Oladapo Oluwatobi Folarin, S. Asala, A. A. Oyerinde, Tolani Islamiat Okelola
Rice is an important staple food in Nigeria, affected by several diseases especially viruses. This study was carried out to evaluate the incidence and severity of two important viruses on rice plants and to identify associated insects in the Federal Capital Territory (F.C.T), Abuja in 2019. Field experiment was carried out from June to October, 2019 at the Teaching and Research Farm of the Faculty of Agriculture, University of Abuja, Nigeria, where ten rice varieties were assessed for incidence and severity. The seed and leaf samples were collected for serological indexing. Data collected was subjected to statistical analysis using SPSS and mean separation was done with Duncan Multiple Range Test. Of the 210 leaf samples collected, FARO 61 and 44 had the lowest incidence (19%), while FARO 65 recorded the highest (25.3%). FARO 52 recorded the highest severity (46%) while FARO 61 and FARO 60 had the lowest severity (30.1%) for rice yellow mottle sobemo-virus (RYMV) and maize streak geminivirus (MSV). Insects such as Spittle bug (Locris rubens and Poophilus costalis), Ladybird beetle (Cheilomenes sulphurea) and Groundhopper (Paratettix sp) were trapped on the field. All rice seed and leaf samples collected did not test positive to RYMV and MSV using Enzyme-Linked immunosorbent assay (ELISA). This study provides the first research work on rice viruses in the FCT and further studies are recommended. Key words: Nigeria, rice, rice yellow mottle sobemo-virus (RYMV), maize streak geminivirus (MSV), incidence, severity, virus symptoms, enzyme linked immuno sorbent assay (ELISA).
{"title":"Evaluating the incidence and severity of rice yellow mottle virus and maize streak virus on rice (Oryza sativa L.) and associated insects in the Federal Capital Territory, Abuja, Nigeria","authors":"Oladapo Oluwatobi Folarin, S. Asala, A. A. Oyerinde, Tolani Islamiat Okelola","doi":"10.5897/ajps2020.2003","DOIUrl":"https://doi.org/10.5897/ajps2020.2003","url":null,"abstract":"Rice is an important staple food in Nigeria, affected by several diseases especially viruses. This study was carried out to evaluate the incidence and severity of two important viruses on rice plants and to identify associated insects in the Federal Capital Territory (F.C.T), Abuja in 2019. Field experiment was carried out from June to October, 2019 at the Teaching and Research Farm of the Faculty of Agriculture, University of Abuja, Nigeria, where ten rice varieties were assessed for incidence and severity. The seed and leaf samples were collected for serological indexing. Data collected was subjected to statistical analysis using SPSS and mean separation was done with Duncan Multiple Range Test. Of the 210 leaf samples collected, FARO 61 and 44 had the lowest incidence (19%), while FARO 65 recorded the highest (25.3%). FARO 52 recorded the highest severity (46%) while FARO 61 and FARO 60 had the lowest severity (30.1%) for rice yellow mottle sobemo-virus (RYMV) and maize streak geminivirus (MSV). Insects such as Spittle bug (Locris rubens and Poophilus costalis), Ladybird beetle (Cheilomenes sulphurea) and Groundhopper (Paratettix sp) were trapped on the field. All rice seed and leaf samples collected did not test positive to RYMV and MSV using Enzyme-Linked immunosorbent assay (ELISA). This study provides the first research work on rice viruses in the FCT and further studies are recommended. \u0000 \u0000 \u0000 \u0000 Key words: Nigeria, rice, rice yellow mottle sobemo-virus (RYMV), maize streak geminivirus (MSV), incidence, severity, virus symptoms, enzyme linked immuno sorbent assay (ELISA).","PeriodicalId":7675,"journal":{"name":"African Journal of Plant Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75205359","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}
Valentine Atieno, G. W. Gatheri, J. Kamau, M. Muthini
This study was conducted to characterize Dioscorea spp. in Kenya using morphological and molecular characteristics. Data on 22 morphological traits were subjected to cluster analysis and multivariate analysis using principal component (PCA). The dendrogram of cluster analysis revealed three main groups: Species distribution based on PC-1 and PC-2 showed the distantly related species in each quarter; D. alata L. (1st quarter), D. bulbifera L. (2nd quarter), D. cayenensis Lam. (3rd quarter) and D. minutiflora Engl. (4th quarter). In molecular characterization, one sub-cluster grouped D. minutiflora Engl. and D. burkilliana J. Miege as one genetic group. However not all D. minutiflora Engl. species were in one specific cluster showing that there may be variation within the species. D. alata L. and D. bulbifera were seen to be potentially related because they shared a common origin. D. bulbifera L. and D. cayenensis Lam. genotypes clustered together, indicating that the species might be closely related. Generally, the rbcL marker demonstrated the phylogeny of Kenyan Dioscorea spp L. Comparison of morphological and molecular data analysis gave almost similar results. From the study, the phylogenetic relationships of Kenyan Dioscorea spp. were established and morphological and molecular characterization was efficient in establishing species relatedness among Dioscorea spp. Key words: Dioscorea spp., rbcL, principal component analysis, molecular characterization, morphological characterization, yams.
{"title":"Morphological and molecular characterization of cultivated yam (Dioscorea species) in selected counties in Kenya","authors":"Valentine Atieno, G. W. Gatheri, J. Kamau, M. Muthini","doi":"10.5897/ajps2020.2020","DOIUrl":"https://doi.org/10.5897/ajps2020.2020","url":null,"abstract":"This study was conducted to characterize Dioscorea spp. in Kenya using morphological and molecular characteristics. Data on 22 morphological traits were subjected to cluster analysis and multivariate analysis using principal component (PCA). The dendrogram of cluster analysis revealed three main groups: Species distribution based on PC-1 and PC-2 showed the distantly related species in each quarter; D. alata L. (1st quarter), D. bulbifera L. (2nd quarter), D. cayenensis Lam. (3rd quarter) and D. minutiflora Engl. (4th quarter). In molecular characterization, one sub-cluster grouped D. minutiflora Engl. and D. burkilliana J. Miege as one genetic group. However not all D. minutiflora Engl. species were in one specific cluster showing that there may be variation within the species. D. alata L. and D. bulbifera were seen to be potentially related because they shared a common origin. D. bulbifera L. and D. cayenensis Lam. genotypes clustered together, indicating that the species might be closely related. Generally, the rbcL marker demonstrated the phylogeny of Kenyan Dioscorea spp L. Comparison of morphological and molecular data analysis gave almost similar results. From the study, the phylogenetic relationships of Kenyan Dioscorea spp. were established and morphological and molecular characterization was efficient in establishing species relatedness among Dioscorea spp. \u0000 \u0000 \u0000 \u0000 Key words: Dioscorea spp., rbcL, principal component analysis, molecular characterization, morphological characterization, yams.","PeriodicalId":7675,"journal":{"name":"African Journal of Plant Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84781614","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}
B. Baatuuwie, L. I. Nasare, Edmond Gameli Tefuttor
A good planting medium is required for raising tree seedlings in the nursery, however Guinea savanna soils are generally poor in nitrogen and organic matter. This poses a challenge in accessing fertile soil for tree nurseries in Northern Ghana. The experiment was conducted in the Nyankpala campus to explore the potential of plant biochar as growth media for raising tree seedlings. Growth media prepared from six different biochar formulations (Groundnut Husk Biochar; Rice Husk Biochar; Wood Biochar; Groundnut Husk Biochar + Soil; Rice Husk Biochar + Soil; Wood Biochar + Soil) and control (untreated topsoil) were each replicated in three seed boxes. Seed boxes were arranged in a Completely Randomized Design with 50 Khaya senegalensis seeds sown in each box. Percentage seed emergence did not vary significantly between treatments (p > 0.05) although Groundnut Husk Biochar recorded a marginally higher emergence (65.71%). Similarly, Groundnut Husk Biochar recorded a significantly higher plant height (10.23 cm) in the second week after planting (p < 0.05) as well as mean number of leaves (6.02) in the sixth week after planting (p < 0.05). In general, Groundnut Husk Biochar had the greatest effect on initial growth performance of K. senegalensis and could therefore be explored as a growth medium for raising tree seedlings in Northern Ghana. Key words: Biochar, growth media, Khaya senegalensis, plant height, soil.
{"title":"Biochar as an alternative growth medium for tree seedlings in the Guinea Savanna Zone of Ghana","authors":"B. Baatuuwie, L. I. Nasare, Edmond Gameli Tefuttor","doi":"10.5897/ajps2019.1796","DOIUrl":"https://doi.org/10.5897/ajps2019.1796","url":null,"abstract":"A good planting medium is required for raising tree seedlings in the nursery, however Guinea savanna soils are generally poor in nitrogen and organic matter. This poses a challenge in accessing fertile soil for tree nurseries in Northern Ghana. The experiment was conducted in the Nyankpala campus to explore the potential of plant biochar as growth media for raising tree seedlings. Growth media prepared from six different biochar formulations (Groundnut Husk Biochar; Rice Husk Biochar; Wood Biochar; Groundnut Husk Biochar + Soil; Rice Husk Biochar + Soil; Wood Biochar + Soil) and control (untreated topsoil) were each replicated in three seed boxes. Seed boxes were arranged in a Completely Randomized Design with 50 Khaya senegalensis seeds sown in each box. Percentage seed emergence did not vary significantly between treatments (p > 0.05) although Groundnut Husk Biochar recorded a marginally higher emergence (65.71%). Similarly, Groundnut Husk Biochar recorded a significantly higher plant height (10.23 cm) in the second week after planting (p < 0.05) as well as mean number of leaves (6.02) in the sixth week after planting (p < 0.05). In general, Groundnut Husk Biochar had the greatest effect on initial growth performance of K. senegalensis and could therefore be explored as a growth medium for raising tree seedlings in Northern Ghana. \u0000 \u0000 \u0000 \u0000 Key words: Biochar, growth media, Khaya senegalensis, plant height, soil.","PeriodicalId":7675,"journal":{"name":"African Journal of Plant Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77648993","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}
The seed germination test under lead (Pb) stress could be a quick test to understand plant tolerance to this heavy metal. The aim of this study was to compare the germination behavior of Raphanus sativus L. germinated in solution with different increasing concentration of lead, also to assess its accumulation and toxicity. The test was carried out in an incubator at 25 ± 1°C for 7 days and in a greenhouse for 11 weeks. Lead caused significant germination behavioral disturbances by changing the velocity coefficient and germination kinetics, with reducing the rate of early and final germination, however, the duration of germination was lengthened. Pb reduced the levels of the chlorophyll, delta-aminolevulinic acid dehydratase (ALAD) activity and growth. It increased lipid peroxidation and induced a significant accumulation of proline, positively correlated with Pb accumulation. Pb has a depressive effect on germination and causes disruptive disturbances of R.. sativus L. revealed by changes in non-enzymatic antioxidants, ALAD activity and growth. Radish has a capacity to accumulate Pb. The present results provide a model for detecting natural compounds able to improve seed germination of radish and counteract the harmful effects of lead. Key words: Radish, concentration, rate, accumulation, proline, lipid peroxidation, chlorophyll.
{"title":"Lead-induced changes in germination behavior, growth and inhibition of -aminolevulinic acid dehydratase activity in Raphanus sativus L.","authors":"K. Ahmed, A. Aoues, O. Kharoubi, I. Hetraf","doi":"10.5897/ajps2019.1899","DOIUrl":"https://doi.org/10.5897/ajps2019.1899","url":null,"abstract":"The seed germination test under lead (Pb) stress could be a quick test to understand plant tolerance to this heavy metal. The aim of this study was to compare the germination behavior of Raphanus sativus L. germinated in solution with different increasing concentration of lead, also to assess its accumulation and toxicity. The test was carried out in an incubator at 25 ± 1°C for 7 days and in a greenhouse for 11 weeks. Lead caused significant germination behavioral disturbances by changing the velocity coefficient and germination kinetics, with reducing the rate of early and final germination, however, the duration of germination was lengthened. Pb reduced the levels of the chlorophyll, delta-aminolevulinic acid dehydratase (ALAD) activity and growth. It increased lipid peroxidation and induced a significant accumulation of proline, positively correlated with Pb accumulation. Pb has a depressive effect on germination and causes disruptive disturbances of R.. sativus L. revealed by changes in non-enzymatic antioxidants, ALAD activity and growth. Radish has a capacity to accumulate Pb. The present results provide a model for detecting natural compounds able to improve seed germination of radish and counteract the harmful effects of lead. \u0000 \u0000 \u0000 \u0000 Key words: Radish, concentration, rate, accumulation, proline, lipid peroxidation, chlorophyll.","PeriodicalId":7675,"journal":{"name":"African Journal of Plant Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89398034","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}
Series of investigations have been carried out on the effect of sowing depths on seed germination and early seedlings growth of Aframomum citratum and has shown that sowing depth influences germination and early growth of most plant species. Thus, the importance of varying planting depths has received much attention from researchers for some time now. The depths studied in this research were 0, 3 and 6 cm, respectively. Using a split plot complete randomized design (CRD) in a non-mist propagator, a total of 864 seeds (432 fresh and 432 dry) of A. citratum were sown with three replicates for each soil type in prepared polyethylene bags. Germination was monitored daily for a period of six weeks while data for germination parameters was collected. Early growth parameters such as average number of leaves (NL), average leaf surface area (SA) and average height of seedlings, (SH) were measured every week for two months. Results revealed that germination started 2 months after fresh seeds were sown in all soil types. Dried seeds being treated with 50% dilution of concentrated sulphuric acid for 20 min did not germinate during the germination period that ranged from 2 to 7 months. Sowing depths significantly affected the cumulative germination percentage and early growth (p<0.05). Thus, the highest percentage of seedlings was produced at 0 cm sowing depth, followed by 3 cm sowing depth and the least was at 6 cm sowing depth. Germination of A. citratum seeds can be done based on the information given in this study. Key words: Aframomum citratum, seeds, sowing depths, germination, early growth.
{"title":"Effects of sowing depth on seed germination and seedling growth of Aframomum citratum (Pereira) K. Schum","authors":"A. M. Grâce, Christiana Ngyete Nyikob Mbogue","doi":"10.5897/ajps2018.1728","DOIUrl":"https://doi.org/10.5897/ajps2018.1728","url":null,"abstract":"Series of investigations have been carried out on the effect of sowing depths on seed germination and early seedlings growth of Aframomum citratum and has shown that sowing depth influences germination and early growth of most plant species. Thus, the importance of varying planting depths has received much attention from researchers for some time now. The depths studied in this research were 0, 3 and 6 cm, respectively. Using a split plot complete randomized design (CRD) in a non-mist propagator, a total of 864 seeds (432 fresh and 432 dry) of A. citratum were sown with three replicates for each soil type in prepared polyethylene bags. Germination was monitored daily for a period of six weeks while data for germination parameters was collected. Early growth parameters such as average number of leaves (NL), average leaf surface area (SA) and average height of seedlings, (SH) were measured every week for two months. Results revealed that germination started 2 months after fresh seeds were sown in all soil types. Dried seeds being treated with 50% dilution of concentrated sulphuric acid for 20 min did not germinate during the germination period that ranged from 2 to 7 months. Sowing depths significantly affected the cumulative germination percentage and early growth (p<0.05). Thus, the highest percentage of seedlings was produced at 0 cm sowing depth, followed by 3 cm sowing depth and the least was at 6 cm sowing depth. Germination of A. citratum seeds can be done based on the information given in this study. \u0000 \u0000 \u0000 \u0000 Key words: Aframomum citratum, seeds, sowing depths, germination, early growth.","PeriodicalId":7675,"journal":{"name":"African Journal of Plant Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79304995","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}
Regardless of the huge yield potential and area under maize production, its current productivity in Ethiopia is by far below its potential. Declining of soil fertility and poor nutrient management is among the major factors limiting the productivity of the crop. As a result, an experiment was conducted at Bako, Ethiopia in 2016 to validate the N application and determine the best rate for side dressing using handheld Normalized Difference Vegetative Index (NDVI) sensor. The experiment was laid out in randomized complete block design in factorial arrangement with three replications. Three N levels (0, 25 and 50 kg N ha-1) all applied at the time planting and four N rates (19, 38, 56 and 75 kg N ha-1) for side dressing. Significant differences were observed between the applied N fertilizer for grain yield and yield components. Higher correlation coefficients (0.78) between grain yield, NDIV and INSEY at V4 were observed. Application of 25 kg N ha-1 and 38 kg N ha-1 at planting and side dressing at 35 days after sowing correspondingly, gave higher grain yield for quality protein maize in the area. Further studies are required across various locations using different maize varieties to provide conclusive recommendations. Key words: INSEY, maize, NDVI, nitrogen.
尽管有巨大的产量潜力和玉米种植面积，但埃塞俄比亚目前的玉米产量远远低于其潜力。土壤肥力下降和养分管理不善是限制作物生产力的主要因素之一。因此，2016年在埃塞俄比亚的Bako进行了一项试验，以验证氮的施用，并使用手持式归一化差异营养指数(NDVI)传感器确定最佳的侧敷料率。试验采用随机完全区组设计，设3个重复。同期施用3个氮肥水平(0、25和50 kg N ha-1)，侧施4个氮肥水平(19、38、56和75 kg N ha-1)。施氮量对籽粒产量和产量构成有显著影响。4期籽粒产量、NDIV与INSEY的相关系数较高(0.78)。在播种和播后35 d补浆时分别施用25 kg N hm -1和38 kg N hm -1可提高该地区优质蛋白玉米的籽粒产量。需要在不同地点使用不同玉米品种进行进一步研究，以提供结论性建议。关键词:INSEY，玉米，NDVI，氮素
{"title":"Sensor based validation of nitrogen fertilizer for quality protein maize variety using a handheld normalized difference vegetative index sensor at Bako, Western Ethiopia","authors":"Hailu Feyisa, T. Abera","doi":"10.5897/AJPS2019.1917","DOIUrl":"https://doi.org/10.5897/AJPS2019.1917","url":null,"abstract":"Regardless of the huge yield potential and area under maize production, its current productivity in Ethiopia is by far below its potential. Declining of soil fertility and poor nutrient management is among the major factors limiting the productivity of the crop. As a result, an experiment was conducted at Bako, Ethiopia in 2016 to validate the N application and determine the best rate for side dressing using handheld Normalized Difference Vegetative Index (NDVI) sensor. The experiment was laid out in randomized complete block design in factorial arrangement with three replications. Three N levels (0, 25 and 50 kg N ha-1) all applied at the time planting and four N rates (19, 38, 56 and 75 kg N ha-1) for side dressing. Significant differences were observed between the applied N fertilizer for grain yield and yield components. Higher correlation coefficients (0.78) between grain yield, NDIV and INSEY at V4 were observed. Application of 25 kg N ha-1 and 38 kg N ha-1 at planting and side dressing at 35 days after sowing correspondingly, gave higher grain yield for quality protein maize in the area. Further studies are required across various locations using different maize varieties to provide conclusive recommendations. \u0000 \u0000 \u0000 \u0000 Key words: INSEY, maize, NDVI, nitrogen.","PeriodicalId":7675,"journal":{"name":"African Journal of Plant Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85238014","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}
Abebe Yadessa, J. Burkhardt, E. Bekele, Kitessa Hundera, H. Goldbach
Coffee quality is a complex trait involving sensory and bean characteristics as well as biochemical contents. The objective of this study was to assess the major factors influencing the quality of wild Arabica coffee (Coffea arabica L.) in the natural coffee forests of southwest and southeast Ethiopia. Results revealed that both natural (soil, aspect, elevation, climate, geographic location) and human factors (cherry harvesting/ handing, theft, forest management) considerably influenced the quality of wild Arabica coffee. The soil factor affected every component of coffee quality (cup quality, bean characteristics and biochemical contents). The cup quality of coffee varied with soil properties, especially with available P and soil texture. The bean size distribution was also affected by soil properties; there was significant positive relationship between soil pH, sand or Mn and the proportion of bold beans (retained on screen 17). Soil organic matter, total N and sand content were inversely correlated with caffeine content, but available P and clay content were positively correlated with caffeine. Increase in elevation led to increase in bean size up to the elevation of about 1600 m above sea level, but thereafter no more increase in bean size (hump-shaped relationship, not monotonic). Bean size increased with increase in longitude, but it decreased with increase in latitude. Cup quality was also significantly influenced by coffee harvesting and handling, but its influence was not noticed on bean size and biochemical contents. Coffee quality is therefore the resultant of an interaction of different natural and human factors prevailing in the respective area. Key words: Arabica coffee, bean size, biochemical content, cup quality, environment, management/handling.
{"title":"The major factors influencing coffee quality in Ethiopia: The case of wild Arabica coffee (Coffea arabica L.) from its natural habitat of southwest and southeast afromontane rainforests","authors":"Abebe Yadessa, J. Burkhardt, E. Bekele, Kitessa Hundera, H. Goldbach","doi":"10.5897/ajps2020.1976","DOIUrl":"https://doi.org/10.5897/ajps2020.1976","url":null,"abstract":"Coffee quality is a complex trait involving sensory and bean characteristics as well as biochemical contents. The objective of this study was to assess the major factors influencing the quality of wild Arabica coffee (Coffea arabica L.) in the natural coffee forests of southwest and southeast Ethiopia. Results revealed that both natural (soil, aspect, elevation, climate, geographic location) and human factors (cherry harvesting/ handing, theft, forest management) considerably influenced the quality of wild Arabica coffee. The soil factor affected every component of coffee quality (cup quality, bean characteristics and biochemical contents). The cup quality of coffee varied with soil properties, especially with available P and soil texture. The bean size distribution was also affected by soil properties; there was significant positive relationship between soil pH, sand or Mn and the proportion of bold beans (retained on screen 17). Soil organic matter, total N and sand content were inversely correlated with caffeine content, but available P and clay content were positively correlated with caffeine. Increase in elevation led to increase in bean size up to the elevation of about 1600 m above sea level, but thereafter no more increase in bean size (hump-shaped relationship, not monotonic). Bean size increased with increase in longitude, but it decreased with increase in latitude. Cup quality was also significantly influenced by coffee harvesting and handling, but its influence was not noticed on bean size and biochemical contents. Coffee quality is therefore the resultant of an interaction of different natural and human factors prevailing in the respective area. \u0000 \u0000 \u0000 \u0000 Key words: Arabica coffee, bean size, biochemical content, cup quality, environment, management/handling.","PeriodicalId":7675,"journal":{"name":"African Journal of Plant Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86842661","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}
Mangroves are plant communities growing in the intertidal zone of tropical to subtropical coastal rivers. Some endophytic fungi which live in the tissues of mangrove plants produce some biologically active substances. By screening these biologically active substances some researchers have found that these substances have antimicrobial activity. This research is aimed to determine the antibacterial activity of endophytic fungi isolated from leaves of mangrove plants Excoecaria agallocha, Avicennia marina, Rhizophora mucronata and Lumnitzera racemosa in Sarasalai area in Jaffna Peninsula in Sri Lanka. Various species of endophytic fungi were isolated from the leaves of mangrove plants and identified based on morphological characteristics. Five fungal species were isolated from E. agallocha four from R. mucronata, A. marina and two from L. racemosa. Fifteen endophytic fungi were tested against six selected bacteria for their antagonistic effect. Antibacterial activity was tested against Escherichia coli, Bacillus sp, Klebsiella sp, Pseudomonas sp, Staphylococcus sp. and Proteus sp. using disc diffusion assay. Almost all endophytic fungi inhibited the growth of bacteria. Aspergillus flavus had the highest amount of inhibition against E. coli, Pseudomonas and Staphylococcus sp. Aspergillus tamari had higher amount of inhibition against Klebsiella sp. Few other species of Aspergillus also showed higher inhibitory activity against different bacteria when compared to other endophytic fungi. Key words: Mangrove, endophytic fungi, bacteria.
{"title":"Antibacterial activity of endophytic fungi isolated from mangroves of Jaffna Peninsula, Sri Lanka","authors":"N. Ravimannan, E. Sepali","doi":"10.5897/ajps2020.1987","DOIUrl":"https://doi.org/10.5897/ajps2020.1987","url":null,"abstract":"Mangroves are plant communities growing in the intertidal zone of tropical to subtropical coastal rivers. Some endophytic fungi which live in the tissues of mangrove plants produce some biologically active substances. By screening these biologically active substances some researchers have found that these substances have antimicrobial activity. This research is aimed to determine the antibacterial activity of endophytic fungi isolated from leaves of mangrove plants Excoecaria agallocha, Avicennia marina, Rhizophora mucronata and Lumnitzera racemosa in Sarasalai area in Jaffna Peninsula in Sri Lanka. Various species of endophytic fungi were isolated from the leaves of mangrove plants and identified based on morphological characteristics. Five fungal species were isolated from E. agallocha four from R. mucronata, A. marina and two from L. racemosa. Fifteen endophytic fungi were tested against six selected bacteria for their antagonistic effect. Antibacterial activity was tested against Escherichia coli, Bacillus sp, Klebsiella sp, Pseudomonas sp, Staphylococcus sp. and Proteus sp. using disc diffusion assay. Almost all endophytic fungi inhibited the growth of bacteria. Aspergillus flavus had the highest amount of inhibition against E. coli, Pseudomonas and Staphylococcus sp. Aspergillus tamari had higher amount of inhibition against Klebsiella sp. Few other species of Aspergillus also showed higher inhibitory activity against different bacteria when compared to other endophytic fungi. \u0000 \u0000 \u0000 \u0000 Key words: Mangrove, endophytic fungi, bacteria.","PeriodicalId":7675,"journal":{"name":"African Journal of Plant Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74516079","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}
Maize is an important staple food for most Ethiopians, but the national average productivity of maize is below that of the world. Development and cultivation of high yielding maize hybrids can improve maize productivity and production. Having information on combining ability and heterosis of maize inbred lines is important for the development of high yielding maize hybrids. The objectives of this study were to identify good hybrids based on grain yield and yield related traits, to estimate the general combining ability (GCA) and specific combining ability (SCA). Thirteen inbred lines were crossed in 2017 with two line testers using a line by tester mating design. The resulting 26 crosses were evaluated in a randomized incomplete block design (RCBD) with three replications during the main rainy seasons between June and November, 2018 at Bako, Ethiopia. In addition, the 13 parental lines including the two tester lines were evaluated using RCBD with three replications in a separate trial. Analysis of variance (ANOVA) showed that mean squares due to crosses were highly significant (P≤0.01) for most of the traits studied, except ear aspect. Also mean square due to line was significantly different (P < 0.01 or P < 0.05) in all studied traits except days to anthesis (AD) and ear aspect (EA). The overall mean grain yields (GY) of the hybrids were 6.32 t/ha ranging from 5.21 to 8.19 t/ha. L7 had the lowest negative GCA for grain yield whereas L6 had the highest positive GCA. Among the crosses with high positive SCA, estimates showed high mean grain yield, which implied good correspondence between SCA effects and mean GY. The result obtained in this study could be useful to design for developing high yielding hybrids and synthetics adapted to the mid altitude sub humid agro ecologies of Ethiopia. Key words: Grain yield, maize inbred lines, line by tester, general combining ability, specific combining ability.
{"title":"Combining ability of maize inbred lines (Zea mays L.) for yields in mid altitude sub-humid Agroecology of Ethiopia","authors":"G. Gemechu, N. Abu","doi":"10.5897/ajps2019.1908","DOIUrl":"https://doi.org/10.5897/ajps2019.1908","url":null,"abstract":"Maize is an important staple food for most Ethiopians, but the national average productivity of maize is below that of the world. Development and cultivation of high yielding maize hybrids can improve maize productivity and production. Having information on combining ability and heterosis of maize inbred lines is important for the development of high yielding maize hybrids. The objectives of this study were to identify good hybrids based on grain yield and yield related traits, to estimate the general combining ability (GCA) and specific combining ability (SCA). Thirteen inbred lines were crossed in 2017 with two line testers using a line by tester mating design. The resulting 26 crosses were evaluated in a randomized incomplete block design (RCBD) with three replications during the main rainy seasons between June and November, 2018 at Bako, Ethiopia. In addition, the 13 parental lines including the two tester lines were evaluated using RCBD with three replications in a separate trial. Analysis of variance (ANOVA) showed that mean squares due to crosses were highly significant (P≤0.01) for most of the traits studied, except ear aspect. Also mean square due to line was significantly different (P < 0.01 or P < 0.05) in all studied traits except days to anthesis (AD) and ear aspect (EA). The overall mean grain yields (GY) of the hybrids were 6.32 t/ha ranging from 5.21 to 8.19 t/ha. L7 had the lowest negative GCA for grain yield whereas L6 had the highest positive GCA. Among the crosses with high positive SCA, estimates showed high mean grain yield, which implied good correspondence between SCA effects and mean GY. The result obtained in this study could be useful to design for developing high yielding hybrids and synthetics adapted to the mid altitude sub humid agro ecologies of Ethiopia. \u0000 \u0000 \u0000 \u0000 Key words: Grain yield, maize inbred lines, line by tester, general combining ability, specific combining ability.","PeriodicalId":7675,"journal":{"name":"African Journal of Plant Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79755130","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}
Moussa Massaoudou, T. Abasse, H. Rabiou, L. Mahamane
Jatropha curcas is a tree species introduced in Niger as a trial experiment to offset land degradation and for biofuel production. The objective of this study is to contribute to the understanding of this species’ potential for adaptation under the edaphic and climatic conditions of Niger through analysis and modeling of the leaf area dynamics. The nondestructive method is used to evaluate the leaf area growth using four provenances and 120 samples of leaves of J. curcas plants. The results show that leaf area is optimal during the wet season of the year with non-significant difference (P > 0.05), while during other periods it is significant (P < 0.05) between provenances. The logarithmic model is the most accurate, and the models developed have a correlation coefficient between 0.95 and 0.99. The error analysis shows a mean absolute percentage of error between 5.92 and 27.43%, depending on the provenances. The accuracies of the developed models were appreciated, with root mean square of error varying from 0.72 to 2.06 cm2. Contrary to the expectation, for production of J. curcas in Niger’s Sahelian climate and soil, it is necessary to ensure additional irrigation water to the plants, especially during the dry period of the year. Key words: Exotic species, Jatropha curcas, adaptation, leaf area models, Niger.
{"title":"Seasonal variation and modeling of leaf area growth in Jatropha curcas L. plants: Implication for understanding the species adaptation in the Sahel of Niger","authors":"Moussa Massaoudou, T. Abasse, H. Rabiou, L. Mahamane","doi":"10.5897/AJPS2020.1985","DOIUrl":"https://doi.org/10.5897/AJPS2020.1985","url":null,"abstract":"Jatropha curcas is a tree species introduced in Niger as a trial experiment to offset land degradation and for biofuel production. The objective of this study is to contribute to the understanding of this species’ potential for adaptation under the edaphic and climatic conditions of Niger through analysis and modeling of the leaf area dynamics. The nondestructive method is used to evaluate the leaf area growth using four provenances and 120 samples of leaves of J. curcas plants. The results show that leaf area is optimal during the wet season of the year with non-significant difference (P > 0.05), while during other periods it is significant (P < 0.05) between provenances. The logarithmic model is the most accurate, and the models developed have a correlation coefficient between 0.95 and 0.99. The error analysis shows a mean absolute percentage of error between 5.92 and 27.43%, depending on the provenances. The accuracies of the developed models were appreciated, with root mean square of error varying from 0.72 to 2.06 cm2. Contrary to the expectation, for production of J. curcas in Niger’s Sahelian climate and soil, it is necessary to ensure additional irrigation water to the plants, especially during the dry period of the year. \u0000 \u0000 \u0000 \u0000 Key words: Exotic species, Jatropha curcas, adaptation, leaf area models, Niger.","PeriodicalId":7675,"journal":{"name":"African Journal of Plant Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73375128","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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