scholarly journals Potential Impact of Climate Change on Six Economically Important Horticultural Crops in West Africa

Author(s):  
Chinedu Felix Amuji

Colocasia esculenta (taro), Ipomoea batatas (sweet potato), Abelmoschus esculentus (okra), Ananas cosmosus (pineapple), Musa paradisiaca (plantain), and Anacardium occidentale (cashew) are economically important horticultural crops in West Africa, which are widely grown across the region under rain fed conditions. They are very important set of crops that provides income for the individuals involved with it and thus contributing to economy of West African nation’s. For Predicting the potential future habitat suitability of these crops under different climate scenarios holds significance for their continuous cultivation and effective management. The Maxent model was used in this study to predict habitat suitability of these crops under current and future climatic conditions based on two representative concentration pathways (RCP4.5 and RCP8.5) for the years 2050s and 2070s. The data used were the occurrence records from Global Biodiversity Information Facility (GBIF) and WorldClim’s bioclimatic environmental predictor variables. The findings of this experiment showed that the habitat suitability of some crop species will =decrease and in some it will increase. Suitable habitat was predicted to decrease within the semi-arid and arid areas of the region, especially on those countries in northern part which includes Niger, Mali and Burkina Faso, as early as by 2070s. For species like okra, sweet potato and taro, there will be further decline as predicted under the higher emission scenario of RCP 8.5. The suitable habitat for cashew remained stable for future in all the models and scenarios used. This work provides the first theoretical guidance for possible future cultivation of these horticultural crops in the West Africa.

2018 ◽  
Vol 31 (3) ◽  
pp. 779-790 ◽  
Author(s):  
PABLO FORLAN VARGAS ◽  
ERIC WATZKE ENGELKING ◽  
LUIS CARLOS FERREIRA DE ALMEIDA ◽  
ELIEL ALVES FERREIRA ◽  
HAMILTON CESAR DE OLIVERIA CHARLO

ABSTRACT The genetic variability within the crop species Ipomoea batatas is broad, hence, in order to support future breeding programs it is of the utmost importance that germplasm banks be created, conserved, and characterized. Therefore, the objective of this work was to rescue and evaluate the genetic divergence in sweet potato accessions collected in traditional communities of Vale do Ribeira Paulista. Sweet potato samples were collected from quilombos, indigenous villages, caiçaras communities, and small farms. The study was conducted between February 2013 and August 2014 in a randomized block design with three replications. Genetic material included 95 collected accessions and two commercial cultivars. Morphological characteristics of the accessions were evaluated and distances in the genetic distance matrix were estimated by means of multi-category variables, the data being subsequently clustered by the Tocher method. Analysis of the relative contribution of each characteristic and phenotypic correlation of descriptors was also performed. Results evidenced wide genetic diversity among the sweet potato accessions collected in Vale do Ribeira, which were not grouped according to the collection point. The descriptors that contributed more than 60% of genetic diversity included: leaf size, general leaf profile, immature leaf color, petiole pigmentation, predominant branch color, branch secondary color, stem length, cortical thickness, predominant periderm color, and periderm color intensity. Correlations between morphological descriptors was observed in 22.26% of the paired traits.


Author(s):  
Ganesh Pant ◽  
Tek Maraseni ◽  
Armando Apan ◽  
Benjamin Allen

Aim Rapidly changing climate is likely to modify the spatial distribution of both flora and fauna. Land use change continues to alter the availability and quality of habitat and further intensifies the effects of climate change on wildlife species. We used an ensemble modelling approach to predict changes in habitat suitability for an iconic wildlife species, greater one-horned rhinoceros due to the combined effects of climate and land use changes. Location Nepal. Methods We compiled an extensive database on current rhinoceros distribution and selected nine ecologically meaningful environmental variables for developing ensemble models of habitat suitability using seven different species distribution modelling techniques in the BIOMOD2 R package; and we did this under current climatic conditions and then projected them onto two possible climate scenarios (SSP1-2.6 and SSp5-8.5) and two different time frames (2050 and 2070). Results Out of seven algorithms, random forest performed the best, and four environmental variables — distance from grasslands, distance from wetlands, annual precipitation, and slope, contributed the most in the model. The ensemble model estimated the current suitable habitat of rhinoceros to be 1,875 km2, about 1.3% of the total area of Nepal. The future habitat suitability under the lowest and highest emission scenarios was estimated to be: (1) 1,637 km2 and 1,417 km2 in 2050; and (2) 1,562 km2 and 1,301 km2 in 2070, respectively. Main conclusions Our results suggest that nearly one-third of the current rhinoceros habitat would become unsuitable within a period of 50 years, with the predicted declines being influenced to a greater degree by climatic changes than land use changes. We have recommended several measures to moderate these impacts, including relocation of the proposed Nijgad International Airport given that a considerable portion of potential rhinoceros habitat will be lost if the airport is constructed on the currently proposed site.


2021 ◽  
Author(s):  
Yusha Meng ◽  
Wenjin Su ◽  
Yanping Ma ◽  
Lei Liu ◽  
Xingguo Gu ◽  
...  

Abstract Sweet potato, a dicotyledonous and perennial plant, is the third most crucial tuber/root crop species behind potato and cassava in terms of production. Long terminal repeat (LTR) retrotransposons are highly abundant in sweet potato, contributing to genetic diversity. These LTR retrotransposons play a significant role in sweet potato genotypes. Retrotransposon-based insertion polymorphism (RBIP) is a high-throughput marker system to study the genetic diversity of plant species. To date, there have been no transposon marker-based genetic diversity analyses of sweet potato. We report a structure-based analysis of the sweet potato genome for the main LTR-retrotransposon subfamilies, Ty3-gypsy and Ty1-copia, which revealed a total of 21555 LTR retrotransposons. By searching using hidden Markov models (HMMs), 1616 LTR retrotransposon sequences containing at least two models were found. A total of 48 RBIP primers were synthesized based on the high copy numbers of conserved LTR sequences. RBIP markers of the genetic diversity and population structure of 105 sweet potato germplasm resources revealed 56 amplicons with an average polymorphism of 91.07%. Sweet potato accessions were collected from 6 provinces of China, Japan and America. A UPGMA dendrogram, a model-based genetic structure and principal component analysis (PCA) divided the sweet potato germplasms into 3 groups containing 8, 53, and 44 germplasms. All three analyses produced significant groupwise consensus. However, almost all the germplasms contained only one primary locus. The analysis of molecular variance (AMOVA) among the groups indicated higher intergroup genetic variation (53%) than intrapopulation genetic variation. In addition, long-term self-retention may cause some germplasm resources to exhibit variable segregation. These results suggest that these sweet potato germplasms are not well evolutionarily diversified, although geographic speciation could have occurred at a limited level. This study highlights the utility of RBIP markers for determining the intraspecies variability of sweet potato.


2019 ◽  
Vol 20 (19) ◽  
pp. 4702 ◽  
Author(s):  
Hongxia Wang ◽  
Yinliang Wu ◽  
Yandi Zhang ◽  
Jun Yang ◽  
Weijuan Fan ◽  
...  

CRISPR/Cas9-mediated genome editing is a powerful technology that has been used for the genetic modification of a number of crop species. In order to evaluate the efficacy of CRISPR/Cas9 technology in the root crop, sweet potato (Ipomoea batatas), two starch biosynthetic pathway genes, IbGBSSI (encoding granule-bound starch synthase I), and IbSBEII (encoding starch branching enzyme II), were targeted in the starch-type cultivar Xushu22 and carotenoid-rich cultivar Taizhong6. I. batatas was transformed using a binary vector, in which the Cas9 gene is driven by the Arabidopsis AtUBQ promoter and the guide RNA is controlled by the Arabidopsis AtU6 promoter. A total of 72 Xushu22 and 35 Taizhong6 transgenic lines were generated and analyzed for mutations. The mutation efficiency was 62–92% with multi-allelic mutations in both cultivars. Most of the mutations were nucleotide substitutions that lead to amino acid changes and, less frequently, stop codons. In addition, short nucleotide insertions or deletions were also found in both IbGBSSI and IbSBEII. Furthermore, a 2658 bp deletion was found in one IbSBEII transgenic line. The total starch contents were not significantly changed in IbGBSSI- and IbSBEII-knockout transgenic lines compared to the wild-type control. However, in the allopolyploid sweet potato, the IbGBSSI-knockout reduced, while the IbSBEII-knockout increased, the amylose percentage. Our results demonstrate that CRISPR/Cas9 technology is an effective tool for the improvement of starch qualities in sweet potato and breeding of polyploid root crops.


PLoS ONE ◽  
2017 ◽  
Vol 12 (5) ◽  
pp. e0177697 ◽  
Author(s):  
Kodjo Glato ◽  
Atsou Aidam ◽  
Ndjido Ardo Kane ◽  
Diallo Bassirou ◽  
Marie Couderc ◽  
...  

2019 ◽  
Vol 86 ◽  
Author(s):  
Samuel Luan Pereira ◽  
Tatiane Carla Reis ◽  
Ivani Teixeira de Oliveira ◽  
Evander Alves Ferreira ◽  
Bárbara Monteiro de Castro e Castro ◽  
...  

ABSTRACT The use of acaricides is the main control method for Tetranychus ludeni (Acari: Tetranychidae) in horticultural crops. This mite has been recorded causing damage to sweet potato (Ipomoea batatas L.). The use of pathogenic fungi is an alternative to chemical control. The objective was to evaluate the pathogenicity of the fungi Metarhizium anisopliae (Meetch) Sorok, and Beauveria bassiana (Bals.) Vuill. to phytophagous mite T. ludeni in sweet potato plants. Conidial suspensions of M. anisopliae and B. bassiana, at concentrations of 106 and 107 con.mL-1 were applied to sweet potato leaves. After 24 hours, five females of T. ludeni newly emerged were released on the leaves. The bioassay was arranged in a completely randomized design with factorial arrangement 2 × 2 (two species of fungi and two concentrations) plus the control (distilled water), with 10 repetitions per treatment. The evaluation consisted of observing of three biological parameters of the mite: mortality, oviposition, and repellency, after 24, 48, 72, and 96 hours of contact with the fungi. The isolates of M. anisopliae cause high mortality rates of T. ludeni in laboratory. Beauveria bassiana has the potential to suppress future generations of mite, reducing its oviposition rate. Repellency behavior was not observed.


Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
D Rosas-Ramírez ◽  
R Pereda-Miranda
Keyword(s):  

2020 ◽  
Vol 641 ◽  
pp. 159-175
Author(s):  
J Runnebaum ◽  
KR Tanaka ◽  
L Guan ◽  
J Cao ◽  
L O’Brien ◽  
...  

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.


2018 ◽  
Vol 15 (2) ◽  
pp. 146
Author(s):  
BRILIAN DINANTI ◽  
FITRI HANDAJANI

<p>Liver is an organ with complex metabolism. When the liver is inflamed, cellular immunity will defend against inflammatory agents by stimulating immune cells to produce reactive oxygen species (ROS). Excessive ROS accumulation cause oxydative stress with increased  liver malondialdehyde (MDA) level. Some researches showed that purple sweet potato contain flavonoids (anthocyanins) that functioned as antioxydants. This study aimed to show the prophylactic effect of purple sweet potato extract to the liver MDA level of male Wistar rats induced by carrageenan.</p><p>This study used post-only control group method using 18 male Wistar rats divided into 3 groups: group of rats without treatment, group of rats induced by 0,1 ml of 1% carrageenan by intraplantar injection on day-8, and group of rats given with 872 mg/kgBW of purple sweet potato extract for 7 days and induced by 0,1 ml of 1% carrageenan. In the end of the study, the liver MDA levels were measured by Thio-Barbituric Acid method on each groups.</p><p>The results of One-Way ANOVA test showed there was no significant difference (p = 0,290) between group of rats without treatment (<em>x̅</em>= 207,50) and group of rats induced by carrageenan (<em>x̅</em>=233,17). Then, there is no significant difference (p = 0.978) between group of rats induced by carrageenan and group of rats given with prophylactic purple sweet potato extract and induced by carrageenan (<em>x̅</em>= 232,50).</p><p>The conclusion of this study is giving intraplantar injection of carrageenan can increase liver MDA level insignificantly and giving prophylactic purple sweet potato extract has an effect to decrease the liver MDA level of rats induced by carragenan insignificantly because it contains anthocyanins as antioxidants.</p><p> </p><strong>Keywords: </strong>Liver, <em>Ipomoea batatas</em> L., Malondialdehyde, Anthocyanins


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