Pub Date : 2016-09-03DOI: 10.32604/phyton.2015.84.331
Ja López-Elías, R. González-Vega, E. Márquez‐Ríos, W. Torres‐Arreola
Proteins are one of the major metabolites in biomass from microalgae that constitute the diet of marine organisms grown in aquaculture, and are essential for their growth. The quantity of this component is influenced by nutrients, temperature and light intensity, among others. We examined the growth, biomass production and protein of Chaetoceros muelleri with two sources of nitrogen (nitrate and urea) at three concentrations, using the medium f/2 (0.88 mol/L) (nitrates) as control. The treatments were the medium 2f (3.53 mol/L) and 4f (7.05 mol/L) with NO3-, and the medium f/2 (0.88 mol/L), 2f (3.53mol/L) and 4f (7.05 mol/L) with urea. In general, the productive parameters were greater using urea than nitrate in the media. Higher cell concentrations (2.83 x 106 cell/mL), average and cumulative growth rates (1.50 div/day and 6.01 divisions), dry weight (0.0044 g/L), and proportion of proteins (23.74%) were found when urea was used as the N source. However, most of the bands on the electrophoretic profile were present in the mediums with NO3- (~6.5 to 90 kDa).
{"title":"Effect of nitrogen source and concentration to produce proteins in mass cultures of the microalgae Chaetoceros muelleri","authors":"Ja López-Elías, R. González-Vega, E. Márquez‐Ríos, W. Torres‐Arreola","doi":"10.32604/phyton.2015.84.331","DOIUrl":"https://doi.org/10.32604/phyton.2015.84.331","url":null,"abstract":"Proteins are one of the major metabolites in biomass from microalgae that constitute the diet of marine organisms grown in aquaculture, and are essential for their growth. The quantity of this component is influenced by nutrients, temperature and light intensity, among others. We examined the growth, biomass production and protein of Chaetoceros muelleri with two sources of nitrogen (nitrate and urea) at three concentrations, using the medium f/2 (0.88 mol/L) (nitrates) as control. The treatments were the medium 2f (3.53 mol/L) and 4f (7.05 mol/L) with NO3-, and the medium f/2 (0.88 mol/L), 2f (3.53mol/L) and 4f (7.05 mol/L) with urea. In general, the productive parameters were greater using urea than nitrate in the media. Higher cell concentrations (2.83 x 106 cell/mL), average and cumulative growth rates (1.50 div/day and 6.01 divisions), dry weight (0.0044 g/L), and proportion of proteins (23.74%) were found when urea was used as the N source. However, most of the bands on the electrophoretic profile were present in the mediums with NO3- (~6.5 to 90 kDa).","PeriodicalId":20184,"journal":{"name":"Phyton-international Journal of Experimental Botany","volume":"12 1","pages":"331-337"},"PeriodicalIF":1.7,"publicationDate":"2016-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76321633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-03DOI: 10.32604/phyton.2015.84.288
A. Maroyi, M. Rasethe
Documentation of use patterns of plants across national boundaries is of relevance in understanding the importance of plant resources to livelihood strategies of different ethnic groups. Plant resources have gained prominence as a natural asset through which families derive food, firewood, income, medicines and timber, enabling particularly poor communities to achieve self-sufficiency. The objective of this study was to investigate the trends in plant usage in South Africa and Zimbabwe. An ethnobotanical investigation was conducted between January 2012 and January 2013 in the Limpopo Province, South Africa and the Midlands Province, Zimbabwe. The study used questionnaire surveys and interviews with a total of 143 participants to explore plant use patterns in South Africa and Zimbabwe. A total of 98 plant species were identified, with Zimbabwe contributing 70 species and 47 species from South Africa. The uses were classified into 15 categories, major use categories were firewood, food plants, medicine and timber. Food plant was a major plant use category in Zimbabwe, contributing 55.1%, followed by medicinal plants (36.8%), firewood (35.7%) and timber (31.6%). In contrast, firewood was the major plant use category in South Africa, contributing 18.4%, followed by food plants (17.3%), medicinal (14.3%) and timber (1.0%). Comparison of the two countries demonstrated remarkable differences in plant use patterns. The results showed that rural households in Zimbabwe were more reliant on plant resources than their counterparts in South Africa. Such a trend could be attributed to a close relationship between the local people, and their natural and agricultural environment leading to a rich knowledge base on plants, plant use and related practices. This comparative analysis strengthens the firm belief that utilization of plant resources represents an important shared heritage, preserved over the centuries, which must be exploited in order to provide further new and useful body of ethnobotanical knowledge.
{"title":"Comparative use patterns of plant resources in rural areas of South Africa and Zimbabwe","authors":"A. Maroyi, M. Rasethe","doi":"10.32604/phyton.2015.84.288","DOIUrl":"https://doi.org/10.32604/phyton.2015.84.288","url":null,"abstract":"Documentation of use patterns of plants across national boundaries is of relevance in understanding the importance of plant resources to livelihood strategies of different ethnic groups. Plant resources have gained prominence as a natural asset through which families derive food, firewood, income, medicines and timber, enabling particularly poor communities to achieve self-sufficiency. The objective of this study was to investigate the trends in plant usage in South Africa and Zimbabwe. An ethnobotanical investigation was conducted between January 2012 and January 2013 in the Limpopo Province, South Africa and the Midlands Province, Zimbabwe. The study used questionnaire surveys and interviews with a total of 143 participants to explore plant use patterns in South Africa and Zimbabwe. A total of 98 plant species were identified, with Zimbabwe contributing 70 species and 47 species from South Africa. The uses were classified into 15 categories, major use categories were firewood, food plants, medicine and timber. Food plant was a major plant use category in Zimbabwe, contributing 55.1%, followed by medicinal plants (36.8%), firewood (35.7%) and timber (31.6%). In contrast, firewood was the major plant use category in South Africa, contributing 18.4%, followed by food plants (17.3%), medicinal (14.3%) and timber (1.0%). Comparison of the two countries demonstrated remarkable differences in plant use patterns. The results showed that rural households in Zimbabwe were more reliant on plant resources than their counterparts in South Africa. Such a trend could be attributed to a close relationship between the local people, and their natural and agricultural environment leading to a rich knowledge base on plants, plant use and related practices. This comparative analysis strengthens the firm belief that utilization of plant resources represents an important shared heritage, preserved over the centuries, which must be exploited in order to provide further new and useful body of ethnobotanical knowledge.","PeriodicalId":20184,"journal":{"name":"Phyton-international Journal of Experimental Botany","volume":"32 1","pages":"288-297"},"PeriodicalIF":1.7,"publicationDate":"2016-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88277302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-07-30DOI: 10.32604/phyton.2016.85.027
X. Li, Y-C Wang, C. Busso, Js Xiang, A. Zhang, Y. Qu, Y. Liu
Long-term continuous cropping of cotton had ledto substantial agricultural losses. However, continuous cottoncropping could maintain high crop yields for many years in someareas. The composition and structure of soil nematode communitieswere investigated to explore the effect of continuous croppingand soil depths on these communities. Soil samples werecollected at two soil depths (0-20 cm and 20-40 cm) from cottonfields with a history of 5, 10, 15 or 20 years of continuouscotton cropping in the Karamay region. The results showed that36 genera were found. Significant differences in the numbers oftotal nematodes and trophic groups were observed among continuouscropping times. The highest number of total nematodeswas observed at 20-40 cm depth under continuous 10-croppingyears, and the lowest number at 20-40 cm depth under continuous5-cropping years. There were significant soil depth effects on thedensity of fungivores and plant parasites. Continuous croppingeffects on soil nematode communities could be reflected by valuesof ecological indexes. Continuous cropping times, soil depths andtheir interaction significantly influenced H´, λ, WI, PPI (index ofplant parasites), MI (maturation index excluding plant parasites),PPI/MI, F/B and NCR. The Shannon index (H´) was higher inthe 10-year cotton field than in the other-year fields. The Simpsonindex (λ) was the lowest in the 10-year cotton field. The lowestvalue of WI (index of Wasilewska) appeared at the 20-year cottonfield, which had the majority of plant parasites. Increases of cottoncropping times determined a decreased trend of NCR [=B/(B + F)], and an increased trend of F/B [F and B represent theconsumer abundance of fungi (F) and bacteria (B)]. The bacterialdecomposition pathway was more important in the 5-year situations,and the fungal decomposition pathway was more importantin the 20-year situations. Nematode analysis showed that changes of soil nematode communities and trophic groups could indicatechanges in the soil environment and nematode community structurewith changes of continuous cropping times.
{"title":"Effects of various continuous cropping times on soil nematode structure in cotton fields of Xinjiang, China","authors":"X. Li, Y-C Wang, C. Busso, Js Xiang, A. Zhang, Y. Qu, Y. Liu","doi":"10.32604/phyton.2016.85.027","DOIUrl":"https://doi.org/10.32604/phyton.2016.85.027","url":null,"abstract":"Long-term continuous cropping of cotton had ledto substantial agricultural losses. However, continuous cottoncropping could maintain high crop yields for many years in someareas. The composition and structure of soil nematode communitieswere investigated to explore the effect of continuous croppingand soil depths on these communities. Soil samples werecollected at two soil depths (0-20 cm and 20-40 cm) from cottonfields with a history of 5, 10, 15 or 20 years of continuouscotton cropping in the Karamay region. The results showed that36 genera were found. Significant differences in the numbers oftotal nematodes and trophic groups were observed among continuouscropping times. The highest number of total nematodeswas observed at 20-40 cm depth under continuous 10-croppingyears, and the lowest number at 20-40 cm depth under continuous5-cropping years. There were significant soil depth effects on thedensity of fungivores and plant parasites. Continuous croppingeffects on soil nematode communities could be reflected by valuesof ecological indexes. Continuous cropping times, soil depths andtheir interaction significantly influenced H´, λ, WI, PPI (index ofplant parasites), MI (maturation index excluding plant parasites),PPI/MI, F/B and NCR. The Shannon index (H´) was higher inthe 10-year cotton field than in the other-year fields. The Simpsonindex (λ) was the lowest in the 10-year cotton field. The lowestvalue of WI (index of Wasilewska) appeared at the 20-year cottonfield, which had the majority of plant parasites. Increases of cottoncropping times determined a decreased trend of NCR [=B/(B + F)], and an increased trend of F/B [F and B represent theconsumer abundance of fungi (F) and bacteria (B)]. The bacterialdecomposition pathway was more important in the 5-year situations,and the fungal decomposition pathway was more importantin the 20-year situations. Nematode analysis showed that changes of soil nematode communities and trophic groups could indicatechanges in the soil environment and nematode community structurewith changes of continuous cropping times.","PeriodicalId":20184,"journal":{"name":"Phyton-international Journal of Experimental Botany","volume":"30 1","pages":"27-35"},"PeriodicalIF":1.7,"publicationDate":"2016-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84901376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-07-27DOI: 10.32604/PHYTON.2016.85.333
S. O. Bamigboye, P. Tshisikhawe, P. Taylor
Over a long period of time, cycads endemic to Africa have been facing high risk of extinction. Several conservation efforts have been made to reduce the risk of losing these highly endangered species. In this study we review the current risk of extinction of allAfrican cycads species. We calculated the percentages of each category of species found in African cycads using the IUCN (International Union of Conservation of Nature) red list of threatened species 2014 version. We compared our result with that of Donaldson (2003) on percentages of different categories of IUCN for cycads in Africa which was carried out a decade ago. We also calculated the percentage of population trend in African cycads. When comparing these results, we discovered that over one decade there was no improvement in cycads conservation despite several conservation efforts that were made during this period. The results of the populationtrend also showed that the majority of African cycads are experiencing population decreases. These results highlight that the risk of extinction of African cycads is still very high and much conservation effort is still required to properly tackle ecological factors pushing these endangered species to extinction.
{"title":"Review of extinction risk in African Cycads","authors":"S. O. Bamigboye, P. Tshisikhawe, P. Taylor","doi":"10.32604/PHYTON.2016.85.333","DOIUrl":"https://doi.org/10.32604/PHYTON.2016.85.333","url":null,"abstract":"Over a long period of time, cycads endemic to Africa have been facing high risk of extinction. Several conservation efforts have been made to reduce the risk of losing these highly endangered species. In this study we review the current risk of extinction of allAfrican cycads species. We calculated the percentages of each category of species found in African cycads using the IUCN (International Union of Conservation of Nature) red list of threatened species 2014 version. We compared our result with that of Donaldson (2003) on percentages of different categories of IUCN for cycads in Africa which was carried out a decade ago. We also calculated the percentage of population trend in African cycads. When comparing these results, we discovered that over one decade there was no improvement in cycads conservation despite several conservation efforts that were made during this period. The results of the populationtrend also showed that the majority of African cycads are experiencing population decreases. These results highlight that the risk of extinction of African cycads is still very high and much conservation effort is still required to properly tackle ecological factors pushing these endangered species to extinction.","PeriodicalId":20184,"journal":{"name":"Phyton-international Journal of Experimental Botany","volume":"25 1","pages":"333-336"},"PeriodicalIF":1.7,"publicationDate":"2016-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84470491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-06-22DOI: 10.32604/phyton.2016.85.125
Chan Zhou, C. Busso, J. Liu, Yg Yang, Y. Sun, Y. Fang, Q. Zhang, Yb Zhou, Yn Wang, Z. Zhang, Zhengwen Wang, Yf Yang
The objective of this study was to analyze the relationshipsbetween total aboveground plant biomass versus altitude, latitude,longitude, mean annual temperature, mean annual precipitation,and species diversity. Simple linear regression analysis was usedto study these relationships. Results showed that altitude was significantly,positively (R2= 0.038, P<0.01) related with total plant abovegroundbiomass. Meanwhile, when longitude (R2= 0.124, P<0.001)and latitude (R2= 0.221, P<0.001) increased, total aboveground biomassdecreased. The relationship between biomass and mean annualprecipitation was significantly, positively linear (R2= 0.149, P<0.001).Mean annual temperature was significantly, negatively correlatedwith biomass (R2= 0.145, P<0.001). The relationship between speciesdiversity and biomass was significant, but relatively weaker (i.e.,R2<0.063, P<0.05) compared with those for the climatic variables.This is, species diversity explained less than 7% of the total variabilityin total aboveground plant biomass. This result agrees with theidiosyncratic response hypothesis which suggests that ecosystem functionchanges when species diversity changes, but the magnitude anddirection of these changes are unpredictable because the roles of individualplant species are complex and varied.
{"title":"Total aboveground plant biomass is more strongly affected by climate than species diversity on a grassland in Liaoning, China","authors":"Chan Zhou, C. Busso, J. Liu, Yg Yang, Y. Sun, Y. Fang, Q. Zhang, Yb Zhou, Yn Wang, Z. Zhang, Zhengwen Wang, Yf Yang","doi":"10.32604/phyton.2016.85.125","DOIUrl":"https://doi.org/10.32604/phyton.2016.85.125","url":null,"abstract":"The objective of this study was to analyze the relationshipsbetween total aboveground plant biomass versus altitude, latitude,longitude, mean annual temperature, mean annual precipitation,and species diversity. Simple linear regression analysis was usedto study these relationships. Results showed that altitude was significantly,positively (R2= 0.038, P<0.01) related with total plant abovegroundbiomass. Meanwhile, when longitude (R2= 0.124, P<0.001)and latitude (R2= 0.221, P<0.001) increased, total aboveground biomassdecreased. The relationship between biomass and mean annualprecipitation was significantly, positively linear (R2= 0.149, P<0.001).Mean annual temperature was significantly, negatively correlatedwith biomass (R2= 0.145, P<0.001). The relationship between speciesdiversity and biomass was significant, but relatively weaker (i.e.,R2<0.063, P<0.05) compared with those for the climatic variables.This is, species diversity explained less than 7% of the total variabilityin total aboveground plant biomass. This result agrees with theidiosyncratic response hypothesis which suggests that ecosystem functionchanges when species diversity changes, but the magnitude anddirection of these changes are unpredictable because the roles of individualplant species are complex and varied.","PeriodicalId":20184,"journal":{"name":"Phyton-international Journal of Experimental Botany","volume":"57 1","pages":"125-130"},"PeriodicalIF":1.7,"publicationDate":"2016-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79152796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-05-20DOI: 10.32604/phyton.2017.86.014
A. González-Franco, L. Robles-Hernández, J. Strap
The Streptomyces genus comprises a large and diversegroup of bacteria, many of which are commercially exploited forthe production of antibiotics and lytic enzymes. The thermophilicspecies are less studied than the predominant mesophilic species.However, the first ones are a potential source of thermostable bioactiveproducts and enzymes with novel properties. In this study, twoselected thermophilic streptomycetes were identified and their chitinolyticactivities were evaluated. The identification of these two isolateswas performed by microscopic morphology, partial 16S rDNAsequences, and its phylogenetic analysis. To study the chitinolyticactivities of these isolates, the effects of colloidal chitin (CC) andfungal cell walls (FCW) on the chitinase activities and chitinase andchitosanase isoform patterns were determined. Additionally, in vitroconfrontations against chitinolytic phytopathogenic fungi wereperformed at 45 °C and 65 °C. Both isolates (AC4 y AC7) wereidentified as members of the streptomycete thermophilic clade. Thehighest chitinolytic activities were observed in the combinations0.1% FCW/0.1% CC and 0.1% FCW/0.3% CC with maximum valuesof 0.7 U/μg and 0.45 U/μg, respectively for the AC4 strain, andwith values of 0.48 U/μg in both treatments for the AC7 strain. Theelectrophoretic profiles of chitinase and chitosanase activity showednot only differences in bands intensity, but also few new bands wereobserved. Both isolates inhibited the growth of Rhizoctonia solaniand Fusarium oxysporum. The present study shows that thermophilicstreptomycetes have potential bioactivities that might be exploitedin horticulture.
{"title":"Chitinase, chitosanase, and antifungal activities from thermophilic streptomycetes isolated from compost","authors":"A. González-Franco, L. Robles-Hernández, J. Strap","doi":"10.32604/phyton.2017.86.014","DOIUrl":"https://doi.org/10.32604/phyton.2017.86.014","url":null,"abstract":"The Streptomyces genus comprises a large and diversegroup of bacteria, many of which are commercially exploited forthe production of antibiotics and lytic enzymes. The thermophilicspecies are less studied than the predominant mesophilic species.However, the first ones are a potential source of thermostable bioactiveproducts and enzymes with novel properties. In this study, twoselected thermophilic streptomycetes were identified and their chitinolyticactivities were evaluated. The identification of these two isolateswas performed by microscopic morphology, partial 16S rDNAsequences, and its phylogenetic analysis. To study the chitinolyticactivities of these isolates, the effects of colloidal chitin (CC) andfungal cell walls (FCW) on the chitinase activities and chitinase andchitosanase isoform patterns were determined. Additionally, in vitroconfrontations against chitinolytic phytopathogenic fungi wereperformed at 45 °C and 65 °C. Both isolates (AC4 y AC7) wereidentified as members of the streptomycete thermophilic clade. Thehighest chitinolytic activities were observed in the combinations0.1% FCW/0.1% CC and 0.1% FCW/0.3% CC with maximum valuesof 0.7 U/μg and 0.45 U/μg, respectively for the AC4 strain, andwith values of 0.48 U/μg in both treatments for the AC7 strain. Theelectrophoretic profiles of chitinase and chitosanase activity showednot only differences in bands intensity, but also few new bands wereobserved. Both isolates inhibited the growth of Rhizoctonia solaniand Fusarium oxysporum. The present study shows that thermophilicstreptomycetes have potential bioactivities that might be exploitedin horticulture.","PeriodicalId":20184,"journal":{"name":"Phyton-international Journal of Experimental Botany","volume":"17 4 1","pages":"14-27"},"PeriodicalIF":1.7,"publicationDate":"2016-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76497224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-05-19DOI: 10.32604/phyton.2014.83.325
P. Grijalba, A. Ridao
Diaporthe phaseolorum var. caulivora is the major causal agent of stem canker in soybean (CTS) in Argentina. It has appeared mainly in the Southern Pampeana sub-region, but also in warm areas, and it has been observed with different levels of incidence, severity and virulence. The objective of this work was to study the growth rate in vitro and the pathogenicity of isolates from soybean plants at different temperatures. Twenty isolates from Buenos Aires Province were selected. The daily growth rate was measured in nine of them and in two reference isolates in potato dextrose agar (APD), under different light/darkness conditions at four temperatures (15, 20, 25 and 30 °C). The toothpick technique was used to inoculate four isolates on 10 plants of a susceptible soybean cultivar, which were incubated in growth chambers at 15, 20 and 25 °C. Another 17 isolates were inoculated in the field and in a greenhouse. The number of dead plants was recorded. The growth rate of the isolates was greater with higher temperature: at 15 °C they were similar, at 20 °C there were small differences, at 25 °C two groups were detected whereas at 30 °C there was no growth. All the isolates were pathogenic. The different incubation temperatures induced different levels of plant death: at 15 and 20 °C in both the chamber and greenhouse (at 20 °C), the percentage of dead plants was less than 40%. It is suggested that temperatures lower than 20 °C would not allow to observe physiological differences between the different varieties which cause CTS. The similarity of growth and the high number of dead plants indicate that the incidence and severity of the disease would be due to environmental factors.
{"title":"Growth rate and pathogenicity of isolates of Diaporthe phaseolorum var. caulivora","authors":"P. Grijalba, A. Ridao","doi":"10.32604/phyton.2014.83.325","DOIUrl":"https://doi.org/10.32604/phyton.2014.83.325","url":null,"abstract":"Diaporthe phaseolorum var. caulivora is the major causal agent of stem canker in soybean (CTS) in Argentina. It has appeared mainly in the Southern Pampeana sub-region, but also in warm areas, and it has been observed with different levels of incidence, severity and virulence. The objective of this work was to study the growth rate in vitro and the pathogenicity of isolates from soybean plants at different temperatures. Twenty isolates from Buenos Aires Province were selected. The daily growth rate was measured in nine of them and in two reference isolates in potato dextrose agar (APD), under different light/darkness conditions at four temperatures (15, 20, 25 and 30 °C). The toothpick technique was used to inoculate four isolates on 10 plants of a susceptible soybean cultivar, which were incubated in growth chambers at 15, 20 and 25 °C. Another 17 isolates were inoculated in the field and in a greenhouse. The number of dead plants was recorded. The growth rate of the isolates was greater with higher temperature: at 15 °C they were similar, at 20 °C there were small differences, at 25 °C two groups were detected whereas at 30 °C there was no growth. All the isolates were pathogenic. The different incubation temperatures induced different levels of plant death: at 15 and 20 °C in both the chamber and greenhouse (at 20 °C), the percentage of dead plants was less than 40%. It is suggested that temperatures lower than 20 °C would not allow to observe physiological differences between the different varieties which cause CTS. The similarity of growth and the high number of dead plants indicate that the incidence and severity of the disease would be due to environmental factors.","PeriodicalId":20184,"journal":{"name":"Phyton-international Journal of Experimental Botany","volume":"10 1","pages":"325-332"},"PeriodicalIF":1.7,"publicationDate":"2016-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87641988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-05-19DOI: 10.32604/phyton.2014.83.243
L. Entío, M. Mujica
Successful establishment of Lotus tenuis, an important legume to improve grasslands in the Pampa Deprimida, might be limited by low seedling vigor. The number of crown stems is an important component of vigor. The objective of this work was to determine the variability in the number of crown stems on seedlings of 11 Lotus tenuis natural populations sown at high density under semi-controlled conditions. Seeds of all populations were collected in the Province of Buenos Aires, Argentina. They were sown in plastic pots and cultivated in a greenhouse. Eight weeks after seeding, seedlings of each population were grouped according to their number of stems per crown. Variability in the crown stem number was studied within and among populations. Number of seedlings with different stem crown numbers within each population, dry weight (PS) of the group of individuals and mean for each group, the predominant groups of crown stem numbers from the total number of seedlings within each population, and those that presented a greater grouped dry weight and average per individual of each group were also determined. Simple linear regression of the crown stem numbers versus dry weight was conducted. ANOVA and Tukey´s tests were used (p≤0.01). The relationships between crown stem numbers and number of seedlings within each population tended to bimodal in 10 out of 11 populations. The crown stem number presented differences among (p≤0.01) and within (variation coefficient=44 to 56%) populations. Classes of 1 to 3 stems per crown were dominant (p≤0.01). Groups of 3 or 5 stems per crown showed greater dry weight (p≤0.01) when they were grouped or taken as a mean per individual, respectively. The regression was significant (p≤0.01) for mean dry weight per individual. Using of high density allowed the expression of variability within and among populations in the number of stems per crown. This variability can be attributed to genetic causes, considering the semi-controlled conditions under which the experiment was conducted. This implies the possibility of improving such parameter and the seedling vigor indirectly.
{"title":"Variability in the number of stems in Lotus tenuis seedlings growing at high density","authors":"L. Entío, M. Mujica","doi":"10.32604/phyton.2014.83.243","DOIUrl":"https://doi.org/10.32604/phyton.2014.83.243","url":null,"abstract":"Successful establishment of Lotus tenuis, an important legume to improve grasslands in the Pampa Deprimida, might be limited by low seedling vigor. The number of crown stems is an important component of vigor. The objective of this work was to determine the variability in the number of crown stems on seedlings of 11 Lotus tenuis natural populations sown at high density under semi-controlled conditions. Seeds of all populations were collected in the Province of Buenos Aires, Argentina. They were sown in plastic pots and cultivated in a greenhouse. Eight weeks after seeding, seedlings of each population were grouped according to their number of stems per crown. Variability in the crown stem number was studied within and among populations. Number of seedlings with different stem crown numbers within each population, dry weight (PS) of the group of individuals and mean for each group, the predominant groups of crown stem numbers from the total number of seedlings within each population, and those that presented a greater grouped dry weight and average per individual of each group were also determined. Simple linear regression of the crown stem numbers versus dry weight was conducted. ANOVA and Tukey´s tests were used (p≤0.01). The relationships between crown stem numbers and number of seedlings within each population tended to bimodal in 10 out of 11 populations. The crown stem number presented differences among (p≤0.01) and within (variation coefficient=44 to 56%) populations. Classes of 1 to 3 stems per crown were dominant (p≤0.01). Groups of 3 or 5 stems per crown showed greater dry weight (p≤0.01) when they were grouped or taken as a mean per individual, respectively. The regression was significant (p≤0.01) for mean dry weight per individual. Using of high density allowed the expression of variability within and among populations in the number of stems per crown. This variability can be attributed to genetic causes, considering the semi-controlled conditions under which the experiment was conducted. This implies the possibility of improving such parameter and the seedling vigor indirectly.","PeriodicalId":20184,"journal":{"name":"Phyton-international Journal of Experimental Botany","volume":"33 2","pages":"243-250"},"PeriodicalIF":1.7,"publicationDate":"2016-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72557628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-05-18DOI: 10.32604/phyton.2016.85.291
L. Hernández, M. Rosetti
The involucral bracts (IB or phyllaries) of the sunflower(Helianthus annuus L.) capitulum constitute an example of photosynthesizingorgans that contribute to the photosynthesis budget duringthe generation of crop yield. The anatomy of IB was analyzed in twodomesticated primitive sunflower genotypes, Havasupai and Hopi, inthe sunflower line HA89B, in the wild Helianthus annuus ssp. annuus,in the sunflower male-fertile line R013 and in the commercial hybridDKOP3845. Stomata and trichomes were counted on the adaxial andabaxial epidermis. In all cases, the IB showed a one-layered adaxialand abaxial epidermis, secretory ducts and parenchymatic cells withabundant chloroplast. The vascular system was similar to that of thenomophylls; however, their bundles were smaller, with an abaxial surfaceshowing abundance of glandular and non-glandular trichomesand stomata. IB of Havasupai, Hopi and the male-fertile line strainshowed higher number of adaxial hypodermic strata than those ofHA89B, DKOP3845 and wild sunflower (2-3 vs. 1), and one mesophyllwith inverted polarity with respect to a foliage leaf: the presenceof a spongy parenchyma on the adaxial side was observed with arudimentary palisade parenchyma on the abaxial side. Stomatal densityof the IB was significantly higher in Hopi and Havasupai than inHA89B and DKOP3845, with values ranging from 132 to 156 vs 73to 110 stomata/mm2, respectively. Like the modern commercial hybrid,the IB of male-fertile line showed lower stomatal density (83stomata/mm2) and scarce abaxial trichomes. The anatomical studies ofphyllaries in Asteraceae remain relatively poor in the literature. Fromthe functional point of view, sunflower breeding produced undesiredchanges in the IB anatomy. Future studies for comparing the physiological(photosynthesis and respiration) and biochemical activities ofthe RuBisCO among the IB of the primitive (Havasupai and Hopi),male-fertile lines and modern sunflower genotypes will help to definethe magnitude of their importance as a morphological trait to be consideredin future plans of sunflower breeding.
{"title":"Is the abaxial palisade parenchyma in phyllaries of the sunflower (Helianthus annuus L.) capitulum a missing trait in modern genotypes","authors":"L. Hernández, M. Rosetti","doi":"10.32604/phyton.2016.85.291","DOIUrl":"https://doi.org/10.32604/phyton.2016.85.291","url":null,"abstract":"The involucral bracts (IB or phyllaries) of the sunflower(Helianthus annuus L.) capitulum constitute an example of photosynthesizingorgans that contribute to the photosynthesis budget duringthe generation of crop yield. The anatomy of IB was analyzed in twodomesticated primitive sunflower genotypes, Havasupai and Hopi, inthe sunflower line HA89B, in the wild Helianthus annuus ssp. annuus,in the sunflower male-fertile line R013 and in the commercial hybridDKOP3845. Stomata and trichomes were counted on the adaxial andabaxial epidermis. In all cases, the IB showed a one-layered adaxialand abaxial epidermis, secretory ducts and parenchymatic cells withabundant chloroplast. The vascular system was similar to that of thenomophylls; however, their bundles were smaller, with an abaxial surfaceshowing abundance of glandular and non-glandular trichomesand stomata. IB of Havasupai, Hopi and the male-fertile line strainshowed higher number of adaxial hypodermic strata than those ofHA89B, DKOP3845 and wild sunflower (2-3 vs. 1), and one mesophyllwith inverted polarity with respect to a foliage leaf: the presenceof a spongy parenchyma on the adaxial side was observed with arudimentary palisade parenchyma on the abaxial side. Stomatal densityof the IB was significantly higher in Hopi and Havasupai than inHA89B and DKOP3845, with values ranging from 132 to 156 vs 73to 110 stomata/mm2, respectively. Like the modern commercial hybrid,the IB of male-fertile line showed lower stomatal density (83stomata/mm2) and scarce abaxial trichomes. The anatomical studies ofphyllaries in Asteraceae remain relatively poor in the literature. Fromthe functional point of view, sunflower breeding produced undesiredchanges in the IB anatomy. Future studies for comparing the physiological(photosynthesis and respiration) and biochemical activities ofthe RuBisCO among the IB of the primitive (Havasupai and Hopi),male-fertile lines and modern sunflower genotypes will help to definethe magnitude of their importance as a morphological trait to be consideredin future plans of sunflower breeding.","PeriodicalId":20184,"journal":{"name":"Phyton-international Journal of Experimental Botany","volume":"25 1","pages":"291-296"},"PeriodicalIF":1.7,"publicationDate":"2016-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87219910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-05-16DOI: 10.32604/phyton.2014.83.101
Jl Piña-González, E. J. Morales-Rosales, A. Dominguez-Lopez, José Francisco Ramírez-Dávila, Gaspar Estrada-Campuzano, Omar Franco-Mora
The aim of this study was to assess the land equivalent ratio, biomass, grain yield and ethereal extract of Helianthus annuus in monoculture and associated with Pisum sativum in function of stabilized urea (0, 40, 80 kg N/ha) in El Cerrillo, Mexico. It was also estimated pod yield obtained by P. sativum as a pure stand and associated with H. annuus. The six treatments (in each experiment) were evaluated in a 2 × 3 factorial experiment in a randomized complete block design with four replications. When F values were significant, the honestly significant difference test at the 5% level of significance was used. The principal component analysis was also used to study the interrelationship among the six treatments and seven variables. The results observed in the biplot indicated that the largest original variation in the data was adequately represented in the first two principal components since both accumulated 87.9%. This analysis revealed that the treatments of H. annuus in monoculture and H. annuus + P. sativum fertilized with 80 kg N/ha were those which achieved the highest grain yields (287.7 and 285 g/m2, respectively). The superiority of these treatments is attributed to the fact that leaf area index and total biomass showed to be the main yield component of H. annuus. The value of the land equivalent ratio (1.47) obtained with the supply of 80 kg N/ha indicates an advantage in the grain and pod yields of the association of both species by 47% over their respective monocultures. As a result, this planting system is a good choice for farmers with scarce economic resources in the region.
研究了稳定尿素(0、40、80 kg N/ha)对墨西哥El Cerrillo单作向日葵(Helianthus annuus)和油菜(Pisum sativum)的土地当量比、生物量、籽粒产量和提取物的影响。此外，还估算了作为纯林分的sativum与H. annuus的荚果产量。采用随机完全区组设计，4个重复，采用2 × 3析因试验对6个处理(每个试验)进行评价。当F值显著时，采用5%显著性水平下的诚实显著性差异检验。采用主成分分析研究了6个处理和7个变量之间的相互关系。在双标图中观察到的结果表明，数据中最大的原始变化在前两个主成分中得到充分体现，因为它们都累积了87.9%。结果表明，单作和施氮量为80 kg / hm2的黄杨+黄杨产量最高，分别为287.7 g/m2和285 g/m2。这些处理的优势在于叶面积指数和总生物量是黄杨产量的主要组成部分。在80 kg N/ha条件下获得的土地当量比(1.47)表明，两种组合的籽粒和豆荚产量比各自的单一栽培高出47%。因此，这种种植制度是该地区经济资源稀缺的农民的一个很好的选择。
{"title":"Land equivalent ratio, grain and pod yield and ethereal extract of Helianthus annuus L. in monoculture and associated with Pisum sativum L. in function of stabilized urea.","authors":"Jl Piña-González, E. J. Morales-Rosales, A. Dominguez-Lopez, José Francisco Ramírez-Dávila, Gaspar Estrada-Campuzano, Omar Franco-Mora","doi":"10.32604/phyton.2014.83.101","DOIUrl":"https://doi.org/10.32604/phyton.2014.83.101","url":null,"abstract":"The aim of this study was to assess the land equivalent ratio, biomass, grain yield and ethereal extract of Helianthus annuus in monoculture and associated with Pisum sativum in function of stabilized urea (0, 40, 80 kg N/ha) in El Cerrillo, Mexico. It was also estimated pod yield obtained by P. sativum as a pure stand and associated with H. annuus. The six treatments (in each experiment) were evaluated in a 2 × 3 factorial experiment in a randomized complete block design with four replications. When F values were significant, the honestly significant difference test at the 5% level of significance was used. The principal component analysis was also used to study the interrelationship among the six treatments and seven variables. The results observed in the biplot indicated that the largest original variation in the data was adequately represented in the first two principal components since both accumulated 87.9%. This analysis revealed that the treatments of H. annuus in monoculture and H. annuus + P. sativum fertilized with 80 kg N/ha were those which achieved the highest grain yields (287.7 and 285 g/m2, respectively). The superiority of these treatments is attributed to the fact that leaf area index and total biomass showed to be the main yield component of H. annuus. The value of the land equivalent ratio (1.47) obtained with the supply of 80 kg N/ha indicates an advantage in the grain and pod yields of the association of both species by 47% over their respective monocultures. As a result, this planting system is a good choice for farmers with scarce economic resources in the region.","PeriodicalId":20184,"journal":{"name":"Phyton-international Journal of Experimental Botany","volume":"4 1","pages":"101-108"},"PeriodicalIF":1.7,"publicationDate":"2016-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78936227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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