AUGUST 2017 | Australian Journal of Crop Science

AUGUST 2017 | 11(08)2017 | doi: 10.21475/ajcs.17.11.08

Cocoa farming patterns for sustainability of Indonesia Lore Lindu National Park (LLNP)

Muhardi* and Effendy

Department of Agriculture, Tadulako University, Palu Indonesia 94119

Department of Agriculture Economics, Tadulako University, Palu Indonesia 94119

Abstract

This research assesses the effects of different patterns of cocoa farming at the margin areas of Lore Lindu National Park (LLNP) forest by estimating species richness, density of vegetation, biomass potential, litter production, litter decomposition rates and farming income. Research was conducted in the LLNP, Central Sulawesi, Indonesia. Five patterns of cocoa farming systems were considered: cocoa farming + mixed wood trees (agroforestry complex), cocoa farming + fruit trees (agroforestry simple), cocoa farming + candlenut trees (agroforestry simple), cocoa farming + teak trees (agroforestry simple), and monoculture cocoa farming. Five sample plots were made in each cocoa-farming pattern, sized 20 x 20 m for tree vegetation sampling. Subplots of 10 x 10 m, 5 x 5 m, and 2 x 2 m were used to sample vegetation at earlier growth stages. The results showed that using a pattern of cocoa + mixed wood trees (agroforestry complex) produced the highest biomass. A pattern of cocoa + candlenut gave the highest average income per year, but the pattern of cocoa + mixed wood trees did differ significantly from that using candlenut. It is suggested that cocoa farming with mixed wood trees (agroforestry complex) along the perimeter of the LLNP forest will support the sustainability in biodiversity, water catchment areas and disaster control.

Pages 917-924 | Read More| doi: 10.21475/ajcs.17.11.08.pne34

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Micropropagation of Crambe Abyssinica Hochst. Ex R.E. Fr.

Elias Terra Werner*, Andreia Barcelos Passos Lima Gontijo, José Augusto Teixeira do Amaral, Jaquelini Luber, Edilson Romais Schmildt

Departamento de Biologia, Centro de Ciências Exatas, Naturais e da Saúde, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Caixa Postal 16, Alegre – ES – Brasil
Departamento de Ciências Agrárias e Biológicas, Centro Universitário Norte do Espírito Santo, Universidade Federal do Espírito Santo, São Mateus – ES – Brasil
Departamento de Produção Vegetal, Centro de Ciências Agrárias e Engenharias, Universidade Federal do Espírito Santo, Alegre – ES – Brasil
Programa de Pós-Graduação em Biodiversidade Tropical, Centro Universitário Norte do Espírito Santo, Universidade Federal do Espírito Santo, São Mateus – ES – Brasil

Abstract

Crambe abyssinica Hochst. Ex. R. E. Fr. is an oilseed species that produces non-edible oil, initially employed in Brazil as a culture for soil surface coverage and animal feed. However, with stimulation of the production and use of renewable energies, it arose as an interesting alternative for biodiesel production. The aim of this work was to describe a protocol for micropropagation of crambe, using apical segments as explants. Crambe seeds germinated in vitro in medium MS½ provided apical segments adequate to the micropropagation process. In the shoot induction phase, testing the interaction of the cytokinins 6-benzylaminopurine (BAP), kinetin (KIN) and thidiazuron (TDZ) as well as different concentrations thereof, the highest numbers of shoots per explant were obtained with 5 µM BAP at 30 days (9.26 shoots) and 15 µM BAP at 60 days (18.08 shoots) of in vitro culture. In the elongation with 1 µM gibberellic acid (GA₃), the mean length of the shoots turned from 3.61 cm to 5.03 cm after 30 days. The highest percentage of rooting was of 30% with 0.25 µM naphthalene-acetic acid (NAA). The results of this work revealed a satisfactory frequency of shoot regeneration from apical segments of crambe in media containing 5 µM BAP, and adequate elongation with 1 µM GA₃. Nevertheless, there is still need for efficient rooting and acclimatization for complete in vitro propagation of crambe.

Pages 925-931 | Read More| doi: 10.21475/ajcs.17.11.08.pne338

Participatory assessment of potato farming systems, production constraints and cultivar preferences in Uganda

Prossy Namugga*, Rob Melis, Julia Sibiya, Alex Barekye

African Centre for Crop Improvement, University of KwaZulu-Natal, School of Agricultural, Earth and Environmental Sciences, Private Bag X01, Scottsville 3209, Pietermaritzburg, South Africa

National Agricultural Research Organisation (NARO), Kachwekano Zonal Agricultural Research and Development Institute, P.O. Box 421 Kabale, Uganda

Abstract

Potato (Solanum tuberosum L.) is a major food and cash crop mainly grown by small-scale farmers in the highland regions of Uganda. Farmer practices and constraints in potato production and management differ from one area to another and so are desired attributes. A survey was conducted in eight major potato producing districts of Uganda. The study districts were from Central, Eastern and South Western regions of the country. The survey was carried out from May to August 2015. A semi-structured questionnaire was administered to 577 individual farmers. The results showed that potato is produced for both food and cash benefits in all the districts. Only 2% of the respondents from Eastern and South western Uganda obtained seed from research stations while all respondents from Central Uganda used farm saved seed. Major production challenges were pests and diseases. The major pests were aphids and cutworms while late blight and bacterial wilt were the prominent diseases. Across the three regions Rwangume and Victoria were the commonly grown cultivars while Cruza and Marierahinda were the most rejected varieties. These were rejected on account of being white skinned with low marketability and Cruza becomes marshy on cooking. High yield, resistance to late blight, early maturity and marketability were the most preferred attributes in new varieties. Late blight had been experienced by 98% of the farmers and 96% of these reported to have used fungicides to manage the disease.

Pages 932-940 | Read More| Supplementary Data| doi: 10.21475/ajcs.17.11.08.pne339

Wheat phenology and yield under drought: A review

Marcos Vinicius Mansano Sarto*, Jaqueline Rocha Wobeto Sarto, Leandro Rampim, Jean Sérgio Rosset, Doglas Bassegio, Poliana Ferreira da Costa, Adriano Mitio Inagaki

São Paulo State University (UNESP), Department of Crop Science, Botucatu, São Paulo, Brazil

State University of Midwest (UNICENTRO), Guarapuava, Paraná, Brazil

West Paraná State University (UNIOESTE), Marechal C. Rondon, Brazil

Abstract

The purpose of this review was to characterize the wheat crop phenology under drought conditions, at different stages of crop growth. Effects of drought on wheat plants are variable, and depend on the phenological stage of the plant as well as the duration, intensity and frequency of the drought. The crop evapotranspiration increases over the course of the phenological cycle, reaching a maximum in the growth stage (from the beginning of heading until the end of flowering), which is the most sensitive stage of the crop to drought. At ripening, the evapotranspiration decreases to save and allocate the energy to grain yield. The drought affects the plant density in the initial phase, tiller number per plant in the tillering phase, and plant height in the stretching phase, most severely. At the flowering stage, the processes related to fertilization and fixation of grain are most severely affected, i.e., the number of viable seeds per area decreases. In the grain formation stage, the ability of the source (leaf) to use and translocate the assimilates to the grain is most severely affected, thus affecting the grain weight.

Pages 941-946 | Read More| doi: 10.21475/ajcs.17.11.08.pne351

Spatial variability of the yield and physical properties of orange (Citros sinensis [L.] Osbeck cv. Monte Parnaso) fruits

Rafaela Fernandes Nicolau*, Erivelto Mercante, Marcio Furlan Maggi, Eduardo Godoy de Souza, Eloi Gasparin, Bruno Bonemberger da Silva

UNIOESTE - Universidade Estadual do Oeste do Paraná, Campus Cascavel, PR, Post-Graduate Program in Agricultural Engineering, Rua Universitária, 2069 – JD. Universitário, 85819-110, Paraná, Brazil

UFOPA - Universidade Federal do Oeste do Pará, Campus Santarém, PA, Institute of Biodiversity and Forests, Unidade Tapajós, Rua Vera Paz, s/n – Salé, 68035-110, Pará, Brazil

Abstract

Precision agriculture (PA) is used as a tool in the citrus industry and aims to increase production, reduce costs and search for answers to explain the spatial variability of yield. The aim of this study was to model the spatial variability of yield and physical properties of fruits of orange trees in relation to the geographic quadrant where the fruits are on the trees. The experiment was carried out in a 1 ha commercial orchard of orange trees cv. Monte Parnaso. A GPS receiver and a total station were used to georeference the experimental area and the position of each sampled tree in the area, as well as the location of the geographic quadrant where the fruits sampled were on the trees. Twelve fruits were collected from each of the 13 sampled trees, resulting 39 fruits per quadrant, totalling 156 fruits each crop-year (2011 and 2012). Yield was estimated after the harvest (kg.quadrant^-1). Physical analyses were performed for each fruit, measuring the following physical properties: equatorial diameter, total mass and juice yield. We conducted analysis of descriptive statistics and spatial variability in the data through techniques related to geostatistics. The results showed the highest spatial variability between the quarters for the juice yield and yield, and the verified juice yield was within the acceptable standard by regulatory bodies.

947-951 | Read More| doi: 10.21475/ajcs.17.11.08.pne426

Molecular identification and pathogenicity of Rhizoctonia spp. recovered from seed and soil samples of the main bean growing area of Argentina

Spedaletti Y, Mercado Cárdenas G, Taboada G, Aban C, Aparicio M, Rodriguero M, Vizgarra O, Sühring S, Galíndez G, Galván M*

Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). CCT-Salta. Av. Bolivia 5150 (4400) Salta, Argentina

Instituto Nacional de Tecnología Agropecuaria (INTA) EEA Salta, Ruta Nac. 68 Km 172 (4403) Cerrillos, Salta, Argentina

Laboratorio de Genética Evolutiva, Departamento de Ecología, Genética y Evolución, UBA, Argentina

Estación Experimental Agroindustrial Obispo Colombres (EEAOC), Tucumán, Argentina

Facultad de Ciencias Naturales, Universidad Nacional de Salta, Av. Bolivia 5150, Salta, Argentina

Abstract

The objective of this study was to perform the molecular and pathogenic characterization of Rhizoctonia solani in bean seed and soil samples from fields with root rot symptoms in northwestern Argentina. Fifty-two Rhizoctonia spp. isolates were collected in ten naturally infested bean fields and characterized by morphological traits, DNA sequencing, and pathogenicity. The mycelium color, the pattern of sclerotia formation, and the number of nuclei per hyphal cell were determined for each isolate. According to the variability in the rDNA-ITS region, isolates were identified as R. solani (85%), Waitea circinata var. zeae (Rhizoctonia zeae) (2%) and Rhizoctonia spp. (13%). Most isolates of R. solani (92%) were found to belong to the anastomosis group (AG) AG 4, including seven AG 4 HG-I and nine AG 4 HG-III isolates. AGs obtained from soil samples were more variable than those obtained from seed samples. Molecular identification of the isolates was in agreement with their morphological characterization. In addition, aggressiveness of the isolates towards bean seedlings was assessed in the greenhouse. Four virulence categories were defined according to the disease reaction on root and foliar tissues, which showed great variability in virulence among the isolates. Our results suggest that both seed and soil-borne inoculum may play a significant role in pathogen dispersal in the region. This is the first study on Rhizoctonia species and AGs in bean seed and soil in this region and it may contribute towards an efficient control strategy for bean diseases caused by Rhizoctonia species.

Pages 952-959 | Read More| Supplementary Data| doi: 10.21475/ajcs.17.11.08.pne432

Copper (Cu) stress affects carbon and antioxidant metabolism in Coffea arabica seedlings

Jacqueline Oliveira dos Santos*, Márcio Espinosa de Fária, Dayane Meireles da Silva, Helbert Rezende de Oliveira Silveira, Cleide Nascimento Campos, Jose Donizeti Alves

Fisiologia Vegetal, Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais, Brasil

Empresa de Pesquisa Agropecuária de Minas Gerais/ EPAMIG SUL, Campus UFLA, Lavras, Minas Gerais, Brasil

Abstract

Although copper is a micronutrient essential for the normal development of plants, both insufficient and supra optimal doses can disrupt the functioning of metabolism and the production of biomass. To study the biochemical and physiological impacts of deficiency and excess of copper in coffee, we treated 6-month-old seedlings of Coffea arabica L. Catuaí cultivar to three copper treatments: control (0.03 ppm), excess (0.12 ppm) and deficiency (0 ppm) for 60 days. The changes in levels of photosynthetic pigments, biomass allocation, carbohydrate partitioning, antioxidant system and proline levels were evaluated. Under deficiency and excess of copper coffee seedlings showed lower levels of chlorophyll, reduction on dry weight of shoot, lower sugar levels and higher content of hydrogen peroxide. We also observed increased levels of proline and enzymatic activity of the antioxidant system, providing conditions for the reduction of oxidative stress triggered by nutritional imbalance. In general, the results showed that coffee plants invest in antioxidant defense system as an alternative to maintain redox balance when exposed to deficiency or excess copper. However, it is not effective to prevent an increase in lipid peroxidation. Authors may indicate an optimum range for application of copper in coffee.

Pages 960-967 | Read More| doi: 10.21475/ajcs.17.11.08.pne445

Automated and estimation methods to count nodule number in common bean

Polianna Alves Silva Dias, Patrícia Guimarães Santos Melo, Helton Santos Pereira, Enderson Petrônio de Brito Ferreira*

Universidade Federal de Goiás, Rodovia GO-462, km 0, Campus Samambaia, Goiânia, GO, 74001-970, Brazil

Embrapa Arroz e Feijão, Rodovia GO-462, km 12, Santo Antônio de Goiás, GO, 75375-000, Brazil

Abstract

The nodulation on legume roots is an important trait to evaluate the symbiotic efficiency, but very laborious and time spending, what can limit the effectiveness of legume breeding programs. Based on the need to simplify the assessment of nodule number, this work aimed to evaluate the accuracy and time spent to assess nodule number in common bean using different methods of estimation and counting, compared to manual count (MC). Counts were performed manually (MC) and it was considered the standard method. The estimation methods consisted of two simple techniques with two sampling range: graph paper with sampling range from 10 to 20 nodules (GPR1) and graph paper with sampling range from 21 to 40 nodules (GPR2), Petri dish with sampling range from10 to 20 nodules (PDR1), Petri dish with sampling range from 21 to 40 nodules (PDR2). The counting was also performed using automated methods: the seeds counters Seedburo and Sanick. The time spent in each of the seven methods was recorded. Among the alternative methods, the automated counting methods stood out. The Seedburo 801 and Sanick ESC2011 counters showed high accuracy and reduced more than 50% of the time spent compared to MC. Among the estimation methods, GPR2 showed good accuracy with 10% reduction in time spent when compared to manual counting, being a good alternative when there are no automated counters.

Pages 968-973 | Read More| doi: 10.21475/ajcs.17.11.08.pne452

Assessment of Roundup Ready 2 (RR2) corn subjected to application of isolated and associated herbicides

Alfredo Junior Paiola Albrecht*, Leandro Paiola Albrecht, Fábio Henrique Krenchinski, Katle Samaya Wobeto, Mateus Dalpubel Mattiuzzi, Caroline Thaís Eckert, Caio Antonio Carbonari, Ricardo Victoria Filho

Federal University of Parana, Palotina Campus, Pioneer Street, 2153 - Garden Dallas, Palotina - PR, CEP: 85950-000, Brazil

State University of the Western of Paraná. University Street, 2069 – University Garden, Cascavel - PR, CEP: 85819-110, Brazil

State University of São Paulo “Júlio de Mesquita Filho”. Dr. José Barbosa de Barros Street, 1780, CEP: 18610-307, Brazil

University of São Paulo/ “Luiz de Queiroz” College of Agriculture. Padua Dias Avenue, 11 - Agronomy, Piracicaba - SP, CEP: 13418-900, Brazil

Abstract

One of the first transgenic traits that has been inserted into commercial crops and being widely used is tolerance to glyphosate herbicide. This technology has provided significant benefits and conveniences to farmers due to the efficacy of glyphosate. However, for a better weed control and prevention of weed resistant biotypes the use of two or more mechanisms is recommended practice. The combination of herbicides is the subject of several studies especially evaluating weed control, aside which the selectivity of the culture is equally important. In this context, this study aimed to evaluate the responses of transgenic corn (RR2) subjected to the application of different herbicides. For this purpose, an experiment was conducted with eight treatments using glyphosate, atrazine and nicosulfuron, sole or in combination along with a control treatment (without herbicide). The experiment was performed twice (first in Piracicaba - SP then Palotina – PR) in greenhouse with different corn hybrids. Several variables related to the performance were analysed such as height measurements, stem diameter, chlorophyll index, fresh and dry shoot, root dry mass. The results showed that nicosulfuron should be positioned cautiously in new RR2 corn hybrids, as it may damage the development of the plant.

Pages 974-981 | Read More| doi: 10.21475/ajcs.17.11.08.pne457

Components of variance and inter-relation of important traits for maize (Zea mays) breeding

Ivan Ricardo Carvalho, Maicon Nardino, Gustavo Henrique Demari, Alan Junior de Pelegrin, Mauricio Ferrari, Vinícius Jardel Szareski, Victoria Freitas de Oliveira, Mauricio Horbach Barbosa, Velci Queiróz de Souza, Antonio Costa de Oliveira, Luciano Carlos da Maia

UFPEL - Federal University of Pelotas, Capão do Leão, RS, Brazil

UFSM-Federal University of Santa Maria Campus de Frederico Westphalen, RS, Brazil

UNIPAMPA - Federal University of Pampa, Dom Pedrito, RS, Brazil

Abstract

The increase of maize yield is possible by increasing either the cultivated area, use of best technologies and also more productive genotypes. So, the aim of this study was to estimate the variance components and genetic parameters (individual REML), phenotypic linear correlations, genetic, environmental and canonical for agronomically important traits in maize. The experiments were conducted in the growing seasons of 2013/2014 in four environment of Rio Grande do Sul, Brazil. The design used was a randomized block arranged in a factorial design, including 79 maize of hybrids (simple/narrow genetic base) × four cultivation environments, arranged in three replicates. The measured traits were plant height, insertion ear height, prolificacy, ear diameter, ear length, number of grain rows per ear, number of grain per row, stem diameter, stem mass, ear mass, grains weight per ear, hundred grains weight and grains yield. The estimates of the variance components and genetics parameters (REML) were made throught the MHPRVG method, obtaining the genotypic variance, the variance of genotype × environment interaction, residual variance, individual phenotypic variance, heritability with broad sense to the total phenotypic effects, heritability of the genotypes mean, accuracy for the selection of the genotypes,determination coefficient to the effects of genotype × environnment interaction, genotypic correlation between performance of the environment, coefficient of genotypic variation,coefficient of residual variation and a overall average. We created a linear phenotypic, genetics, environmental and a canonical correlation. The variance components and genetics parameters (REML) identified a contribuition of the genetic variation for genotype × environment interaction, and heritability in a broad sense for the ear diameter, number of grains row and stem diameter. Phenotypic, genetic and environment linear positive trends was presented between the prolificacy as ear diameter and the grains mass per ear with the grain yield. The three canonical pairs were significant with intergroup dependence, by which the grains yield favored by the plant height, insertion ear height, prolificacy, ear diameter and number of grains per row. The criteria established by this study can be used in quantitative genetics research and maize genetic improvement to increase grain yield.

Pages 982-988 | Read More| doi: 10.21475/ajcs.17.11.08.pne474

Gas exchange and biomass production in young plants of Acapu (Voucapoua americana Aubl.) subjected to drought condition

Joze M. N. de Freitas, Kerolém P. S. Cardoso*, Glauco A. dos S. Nogueira, Vitor R. do Nascimento, Cândido F. de Oliveira Neto, Roberto C. L. da Costa, Diocléa A. S. Silva, Allan K. da S. Lobato, Ismael de J. M. Viégas

Institute of Agrarian Sciences, Laboratory of Biodiversity Studies of Upper Plants in Federal Rural University of Amazonia, Pará, Brazil

Laboratory of Biodiversity Studies of Upper Plants in Federal University Rural of Amazônia, Capanema city, Brazil

Core Research and Plant Production, Federal University Rural of Amazônia, Paragominas city, Brazil

Abstract

The experiment was conducted in a greenhouse at the Federal Rural University of Amazonia (UFRA) from November 2011 to July 2012. The plants were subjected to two water regimes: control (adequate irrigation) and water deficiency (water suspension) for 0, 10, 20 and 30 days period. The water potential in stressed plants was reduced after 30 days of drought. The photosynthetic rate, stomatal conductance and transpiration rate were reduced with increased water stress time in plant with more pronounced reductions in the 20th and 30^th after induction of treatments. The concentration of ABA increased in leaves and roots of plants submitted to water deficit. Dry mass of shoot, root and total mass were decreased in plants under water stress. The suspension of irrigation for 10 days was sufficient to alter the metabolism of young Acapu plants. These results showed that young Acapu plants tolerate a water potential of up to -2.86 MPa, indicating that this species is not susceptible to water stress/suspension. This condition may favor the development and expansion of Voucapoua americana for the recovery of degraded areas in regions with limited available water.

Pages 989-996 | Read More| doi: 10.21475/ajcs.17.11.08.pne499

Impact of heat stress on Fusarium wilt (F. solani) incidence in cultivated tomato and related species

Muhammed Alsamir, Nabil. M. Ahmad*, Tariq Mahmood, Richard Trethowan

Plant Breeding Institute, Faculty of Agriculture and Environment, University of Sydney, Cobbitty, NSW 2570, Australia

The Date Palm Research Center, University of Basrah, Basrah, Iraq

Abstract

The incidence of Fusarium wilt on tomato is increasing with rising global temperatures. To assess the impact of this disease, a factorial experiment of ten tomato genotypes grown at two temperatures and two levels of disease severity was established using hydroponics in a poly tunnel house. Fusarium wilt inoculum was used to promote disease and the heat treatment produced temperatures >40^oC for most of the growing season. Genotypes varied significantly for disease incidence and response to heat stress. Significant temperature x disease treatment interactions were observed for number of inflorescences per plant (IPP), fruit set ratio (FSR), number of fruits per plant (FPP), fresh fruit weight (FFW), plant dry weight (PDW) and disease severity index (DSI). A highly significant correlation (R² = 0.98) was observed between disease incidence under both control and high-temperature treatments, even though the treatments were significantly different. Biomass was reduced under both heat and disease stress and was correlated across treatments (R² = 0.86). The genotype LA3847, characterized by relatively low fruit set inhibition and high fruit yield, was classified as tolerant to both heat and disease stress. Concurrent selection for improved disease and heat tolerance appears possible as the disease severity index and the heat stress response were not correlated (R² = 0.11).

Pages 997-1004 | Read More| doi: 10.21475/ajcs.17.11.08.pne500

Integration of quantitative and qualitative descriptors for genetic diversity studies of watermelon accessions

Mariana Neto Rosa Lima*, Manoel Abilio de Queiróz, Anne Emanuelle Flor da Silva Oliveira, Izaias da Silva Lima Neto, Ronaldo Simão de Oliveira

Centro de Ciências Agrárias, Universidade Federal do Vale do São Francisco – UNIVASF, Rodovia BR 407, KM 119, Lote 543 PSNC, s/n, C1, CEP 56300-990, Petrolina-PE, Brazil

Departamento de Tecnologias e Ciências Sociais, Universidade do Estado da Bahia - UNEB, Av. Edgard Chastinet, s/n, São Geraldo, CEP 48900-000, Juazeiro-BA, Brazil

Departamento de Ciências Biológicas, Universidade Estadual de Feira de Santana - UEFS, Avenida Transnordestina, S/N. Novo Horizonte, CEP 44036-900 Feira de Santana-BA, Brazil

Abstract

Most of genetic diversity studies are based only on quantitative descriptors. The aim of this study was to apply different analysis strategies with quantitative and qualitative descriptors to identify which is the most suitable to integrate descriptors for genetic diversity studies of watermelon (Citrullus lanatus) germplasm using different assays. A total of 20 watermelon accessions were evaluated in the State of Rio Grande do Norte and two commercial cultivars were used as witness (control) (Crimson Sweet and Charleston Gray) in two cultivation seasons (2014/2015), using 49 descriptors, in which 26 were quantitative and 23 were qualitative. The genetic diversity of the accessions was obtained using eight analysis strategies that combined the Mahalanobis Distance, Average Standardized Euclidean Distance (SED), and Weighted Average Euclidean Distance, followed by groupings using the Tocher optimization method. A wide morphological variability was observed between and within accessions. The eight different strategies of genetic dissimilarity analyses resulted in 36 different groups. The clustering strategy, by which dissimilarity between accessions calculated using SED (quantitative descriptors) and WED (qualitative descriptors) is the most suitable for integrating quantitative and qualitative descriptors in genetic diversity studies of watermelon germplasm.

Pages 1005-1015 | Read More| Supplementary Data| doi: 10.21475/ajcs.17.11.08.pne510

Phenolics metabolism provides a tool for screening drought tolerant Eucalyptus grandis hybrids

Clarice Noleto Dias, Edgard Augusto de Toledo Picoli*, Genaina Aparecida de Souza, Mohamed Ali Farag, Marcus Tullius Scotti, José Maria Barbosa Filho, Marcelo Sobral da Silva, Josean Fechine Tavares

Natural and Synthetic Bioactive Products Graduate Program, Federal University of Paraíba, João Pessoa, Paraíba, 58051-900, Brazil

Plant Biology Department, Federal University of Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil

Pharmacognosy Department, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt

Abstract

Eucalyptus L’Hér. (Myrtaceae) is one of the most economically important plant genera worldwide. Breeding programs aim to adjust productivity and tolerance to abiotic stresses such as water deficit. Plants under stress can overcome the excessive production of reactive oxygen species via the production of phenolics. Therefore, the aim of the present study is to investigate the variation of leaf phenolics content among 4 commercial clones of E. grandis hybrids subjected to simulated water deficit (moderate and severe treatment). Seedlings of E. grandis hybrids were exposed to adequate water supply (control) and two concentrations of polyethylene glycol solutions (moderate and severe stress) for 60 days. Then, leaves were harvested and their phenolic contents were measured by high-performance liquid chromatography and colorimetric assays. Each clone showed a different tolerance level and reacted in a specific manner against this stress. Principal component analysis of controls of each clone revealed that caffeic acid and quercitrin contents were found at very low levels in the sensitive and in the tolerant clone leaves, respectively. The tolerant (E. grandis × urophylla- EGU–EGU1) and EGU3 clones had higher phenolic contents in the stressed seedlings than in the control ones. In contrast, this variation was not detected in the sensitive clone leaves (E. grandis hybrid–EGR). Chemical analysis of these phenolics can be used as a reliable screening tool for drought tolerant hybrids in Eucalyptus. Our results also support the selection of more efficacious Eucalyptus hybrids for field cultivation, thereby enhancing its environmental competitiveness.

Pages 1016-1024 | Read More| Supplementary Data| doi: 10.21475/ajcs.17.11.08.pne511

Boron fertilisation at different phenological stages of soybean

Ivana da Silva Gomes, Cleiton Gredson Sabin Benett*, Rogerio Lamim Silva Junior, Ricardo Caldas Xavier, Katiane Santiago Silva Benett, Anderson Rodrigo da Silva and Ademilson Coneglian

State University of Goiás (Universidade Estadual de Goiás), Campus Ipameri, highway GO-330, km 241, 75780-000 Zip, Ipameri, Goias, Brazil

Federal Institute Goiás (Instituto Federal Goiano), Campus Urutaí, highway Geraldo Silva Nascimento, km 2.5, 75790-000 Zip, Urutaí, Goias, Brazil

Abstract

The high global food demand has led to crop management practices such as the use of micronutrients to increase soybean productivity. The aim of the present study was to evaluate the effect of boron fertilisation applied to two varieties of soybeans at different doses and different phenological stages on yield components, productivity and physiological quality of seeds. Two different soybean varieties were tested, one conventional (variety BRS 7980) and one transgenic (variety M 7739 IPRO), in two field experiments performed in parallel during the 2014/2015. A randomised block experimental design was used in both experiments, with a 3 x 5 factorial scheme, with four replicates per treatment. The tested factors were three phenological stages (V6, V9 and R1) and five boron doses (0, 1, 2, 3 and 4 B kg ha^-1). The following parameters were analysed: leaf boron concentration, chlorophyll concentration, yield components and productivity. Boron fertilisation at different phenological stages had no effect on most agronomic traits, but it did increase productivity in both varieties, independent of the phenological stage of application. The boron dose indicated for maximum production for both varieties is 3.51 kg B ha^-1.

Pages 1026-1032 | Read More| doi: 10.21475/ajcs.17.11.08.pne558

Microsatellite-based genetic diversity among accessions of Citrullus spp. collected from 36 countries

Chia M.V. Angui, Kouamé K. Koffi*, Kouamé G. Koffi, Marie-Christine Flamand, Pierre Bertin,Jean-Pierre Baudoin, Yao Djè, Bi I.A. Zoro

Université Nangui Abrogoua, Unité de Phytotechnie et Amélioration génétique, 02 BP 801 Abidjan 02, Côte d’Ivoire

Institut des Sciences de la Vie (ISV), Université catholique de Louvain, Croix du Sud 4-5, (L7.07.14), 1348 Louvain-la-Neuve, Belgium

Earth and Life Institute (ELI), Université catholique de Louvain, Croix du Sud 2, (L7.05.11), 1348 Louvain-la-Neuve, Belgium

Laboratoire d’Agroécologie tropicale et Horticulture, Gembloux Agro-Bio Tech, Université de Liège, Gembloux, Belgium

Abstract

Watermelon (Citrullus lanatus) is one of the most economically important vegetable cucurbits. However, the genetic and taxonomic statuses of its closely related species remain scantly documented, limiting their full use for agronomic purposes. The genetic diversity and structure of 74 accessions covering 47 dessert type (C. lanatus subsp. vulgaris), 21 oilseed type (C. mucosospermus), and 6 citron melon (C. lanatus subsp. lanatus var citroides) collected from 36 countries throughout 4 continents, were analyzed using 18 polymorphic SSR markers. The mean values of proportion of polymorphic loci (P = 29.73), number of alleles per locus (A = 1.243), effective number of alleles per locus (Ae = 1.153) Shannon index (I = 0.191), observed and expected heterozygosities (Ho = 0.124; He = 0.149) confirmed the narrow genetic basis of C. lanatus. According to molecular variance analysis the most important component of the genetic variation was obtained among accessions (70%). On the contrary, lower genetic variation was noted among species (16%), countries (37%), and continents (14%). It is suggested that the cultivated forms of Citrullus spp. originated from or successive selection cycles aimed at few and/or common traits, in few ancestral populations. Clustering based on both Bayesian approach and an unweighted pair group method with arithmetic mean pointed out three groups of accessions corresponding to use types and collecting countries. Based on these results, future collecting missions could be focused mainly on representative ecological sites in Citrullus spp. distribution areas, and increasing the number of accessions and seeds per accession.

Pages 1033-1041 | Read More| Supplementary Data| doi: 10.21475/ajcs.17.11.08.pne572

Diversity and indicator species in the Cerrado Biome, Brazil

Fernanda Gomes Ferreira*, Evandro Luiz Mendonça Machado, Carlos de Melo e Silva-Neto, Manoel Cláudio Silva Júnior, Mariana Martins Medeiros, Anne Priscila Dias Gonzaga, Alexandro Solórzano, Fábio Venturoli, Jeanine Maria Felfili Fagg

Department of Forest Engineering, School of Agronomy, Federal University of Goiás (UFG), Goiânia, Brazil

Department of Forest Engineering, Federal University of the Jequitinhonha and Mucuri Valleys (UFVJM), Diamantina, Brazil

Federal Institute of Education, Science and Technology of Goiás (IFG), Cidade de Goiás, Brazil

Department of Forest Engineering, College of Technology, University of Brasília (UNB), Brasília, Brazil

Department of Forest Engineering, Amapá State University (UEAP), Macapá, Brazil

Interdisciplinary College of Humanities, Federal University of the Jequitinhonha and Mucuri Valleys (UFVJM), Diamantina, Brazil

Department of Geography and Environment, Pontifical Catholic University of Rio de Janeiro (PUC), Rio de Janeiro, Brazil

Abstract

The Cerrado biome has high species richness, endemism and spatial heterogeneity. Knowing the main characteristics and peculiarities of the flora is essential to adequately protect the species richness of the Cerrado. Therefore, the objective of this study was to analyze the species richness, alpha diversity and beta diversity of four vegetation types in the Paracatu River Basin (15°30’/19°30’S and 45°10’/47°30’W), Paracatu-MG. The four vegetation types cerrado (stricto sensu, “cerradão” or Savannah woodland, deciduous seasonal forest and riparian forest) were sampled following the Manual for Monitoring Permanent Plots of the Cerrado and Pantanal Biomes. Alpha diversity was assessed using the Simpson (Ds´) and Shannon & Wiener (H’) indexes, and beta diversity using the Sørensen and Jaccard similarity indexes. The “Cerradão” vegetation type had the highest number of species (106) and highest alpha diversity (3.83nats.ind^-1). The Cerrado stricto sensu had the lowest species richness (54 species) and alpha diversity value (2.65 nats. ind ^-1). Beta diversity was high (low Jaccard and Sørensen similarity) except between Cerrado stricto sensu and “cerradão”. The initial hypothesis of this study was rejected, because although the phytophysiognomies are located on the same land system, the beta diversity is high, except for the Cerrado stricto sensu and "Cerradão”, which had similar diversity.

Pages 1042-1050 | Read More| doi: 10.21475/ajcs.17.11.08.pne615

Stalk yield and nitrogen (¹⁵N) recovery of irrigated sugarcane during the plant-cane cycle using urea

Alefe Viana Souza Bastos, Marconi Batista Teixeira, Edson Cabral da Silva, Frederico Antônio Loureiro Soares, Takashi Muraoka

Irrigation Department, Goiano Federal Institute, Rio Verde, Goiás State, Brazil

Soil Fertility Department (CENA-USP), Piracicaba, São Paulo State, Brazil

Abstract

Sugarcane is the most promising among crops that produce renewable biofuels. An adequate availability of water and nutrients, especially nitrogen (N), is of utmost importance. The objective of this study was to evaluate stalk yield and the recovery of N-urea by sugarcane (plant-cane) subjected to different levels of water replacements and nitrogen fertilization doses using the ¹⁵N isotopic dilution technique. The experiment was conducted in the southwest region of the state of Goiás, Brazil, using plastic pots. The experimental design was complete randomized blocks analyzed in 3 × 3 split plots with three replications. The treatments consisted of three levels of water replacements (75, 50 and 25%) and three N doses (60, 120 and 180 kg ha-1) in the form of enriched ¹⁵N urea. N doses did not affect stalk yield, probably because 91.14% of all N accumulated in culms came from the soil and other sources. The rainfall (1,194.2 mm) was sufficient to meet the water requirements of the crop. The recovery of N-urea was not influenced by the N doses and represented on average of 20.5% of the total amount applied. The soil and other sources were the main providers of N to sugarcane plants regardless of the mineral-N dose applied.

Pages 1051-1057 | Read More| doi: 10.21475/ajcs.17.11.08.pne621

Chemical composition of garlic wood (Gallesia integrifolia) (Phytolaccaceae) volatile compounds and their activity on cattle tick

Keila Fernanda Raimundo, Wanessa de Campos Bortolucci, Eloísa Schneider Silva, Ana Flávia Balisk Pereira, Otávio Akira Sakai, Ranulfo Piau Júnior, José Eduardo Gonçalves, Giani Andréa Linde, Zilda Cristiani Gazim

Programa de Pós-Graduação em Biotecnologia Aplicada à Agricultura. Universidade Paranaense - Unipar, Umuarama–PR, Brazil

Curso de Graduação em Farmácia. Universidade Paranaense - Unipar, Umuarama-PR, Brazil

Instituto Federal do Paraná - IFPR, Campus Umuarama-PR, Brazil

Programa de Pós-Graduação em Ciência Animal da Universidade Paranaense - Unipar, Umuarama-PR, Brazil

Mestrado em Tecnologia Limpas e Mestrado em Promoção da Saúde, UniCesumar, Maringá-PR, Brazil

Instituto Cesumar de Ciência, Tecnologia e Inovação - ICETI, Maringá-PR, Brazil

Abstract

The objective of this study was to evaluate the acaricidal and larvicidal activities of essential oil (EO) from fruits, leaves and flowers of garlic wood on cattle tick [Rhipichephalus (Boophilus) microplus]. The fruits were harvested from May to June (2015) and the leaves and flowers in December (2015). The EO was obtained by hydrodistillation (2h) and identified by GC/MS. Bioassays consisted of Adult Immersion Test and Larval Immersion Test. The results made the following major compounds evident: 2,3,5-trithiahexane (35.29%) in fruits, dimethyl sulfide (42.42%) in leaves and methanethiol (44.91%) in flowers. The EOs from fruits, leaves and flowers showed high activity on the tick larval cycle, presenting LD_99.9 of (0.23 ± 0.01 mg/mL), (2.15 ± 0.11 mg/mL) and (0.08 ± 0.00 mg/mL), respectively. However, when we compared different phases of cattle tick’s live cycle, EO from fruits was more active on females’ mortality, and EO from leaves was more efficient on the egg hatching inhibition, whereas EO from flowers presented better results on bovine tick larva. Thus, garlic wood (Gallesia integrifolia), a native plant of the Atlantic forest can be considered as a promising natural agent to control bovine tick.

Pages 1058-1067 | Read More| Supplementary Data| doi: 10.21475/ajcs.17.11.08.pne632

Low water input confers sustainable rice production without affecting soil, plant physiological and yields parameters

Mohd Khairi, Syed Ahmad Naqib, Md. Mainul Hasan, Md. Sarwar Jahan*

Faculty of Bioresources and Food Industry, Universiti Sultan Zainal Abidin, Besut, Terengganu, 22200 Malaysia

Department of Agricultural Botany, Faculty of Agriculture. Patuakhali Science and Technology University, Dumki, Patuakhali, 8602 Bangladesh

Abstract

The demand for fresh water is increasing progressively for the use of the community and during crop production. An experiment was conducted to investigate the effect of low water input (LWI) on soil health, and crop yield. Soil chemical properties, physiological and yield parameters of rice plants which were grown under different water input treatments were examined. The treatments were as W1 (control; 5 cm flooding), W2 (1 cm flooding), W3 (saturated condition) and W4 (field capacity). Treatments were arranged according to the completely randomized design with five replications. The result revealed that LWI (e.g. saturation and 1 cm flooding) did not affect phytoavailability of nutrients in soil compared to the control. However, concentrations of nutrients such as nitrogen calcium, potassium, magnesium, cupper and manganese decreased with increasing plant age regardless of treatments except for phosphorus, zinc and iron. The redox potential (Eh) decreased significantly in control treatment than low water input condition. The soil pH showed moderately acidic to near neutral whilst the soil electrical conductivity (EC) remained same. The W1 treatment significantly reduced relative water content (RWC), light- and gas exchange-related parameters, yield parameters, harvest index (HI) and water use efficiency (WUE) compared to the LWI and control. This study suggests that low water input sustains rice production without affecting the soil health, physiological and yield parameters of rice plants.

Pages 1068-1077 | Read More| doi: 10.21475/ajcs.17.11.08.pne653

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