Australian Journal of Crop Science   AJCS

January 2017 | Early View | 11(1):2017 | doi: 10.21475/ajcs.2017.11.01

Genetic parameters of pollen viability in guava (Psidium guajava L.)

Séphora Neves da Silva, Matheus Alves Silva, Tiago de Souza Marçal, Adésio Ferreira, Milene Miranda Praça Fontes, Marcia Flores da Silva Ferreira*

Universidade Federal do Espírito Santo, Centro de Ciências Exatas Naturais e da Saúde, Departamento de Biologia. Alto Universitário. 29.500-000 Alegre – ES, Brazil
Universidade Federal do Espírito Santo, Centro de Ciências Agrárias e Exatas, Departamento de Produção Vegetal. Alto Universitário. 29.500-000 Alegre – ES, Brazil


Abstract
Pollen viability is essential for the sexual reproduction in plants. Genetic and environmental factors as well as plant age can influence this characteristic. In this work, pollen viability was studied in guava (Psidium guajava L.), a cross-pollination species. The genetic parameters for this characteristic were estimated considering 22 genotypes, two environments and different plant ages. For that, the pollen viability of the genotypes was evaluated for three years (2013, 2014 and 2015) in two experimental orchards (installed in randomized block design, with three blocks and two plants per plot) and at two different regions of the state of Espírito Santo, Brazil. The plants were analyzed at 19, 24 and 38 months of age in the years 2013 and 2014 in Mimoso do Sul (ES) and 2015 in Linhares (ES), respectively. The flower buds, at pre-anthesis stage, were collected, fixed in ethanol:acetic acid (3:1) and stored at -20°C. Pollen viability was obtained by colorimetric methods (Alexander’s, Acetic Orcein and Lugol dyes) and the genetic parameters estimated by means of mixed models. The pollen viability of the genotypes was high, with an overall mean of 93.46% in the three harvests. Mean heritability was lower in the harvests of 2013 (0.479) and 2014 (0.126) in relation to 2015 (0.583), indicating a slighter possibility of predicting genetic gains based on this characteristic. Altogether, these results provide information about pollen viability in commercial and superior genotypes of the guava crop used in this study, given that pollen-donor genotypes are reported to influence characteristics related to weight and fruit quality in this species. In addition, these genotypes showed good potential for cross-pollination, and can therefore be used as pollinators in orchards and crosses within breeding programs.

Pages 1-8 | Read MoreSupplementary Data| doi: 10.21475/ajcs.2017.11.01.PNE91
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Identifying potential RNAi targets in aphid species (Macrosiphum rosae, Rhopalosiphum maidis, Sitobion avenae, Toxoptera aurantii) in sub-tropical region with extreme summer

Amber Afroz, Maria Hashmi, Umer Rashid, Nadia Zeeshan

Department of Biochemistry and Molecular Biology, Nawaz Sharif Medical College, University of Gujrat, Hafiz Hayat Campus Gujrat, Gujrat, Pakistan

Abstract
RNA interference is a useful and efficient tool that had been used to incorporate tolerance against different stresses. Five unigene sequences were selected from exotic grain aphid that were reported to be an ideal RNAi targets. Aphids (Macrosiphum rosae, Rhopalosiphum maidis, Sitobion avenae, Toxoptera aurantii) were reared on Rosa indica, Zea mays, Triticum aestivum, Chrysanthemum hibiscus, Solanum melongena, Abelmoschus esculentus. PCR of unigene 28469 and 21789 was positive for all aphids and there is no ortholog found for them so unique and effective to be used in RNAi technology. Cytochrome c oxidase was found to be positive for M. rosae, S. avenae, T. aurantii and negative for R. maidis. Zinc finger protein was found to be positive for R. maidis, S. avenae and negative for M. rosae, and T. aurantii. Cuticular proteins was found to be positive for S. avenae and M. rosae and negative for R. maidis and T. aurantii. Genes identified in the aphids are defense and as important structural genes and their suppression with RNAi technology will be important target to have insect resistant crops. From these gene sequences cytochrome c oxidase is reported as bar coding gene and can be used in future for interspecific genetic variation in these aphids. Results revealed the high expression of these sequences in local aphid species and can be used as RNAi target for them. That can be used in future or applications as pest management, monitoring and plant quarantine.

Pages 9-17 | Read More| Supplementary Data| doi: 10.21475/ajcs.2017.11.01.pne157
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Effect of chemical treatment on physiological quality of seed and control of Meloidogyne javanica in watermelon plants

Hélen Claudine Saliba Rodrigues*, Carolina Terra Borges, Renan Navroski, Vanessa Nogueira Soares, Gizele Ingrid Gadotti, Géri Eduardo Meneghello

UFPEL, Faculdade de Agronomia Eliseu Maciel, Cx 354, Campus Capão do Leão, RS, Plant Science Department, Universidade Federal de Pelotas, RS, BR, Brazil
Engineering Center, Universidade Federal de Pelotas, RS, BR, Brazil

Abstract
This study aimed to evaluate the efficacy of different concentrations of abamectin, in combination with thiabendazole and thiamethoxam, on seed physiological quality and on the control of Meloidogyne javanica in watermelon plants. To this purpose watermelon seeds of the Crimson Sweet variety were employed in the study. The treatment of the seeds consisted of abamectin (nematicide) at concentrations of 0.075 g (ST2), 0.150 g (ST3), 0.300g (ST4) and 0.600 g (ST 5) ai (active ingredients) per 1000 seeds in combination with thiabendazole and thiamethoxam at concentrations of 0.080 g, 0,019 g ai per 1000 seeds, respectively. Untreated seeds (ST1) were also employed as a control. The volume of the mixed solution used to this purpose was 4.9 mL 1000 seed–1. The untreated and treated seeds were divided in two parts; the first part was sowed on paper towels and placed in chambers maintained at a constant 25 ºC while the second part was planted in trays in a greenhouse so as to enable evaluation of shoot length, shoot fresh weight, root weight, galls number, egg number, and reproduction factor. The physiological quality of the seeds was evaluated by standard germination tests, cold tests, and emergence speed index. The results indicated that the watermelon seed quality was not affected by concentration of abamectin when used in combination with thiabendazole and thiamethoxam. Further investigations are warranted in order to verify nematicidal toxicity on seed quality at higher levels of treatment. Based on the results of our study, we propose that abamectin (0.75 to 600 g/ ai per 1000 seeds) when applied in combination with thiabendazole and thiamethoxam, is an effective control agent for reducing the number of eggs and second-stage juveniles (J2) in ‘Crimson Sweet’ watermelon plants.

Pages 18-24 | Read More| doi: 10.21475/ajcs.2017.11.01.pne165
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Effect of antioxidants on the callus induction and the development of somatic embryogenesis of cocoa [Theobroma cacao (L.)]

Kouassi Kan Modeste*, Manlé Tokpapon Eliane, Koné Daouda, Soumahoro André Brahima, Koné Tchoa, Koffi Edmond Kouablan, Koné Mongomaké

Centre National de Recherche Agronomique (CNRA), Laboratoire Central de Biotechnologies (LCB), KM 17 Adiopodoumé, 01 BP 1740 Abidjan 01, Côte d’Ivoire
Université Nangui Abrogoua, UFR Sciences de la Nature, Laboratoire de Biologie et Amélioration des Productions Végétales, 02 BP 801 Abidjan 02, Côte d’Ivoire
Université Félix Houphouët-Boigny, UFR Biosciences, Laboratoire de Génétique, 22 BP 582 Abidjan 22, Côte d’Ivoire


Abstract
The browning of plant tissue and organs is a major constraint in tissue culture of cocoa (Theobroma cacao L.). This study aims to evaluate callogenic and embryogenic potentialities of three genotypes cocoa on culture media supplemented with different types and concentrations of antioxidants. Polyvinylpyrrolidone (PVP), ascorbic acid, silver nitrate and cysteine were used as antioxidant agents. The explants staminode and petal were excised from immature buds of the flowers of genotypes cocoa C1, C8 and C14. The results showed that the induction rate of callus derived from the petal and the staminode varied with the genotypes tested. Except 21 mg/l of silver nitrate, the others antioxidants used namely ascorbic acid, PVP and cysteine have enhanced the callus induction of the genotype C8. In comparison with the control, the callus browning of the three genotypes was reduced two to three times when the culture media were supplemented with various concentrations of the silver nitrate. After 72 days of culture, somatic embryos were induced on callus derived the petal explants with all the studied genotypes. Addition of PVP (300 mg/l) in the induction medium improved the rate of somatic embryos of the genotypes C1 and C14. The improvement of responses to somatic embryogenesis in reducing the rate of browning of cultures will allow a mass production of the high-yield cocoa genotypes.

Pages 25-31 | Read More| doi: 10.21475/ajcs.2017.11.01.pne174
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Growth and biomass of sunflower under different nitrogen levels and available water in the soil of a semi-arid region

Samuel Silva, José Alberto Ferreira Cardoso, Hallyson Oliveira, Ronaldo do Nascimento, Rafaela Félix Basílio Guimarães, Armindo Bezerra Leão

Federal University of Campina Grande, Academic Unit of Agricultural Engineering, Campina Grande, 58.109-970, Paraíba, Brazil

Abstract
The adequate water supply and nitrogen in the soil is essential for the growth and development of plants. Sunflower is the target of several studies of such factors due to the economic importance and the needs to expand in the semi-arid regions of Brazil. This work aimed to evaluate the growth variables, measured at 80 days after sowing (DAS), and the biomass obtained at 100 DAS of the Helio 253 sunflower hybrid under the effect of nitrogen and water levels. The experiment was conducted in a greenhouse in the city of Campina Grande- PB, in split-plot of a completely randomized design with four moisture levels in the soil (50, 75, 100 and 125% of available water) and four nitrogen rates (30, 60, 90 and 120 kg ha-1). Among all levels of available water in the soil, the stem diameter (SD) ranged from 13.6 to 19.6 mm and the plant height (PH) from 93 to 107 cm. Plants with 100% AW showed a leaf area (LA) 45% greater than the treatment with higher water stress. The chapters had an average diameter between 83 and 98 mm, the dry biomass of the chapters (DBC) and total dry biomass (TDB) ranged from 45 to 55 g and of 65 to 101 g, respectively. The weight of a thousand seeds per chapter (W1000) obtained minimum and maximum of 49 and 66 g. The stem diameter ranged between 14.4 to 18.3 mm and the minimum and maximum plant height values were 93 and 110 cm, using applied N levels. The leaf area varied from 22 to 36 dm2 and the chapters had average diameter of 86 to 99 mm. With respect to the dry biomass of the chapters, there was a variation of 38 to 68 g and TDB of 68 to 107 g and W1000 valued between 52 and 65 g under doses of N. There is considerable variation in all variables mainly due to increased water level in the soil and nitrogen fertilization.

Pages 32-37 | Read More| doi: 10.21475/ajcs.2017.11.01.pne180
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Elephant grass response to amino-acid synthesis inhibitor herbicides

Alexandre Magno Brighenti*, Francisco José da Silva Ledo, Juarez Campolina Machado, Leonardo Henrique Ferreira Calsavara, Yago Vieira Guerra Varotto

Embrapa Dairy Cattle, Rua Eugênio do Nascimento 610, Juiz de Fora, MG, 36038-330 Brazil
Emater-MG, Rua Major Mendonça 106, Coronel Xavier Chaves, MG, 36330-000 Brazil
Centro de Ensino Superior de Juiz de Fora, Rua Luz Interior 345, Juiz de Fora, MG, Brazil

Abstract
Elephant grass (Pennisetum purpureum Schum.) fodder productivity and quality are directly affected by weed interference. The difficulty in controlling weed species is one of the major limitations to the production and use of elephant grass as a forage crop in dairy farming and biomass for energy production. In this study, field experiments were conducted in 2014 and 2015 at two locations in Minas Gerais State, Brazil, to evaluate the tolerance of elephant grass pasture to acetolactate synthase inhibitor herbicides. The experimental pastures were treated at 1× and 2× the normal field-use rates (g ai ha-1) with metsulfuron-methyl (7.8 and 15.6), chlorimuron-ethyl (15 and 30), halosulfuron (112.5 and 225), ethoxysulfuron (150 and 300), and nicosulfuron (60 and 120). A non-treated control was also included. The results showed that metsulfuron-methyl, chlorimuron-ethyl, halosulfuron, and ethoxysulfuron caused mild injury symptoms on elephant grass plants, but did not reduce forage biomass production. Nicosulfuron caused considerable percentage injury to the plants, which varied from 53% to 75% and from 65% to 75% for the lower and higher rates, respectively. Elephant grass was tolerant of metsulfuron-methyl, chlorimuron-ethyl, halosulfuron, and ethoxysulfuron. Therefore, these herbicides could potentially control weeds in elephant grass fields.

Pages 38-42 | Read More| doi: 10.21475/ajcs.2017.11.01.pne187
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Greater water availability increases the water use efficiency and productivity of corn and bean species grown in secondary crop systems

Felipe Schwerz, Braulio Otomar Caron, Elvis Felipe Elli, John Robert Stolzle, Elder Eloy*, Denise Schmidt, Luciano Schwerz, Velci Queiróz de Souza

Federal University of Santa Maria, Frederico Westphalen Campus, 98400-000, Frederico Westphalen, Rio Grande do Sul, Brazil
Federal University of Pampa, Don Pedrito Campus, 96450-000, Don Pedrito, Rio Grande do Sul, Brazil


Abstract
Secondary crop cultivation is very important for producers of corn and beans crops worldwide, and can reach high levels of productivity. The study aimed to evaluate water use efficiency and grain yield response of corn and bean species cultivated in a secondary crop system, when subjected to different water levels. Two experiments were carried out, one for the corn cultivar DKB 240 and another for the bean cultivar IPR Gralha; the study was developed in an experimental area classified as Oxisol typical, both experimental designs consisted of a randomized single factor block design with five water levels (0, 50, 75, 100 and 125% of reference evapotranspiration; Eto) with three replications. The following variables were analyzed: number of rows per ear, number of grain per row, thousand grain mass and grain yield for corn; number of pods per plant, number of seeds per pod, thousand grains mass and grain yield for beans. Water use efficiency was calculated as the relationship between grain yield and the applied water level. The corn and bean crops had the highest water use efficiency in the levels of 100% and 125% of reference evapotranspiration, respectively. These levels showed the highest yield of crops. Both corn and beans can be recommended for planting in the second crop system as they present a high yield potential under favorable water conditions; in order to meet water demands, they require a total of 413.53 mm for corn and 447.12 mm for the bean cultivar distributed throughout the crop cycle.

Pages 43-49 | Read More| doi: 10.21475/ajcs.2017.11.01.pne205
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The high density of plants increases the radiation use efficiency of photosynthetically active seedlings of Japanese grape (Hovenia dulcis)

Felipe Schwerz*, Braulio Otomar Caron, Elvis Felipe Elli, Elder Eloy, Denise Schmidt, John Robert Stolzle, Sandro Luiz Petter Medeiros, Jaqueline Sgarbossa, Rômulo Trevisan

Department of Agronomic Sciences, Federal University of Santa Maria, Frederico Westphalen Campus, 98400-000, Frederico Westphalen, Rio Grande do Sul, Brazil
Department of Forest Engineering, Federal University of Santa Maria, Frederico Westphalen Campus, 98400-000, Frederico Westphalen, Rio Grande do Sul, Brazil
Department of Plant Science, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil


Abstract
The objective of this study was to determine the use efficiency intercepted photosynthetically active solar radiation of Hovenia dulcis seedlings grown under different plant density treatments. The experiment was conducted in a greenhouse at the forestry nursery. A complete randomized block design was applied. The study was characterized by two plant densities; high (494 plants m-2) and medium (247 plants m-2) densities of seedling in the trays, and fifteen evaluation periods that began after first emergence. Evaluations were carried out every 15 days, totaling 210 days, with six replications. The leaf area index, total dry biomass of seedlings, partitioning of dry biomass, interception of global radiation, accumulated intercepted photosynthetically active radiation, and use efficiency of radiation were evaluated. The high density treatments promoted greater use efficiency and accumulation of intercepted photosynthetically active radiation in dry biomass of Hovenia dulcis seedlings. In this work, a model is present for analyzing the growth and development of plants and their relation to both photosynthetic rate and radiation use efficiency.

Pages 50-54 | Read More| doi: 10.21475/ajcs.2017.11.01.pne206
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Genotype by trait biplot analysis to study associations and profiles of Ethiopian white lupin (Lupinus albus) landraces

Mulugeta Atnaf*, Kassahun Tesfaye, Kifle Dagne, Dagne Wegary

Ethiopian Institute of Agricultural Research, Pawe Research Center, P. O. Box 25, Pawe, Ethiopia
Addis Ababa University, College of Natural Sciences, Department of Microbial, Cellular and Molecular Biology, P.O. Box 1176, Addis Ababa, Ethiopia
CIMMYT-Ethiopia, ILRI Campus, CMC Road, P.O. Box 5689, Addis Ababa, Ethiopia


Abstract
Limited information is available on trait relations and profiles of white lupin landraces in tropical growing conditions including Ethiopia. The objectives of this study were to understand the relationships among traits, and to document trait profile of Ethiopian white lupin landraces. As a component of this study, two sets of experiments were conducted. The first comprehensive experiment that consisted of 144 accessions collected from major lupin growing areas of Ethiopia was evaluated at Merawi and the second experiment that consisted of 12 selected accessions was evaluated across six locations. In both experiments, significant variations were observed among the accessions for most studied traits. Higher heritability and genetic advance as percent of mean was observed for grain yield, indicating the possibility of improving this trait through selection. Genotype by trait biplots captured 55% - 66% of the variations due to genotype by trait interactions. Trait association and trait profile biplots were constructed for highland, mid altitude and low land environments, and across all locations. Different patterns of associations and genotype (accession) by trait interactions were observed in different environments. However, genotype by trait biplots consistently indicated that grain yield had positive associations with most of the traits; especially, with number of pods per plant, plant height and seeds per pod. The study identified some accession with desirable performances as good for specific trait and/or trait groups that could be considered as sources of genes for the traits they have best performed. G8 consistently showed higher grain yield, G2 had higher number of branches and higher number of seeds per plant, G7 had more number of pods per plant and larger seed size and G4 produced longer pods. The accessions used in this study were found to be useful sources for genetic variability for future breeding that targets to improve grain yield and other agronomic traits of white lupin in Ethiopia.

Pages 55-62 | Read More| Supplementary Data| doi: 10.21475/ajcs.2017.11.01.pne226
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Manganese accumulation and dry matter production of Guinea Grass (Panicum maximum) after application of increasing doses of Mn fertilizer

Rilner Alves Flores*, Virgínia Damin, Yoná Serpa Mascarenhas, Deyvid Diego Carvalho Maranhão, Everton Martins Arruda, Humberto Oliveira Guimarães, Tiago Carvalhais de Oliveira, Ana Paula Marquez Belo, Tatiana Carvalho Faria

Department of Soil Science, Agronomy School, Federal University of Goias, Goiania, GO, Brazil
Department of Soil Science, Rural Federal University of Rio de Janeiro, Seropedica, RJ, Brazil


Abstract
The manganese (Mn) is an important nutrient to forage development; however, there is a lack of information regarding to adequate Mn-fertilizer rates for Guinea Grass (Panicum maximum) species growing in Brazilian soils. The objective of this research was to evaluate the effect of Mn on growth, nutrition and yield of Guinea Grass. The study was carried out under greenhouse conditions in a randomized block design, with five Mn rates (0, 15, 30, 60 and 120 mg dm-3) and four replicates, using manganese sulfate (35.5% Mn) as Mn source. Plant’s growth parameters, dry mass production, Mn2+ levels and accumulation in plant’s tissues were measured and Mn efficiencies of absorption, transport and utilization were calculated. Enhancing Mn doses, there was a proportional increase of Mn2+ levels in the leaves and the roots. Regarding to the growth parameters, the number of leaves and both root and aboveground dry mass were slightly affected by Mn application. The highest Mn efficiency of absorption and transport by Guinea Grass was ob using 30 mg dm-3 of Mn; however, the Mn utilization efficiency was higher when Mn was not applied. In this way, the Mn fertilization in Guinea Grass is economically viable using doses up to 30 mg dm-3.

Pages 63-70 | Read More| doi: 10.21475/ajcs.2017.11.01.pne234
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Phosphorus use efficiency in maize as a function of different sources

Adilson Pelá*, Rogério Nunes Gonçalves, Faber de Souza Pereira, Fabrício Rodrigues, Sihélio Júlio Silva Cruz

Universidade Estadual de Goiás, Câmpus Ipameri, Rodovia GO 330, km 241, s/n Anel Viário, Ipameri, Goiás, CEP: 75780-000 Brazil
Instituto Federal Goiano - Campus Iporá. Av. Oeste, nº 350, Parque União, Iporá – GO, CEP: 76.200-000 - Brazil


Abstract
The objective of this study was to evaluate the initial growth of maize plants and phosphorus use efficiency due to phosphate fertilization with or without polymer coating for controlled nutrient release. The experiment was conducted in a greenhouse. Ten treatments were accomplished under a 5 x 2 factorial scheme, with five doses of phosphorus and two types of monoammonium phosphate (MAP), with and without polymer coating. The experimental design consisted of three maize plants grown in a 5 liter plastic pot. The study was conducted for 30 days when the phosphorus content, dry matter production and nutrient use efficiency were measured in the plant. The data obtained were submitted to analysis of variance by the F-test at 5% probability, the quantitative data were submitted to regression analysis according to the doses, and the qualitative data according to the source by the Tukey test. The plants fertilized with conventional MAP had averages higher than the ones fertilized with polymer-coated MAP at 50, 150 and 200 mg doses of P dm-3 soil. The initial growth of maize plants was higher when they were fertilized with conventional MAP. The efficiency in P use did not increase with the polymer-coated source, but decreased with doses of both sources

Pages 71-75 | Read More| doi: 10.21475/ajcs.2017.11.01.236
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The effect of applying different amounts of nitrogen to tobacco seedlings on their growth and physiological characteristics

Jiang Houlong, Tian Fengjin, Wang Daibin, Xu Chen*, Li Najia, Wang Hongfeng, Yang Chao, Chen Yiyin

Chongqing Tobacco Science Research Institute, ChongQing 400715, China
Tobacco Leaf Branch of Chongqing Tobacco Corporation, Chongqing 400023, China


Abstract
In this study, we sought to elucidate how under- and over-application of fertilizers, which results often from erroneous calculation of the amount of fertilizer applied, affects tobacco seedling growth. Specifically, the effect of application of different amounts of nitrogen on the growth and physiological characteristics of seedlings of flue-cured tobacco K326 was investigated. Nitrogen treatment was done at four levels: 6 mg/plant (T1), 11 mg/plant (T2), 16 mg/plant (T3), and 21 mg/plant (T4). The root activity, enzyme activity, chlorophyll, photosynthetic performance, and root morphology were measured at 39, 45, 51, 57, and 63 days after seeding. Root activity exhibited a declining trend with increase in the amount of nitrogen applied at the late growth stage of tobacco seeding. Root activity decreased from 115.24 μg g-1 h-1 (T1) to 109.65 μg g-1 h-1 (T2), then to 85.07 μg g-1 h-1 (T3), and finally to 76.86 μg g-1 h-1 (T4) at 63 days after seeding. Moreover, nitrogen application also significantly increased the activity of resistance-related peroxidase, polyphenol oxidase, and phenylalanine, and enhanced the resistance of tobacco seedlings to pathogens. Applying the appropriate amount of nitrogen (6–11 mg/plant) could significantly increase the photosynthetic rate of tobacco seedling leaves, intercellular CO2 content, transpiration rate, and water use efficiency. The amount of nitrogen most suitable for growth of tobacco seedlings with strong roots and resistance on a floating bed was 6-11 mg/plant.

Pages 76-82 | Read More| doi: 10.21475/ajcs.2017.11.01.262
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The effects of oil palm’s empty fruit bunch compost with hexaconazole on biomass production and nutrient contents of sweet potato var. VitAto cultivated on sandy soil

Borhan Abdul Haya*, Mohd Yusoff Abdullah, Nur Kharunisa Tajarudin

Faculty of Plantation and Agrotechnology, Universiti Teknologi MARA (UiTM), 40450, Shah Alam, Selangor, Malaysia

Abstract
This experiment was conducted to investigate the effects of various treatment combinations consisting of oil palm’s empty fruit bunch (EFB) compost and hexaconazole (HEX) on dry mass production, partitioning and nutrient concentrations and contents of sweet potato var. VitAto. The treatments consisted of the recommended inorganic fertilizer for VitAto cultivation (control), solely EFB compost and the combination of treatments consisting of EFB compost with 10 or 30 ppm HEX, using a randomized complete block design (RCBD) replicated four times on sandy soil. The destructive biomass analysis was carried out at 30, 55, 77 and 99 days after planting, which corresponded to the following growth stages, storage root initiation, early and middle bulking and maturity, respectively. The final biomass harvest (99 days after planting) was used for N, P and K nutrient analysis. The greatest response was observed using EFB compost plus 30 ppm HEX treatment, which significantly increased storage root dry mass production, storage root mass ratio, root to shoot ratio, plant total K content, storage root K concentration and content by 16.9%, 15.2%, 58.8%, 75.5%, 69.4% and 106.9% at the maturity stage, respectively. The results showed that the control treatment favored the growth of leaf and stem, while the EFB compost with 30 ppm HEX treatment favored the growth of storage root. The EFB treatment was able to supply high K nutrient to the plant. Both K and HEX were able to increase the assimilate translocation to storage root and consequently increased the storage root dry mass production. Based on the finding of this study, it is proposed that the EFB compost with 30 ppm HEX combination treatment could be used by farmers as alternative inputs to the inorganic fertilizer application in VitAto cultivation on sandy soil.

Pages 83-94 | Read More| doi: 10.21475/ajcs.2017.11.01.266
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Growth, nutrition and production of dry matter of rubber tree (Hevea brasiliensis) in function of K fertilization

Marcus André Ribeiro Correia, Deyvid Diego Carvalho Maranhão, Rilner Alves Flores*, Sebastião Feitosa da Silva Júnior, Melquisedec Almeida de Araujo, Raimundo Laerton de Lima Leite

Federal Institute of Tocantins, Campus of Colinas of Tocantins, Colinas of Tocantins, TO, Brazil
Department of Soil Science, Rural Federal University of Rio de Janeiro, Seropedica, RJ, Brazil
Department of Soil Science, Agronomy School, Federal University of Goiás, Goiania, GO, Brazil
Federal Institute of Tocantins, Campus of Araguatins, Araguatins, TO, Brazil


Abstract
The rubber tree crop (Hevea brasiliensis) is raw material used for the production of rubber. However, the Brazilian production accounts for only a third of the demand, resulting in large cultivation areas concomitantly concerned with aspects related to production system. Hence, this study aims to evaluate the effects of potassium fertilization on the growth, nutrition and dry matter production of Hevea brasiliensis seedlings up to 35 days after planting. Potassium rates were 0 (control), 0.25, 0.5, 0.75 and 1 kg m-3 of K2O soil. Biometric evaluations such as rootstock diameter, leaf number and plant height, as well as dry matter production and potassium accumulation in shoots and roots of rubber tree seedlings were evaluated up to 85 days after transplanting. The efficiency of absorption, transport and use of potassium by rubber tree seedlings were also assessed. Potassium rates influenced plant height, stem diameter and number of leaves. However, with the increase in rates these parameters decreased. Plants obtained a maximum production of total dry matter of 141.72 g plant-1 at a rate of 0.2 kg m-3 of K2O, suggesting that it is the best rate to be applied to plants during seedling stage. Absorption and transportation efficiencies were not affected by potassium application in the soil, while the use efficiency was lower as the rate applied was higher.

Pages 95-101 | Read More| doi: 10.21475/ajcs.2017.11.01.268
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Reuse of substrate and nutritive solution concentration on the cultivation of salad tomato

Marcus Vinicius Marin*, Danilo Mesquita Melo, Rafaelle Fazzi Gomes, Flávia Martins da Silva, Hamilton César de Oliveira Charlo, Leila Trevisan Braz, Carolina Fernandes

Universidade Estadual Paulista/UNESP-FCAV–Department of Crop Science – Via de Acesso Prof. Paulo Donato Castellane - s/n – CEP: 14.884-900 – Jaboticabal, SP – Brazil
Universidade Federal Rural da Amazônia/UFRA–Rua João Pessoa - n 121 – Centro. CEP: 68700-030 – Capanema, PA – Brazil
Instituto Federal do Triângulo Mineiro/IFTM–Rua João Batista Ribeiro – 4000 – Mercês – CEP: 38064-790 – Uberaba, MG – Brazil
Universidade Estadual Paulista/UNESP-FCAV–Department of Soil Science – Via de Acesso Prof. Paulo Donato Castellane - s/n – CEP: 14.884-900 – Jaboticabal, SP – Brazil


Abstract
Among the most modern techniques of vegetables production cultivation in substrate is highlighted. In this method the substrate and the nutritive solution are main components that deliver nutrients to the crop and directly influence the performance of the plants. The objective of this study was to evaluate the reuse of substrate with several concentration of the nutritive solution in cultivation of tomato plants of the salad group 'Paronset'. The experimental design was a randomized blocks in a factorial scheme 3x5, with four replicates. The plants were grown in coconut husk fiber, in three substrate reuse levels (new substrate, reused once and reused twice) and five concentrations of the nutritive solution recommended for the culture [25%; 50%; 100% (original solution); 150% and 200%]. The chemical and physical characterization of the substrate after cultivation was done such as fruit productivity and quality and nutritional status of the plants. Physical characteristics were only influenced when substrate was reutilized. Chemical characteristics of the substrate were influenced by both the reuse of the substrate and the concentration of the nutritive solution. It was observed that the nutritional status of the plants was influenced only by the concentration of the nutritive solution. It was also noted that the productivity and fruit mass decreased after the second reuse of the substrate. The use of the original solution (100%) allowed the highest productivity; however, the largest fruit mass was obtained with the most dilute solution (25%).

Pages 102-111 | Read More| doi: 10.21475/ajcs.2017.11.01.287
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Identifying superior spring wheat genotypes through diallel approaches

Eduardo Stefani Pagliosa, Giovani Benin*, Eduardo Beche, Cristiano Lemes da Silva, Anderson Simionato Milioli, Matheus Tonatto

Universidade Tecnológica Federal do Paraná (UTFPR), Campus Pato Branco, Via do Conhecimento, Km 01, Pato Branco, PR, CEP 85501-970, Brazil
Division of Plant Science, University of Missouri, Columbia, MO 65211, USA
Kansas State University, 204 Throckmorton Hall, 66506, Manhattan, Ks, USA


Abstract
Diallel crosses enable plant breeders taking decisions concerning the parental choice for developing new varieties. Recently, a large number of methodological models have been reported. The objective of this study was to investigate the relationship between different methods of diallel analysis and their associations with grain yield performance in wheat (Triticum aestivum L.) segregating populations. In this study, four methods of diallel analysis were used to estimate the general (GCA) and specific (SCA) combining abilities: (a) Griffing, (b) Multivariate analyses of diallel crosses, (c) Restricted Maximum Likelihood / Best Linear Unbiased Prediction (REML/BLUP) and d) Genotypes and Genotypes x Environments biplot (GGE biplot). Six wheat cultivars were hybridized in a partial diallel scheme and later evaluated in the along with 15 F2 segregating populations. Griffing and REML/BLUP analysis produced equivalent results for GCA and SCA and are meaningful for identifying superior inbred lines. Multivariate diallel analysis suggested the best crosses for simultaneous improvement of traits. GGE biplot method is an effective method for visual comparisons of GCA and SCA effects. Conventional and innovative methods of diallel analysis are useful, complementary and should be applied in the selection of parents and superior crosses.

Pages 112-117 | Read More| doi: 10.21475/ajcs.2017.11.01.289

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Accumulation of antioxidants in rice callus (Oryza sativa L.) induced by β-glucan and salt stress

Arshad Naji Alhasnawi*, Che Radziah Zain*, Ahsan A. Kadhimi*, Anizan Isahak, Azhar Mohamad, Wan Mohtar Wan Yusoff

School of Biosciences & Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangim, Selangor, Malaysia
University Presidency, AL- Muthanna University, 66001 Samawah, Iraq
University of Baghdad, Jadriyah, 10070 Baghdad, Iraq
School of Environmental Science and Natural Resources, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangim, Selangor, Malaysia
Malaysian Nuclear Agency, 43000 Kajang, Bangi, Malaysia


Abstract
Salinity stress causes a considerable reduction in callus growth. Mushroom polysaccharides (β-glucan) are the most promising groups of antioxidant compounds. An in vitro experiment was conducted to evaluate the potential function of exogenously applied β-glucan in alleviating the accumulation of antioxidants in rice callus. In this study, morphological, chemical, and biochemical parameters of an embryogenic callus of the rice variety, MR269, were investigated under 200mM NaCl stress conditions after pre-treatment with (0, 0.5, 1 and 1.5 mg/L) β-glucan in culture media. The present study sought to evaluate chemical, biochemical, and callus growth characterization. The results revealed that callus exposed to stressful media exhibited a significant decrease in callus growth and contents of K+ and Ca+2. In addition, significant accumulation of Na+ and Na+/K+ was found, as well as an enhanced enzymatic antioxidant system and elevated proline activities under NaCl conditions. Furthermore, exogenous addition of β-glucan at 0.5-1.5mg/L under NaCl stress induced a pronounced, significant increase of callus growth, K+ and Ca+2 contents, and enzymatic antioxidant and proline activities. In contrast, a significant decrease was found in the levels of Na+ and Na+/K+, particularly in callus treated with NaCl. β-Glucan ameliorates the adverse effects of NaCl stress, and the extent of amelioration depends on the type of β-glucan agent as well as treatment duration (three months). The changes mentioned are important for determining the morphological, chemical, and biochemical parameters of salinity tolerance in callus. This study demonstrated that exogenous β-glucan exhibits alleviation of the harmful effects of salt stress and increases salinity resistance in callus rice.

Pages 118-125 | Read More| doi: 10.21475/ajcs.2017.11.01.296


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