Strategies and prospects in the recovery of contaminated soils by phytoremediation: an updated overview
Jhonatan da Silva¹, Gabriel Bachega Rosa², William Gustavo Sganzerla³, Jocleita Peruzzo Ferrareze², Flávio José Simioni¹ and Mari Lucia Campos¹

¹University of the State of Santa Catarina – Center of Agroveterinary Sciences (UDESC-CAV), Lages, SC, Brazil.
²Federal Institute of Education Science and Technology (IFSC), Lages, SC, Brazil.
³University of Campinas (UNICAMP), School of Food Engineering (FEA), Campinas, SP, Brazil.

Abstract
The contamination of soils and groundwater has attracted worldwide attention, since many contaminants are poorly biodegradable and can accumulate in living organisms, causing implications for plants, animals, and human health. The high cost of conventional remediation processes stimulates research for the development of innovative and more sustainable techniques. Likewise, phytoremediation is a cheap technology that uses plants to absorb, transform, and detoxify contaminants through in situ (phytoextraction, phytotransformation, and phytovolatilization) and ex situ mechanisms (phytostabilization and phytostimulation). Recently, phytoremediation has been adopted as a more profitable technique than physicochemical processes. Otherwise, the existence of variables, such as interactions between climate, soil, and plants, requires analysis methods for its implementation, which ensure the reduction of time and cost and improve its efficiency. Research on the application of different phytoremediation techniques is still in progress, and therefore, this study evaluated the main advantages of phytoremediation through a literature overview, comparing the most adequate remediation models in terms of economic, social, and environmental aspects.

Highlighted Conclusions
1. Phytoremediation consists of the use of plants and their associated microbes for environmental cleanup and recovery of contaminate soil.
2. Phytoremediation promotes social-economics benefits comparing to the conventional techniques, and ensures sustainability in environmental rehabilitation.

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Periods of interference of Alexandergrass on morphophysiological and productive characteristics of transgenic soybean
Leandro Galon, Alessandro Konzen, Hugo Von Linsingen Piazzetta, Germani Concenço, Maico André, Michelon Bagnara, Antonio Marcos Loureiro da Silva and Gismael Francisco Perin
Universidade Federal da Fronteira Sul, Erechim, RS, Brasil.

Abstract
Among the weed species infesting soybean, Alexandergrass (Urochloa plantaginea) is highlighted as one of the most competitive. The objective of this work was to determine the periods of interference of Alexandergrass, and is effects, on morphophysiology and yield components of soybean. Treatments were pooled into two groups: the group “convivence” comprised soybean growing among Alexandergrass for increasing periods: 0, 7, 14, 21, 28, 35 and 42 days after emergence (DAE), as well as along all the crop cycle. The “control” group comprised soybean free from competition for the same time lapses. Forty-two DAE, soybean morphophysiology was assessed. There was no effect of the time lpse of Alexandergrass “control” or “convivence” on soybean physiological performance. Plant height, stem diameter, plant dry mass, leaf area and grain yield components of soybean were, however, affected by Alexandergrass. The critical period of interference prevention comprises 26-41 DAE; the period prior to interference is 26 DAE; and the total period of interference prevention is 41 DAE.

Highlighted Conclusions
1. The yield components of soybean are negatively affected by Alexandergrass (Urochloa plantaginea) interference.
2. The control and coexistence periods of Alexandergrass did not change the physiological traits of soybean plants.
3. The critical periods of interference of Alexandergrass in competition with soybean were 26, 41 and 26 – 41 days, respectively for PAI, PTPI and PCPI.

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Identification and characterization of a soybean protein with adenylyl cyclase activity
Enetia Desberia Bobo, Katlego Selaelo Sehlabane, Tshegofatso Bridget Dikobe, Mutsa Monica Takundwa, David Tonderai Kawadza and Oziniel Ruzvidzo
North-West University, Mmabatho, North West, South Africa.

Abstract
Soybean [Glycine max (L.) Merrill] is a high value leguminous crop characterized by its excellent protein content and ability to improve soil quality through nitrogen fixation. Whereas this plant has attractive human and animal feed attributes in addition to its pharmaceutical and industrial uses, its growth and yield are severely affected by drought. Thus any research aimed at understanding the genome response of this plant to drought and other related environmental stress factors would be worthwhile. In plants, in general, second messengers have a key role in linking and coordinating environmental stimuli to cellular communication and responses. One group of such messengers are adenylyl cyclases (ACs) and their catalytic product 3′,5′-cyclic adenosine monophosphate (cAMP), involved in plant growth, cell division, reproduction, development and response to stress. However, while ACs have been reported in some plant species such as Arabidopsis and maize, their presence together with their cAMP-dependent systems in G. max have largely remained unavailable. Fortunately, a putative molecule, Glyma.07G251000 (accession number: XP_003529590), with a predicted function as an AC in G. max has at some point been reported. This molecule harbors a domain annotated AC catalytic center and therefore, was herein targeted for study. In order to characterize the Glyma.07G251000, we cloned and expressed it, followed by purification of the resultant recombinant protein (GmAC). When tested in vitro for AC activity, the GmAC protein showed a Mn²⁺-dependent activity that is positively enhanced by calcium. GmAC also complemented the AC-deficiency (cyaA mutation) of an SP850 mutant strain when expressed in Escherichia coli. When analysed by a web-based approach system, the GmAC protein was found to be co-expressed and co-regulated with various other proteins responsible for early plant development and stress response, strongly suggesting that it has a central role in these two key cellular processes. In addition, the GmAC protein conferred stress resistance to EXPRESS BL21 (DE3) pLysS DUOs cells when expressed in these host cells under salt (200 mM NaCl) and oxidative stress (0.2 mM H₂O₂). Conceivably, our findings showed that GmAC is an AC protein with a role in early plant development and stress response.

Highlighted Conclusions
1. GmAC is an adenylyl cyclase and the first ever such protein to be identified in soybean.
2. GmAC confers stress tolerance to Escherichia coli and is co-expressed/co-regulated with other soybean proteins responsible for early plant development and stress response.

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Quality of potato tubers according to the storage time
Helis Marina Salomão¹, Adriano Suchoronczek², Sidnei Osmar Jadoski³, Andréia Suchoronczek⁴, Katia Cristina Dalpiva Hartmann¹ and Janaina Cosmedamiana Metinoski Bueno^2
1Federal University of Technology, Pato Branco, PR, Brazil.
²Faculdade Mater Dei, Pato Branco, PR, Brasil.
³UNICENTRO, Cedeteg, PR, Brasil.
⁴Biologist, Master’s in Biology.

Abstract
The storage of potato tubers, even for short periods, is essential to stabilize the supply of the product on the market. However, it can affect several physicochemical and biochemical properties of the product, negatively impacting its quality. This study aimed to evaluate the effect of storage time on the physical and biochemical properties of two potato cultivars. Potato tubers of Ágata and Atlantic cultivars were stored at room temperature for 35 days. At 0, 7, 21, and 35 days of storage, analyses of pulp firmness, total soluble sugar contente (ºBrix), dry mass contente (MS), and tuber mass loss were performed. Also, the activity of the enzymes, superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), the hydrogen peroxide contente (H₂O₂), total soluble sugars (AT), and reducing sugars (AR) was monitored. The reduction in pulp firmness was linear for both cultivars and is related to the loss of tuber mass. The observed decrease in enzymatic activity is a negative factor as it reduces the ability to defend against oxidative stress. The reduction in the sugar content is interesting, as it maintains the quality of the tubers, especially for industrial processing.

Highlighted Conclusions
1. Potato tubers of cultivars Ágata and Atlantic stored under ambient conditions showed loss of fresh mass, reduced firmness, and increased soluble sugar content.
2. The cultivars Ágata and Atlantic can be stored for up to 35 days under ambient conditions without damaging their physicochemical quality significantly.

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Quality of bean seeds submitted to doses of desiccant herbicides at application periods
Camile Tais Castoldi, Leandro Galon, Lauri Lourenço Radünz, Josiel Ricardo Toni, Francisco Wilson Reichert Júnior, Mauricio Albertoni Scariot, Daniel de Oliveira e Souza and Gismael Francisco Perin
Universidade Federal da Fronteira Sul, Erechim, RS, Brasil.

Abstract
In view of the high nitrogen availability required by soybean, inoculation with nitrogen fixing bacteria, such as Bradyrhizobium japonicum, is an economically viable option. Moreover, the co-inoculation of these microorganisms with plant growth promoting bacteria, such as Azospirillum brasilense, presents high efficiency compared to the isolated use of these microorganisms. Given the above, the study aimed to determine the effects of applying a soil bio-activator associated with the inoculation of Bradyrhizobium japonicum and Azospirillum brasilense bacteria, on morphometric, physiological and productive variables of soybean crop. The experiment was conducted in the field, in a randomized block design with four replicates. The treatments were: control; seed inoculation with Bradyrhizobium japonicum; seed inoculation with Azospirillum brasilense; application of soil bio-activator; seed inoculation with B. japonicum and A. brasilense; seed inoculation with B. japonicum and application of soil bio-activator; seed inoculation with A. brasilense and application of soil bio-activator; and seed inoculation with B. japonicum and A. brasilense and application of soil bio-activator. In the morphometric analysis, plants inoculated with B. japonicum presented a greater number of nodules compared to the control. The co-inoculation associated with use of soil bio-activator increased the chlorophyll relative content, at the beginning of the cycle, in 6.37% in relation to the control. In gas exchange analysis, the isolated use of soil bio-activator obtained higher intrinsic water use efficiency (iWUE) in V₄. No increases in relation to the control were observed in the other variables evaluated, rejecting the hypothesis that co-inoculation associated with the use of soil bio-activator would promote increases in morphometric, physiological and productive characteristics of the soybean crop.

Highlighted Conclusions
1. Harvesting bean seeds with water contents of 30 and 42% and without the application of desiccants provided the best physical and sanitary quality of the seeds.
2. The desiccation in bean seeds using the recommended average dose increases electrical conductivity, reduces the hectoliter weight, and causes a loss in sanitary quality of the seeds.
3. It is feasible the application glufosinate-ammonium, saflufenacil, and diquat for anticipating harvest when 50% of the recommended average dose is used.

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Inoculation and co-inoculation of Bradyrhizobium japonicum and Azospirillum brasilense in soybean crop with the use of soil bio-activator
Victor Matheus Röske¹*, Vandeir Francisco Guimarães², Tauane Santos Brito², Alexandre Wegner Lerner², Roberto Cecatto Junior², André Silas Lima Silva² and Michele Aline Anklan²
¹C. Vale Cooperativa Agroindustrial, Palotina, Paraná, Brasil.
²Universidade Estadual do Oeste do Paraná, Marechal Candido Rondon, Paraná, Brasil.

Abstract
In view of the high nitrogen availability required by soybean, inoculation with nitrogen fixing bacteria, such as Bradyrhizobium japonicum, is an economically viable option. Moreover, the co-inoculation of these microorganisms with plant growth promoting bacteria, such as Azospirillum brasilense, presents high efficiency compared to the isolated use of these microorganisms. Given the above, the study aimed to determine the effects of applying a soil bio-activator associated with the inoculation of Bradyrhizobium japonicum and Azospirillum brasilense bacteria, on morphometric, physiological and productive variables of soybean crop. The experiment was conducted in the field, in a randomized block design with four replicates. The treatments were: control; seed inoculation with Bradyrhizobium japonicum; seed inoculation with Azospirillum brasilense; application of soil bio-activator; seed inoculation with B. japonicum and A. brasilense; seed inoculation with B. japonicum and application of soil bio-activator; seed inoculation with A. brasilense and application of soil bio-activator; and seed inoculation with B. japonicum and A. brasilense and application of soil bio-activator. In the morphometric analysis, plants inoculated with B. japonicum presented a greater number of nodules compared to the control. The co-inoculation associated with use of soil bio-activator increased the chlorophyll relative content, at the beginning of the cycle, in 6.37% in relation to the control. In gas exchange analysis, the isolated use of soil bio-activator obtained higher intrinsic water use efficiency (iWUE) in V₄. No increases in relation to the control were observed in the other variables evaluated, rejecting the hypothesis that co-inoculation associated with the use of soil bio-activator would promote increases in morphometric, physiological and productive characteristics of the soybean crop.

Highlighted Conclusions
1. The use of soil bio-activator associated with inoculation and coinoculation of Bradyrhizobium japonicum and Azospirillum brasilense does not provide increases in morphometric, physiological, and productive variables of the soybean crop.
2. Further studies are needed on the influence of soil bio-activators on the bacteria used in this study, enabling further verification of their applicability.

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In vitro rooting and acclimatization of ‘Marubakaido’ apple rootstock using indole-3-acetic acid from rhizobacteria
Juliana Aparecida Souza^1,3, Jean Carlos Bettoni¹, Murilo Dalla Costa², Tiago Celso Baldissera², João Frederico Mangrich dos Passos² and Silmar Primieri^3
1The New Zealand Institute for Plant and Food Research Limited, Palmerston North, Manawatu, New Zealand.
²Agricultural Research and Rural Extension of Santa Catarina, Santa Catarina, Brazil.
³Federal Institute of Education, Science and Technology of Santa Catarina, Lages, Santa Catarina, Brazil.

Abstract
Rooting tissue-cultured shoots and acclimatizing the rooted plantlets are key final steps in successful micropropagation protocols. We assessed the effect of indole-3-acetic acid (IAA) from synthetic and biological sources for effects on in vitro rhizogenesis and acclimatization stages in micropropagated ‘Marubakaido’ (Malus prunifolia) apple rootstock. Shoots of 3 cm length were transferred to rooting medium, composed of Murashige and Skoog (MS) medium supplemented with up to 2 mg L^-1 AIA and grown for 60 days in a controlled environment before assessment. Root initiation rate, callus formation, dry-root biomass, dry-shoot biomass, root length, root volume and diameter were evaluated. After the acclimatization stage, survival rate was determined. The root initiation rate of micropropagated ‘Marubakaido’ apple rootstock was higher in culture media supplemented with IAA, independent of the source. Callus formation at the base of shoots was higher according to increases of synthetic IAA concentration. In contrast, there was no callus formation from shoots cultured on MS medium supplemented with bacterial. ‘Marubakaido’ shoots rooted in vitro were successfully acclimatized. Survival of the plantlets during acclimatization was affected by both IAA concentration and source. Plant survival rate at the acclimatization stage decreased from 96% to 66% as the concentration of synthetic IAA increased. ‘Marubakaido’ inoculated in MS medium supplemented with bacterial IAA had thinner roots without callus formation, resulting in higher survival (up to 98 %) during acclimatization. Strain N39 was particularly effective in inducing in vitro rooting and acclimatization of ‘Marubakaido’ apple rootstock, resulting in high-quality rooted plantlets.

Highlighted Conclusion
1. Supplementation with indole-3-acetic acid (IAA) produced by rhizobacteria during in vitro rooting of apple rootstock increased survival rates at the acclimatization stage, and may be an efficient and sustainable alternative to synthetic IAA within micropropagation protocols.

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Heritability estimates and genetic distance of s₁ progenies from landrace maize populations
Mauricio Ferrari¹, Ivan Ricardo Carvalho²*, Alan Junior de Pelegrin¹, Vinícius Jardel Szareski¹, Maicon Nardino¹, Tiago Corazza da Rosa¹, Nathan Löbler dos Santos¹, Tamires da Silva Martins¹, Velci Queiróz de Souza³, Antonio Costa de Oliveira¹ and Luciano Carlos da Maia^1
1Universidade Federal de Pelotas, Capão do Leão, RS, Brasil.
²Universidade Regional do Noroeste do Estado do Rio Grande do Sul, Ijuí, RS, Brasil.
³Universidade Federal do Pampa, São Gabriel, RS, Brasil.

Abstract
The aim of study to estimate the broad sense heritability of S1 progenies and to quantify the genetic variance through multivariate analyzes of S1 progenies from landrace maize populations grown in the southern region of Rio Grande do Sul. The experimental design utilized was the augmented blocks, with ten S1 progenies groups (Amarelão, Argentino Branco, Argentino Amarelo, Branco Vermelho Indio, Branco Oito Carreiras, Caiano Rajado, Cateto Branco, Criolão Dente de Ouro and BRS Planalto), and two commercial controls, the simple cross hybrids Pioneer 30F53 and Agroeste 1590, allocated in four repetitions. The traits grain depth and spike insertion height express the largest estimates of broad sense heritability. The S₁ progeny Argentino Amarelo provides the largest estimates of broad sense heritability for the set of evaluated traits. The S₁ progenies Caiano Rajado, Criolão, Branco Roxo Índio, BRS Planalto, Dente de Ouro, Amarelão and Branco Oito Carreiras have similar heritability patterns for the studied traits, allowing to employ a similar selection strategy in the next generations. The S₁ progenies from landrace maize populations present genetic variability for the agronomic traits studied.

Highlighted Conclusions
1. The traits grain depth and spike insertion height express the largest estimates of broad sense heritability.
2. The S₁ progeny Argentino Amarelo provides the largest estimates of broad sense heritability for the set of evaluated traits.
3. The S₁ progenies Caiano Rajado, Criolão, Branco Roxo Índio, BRS Planalto, Dente de Ouro, Amarelão and Branco Oito Carreiras have similar heritability patterns for the studied traits, allowing to employ a similar selection strategy in the next generations.
4. The S₁ progenies from landrace maize populations present genetic variability for the agronomic traits studied.

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Time of potato plant harvest in soilless cultivation for screening phosphorus use efficient genotypes
Darlene Sausen¹, Ivan Ricardo Carvalho², Franciele Antônia Neis¹, Suzi Cerezer Uliana¹, Ritieli Baptista Mambrin³, Raíssa Schwalbert³, Miriam da Silva Tavares⁴ and Fernando Teixeira Nisoloso^3
1Federal University of Santa Maria, Santa Maria, RS, Brazil.
²Regional University of Northwest of Rio Grande do Sul, Ijuí, RS, Brazil.
³Centro De Ensino Superior Riograndense, Marau, RS, Brazil.
⁴Goias State University, Posse, GO, Brazil.

Abstract
The shorter the duration of the selection process of potato genotypes more efficient in the use of P, the lower the casting time of a new plant variety in the market and its growing field, where effectively verify the reduction of use of phosphate fertilizers, which may help to increase the sustainability of the potato production chain.  Therefore, the objective of this study was to determine the time of collection of potato plants grown in a closed system with sand as substrate and subjected to P restriction in nutrient solution aiming at the selection of more efficient genotypes on the P use. For this purpose, seven potato genotypes (SMIC 148-A, Dakota Rose, Sminia 793103-3, SMIB 106-7, 212-3 SMIF, SMIJ 319-1 and P 150), were grown in a closed soilless system with sand as substrate and nutrient solution containing two P levels (low: 2.32mg L^-1; and high: 23.2mg L^-1). The plants were harvested three sampling times (18, 39 and 62 days after transplanting (DAT)). The data showed that it is not advisable to use the plant growth assessment carried out until 18 DAT for screening of genotypes efficient in the use of phosphorus. However, at 39 DAT most potato genotypes already showed differences in all growth parameters evaluated between P levels, enabling the selection of the most efficient in P use and therefore not necessary cultivation by the end of the crop cycle.

Highlighted Conclusions
1. Selection of potato genotypes for P efficiency based on evaluations performed until 18 days after transplanting is not recommended.
2. At 39 days after transplanting, most potato genotypes already exhibit differences between the levels of P for all growth parameters evaluated, allowing the selection of the most efficient ones with respect to P, thus eliminating the need for cultivation until the end of the crop cycle.

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Inoculation methods of Azospirillum brasilense associated to the application of soil bioactivator in the maize crop
Alexandre Wegner Lerner¹, Vandeir Francisco Guimarães², Tauane Santos Brito²*, Victor Matheus Röske², Roberto Cecatto Junior², André Silas Lima Silva² and Julia Carolina Weizenmann^2
1Case IH, Sorocaba, São Paulo, Brasil.
²Universidade Estadual do Oeste do Paraná, Cidade, PR, Brasil.

Abstract
Seeking greater productivity, cost reduction and greater sustainability, plant growth promoting bacteria and soil bioactivators become a viable alternative for maize producers. The objective was to evaluate the effects of inoculation and foliar application of Azospirillum brasilense associated with the application of soil bioactivator on morphometric, physiological and productive characteristics of the maize crop.  Conducted in the field, the experimental design adopted was randomized blocks, with 4 repetitions and the following treatments: control; seed inoculation with Azospirillum brasilense (100 mL per 60,000 seeds); foliar spraying of A. brasilense at the V5 stage of maize; application of soil bioactivator; seed inoculation with A. brasilense + foliar spraying of A. brasilense at the V5 stage of maize; seed inoculation with A. brasilense + application of soil bioactivator; foliar spraying of A. brasilense at the V5 stage of maize + application of soil bioactivator; seed inoculation with A. brasilense + foliar spraying of A. brasilense at the V5 stage of maize + application of soil bioactivator. At the V8, VT and R3 stages morphometric and physiological evaluations were performed. At the VT stage, the inoculation methods of A. brasilense and the application of bioactivator were significant only for the dry mass of reproductive structures. In the R3 stage, plants inoculated by foliar spraying of A. brasilense together with the application of soil bioactivator showed statistically superior heights. The inoculation methods with A. brasilense and the application of soil bioactivator did not influence morphometric attributes throughout the development of maize, not influencing physiological variables. The production components and yield were not affected by the treatments applied.

Highlighted Conclusions
1. The methods of inoculation with Azospirillum brasilense and the application of soil bioactivator did not influence morphometric attributes throughout maize development, and did not influence physiological variables.
2. The yield and production components were not affected by inoculation with A. brasilense and application of soil bioactivator.

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