Pub Date : 2020-12-10DOI: 10.21475/AJCS.20.14.12.2700
Flávia Nicácio Viana, Jocarla Ambrosim Crevelari, Gabriel Moreno Bernardo Gonçalves, José Arantes Ferreira Júnior, De Franca, M. G. Pereira, A. T. A. Junior
Maize cultivars developed for silage production are desirable because ensiling enables the production of high-quality feed and, increases farmers profit. Diallel cross is an efficient and advantageous mating technique that allows the selection of the best parents and crossings. The objective of this study was to estimate the general combining ability (GCA) and specific combining ability (SCA) of hybrids and their parents and to evaluate promising hybrid crosses that can be used in breeding programs. Six genotypes were crossed in a complete diallel system. Fifteen hybrid combinations, six parents, and three commercial controls were evaluated in the 2017/2018 growing season in the north and northwest regions of Rio de Janeiro state, Brazil. Nine agronomic traits were analyzed at the silage stage: plant and ear height, stem diameter, stand, husk covering, number of cobs, husked ear weight, unhusked ear weight, and fresh mass yield. The study employed a completely randomized block design with four repetitions. The parents UENF 2210, Piranão 12, and UENF 2208 presented higher GCA values for fresh matter yield and were indicated for the generation of single cross (F1) hybrids. The parental combinations of UENF 2208 Piranão 12, UENF 2208 UENF 2205, and UENF 2209 UENF 2205 had high SCA for most of the evaluated traits and were promising for the use in breeding programs. The crosses with higher average yield were UENF 2208 Piranão 12, UENF 2210 Piranão 12, and UENF 2208 UENF 2205
{"title":"Combining ability in maize hybrid for yield-related traits and silage production","authors":"Flávia Nicácio Viana, Jocarla Ambrosim Crevelari, Gabriel Moreno Bernardo Gonçalves, José Arantes Ferreira Júnior, De Franca, M. G. Pereira, A. T. A. Junior","doi":"10.21475/AJCS.20.14.12.2700","DOIUrl":"https://doi.org/10.21475/AJCS.20.14.12.2700","url":null,"abstract":"Maize cultivars developed for silage production are desirable because ensiling enables the production of high-quality feed and, increases farmers profit. Diallel cross is an efficient and advantageous mating technique that allows the selection of the best parents and crossings. The objective of this study was to estimate the general combining ability (GCA) and specific combining ability (SCA) of hybrids and their parents and to evaluate promising hybrid crosses that can be used in breeding programs. Six genotypes were crossed in a complete diallel system. Fifteen hybrid combinations, six parents, and three commercial controls were evaluated in the 2017/2018 growing season in the north and northwest regions of Rio de Janeiro state, Brazil. Nine agronomic traits were analyzed at the silage stage: plant and ear height, stem diameter, stand, husk covering, number of cobs, husked ear weight, unhusked ear weight, and fresh mass yield. The study employed a completely randomized block design with four repetitions. The parents UENF 2210, Piranão 12, and UENF 2208 presented higher GCA values for fresh matter yield and were indicated for the generation of single cross (F1) hybrids. The parental combinations of UENF 2208 Piranão 12, UENF 2208 UENF 2205, and UENF 2209 UENF 2205 had high SCA for most of the evaluated traits and were promising for the use in breeding programs. The crosses with higher average yield were UENF 2208 Piranão 12, UENF 2210 Piranão 12, and UENF 2208 UENF 2205","PeriodicalId":20643,"journal":{"name":"Proposed for presentation at the 2020 Virtual MRS Fall Meeting & Exhibit held November 27 - December 4, 2020.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76782262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-10DOI: 10.21475/AJCS.20.14.12.2822
N. D. F. Guimarães, A. A. Otsubo, R. A. Garcia, A. D. S. Gallo, E. M. Carvalho, Rogério Ferreira da Silva
This study aimed to identify and assess the edaphic invertebrate macrofauna associated with cassava crop in succession to different soil coverages. The experimental design was randomized blocks as 6 x 3 factorial design with four replications. The first factor was soil cover cultivated from December 2014 to April 2015 (fallow, pearl millet, forage sorghum, Crotalaria ochroleuca, Urochloa ruziziensis and Corn+Urochloa ruziziensis). The second factor was sampling periods (March/2015, October/2015 and June/2016). We sampled four blocks of 0.25 x 0.25 x 0.20 m in each system, following the TSBF (Tropical Soil Biology and Fertility) collection method. The taxonomic composition and abundance of organisms, richness of groups and the diversity indexes of Shannon, Pielou equitability and Simpson dominance were evaluated. There was no interaction between the factors (soil cover x season) for the variables studied. There was difference in the dominance of organisms according to the soil cover (isolated), being the highest index (0.44) obtained by previous cultivation of forage sorghum. The abundance of organisms, group richness and diversity index were influenced by sampling period, demonstrating the influence of seasonality on the invertebrate macrofauna community of the soil
本研究旨在鉴定和评价不同土壤覆盖度下与木薯作物相关的大型无脊椎动物。试验设计为随机分组6 × 3因子设计，4个重复。第一个因子为2014年12月- 2015年4月种植的土壤覆盖(休耕、珍珠粟、饲草高粱、Crotalaria ochroleuca、Urochloa ruziziensis和玉米+Urochloa ruziziensis)。第二个因素是采样周期(2015年3月、2015年10月和2016年6月)。我们按照TSBF(热带土壤生物学和肥力)收集方法，在每个系统中采样0.25 x 0.25 x 0.20 m的四个块。评价了生物的分类组成和丰度、类群丰富度以及Shannon、Pielou公平度和Simpson优势度的多样性指数。各因子(土壤覆盖x季节)之间不存在交互作用。不同土壤覆被对生物优势度的影响存在差异(孤立)，以往栽培饲草高粱的优势度指数最高(0.44)。生物丰度、类群丰富度和多样性指数受采样周期的影响，反映了季节对土壤无脊椎大型动物群落的影响
{"title":"Edaphic invertebrate macrofauna associated with cassava crop in different soil coverages","authors":"N. D. F. Guimarães, A. A. Otsubo, R. A. Garcia, A. D. S. Gallo, E. M. Carvalho, Rogério Ferreira da Silva","doi":"10.21475/AJCS.20.14.12.2822","DOIUrl":"https://doi.org/10.21475/AJCS.20.14.12.2822","url":null,"abstract":"This study aimed to identify and assess the edaphic invertebrate macrofauna associated with cassava crop in succession to different soil coverages. The experimental design was randomized blocks as 6 x 3 factorial design with four replications. The first factor was soil cover cultivated from December 2014 to April 2015 (fallow, pearl millet, forage sorghum, Crotalaria ochroleuca, Urochloa ruziziensis and Corn+Urochloa ruziziensis). The second factor was sampling periods (March/2015, October/2015 and June/2016). We sampled four blocks of 0.25 x 0.25 x 0.20 m in each system, following the TSBF (Tropical Soil Biology and Fertility) collection method. The taxonomic composition and abundance of organisms, richness of groups and the diversity indexes of Shannon, Pielou equitability and Simpson dominance were evaluated. There was no interaction between the factors (soil cover x season) for the variables studied. There was difference in the dominance of organisms according to the soil cover (isolated), being the highest index (0.44) obtained by previous cultivation of forage sorghum. The abundance of organisms, group richness and diversity index were influenced by sampling period, demonstrating the influence of seasonality on the invertebrate macrofauna community of the soil","PeriodicalId":20643,"journal":{"name":"Proposed for presentation at the 2020 Virtual MRS Fall Meeting & Exhibit held November 27 - December 4, 2020.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81208880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-10DOI: 10.21475/AJCS.20.14.12.2849
N. Minh, D. Hoang, N. V. Lộc, Nguyen Viet Long
Because of rainfall shortage, quinoa has the potential to supersede traditional crops that contribute to agricultural production less effectively. The current study determined the quinoa genotypes and plant density suitable for production under rain-fed conditions in red basalt soil regions. The experiments were conducted in the rainy and dry seasons of 2018/2019 using split-plot designs with three replications. In these, the main factor consisted of four quinoa genotypes and the subfactor four plant densities (13.3, 10.0, 8.0 and 6.6 plants m-2) with a row interval of 50cm and a plant interval of 15, 20, 25 and 30cm, respectively. The current study’s results showed that plant density significantly affected polynomial trends on panicle length, panicle number/plant, seed number/panicle, 1000-seed weight, seed yield, protein content, and ash content. The plant density of 8.0 plants m-2 seems to be the optimal density for quinoa under the studied conditions. Results here also indicate significant differences among quinoa genotypes for agronomical and seed quality performance. Better performances of quinoa occurred in the dry season compared to the rainy season. Atlas and Cahuil were the best adaptive quinoa genotypes in the red basalt soil regions
{"title":"Effects of plant density on growth, yield and seed quality of quinoa genotypes under rain-fed conditions on red basalt soil regions","authors":"N. Minh, D. Hoang, N. V. Lộc, Nguyen Viet Long","doi":"10.21475/AJCS.20.14.12.2849","DOIUrl":"https://doi.org/10.21475/AJCS.20.14.12.2849","url":null,"abstract":"Because of rainfall shortage, quinoa has the potential to supersede traditional crops that contribute to agricultural production less effectively. The current study determined the quinoa genotypes and plant density suitable for production under rain-fed conditions in red basalt soil regions. The experiments were conducted in the rainy and dry seasons of 2018/2019 using split-plot designs with three replications. In these, the main factor consisted of four quinoa genotypes and the subfactor four plant densities (13.3, 10.0, 8.0 and 6.6 plants m-2) with a row interval of 50cm and a plant interval of 15, 20, 25 and 30cm, respectively. The current study’s results showed that plant density significantly affected polynomial trends on panicle length, panicle number/plant, seed number/panicle, 1000-seed weight, seed yield, protein content, and ash content. The plant density of 8.0 plants m-2 seems to be the optimal density for quinoa under the studied conditions. Results here also indicate significant differences among quinoa genotypes for agronomical and seed quality performance. Better performances of quinoa occurred in the dry season compared to the rainy season. Atlas and Cahuil were the best adaptive quinoa genotypes in the red basalt soil regions","PeriodicalId":20643,"journal":{"name":"Proposed for presentation at the 2020 Virtual MRS Fall Meeting & Exhibit held November 27 - December 4, 2020.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90781472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-10DOI: 10.21475/AJCS.20.14.12.1589.PDF
Maizura Abu Sin, G. Saleh, N. Abdullah, P. Kashiani
Genetic diversity and phenotypic superiority are important attributes of parental inbred lines for use in hybrid breeding programs. In this study, genetic diversity among 30 maize (Zea mays L.) inbred lines comprising of 28 introductions from the International Maize and Wheat Improvement Center (CIMMYT), one from Indonesia and a locally developed, were evaluated using 100 simple sequence repeat (SSR) markers, as early screening for potential parents of hybrid varieties. All markers were polymorphic, with a total of 550 unique alleles detected on the 100 loci from the 30 inbred lines. Allelic richness ranged from 2 to 13 per locus, with an average of 5.50 alleles (na). Number of effective alleles (ne) was 3.75 per locus, indicating their high effectiveness in revealing diversity among inbred lines. Average polymorphic information content (PIC) was 0.624, with values ranging from 0.178 to 0.874, indicating high informativeness of the markers. High gene diversity was observed on Chromosomes 8 and 4, with high number of effective alleles, indicating their potential usefulness for QTL analysis. The UPGMA dendrogram constructed identified four heterotic groups within a similarity index of 0.350, indicating that these markers were able to group the inbred lines. The three-dimensional PCoA plot also supports the dendrogram grouping, indicating that these two methods complement each other. Inbred lines in different heterotic groups have originated from different backgrounds and population sources. Information on genetic diversity among the maize inbred lines are useful in developing strategies exploiting heterosis in breeding programs
{"title":"Genetic diversity among tropical maize inbred lines as revealed by SSR markers","authors":"Maizura Abu Sin, G. Saleh, N. Abdullah, P. Kashiani","doi":"10.21475/AJCS.20.14.12.1589.PDF","DOIUrl":"https://doi.org/10.21475/AJCS.20.14.12.1589.PDF","url":null,"abstract":"Genetic diversity and phenotypic superiority are important attributes of parental inbred lines for use in hybrid breeding programs. In this study, genetic diversity among 30 maize (Zea mays L.) inbred lines comprising of 28 introductions from the International Maize and Wheat Improvement Center (CIMMYT), one from Indonesia and a locally developed, were evaluated using 100 simple sequence repeat (SSR) markers, as early screening for potential parents of hybrid varieties. All markers were polymorphic, with a total of 550 unique alleles detected on the 100 loci from the 30 inbred lines. Allelic richness ranged from 2 to 13 per locus, with an average of 5.50 alleles (na). Number of effective alleles (ne) was 3.75 per locus, indicating their high effectiveness in revealing diversity among inbred lines. Average polymorphic information content (PIC) was 0.624, with values ranging from 0.178 to 0.874, indicating high informativeness of the markers. High gene diversity was observed on Chromosomes 8 and 4, with high number of effective alleles, indicating their potential usefulness for QTL analysis. The UPGMA dendrogram constructed identified four heterotic groups within a similarity index of 0.350, indicating that these markers were able to group the inbred lines. The three-dimensional PCoA plot also supports the dendrogram grouping, indicating that these two methods complement each other. Inbred lines in different heterotic groups have originated from different backgrounds and population sources. Information on genetic diversity among the maize inbred lines are useful in developing strategies exploiting heterosis in breeding programs","PeriodicalId":20643,"journal":{"name":"Proposed for presentation at the 2020 Virtual MRS Fall Meeting & Exhibit held November 27 - December 4, 2020.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84145286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-10DOI: 10.21475/AJCS.20.14.12.2792
N. K. Njeru, C. Midega, J. Muthomi, J. Wagacha, Z. Khan
Maize grown under push-pull cropping system has been reported to contain lower concentrations of fumonisin and aflatoxin than maize monocrop. This study determined the inhibitory effect of desmodium root extracts on spore germination and radial growth of toxigenic Aspergillus flavus and Fusarium verticillioides. Aspergillus flavus and F. verticillioides were isolated from maize and soil and tested for ability to produce aflatoxin and fumonisin by inoculation on mycotoxin-free maize. Aflatoxin and fuminisin were detected and quantified by direct competitive ELISA. Desmodium roots were dried, ground to fine powder and extracted with methanol and dichloromethane and evaluated for anti-fungal activity by inhibition of spores of A. flavus and F. verticillioides potato dextrose agar (PDA) medium. Isolates of F. verticillioides produced up to 599,741 µg/kg fumonisin while isolates of A. flavus produced up to 199,184 µg/kg aflatoxin. Desmodium root extracts reduced germination of A. flavus spores and F. verticillioides by 9.6% and 43.8%, respectively and reduced their respective colony radial growth by 15% and 57%. The results suggested that desmodium roots contain chemical compounds that inhibit growth of A. flavus and F. verticillioides. This may explain the reduction in infection of maize with mycotoxin-producing fungi before harvest in push-pull cropping systems by reducing the pathogen inoculum in the soils. Determination of the active compounds in the root exudates is recommended
{"title":"In vitro antifungal activity of Desmodium intortum and D. uncinatum root extracts against growth of toxigenic Fusarium verticillioides and Aspergillus flavus","authors":"N. K. Njeru, C. Midega, J. Muthomi, J. Wagacha, Z. Khan","doi":"10.21475/AJCS.20.14.12.2792","DOIUrl":"https://doi.org/10.21475/AJCS.20.14.12.2792","url":null,"abstract":"Maize grown under push-pull cropping system has been reported to contain lower concentrations of fumonisin and aflatoxin than maize monocrop. This study determined the inhibitory effect of desmodium root extracts on spore germination and radial growth of toxigenic Aspergillus flavus and Fusarium verticillioides. Aspergillus flavus and F. verticillioides were isolated from maize and soil and tested for ability to produce aflatoxin and fumonisin by inoculation on mycotoxin-free maize. Aflatoxin and fuminisin were detected and quantified by direct competitive ELISA. Desmodium roots were dried, ground to fine powder and extracted with methanol and dichloromethane and evaluated for anti-fungal activity by inhibition of spores of A. flavus and F. verticillioides potato dextrose agar (PDA) medium. Isolates of F. verticillioides produced up to 599,741 µg/kg fumonisin while isolates of A. flavus produced up to 199,184 µg/kg aflatoxin. Desmodium root extracts reduced germination of A. flavus spores and F. verticillioides by 9.6% and 43.8%, respectively and reduced their respective colony radial growth by 15% and 57%. The results suggested that desmodium roots contain chemical compounds that inhibit growth of A. flavus and F. verticillioides. This may explain the reduction in infection of maize with mycotoxin-producing fungi before harvest in push-pull cropping systems by reducing the pathogen inoculum in the soils. Determination of the active compounds in the root exudates is recommended","PeriodicalId":20643,"journal":{"name":"Proposed for presentation at the 2020 Virtual MRS Fall Meeting & Exhibit held November 27 - December 4, 2020.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78031362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-10DOI: 10.21475/AJCS.20.14.12.2871
R. R. Costa, T. D. O. Ferreira, Antônio Augusto Marques Rodrigues, Eugenio Ribeiro de Andrade Neto, M. Lima
Production system and environmental factors might cause changes in grapevine physiology, affecting grape yield, quality, phenolic composition, and antioxidant potential. The aim of this study was to characterize the quality and antioxidant potential of 'Isabel Precoce' grapes on different training systems and rootstocks in warmer seasons, in tropical conditions. Experimental design was in randomized blocks, in sub-subplots through time and four replicates. Three training systems (overhead trellis, lyre and vertical shoot positioning - VSP) and two rootstocks (‘IAC 572’ and ‘IAC 766’) were studied in the production cycles from July to October, 2017 and from July to October, 2018 in the Submedium of São Francisco Valley. Berry weight; cluster weight; color attributes; berry resistance to compression (COMP); titratable acidity; soluble solids; total soluble sugars (TSS); yellow flavonoids; total anthocyanins; total extractable polyphenols and antioxidant activity by ABTS●+ and DPPH● free radical capture methods were analyzed. Lyre and VSP resulted on increases of 6% and 17% in berry weight and COMP, respectively. Moreover, differences between production cycles were more intense for both variables. In production cycle from July to October 2017, lyre and VSP systems provided increases of 2 g 100 g-1 of TSS and higher anthocyanin and yellow flavonoid contents, while grapes trained in VSP had higher antioxidant activity. Mean values of anthocyanins reached 529.34 mg 100 g-1 in grapes harvested in October 2017. Some grape quality and chemical components showed high variation in warmer seasons of sucessive years, according to training system or rootstock and their combinations
{"title":"Quality and antioxidant activity of 'Isabel Precoce' grapes installed on different training systems and rootstocks in warmer seasons in a tropical semi-arid region","authors":"R. R. Costa, T. D. O. Ferreira, Antônio Augusto Marques Rodrigues, Eugenio Ribeiro de Andrade Neto, M. Lima","doi":"10.21475/AJCS.20.14.12.2871","DOIUrl":"https://doi.org/10.21475/AJCS.20.14.12.2871","url":null,"abstract":"Production system and environmental factors might cause changes in grapevine physiology, affecting grape yield, quality, phenolic composition, and antioxidant potential. The aim of this study was to characterize the quality and antioxidant potential of 'Isabel Precoce' grapes on different training systems and rootstocks in warmer seasons, in tropical conditions. Experimental design was in randomized blocks, in sub-subplots through time and four replicates. Three training systems (overhead trellis, lyre and vertical shoot positioning - VSP) and two rootstocks (‘IAC 572’ and ‘IAC 766’) were studied in the production cycles from July to October, 2017 and from July to October, 2018 in the Submedium of São Francisco Valley. Berry weight; cluster weight; color attributes; berry resistance to compression (COMP); titratable acidity; soluble solids; total soluble sugars (TSS); yellow flavonoids; total anthocyanins; total extractable polyphenols and antioxidant activity by ABTS●+ and DPPH● free radical capture methods were analyzed. Lyre and VSP resulted on increases of 6% and 17% in berry weight and COMP, respectively. Moreover, differences between production cycles were more intense for both variables. In production cycle from July to October 2017, lyre and VSP systems provided increases of 2 g 100 g-1 of TSS and higher anthocyanin and yellow flavonoid contents, while grapes trained in VSP had higher antioxidant activity. Mean values of anthocyanins reached 529.34 mg 100 g-1 in grapes harvested in October 2017. Some grape quality and chemical components showed high variation in warmer seasons of sucessive years, according to training system or rootstock and their combinations","PeriodicalId":20643,"journal":{"name":"Proposed for presentation at the 2020 Virtual MRS Fall Meeting & Exhibit held November 27 - December 4, 2020.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76387703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-10DOI: 10.21475/AJCS.20.14.12.2883
M. Arias, N. Curbelo, Pablo González Rabelino, E. Vicente, G. Giménez, G. Galván
Onion downy mildew (DM) caused by Peronospora destructor is a very destructive leaf disease. Genetic resistance is an economic and environmentally friendly way of disease control. In this research, the segregation of DM resistance was analysed in six offspring from crosses between national cultivars and the cv. ‘Regia’, a partial resistance source. F1 plants were self-fertilised, and F1S1 derived progenies were evaluated. The segregations in DM severity were skewed towards susceptibility, with transgressive segregation in five of six progenies. The recessive inheritance could be associated with loss of susceptibility mechanisms. In another experiment, the response of advanced F1S2 lines ‘Regia’ x ‘Pantanoso del Sauce’ were evaluated two times (August and November 2017) in DM disease severity, DM histological quantitative differences, and agronomic traits. F1S2 lines, which have had an earlier selection process, presented an intermediate DM severity between the parents. Disease severity was positively correlated with histological differences in the proportion of infected stomata. ‘Regia’ presented the lowest DM severity and the highest percentage of healthy stomata. Most resistant F1S2 lines did not differ from control cultivars in bulb yield, bulb quality traits and postharvest behaviour, and could be the basis to develop a DM resistant cultivar in comparison to currently grown cultivars
洋葱霜霉病是由Peronospora destructor引起的一种极具破坏性的叶病。遗传抗性是一种既经济又环保的疾病控制方式。本研究分析了6个国家品种与变异品种杂交后代的抗白粉病分离。' rega '，部分电阻源。对F1植株进行自交受精，并对F1S1衍生后代进行评价。糖尿病严重程度的分离倾向于易感性，6个后代中有5个存在海侵性分离。隐性遗传可能与易感机制缺失有关。在另一项试验中，研究人员于2017年8月和11月两次评估了先进F1S2系“Regia”和“Pantanoso del Sauce”对糖尿病疾病严重程度、糖尿病组织学数量差异和农艺性状的反应。选择过程较早的F1S2系在亲本之间表现出中度糖尿病的严重程度。疾病严重程度与感染气孔比例的组织学差异呈正相关。‘Regia’的DM严重程度最低，健康气孔比例最高。大多数抗病品种F1S2在鳞茎产量、鳞茎品质性状和采后行为方面与对照品种没有差异，与现有品种相比，可作为培育抗DM品种的基础
{"title":"Inheritance of resistance against Peronospora destructor in onion cv. ‘Regia’","authors":"M. Arias, N. Curbelo, Pablo González Rabelino, E. Vicente, G. Giménez, G. Galván","doi":"10.21475/AJCS.20.14.12.2883","DOIUrl":"https://doi.org/10.21475/AJCS.20.14.12.2883","url":null,"abstract":"Onion downy mildew (DM) caused by Peronospora destructor is a very destructive leaf disease. Genetic resistance is an economic and environmentally friendly way of disease control. In this research, the segregation of DM resistance was analysed in six offspring from crosses between national cultivars and the cv. ‘Regia’, a partial resistance source. F1 plants were self-fertilised, and F1S1 derived progenies were evaluated. The segregations in DM severity were skewed towards susceptibility, with transgressive segregation in five of six progenies. The recessive inheritance could be associated with loss of susceptibility mechanisms. In another experiment, the response of advanced F1S2 lines ‘Regia’ x ‘Pantanoso del Sauce’ were evaluated two times (August and November 2017) in DM disease severity, DM histological quantitative differences, and agronomic traits. F1S2 lines, which have had an earlier selection process, presented an intermediate DM severity between the parents. Disease severity was positively correlated with histological differences in the proportion of infected stomata. ‘Regia’ presented the lowest DM severity and the highest percentage of healthy stomata. Most resistant F1S2 lines did not differ from control cultivars in bulb yield, bulb quality traits and postharvest behaviour, and could be the basis to develop a DM resistant cultivar in comparison to currently grown cultivars","PeriodicalId":20643,"journal":{"name":"Proposed for presentation at the 2020 Virtual MRS Fall Meeting & Exhibit held November 27 - December 4, 2020.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78812584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-10DOI: 10.21475/AJCS.20.14.12.2666
P. L. Pinheiro, R. R. Passos, Anderson Lopes Peçanha, E. Mendonça
Recovery of degraded pastures improves the sustainability of meat and milk production systems. Humic acids (HA) and endophytic diazotrophic bacteria (EDB) are known to have bio-stimulating effects on several crops but have not been tested for the recovery of degraded pastures. The aim of the present study was to evaluate soil C and N dynamics, nutrient uptake and forage yield of Brachiaria decumbens following the foliar application of HA and EDB in a degraded pasture. A randomized block design with six replications was used. The four treatments were: HA, EDB, HA+EDB and Control. The subplots consisted of four evaluation times for soil characteristics: before treatment application (0) and 30, 60 and 120 days after treatment application (ATA). Soil total organic carbon (TOC), recalcitrant carbon (Crecal), labile carbon (Clabil), total nitrogen (TN) and C and N stocks were determined in the 0-5, 5-10, 10-20 and 20-40 cm of soil layers. Forage yield and leaf nutrient contents were evaluated at 30 days ATA. The application of the HA and EDB increased the TOC, Clabil, soil C stock (≈18%), forage dry matter yield (16 to 52%) and nutrient uptake (≈30%) after 30 days ATA. Our results showed that the application of HA combined with EDB may be a strategy for the recovery of degraded pastures in the tropical region.
退化牧场的恢复提高了肉类和牛奶生产系统的可持续性。腐植酸(HA)和内生重氮营养细菌(EDB)已知对几种作物具有生物刺激作用，但尚未对退化牧场的恢复进行测试。以退化牧草为研究对象，研究了叶面施用HA和EDB对躺椅(Brachiaria decumbens)土壤碳氮动态、养分吸收和饲料产量的影响。采用随机区组设计，共6个重复。四种处理分别为:HA、EDB、HA+EDB和对照组。子样区包括施用前(0)和施用后30、60和120 d (ATA) 4个土壤特性评价时间。测定了0-5、5-10、10-20和20-40 cm土层的土壤总有机碳(TOC)、顽固性碳(Crecal)、活性碳(Clabil)、全氮(TN)和碳氮储量。第30天测定饲料产量和叶片养分含量。施用HA和EDB可提高30 d土壤TOC、Clabil、土壤C储量(≈18%)、牧草干物质产量(16% ~ 52%)和养分吸收量(≈30%)。结果表明，在热带地区，HA与EDB联合施用可能是恢复退化牧场的一种策略。
{"title":"Application of biofertilizer in degraded pasture modified C dynamics and improved forage yield in a short-term period at the tropical region","authors":"P. L. Pinheiro, R. R. Passos, Anderson Lopes Peçanha, E. Mendonça","doi":"10.21475/AJCS.20.14.12.2666","DOIUrl":"https://doi.org/10.21475/AJCS.20.14.12.2666","url":null,"abstract":"Recovery of degraded pastures improves the sustainability of meat and milk production systems. Humic acids (HA) and endophytic diazotrophic bacteria (EDB) are known to have bio-stimulating effects on several crops but have not been tested for the recovery of degraded pastures. The aim of the present study was to evaluate soil C and N dynamics, nutrient uptake and forage yield of Brachiaria decumbens following the foliar application of HA and EDB in a degraded pasture. A randomized block design with six replications was used. The four treatments were: HA, EDB, HA+EDB and Control. The subplots consisted of four evaluation times for soil characteristics: before treatment application (0) and 30, 60 and 120 days after treatment application (ATA). Soil total organic carbon (TOC), recalcitrant carbon (Crecal), labile carbon (Clabil), total nitrogen (TN) and C and N stocks were determined in the 0-5, 5-10, 10-20 and 20-40 cm of soil layers. Forage yield and leaf nutrient contents were evaluated at 30 days ATA. The application of the HA and EDB increased the TOC, Clabil, soil C stock (≈18%), forage dry matter yield (16 to 52%) and nutrient uptake (≈30%) after 30 days ATA. Our results showed that the application of HA combined with EDB may be a strategy for the recovery of degraded pastures in the tropical region.","PeriodicalId":20643,"journal":{"name":"Proposed for presentation at the 2020 Virtual MRS Fall Meeting & Exhibit held November 27 - December 4, 2020.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84404297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-10DOI: 10.21475/AJCS.20.14.12.2770
R. Wanna, Bunyaporn Satongrod
Essential oils of plants with insecticidal properties have been considered as replacements for synthetic chemical pesticides to combat and control insect pests. The chemical composition of the essential oil from dried seeds of Zanthoxylum limonella Alston was determined by the Gas Chromatograph-Mass Spectrometry technique. Insecticidal activity was investigated on Tribolium castaneum Herbst using impregnated filter paper with six concentrations of essential oil at 0, 1, 2, 3, 4, and 5% for adults and larvae mortality tests, and 0, 2, 4, 6, 8 and 10% for egg mortality. All experiments were performed under completely randomized design (CRD) with four replications at 30±5°C and 70±5% relative humidity in 16:8 hours light/dark cycle. A total of 83 components were identified. The principal compounds in the essential oil of Z. limonella were beta-pinene (19.65%), 9-octadecanone (18.80%), D-limonene (9.76%), alpha-fenchene (8.48%), p-mentha-1,5,8-triene (7.16%), 1,8-cineole (6.88%), gamma-terpinene (5.46%), terpinen-4-ol (3.81%), linalool (2.73%), alpha-thujene (1.34%), decanal (1.32%), alpha-phellandrene (1.20%) and linalyl propionate (1.13%). Insecticidal activity presented that 5% of essential oil had the highest effect against T. castaneum at 120 h for adults and 48 h for larvae, while 10% of essential oil at 14 days obtained 100% mortality against eggs of T. castaneum. Results indicated that the essential oil of Z. limonella from dried seeds showed potential for use in the control of T. castaneum
{"title":"Potential effects of essential oil from Zanthoxylum limonella seeds against Tribolium castaneum (Coleoptera: Tenebrionidae)","authors":"R. Wanna, Bunyaporn Satongrod","doi":"10.21475/AJCS.20.14.12.2770","DOIUrl":"https://doi.org/10.21475/AJCS.20.14.12.2770","url":null,"abstract":"Essential oils of plants with insecticidal properties have been considered as replacements for synthetic chemical pesticides to combat and control insect pests. The chemical composition of the essential oil from dried seeds of Zanthoxylum limonella Alston was determined by the Gas Chromatograph-Mass Spectrometry technique. Insecticidal activity was investigated on Tribolium castaneum Herbst using impregnated filter paper with six concentrations of essential oil at 0, 1, 2, 3, 4, and 5% for adults and larvae mortality tests, and 0, 2, 4, 6, 8 and 10% for egg mortality. All experiments were performed under completely randomized design (CRD) with four replications at 30±5°C and 70±5% relative humidity in 16:8 hours light/dark cycle. A total of 83 components were identified. The principal compounds in the essential oil of Z. limonella were beta-pinene (19.65%), 9-octadecanone (18.80%), D-limonene (9.76%), alpha-fenchene (8.48%), p-mentha-1,5,8-triene (7.16%), 1,8-cineole (6.88%), gamma-terpinene (5.46%), terpinen-4-ol (3.81%), linalool (2.73%), alpha-thujene (1.34%), decanal (1.32%), alpha-phellandrene (1.20%) and linalyl propionate (1.13%). Insecticidal activity presented that 5% of essential oil had the highest effect against T. castaneum at 120 h for adults and 48 h for larvae, while 10% of essential oil at 14 days obtained 100% mortality against eggs of T. castaneum. Results indicated that the essential oil of Z. limonella from dried seeds showed potential for use in the control of T. castaneum","PeriodicalId":20643,"journal":{"name":"Proposed for presentation at the 2020 Virtual MRS Fall Meeting & Exhibit held November 27 - December 4, 2020.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76618449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-10DOI: 10.21475/AJCS.20.14.12.2650
S. Roehrs, Aracéli Ciotti de Marins, Deonir Secco, Rogério Luís Rizzi, L. A. Z. Júnior, Pablo Chang, Claudia Borgmann, B. D. Villa, L. D. Silveira, Luciene Kazue Tokura
The use and management of the soil cause occasional changes in its physical properties; thus, altering its spatial variability. This work aimed to show the spatial distribution of physical attributes of a clay latosol under different management systems, through thematic maps of spatial distribution for values of these attributes. The experimental area consisted of three treatments: scarified no-tillage at 0.3 m depth (T1), no-tillage with 3 t ha-1 of plaster applied to the surface (T2) and; the control as traditional no-tillage system (T3). The attributes such as density, macroporosity, and microporosity in three soil layers were evaluated: 0-0.1; 0.1-0.2; and 0.2-0.3 m. The analysis of the experimental results indicates that all physical attributes presented spatial dependence between the data, with higher density values (values ranged from 0.95 to 1.37 Mg m3) and lower macroporosity in areas with T1 (SPD with scarification) and T2 (SPD gypsum) management systems. However, in all treatments, the Macro values presented a volume above 10.51%, which is above the limit value for good aeration and water movement in the soil. Treatment T3 (traditional SPD) showed favorable physical soil conditions, even after compaction
{"title":"Spatial distribution of physical attributes of a clayey Latosol under different management systems","authors":"S. Roehrs, Aracéli Ciotti de Marins, Deonir Secco, Rogério Luís Rizzi, L. A. Z. Júnior, Pablo Chang, Claudia Borgmann, B. D. Villa, L. D. Silveira, Luciene Kazue Tokura","doi":"10.21475/AJCS.20.14.12.2650","DOIUrl":"https://doi.org/10.21475/AJCS.20.14.12.2650","url":null,"abstract":"The use and management of the soil cause occasional changes in its physical properties; thus, altering its spatial variability. This work aimed to show the spatial distribution of physical attributes of a clay latosol under different management systems, through thematic maps of spatial distribution for values of these attributes. The experimental area consisted of three treatments: scarified no-tillage at 0.3 m depth (T1), no-tillage with 3 t ha-1 of plaster applied to the surface (T2) and; the control as traditional no-tillage system (T3). The attributes such as density, macroporosity, and microporosity in three soil layers were evaluated: 0-0.1; 0.1-0.2; and 0.2-0.3 m. The analysis of the experimental results indicates that all physical attributes presented spatial dependence between the data, with higher density values (values ranged from 0.95 to 1.37 Mg m3) and lower macroporosity in areas with T1 (SPD with scarification) and T2 (SPD gypsum) management systems. However, in all treatments, the Macro values presented a volume above 10.51%, which is above the limit value for good aeration and water movement in the soil. Treatment T3 (traditional SPD) showed favorable physical soil conditions, even after compaction","PeriodicalId":20643,"journal":{"name":"Proposed for presentation at the 2020 Virtual MRS Fall Meeting & Exhibit held November 27 - December 4, 2020.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79372930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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