Communications in Plant Sciences, vol 8, p. Accepted, 2019 (2019004)
DOI: http://dx.doi.org/10.26814/cps2019004

The hidden half of Brazilian rice: putting roots on the table to better evidence the genetic variability available for breeding

Camila dos Santos Alvos, Henrique Pasquetti Carbonari, Cristiano Stülp, Victoria Freitas de Oliveira, Maicon Nardino, Viviane Kopp da Luz, Eduardo Venske, Ariano Martins de Magalhães Jr. and Antonio Costa de Oliveira*
*Correspondence to: antonio.oliveira@pq.cnpq.br

Abstract: Assessing genetic variability is essential to crop breeding and represents the basis for a successful crop selection, including rice (Oryza sativa L.). Root system shows a large range of roles that could be improved genetically. However, it has been virtually neglected by most breeders. The objective was to characterize a selected sample of the Brazilian rice germplasm, regarding on root growth and development, and to combine this data to shoot traits, aiming to depict the genetic variability within this germplasm. Sixteen Brazilian accessions of rice were analyzed with basis on root and shoot traits in two distinct experiments, mainly cultivars launched in the past four decades and presenting unique characteristics. The first experiment was carried out at hydroponic conditions to evaluate the performance of rice accessions during the seedling stage. The second was carried out in long PVC tubes to assay the rice accessions at the reproductive period. Traits were treated individually as well as analyzed jointly by different multivariate methods of genetic variability assessment. Most of the rice accessions showed similar results for a part of the studied traits, however differences were observed for some traits. The clustering methods agreed to group a large number of rice accessions into a single group, distinguishing only the best performing genotypes.

Highlighted Conclusions
1) The genetic variability within a group of Brazilian rice accessions is narrow when based on both root and shoot traits.
2) The accessions BRS Pampeira, at seedling period, and BRS Pampa, at reproductive stage, show prominent root performance, being promising parents for breeding programs focused on root system improvements.

Keywords: Genetic distance, Soil-free phenotyping, Trait-based breeding. (more…)

Communications in Plant Sciences, vol 8, p. 13-19, 2019 (2019003)
DOI: http://dx.doi.org/10.26814/cps2019003

Hydrogel effects in biochemical composition of soybean grains cultivated under water deficit in Brazilian Cerrado

Vitor L. Nascimento*, Wagner A. Rauber, Guilherme S. Silva, Susana C. Siebeneichler and Rodrigo R. Fidelis*
*Correspondence to: vitorlnasc@gmail.com, fidelisrr@uft.edu.br

Abstract: The aim of this work was to verify the influence of hydrogel application during plant development on the biochemical composition of soybean grains. The experiment was carried out in a randomized complete block design with four replicates, in a 5×2 factorial scheme, with five concentrations (0, 5, 10, 15 and 20 kg ha^-1) and two hydrogels sources (Hydroplan and Polim-Agri). The soybean cultivar used was MonSoy 8644.The biochemical contents evaluated were: oil, soluble carbohydrates, amino acids, starch, and proteins. The use of hydrogel was an alternative for grain production, since there no major changes in the contents of the biochemical compounds analyzed here.

Highlighted Conclusions
1) The use of hydrogel for the maintenance of soybean yield when cultivated in water deficit do not impaired the grain biochemical quality.
2) There is an interaction between carbohydrates and proteins levels, but not between oil and proteins in the treatment with hydrogel’s doses.

Keywords: Crop management, Food production, Glycine max, Grain composition, Short drought, Soil conditioner. (more…)

Communications in Plant Sciences, vol 8, p. 6-12, 2019 (2019002)
DOI: http://dx.doi.org/10.26814/cps2019002

Germination of quinoa seeds prevenient from agroecological and conventional crop systems

Cristiani Belmonte, Edmar Soares de Vasconcelos, Eloisa Lorenzetti, Alexandra da Silva Martinez, Renan Pan* and Tauane Santos Brito
*Correspondence to: renanpan45@hotmail.com

Abstract: The quinoa crops have been prominent at national and global level, however, there are still few materials adapted to the crop conditions in Brazil, especially in agroecological and conventional systems. So, this research was developed with the objective of evaluate the seeds quality of sixteen genotypes of quinoa cultivated in agroecological and conventional system, in the 2015/2016 season. The experimental essays were conducted at lab conditions. The agroecological and conventional seeds were placed in plastic boxes with germinating paper. Evaluations were carried at 5 and 8 days after implemented the germination test, being quantified normal seedlings, abnormal seedlings and parallelly seeds impurities. It was verified that exists a difference in the genotype’s germination as well as the number of abnormal seedlings obtained for each of them. The genotype Q13-21 showed better quality of seeds when cultivated in agroecological and conventional system.

Highlighted Conclusion
The quinoa genotypes “Q-seleção”, Q13-01, Q13-04, Q13-10, Q13-17, Q13-18, Q13-20, Q13-23, Q13-24, Q13-31 and Q2014 can show more than 80% of seed germination when cropped in conventional system, which was not observed when the seeds are produced under agroecological system.

Keywords: Chenopodium quinoa, Impurities, Organic, Seedlings. (more…)

Communications in Plant Sciences, vol 8, p. 1-5, 2019 (2019001)
DOI: http://dx.doi.org/10.26814/cps2019001

Comparison between extraction methods of photosynthetic pigments in Acacia mangium

Susana Cristine Siebeneichler, Jacqueline Silva Barbosa, Antônio Marcos Milhomem Cruz, Marilene Alves Dias Ramos, Hallefy Elias Fernandes and Vitor L. Nascimento^*
*Correspondence to: vitorlnasc@gmail.com

Abstract: The aim of this work was to determine a simple and rapid protocol for the extraction of photosynthetic pigments (chlorophylls and carotenoids) from Acacia mangium (Willd.), a pioneer species with rapid growth and that has been used in commercial forests in northern Brazil. The experiment consisted of 4×5 factorial, 4 solvents (ethanol, dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), and 80% acetone) and 5 extraction times (24, 48, 72, 96, and 120 hours). The equations used for calculations varied according to the solvent used. For a quantification of the photosynthetic pigment contents of A. mangium it is recommended to use 80% acetone with 84 hours of extraction since this solvent allows the efficient extraction of both chlorophylls and carotenoids with a single protocol.

Highlighted Conclusion
Determination of the Acacia leaves pigments (chlorophylls and carotenoids) it is possible with a single protocol in 84 hours, using an extraction with 80% acetone.

Keywords: Acacia, Carotenoids, Chlorophylls, Extraction time, Solvents. (more…)

Communications in Plant Sciences, vol 8, p. 112-115, 2018 (2018015)

DOI: http://dx.doi.org/10.26814/cps2018015

Authors: Gilberto Coutinho Machado Filho, Marcelo Almeida Mota, André Buarque Montelo, David Ingsson Oliveira Andrade de Farias, Ildon Rodrigues do Nascimento, and Manoel Mota dos Santos

Abstract: Weed chemical control in cassava crop is an alternative that contributes to increase productivity and costs reduction. However, there are few registered products, becoming a trouble for this crop exploration. Therefore, the present research had the objective evaluate selectivity of post-emergent herbicides applied in cassava in two plant development stages. The experiment was carried out in greenhouse at Federal University of Tocantins – UFT, Campus Gurupi, TO Brazil. The experiment design was completely randomized, arranged in factorial 6×2, combination of 5 herbicide molecules with different mechanisms of action (mesotrione, carfentrazone-ethyl, Chlorimuron-ethyl, nicosulfuron and imazethapyr) and a control with no application, applied in two stages, 30 and 45 days after plant emergence, with four replications. The results were submitted to analysis of variance by F test, and means were statistically analyzed by LSD test, at 5% probability. Mesotrione, and chlorimuron herbicides were not toxic for the crop, promoting results similar to those observed for control. Differences in tolerance level of herbicides studied was founded between application stages.

Highlighted Conclusions
1) The herbicides mesotrione, chlorimuron and carfentrazone-ethyl applied in post-emergence are highly selective to cassava.
2) The herbicides nicosulfuron and imazethapyr show differences in the level of toxicity to cassava, depending on the growth stage, being less selective at 30 days after emergence.

Keywords: Chemical control, Manihot esculenta, Weed control. (more…)

Communications in Plant Sciences, vol 8, p. 100-111, 2018 (2018014)

DOI: http://dx.doi.org/10.26814/cps2018014

Authors: Gabriela de Magalhães da Fonseca, Viviane Kopp da Luz, Maicon Nardino, Victoria Freitas de Oliveira, Juliana de Magalhães Bandeira, Ariano Martins de Magalhães Júnior, Luciano Carlos da Maia and Antonio Costa de Oliveira

Abstract: The use of nutrient solution combined with different herbicide concentrations allows the evaluation and discrimination of tolerant and non-tolerant genotypes to imidazolinone herbicides. The objectives of this research were to identify possible morphological characteristics to be used as markers of resistance to imidazolinones, as well as the identification of herbicide doses and evaluation time to discriminate sensitive and tolerant genotypes of rice under hydroponic systems. Six rice genotypes four characterized as sensitive, BRS Querência, BRS Border, BRS Atalanta and BRS Pampa and two as tolerant, BRS Sinuelo CL and PUITA INTA CL to imidazolinones were tested in a hydroponic system. Four doses of herbicide were tested, which were evaluated at 7, 14, 21 and 28 days after transplantation. The IFL was the most responsive variable and can be used as morphological marker in experiments for selecting rice genotypes tolerant to imidazolinones. The best time to discriminate genotypes is the 7th day of development. The concentration of herbicide that enables better discrimination between tolerant and sensitive genotypes is 25 µg L^-1, according to the methods described in this bioassay.

Highlighted Conclusion
The insertion of the first leaf can be used as morphological marker for selecting rice genotypes tolerant to imidazolinones at 7^th day of development.

Keywords: Oryza sativa L., Morphological marker, Sensitivity, Tolerance. (more…)

Communications in Plant Sciences, vol 8, p. 90-99, 2018 (2018013)

DOI: http://dx.doi.org/10.26814/cps2018013

Authors: Gabriela de Magalhães da Fonseca, Viviane Kopp da Luz, Maicon Nardino, Victoria Freitas de Oliveira, Marina de Magalhães da Fonseca, Camila Bedin Scalco, Juliana de Magalhães Bandeira, Rosa Maria Vargas Castilhos, Ariano Martins de Magalhães Júnior, Luciano Carlos da Maia and Antonio Costa de Oliveira

Abstract: Soils with high salt concentrations (NaCl) may affect plant development and nutrient uptake in rice. The objective of this experiment was to evaluate the response of rice cultivars released by Embrapa Clima Temperado to salt stress at the germination and seedling stages. Four NaCl concentrations (0, 40, 80 and 120 mM) and a random factorial design 4×6 (dose × genotype), the cultivars belonging to the Embrapa germplasm collection were evaluated, BRS Bojuru (the only tolerant variety), BRS Pampa, BRS 7 Taim, BRS Querência, BRS Atalanta and BRS Sinuelo CL, with three replicates. After 14 days, the levels of Na, K, Ca and Mg absorbed by the plant shoots and roots were determined. NaCl was not significantly present in the germination stage. In the first germination count, BRS Bojuru and BRS 7 Taim decreased the germination with the increase in salt. The length of the first leaf in the 40 mM dose at 14 days of development (vegetative stage) is indicated as morphological marker for discriminating sensitive and tolerant genotypes to salinity in hydroponic system. The cultivar BRS Pampa showed higher ability of leaf Ca and Mg translocation under salt stress conditions.

Highlighted Conclusions
1) The genotypes have contrasting responses in relation to the increase of NaCl doses, due to the interaction G x D for all evaluated variables.
2) The length of the first leaf in the 40 mM dose at 14 days of development (vegetative stage) is indicated as morphological marker for discriminating sensitive and tolerant genotypes to salinity in hydroponic system.

Keywords: Oryza sativa L., Salinity, Abiotic stress, Morphological marker, Germination. (more…)

Communications in Plant Sciences, vol 8, p. 82-89, 2018 (2018012)

DOI: http://dx.doi.org/10.26814/cps2018012

Authors: Tauane Santos Brito, Renan Pan, Elisiane Inês Dall’Oglio Chaves, and Vandeir Francisco Guimarães

Abstract: The objective of the present research was to evaluate the initial development of maize (Zea mays) inoculated with plant growth-promoting diazotrophic bacteria Azospirillum brasilense, Burkholderia ambifaria and Herbaspirillum seropedicae in vitro and in protected culture. The experiment in protected culture consisted in the comparison of four methods of nitrogen fertilizations in maize crop (absence, broadcast, placement, broadcast and placement) associated or not to inoculation with growth-promoting bacteria. Morphological parameters, foliar nitrogen content and bacterial population were evaluated at 30 and 45 days after sowing.  The in vitro essay consisted in the cultivation of inoculated plants in culture medium, with and without nitrogen and then, at seven days after seeding, evaluated morphological parameters, foliar nitrogen content and bacterial population. A. brasilense was more responsive to placement fertilization, while H. seropedicae for the association between placement and broadcast fertilization, or else the absence of fertilization. Yet, B. ambifaria was responsible to the absence of fertilization. Bacterial populations in protected culture varied according to the fertilization used and the period of collection. In vitro, the bacterial population was higher epiphytically.

Highlighted Conclusions
1) A. brasilense is more responsive to placement fertilization, and B. ambifaria to the absence of fertilization. H. seropedicae is more responsive the association between placement and broadcast fertilization, or else the absence of fertilization.
2) Bacterial populations vary according to the fertilization and the period of collection in protected culture, and they are higher epiphytically in vitro.

Keywords: Zea mays, Azospirillum brasilense, Burkholderia ambifaria, Herbaspirillum seropedicae, Diazotrophic bacteria. (more…)

Communications in Plant Sciences, vol 8, p. 75-81, 2018 (2018011)

DOI: http://dx.doi.org/10.26814/cps2018011

Authors: Mayeve Didomenico Melo, William Gustavo Sganzerla, Guilherme Cruz Duarte, Jocleita Peruzzo Ferrareze, Ana Paula de Lima Veeck, and Paula Iaschitzki Ferreira

Abstract: The growing concern about food safety makes necessary to search for alternative methods of food conservation. The objective of this work was to evaluate postharvest conservation of kale leaf using aqueous vegetal extracts. The experimental design was completely randomized, with the concentrations of 5, 10, 15, 20 and 25% of Rosmarinus officinalis, Allium sativum, Capsicum baccatum, Cymbopogon citratus and the control treatment using deionized water. The extracts were sprayed on kale leaves with manual spray over the entire adaxial and abaxial epidermis. The evaluated parameters were chlorophyll a and b, weight loss, total phenolics compounds, antioxidant activity and a visual analysis. The leaves remained at ambient temperature for six days. The results indicate that there was no significant conservation in the content of chlorophyll a, b and visual analysis when compared to the control, and the extracts did not have influence in the weight loss. There was an increase of total phenolic content and antioxidant activity with rosemary, lemongrass and pepper extracts, the garlic extract reduced the concentration of these bioactive compounds when compared to the control. In general, the application of the vegetal extracts did not influence in the postharvest conservation of kale leaves.

Highlighted Conclusion
The application of aqueous extracts in general does not influence positively postharvest conservation of kale leaves.

Keywords: Aqueous vegetal extracts, Postharvest, Storage, Kale. (more…)

Communications in Plant Sciences, vol 8, p. 69-74, 2018 (2018010)

DOI: http://dx.doi.org/10.26814/cps2018010

Authors: Ana Kelly Chornobay, Luiz Antonio Odenath Penha, and Renato Yagi

Abstract: In soybean production in Brazil, the ends often justify the means. The high marketing prices of grains have motivated producers to adopt new techniques for cultivation of the legume in an empirical way or without adequate scientific support. Thus, we hypothesized that soybean cross-sowing in equal populations or twice (as used in conventional sowing in parallel rows) may increase soybean yield and decrease weed infestation in crops. In this study, we aimed to evaluate the spatial arrangements of plants associated with the presence or absence of chemical treatment for weed control in the soybean crop. A randomized block design was used with five treatments (four replicates per treatment): 1) uncrossed with the recommended plant population; 2) crossed with the recommended plant population; 3) crossed with double the plant population; 4) crossed with the same plant population and without herbicide; and 5) crossed with double the plant population and without herbicide. Soybeans cross-sowed with the recommended plant population had the same growth as uncrossed soybeans in terms of height and dry matter of shoot and roots, but had a higher leaf area index. Moreover, root nodulation increased in number with soybeans cross-sowed with the recommended plant population and in mass for soybeans cross-sowed with double the plant population, without differences in indirect measures of chlorophyll. Thus, our findings suggested that cross-sowing with the recommended plant population or double the recommended plant population did not aid in weed control and did not increase the yield of soybean grains.

Highlighted Conclusion
Soybean cross-sowing with the recommended or double the recommended plant population does not aid in weed control or increase soybean grain yields.

Keywords: Glycine max (L.) Merr., Spatial arrangement, Plasticity. (more…)