level (Cd5). Only the Se1 treatment effectively increased the Gs, Tr and Ci under the Cd5 treatment. When Cd stress was at the high level (Cd10), the Se5 treatment had greater effects on root growth than the Se1 treatment, the Se levels had no pronounced effect on the shoot dry weight and Cd concentration in winter wheat. Meanwhile, the root Se concentration was closely related to each root morphology parameter. Cd stress inhibited the root growth and leaf photosynthesis of winter wheat, and a high enough Se supply reduced the Cd toxicity by enhancing the root growth of winter wheat.

Residual effect of organic fertilization on radish production

ABSTRACT this research aimed to evaluate the residual effect of doses of organic compost on the radish production, as well as its effect on soil chemical properties. experiments were conducted in two areas (“low” and “high” soil fertility). prior to this, these areas were first used to evaluate the influence of organic compost doses on endive production. after harvesting endive, radish seeds were sown into the same plots used for endive to evaluate the residual effect. the six treatments consisted of organic compost doses (0, 35, 70, 105, 140 and 175 t ha-1), evaluated in a complete block experimental design, with four replications. vegetative characteristics of radish plants (shoot, root and total fresh and dry matter weight, plant height and root diameter) and soil characteristics (macronutrient content, ph, h+al, organic matter, sum of bases, cation exchange capacity and base saturation) in two dates (11 days after the endive transplant and at the end of the radish cycle) were evaluated. no significant difference was observed for all doses of organic compost in the “low” soil fertility area, obtaining only non-commercial roots (average fresh weight of 5.01 g per root). in the “high” soil fertility area, the higher the organic compost doses, the higher the values of most vegetatitve characteristics of radish plants and the chemical properties of the soil in both dates. for root fresh weight, the values ranged from 4.63 to 9.15 g in the control without organic compost and in the highest dose, respectively. in “high” soil fertility area, only k content in soil has not remained high for all organic compost doses, and the values ranged from 2.8 and 4.5 mmolc dm-3, in control without organic compost and in the highest dose, respectively. the residual effect of organic compost was confirmed by the increasing on the radish production in initial “high”soil fertility area.

Case of carbonized rice in the composition of substrates for emergency and production of changes Acacia mangium Willd

The objective of this study was to evaluate the influence of carbonized rice husk on initial growth of Acacia mangium Willd seedlings. The experiment was carried out in the forest of the Federal University of Tocantins, Campus of Gurupi-TO, conducted in a completely randomized design, with five treatments T1: 0% Carbonized Rice Peel (CAC) + 100% Bioflora® Commercial Substrate, T2 : 25% CCS + 75% Commercial substrate; T3: 50% CAC + 50% Commercial substrate; T4: 75% CAC + 25% Commercial substrate; T5: 100% CAC + 0% Commercial substrate, with 4 replicates, each replicate with 18 seeds. The percentage of emergence (% E), shoot height (H), shoot diameter (DC), shoot dry matter weight (PMSPA), root dry weight (PMSR) and dry matter weight Total (PMST). The results indicated that the use of carbonized rice husk added in different proportions to commercial Bioflora ® substrate presented significant results in the parameters analyzed in Acacia mangium Willd seedlings. It is suggested that 25% CAC + 75% of Bioflora® commercial substrate is used in the alternative substrate formulation, considering that this treatment was the one that presented the best result in initial growth of Acacia mangium Willd seedlings.

Germinação in vitro e aclimatização de Hamatocactus setispinus

Seed propagation preserves the population genetic variability and helps selecting desirable features. This study evaluated the in vitro germination of Hamatocactus setispinus in six different culture media, 1- MS basal medium full strength; 2- half-strength MS basal medium; 3- 1.0 g L-1 of Peter’s CalMag® 15-05-15 formulation; 4- 0.5 g L-1 of Peter’s CalMag® 15-05-15 formulation; 5- MS basal medium supplemented with 10% coconut water and; 6- water and agar, with and without activated charcoal, and the speed of germination index, the mean germination time and the germination rate, root length, shoot length and the number of roots were evaluate. The seedlings with superior development obtained from in vitro germination were acclimatized in two substrates: Biomix® Floreira; Biomix® Floreira + sand. Seedling survival, shoot length, shoot diameter, root length, root number, shoot fresh matter weight, root fresh matter weight, shoot dry matter weight and root dry matter weight were evaluated. Peter’s 1.0 g L-1 medium without activated charcoal led to the best results for root length (11.36 mm) and root number (3.84). There was 100% of seedling survival. Acclimatization substrates did not differ among themselves and, therefore, they did not affect seedling growth.

English

Brazil is the largest producer of passion fruit, having the Northeast region as the main producing region, where orchards are formed almost exclusively from seed. This work aimed to evaluate the influence of different qualities of water and four levels of liquid manure applied to the soil in the absence and presence of mineral NPK fertiliser on the physiological attributes of yellow passion fruit seeds. The seeds were produced in a field experiment conducted in Jacana county, Rio Grande do Norte State-Brazil and seed quality was assessed in the Laboratory of Seed Analysis (LSA) from Agrarian Sciences Centre of Federal University of Paraiba in Areia County, Paraiba State, Brazil. In the laboratory, the experimental design was completely randomised with 16 treatments in four repetitions. The bovine biofertiliser inhibited the seed quality obtained for plants irrigated with non-saline water, but increased the viability of seeds in plants irrigated with saline water. Characteristics evaluated were the first count of normal seedlings, and speed index germination (SIG, dry matter weight of roots and shoot). The mineral fertilisation of the soil with NPK increased the seed viabilityin plants irrigated with both non-saline and saline waters. Key words: Passiflora edulis, salinity, organic fertilization, mineral fertilisation, seed production.