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Dynamic seed zones to guide climate-smart seed sourcing for tropical dry forest restoration in Colombia
Author(s): Fremout, Tobias; Thomas, Evert; Bocanegra-González, Kelly Tatiana; Aguirre-Morales, Carolina Adriana; Morillo-Paz, Anjuly Tatiana; Atkinson, Rachel; Kettle, Christopher; González-M., Roy; Alcázar-Caicedo, Carolina; González, Mailyn Adriana; Gil-Tobón, Carlos; P. Gutiérrez, Janneth; Moscoso-Higuita, Luis Gonzalo; Becerra, Augusto; de Carvalho, Dulcinéia; Muys, Bart (Elsevier (12 months), 2021-06-01)
Date: 2021-03-16
Type: Journal Article
Status: Timeless limited access
Tree-based forest landscape restoration interventions require knowledge on the suitability and origin of seed sources and planting material. A common recommendation is to select locally sourced material based on the assumption that it is well adapted to local environmental conditions and to avoid introduction of maladapted genes. However, faced with accelerating climate change, it may be prudent to supplement local provenances with ‘climate-matched’ provenances, i.e. where current climate conditions are similar to those anticipated in the future at the planting site. Restoration practitioners usually do not have access to the necessary information to implement such climate-smart seed sourcing. Here, we combine genetic data of 11 socio-economically important tree species of the tropical dry forests of Colombia with spatial environmental data to inform the delineation of dynamic seed zones for the restoration of this highly threatened ecosystem. Analysis of Molecular Variance (AMOVA) indicates significant population genetic differentiation within all 11 species. We fitted linear mixed effects models to evaluate if the genetic distance between trees was mainly related to geographic distance (i.e. isolation by distance; IBD), environmental distance (i.e. isolation by environment; IBE), or both. Observed scales of genetic differentiation were best explained by the model including both geographic and environmental distance (IBD + IBE) for 6 out of 11 species, and by the IBE model for the remaining species, suggesting that the observed differentiation is at least partly driven by adaptive processes. Aiming at capturing as much as possible of the observed genetic differentiation, we propose a set of 36 provisional seed zones that are applicable across species and dynamic under climate change, based on the clustering of environmental data and geographical coordinates. We project these seed zones to future climate conditions using five general circulation models and two emission scenarios, and discuss how they can be used to implement different climate-smart seed sourcing strategies in a pragmatic way. The seed zone maps are made available in a user-friendly online tool.
Field-transcriptome analyses reveal developmental transitions during flowering in cassava (Manihot esculenta Crantz)
Author(s): Behnam, Babak; Higo, Asuka; Yamaguchi, Kaho; Tokunaga, Hiroki; Utsumi, Yoshinori; Selvaraj Gomez, Michael; Seki, Motoaki; Ishitani, Manabu; Ceballos, Hernan; Becerra, Augusto; Tsuji, Hiroyuki (Springer Verlag (Germany), 2021-04-15)
Date: 2021-04-15
Type: Journal Article
Status: Timeless limited access
Cassava is an important crop for both edible and industrial purposes. Cassava develops storage roots that accumulate starch, providing an important source of staple food in tropical regions. To facilitate cassava breeding, it is important to elucidate how flowering is controlled. Several important genes that control flowering time have been identified in model plants; however, comprehensive characterization of these genes in cassava is still lacking. In this study, we identified genes encoding central flowering time regulators and examined these sequences for the presence or absence of conserved motifs. We found that cassava shares conserved genes for the photoperiodic flowering pathway, including florigen, anti-florigen and its associated transcription factor (GIGANTEA, CONSTANS, FLOWERING LOCUS T, CENTRORADIALIS/TERMINAL FLOWER1 and FD) and florigen downstream genes (SUPRESSOR OF OVEREXPRESSION OF CONSTANS1 and APETALA1/FRUITFUL). We conducted RNA-seq analysis of field-grown cassava plants and characterized the expression of flowering control genes. Finally, from the transcriptome analysis we identified two distinct developmental transitions that occur in field-grown cassava.
Calibration and validation of the FAO AquaCrop water productivity model for cassava (Manihot esculenta Crantz)
Author(s): Wellens, Joost; Raes, Dirk; Fereres, Elias; Diels, Jan; Coppye, Cecilia; Adiele Joy, Geraldine; Ezui, Kodjovi; Becerra, Augusto; Selvaraj Gomez, Michael; Dercon, Gerd; Kheng Heng, Lee (Elsevier, 2022-04-01)
Date: 2022-01-20
Type: Journal Article
Status: Open access
FAO’s water-driven crop growth simulation model, AquaCrop, was calibrated and validated for cassava (Manihot esculenta Crantz). Existing datasets, used in similar published works, were shared covering several years and regions (Colombia, Nigeria and Togo). Different varieties were tested for the case of Colombia and a single variety (TME-419) for Nigeria and Togo. Overall calibrated biomass simulations resulted in an R2 of 0.96 and a RMSE of 1.99 tonne DM/ha. As for dry tuber yield estimates, it was not possible to find a single harvest index for the ensembled varieties given their varying characteristics and limited data per variety. However, for the TME-419 variety (Nigeria and Togo) calibrated root tuber simulations yielded and R2 of 0.94 and a RMSE of 2.37 tonne DM/ha. A single crop-file was developed for different cassava varieties and agro-ecological regions, which can be applied with confidence to further study cassava related food security, water productivity, improved agronomic practices, etc.
Processors' Experience in the Use of Flash Dryer for Cassava-derived Products in Nigeria
Author(s): Ojide, Makuachukwu; Suraju Adeyemi, Adegbite; Tran, Thierry; Taborda, Luis; Chapuis, Arnaud; Lukombo, Simon; Totin, Edmond; Sartas, Murat; Schut, Marc; Becerra, Augusto; Dufour, Dominique; Abass, Adebayo (Frontiers Media S.A., 2022-02-17)
Date: 2022-02-17
Type: Journal Article
Status: Open access
This study was designed and carried out to ascertain the situation and perceptions of end users of cassava flash drying equipment in Nigeria with the aim of giving suggestions to policies and approaches for improved technology. Forty-one processing firms were selected and interviewed. Descriptive analyses were used and a logistic regression model was estimated. The results revealed that 49% of the firms stopped using their flash dryers due to the low demand for high-quality cassava flour (HQCF) resulting from the high cost of processing occasioned by an inefficient heat-generating component. The estimated model provides evidence that cost effectiveness (p < 0.05) and energy cost (p < 0.10) are the two major determinants of the continuous usage of flash dryers in the study area. Forty-one percent of the firms indicated willingness to pay for any technical adjustment of their flash dryers, supposing such adjustment would improve on drying and the energy efficiency of the equipment up to 40%. The study recommends that machine fabricators in Nigeria and other African countries should be trained on the production of energy- and cost-efficient small-scale flash dryers. Again, the design and commercialization of flash dryers that can be mounted on mobile trucks for farm-gate processing should be encouraged to facilitate farm-gate processing, thereby reducing postharvest losses resulting from transporting perishable and bulky roots over a long distance.
Characterization of cassava ORANGE proteins and their capability to increase provitamin A carotenoids accumulation
Author(s): Jaramillo, Angelica; Sierra, Santiago; Chavarriaga, Paul; Castillo, Diana Katherine; Gkanogiannis, Anestis; Becerra, Augusto; Arciniegas, Juan Pablo; Sun, Tianhu; Li, Li; Welsch, Ralf; Boy, Erick; Álvarez, Daniel (Public Library of Science, 2022-01-07)
Date: 2022-01-07
Type: Journal Article
Status: Open access
Cassava (Manihot esculenta Crantz) biofortification with provitamin A carotenoids is an ongoing process that aims to alleviate vitamin A deficiency. The moderate content of provitamin A carotenoids achieved so far limits the contribution to providing adequate dietary vitamin A levels. Strategies to increase carotenoid content focused on genes from the carotenoids biosynthesis pathway. In recent years, special emphasis was given to ORANGE protein (OR), which promotes the accumulation of carotenoids and their stability in several plants. The aim of this work was to identify, characterize and investigate the role of OR in the biosynthesis and stabilization of carotenoids in cassava and its relationship with phytoene synthase (PSY), the rate-limiting enzyme of the carotenoids biosynthesis pathway. Gene and protein characterization of OR, expression levels, protein amounts and carotenoids levels were evaluated in roots of one white (60444) and two yellow cassava cultivars (GM5309-57 and GM3736-37). Four OR variants were found in yellow cassava roots. Although comparable expression was found for three variants, significantly higher OR protein amounts were observed in the yellow varieties. In contrast, cassava PSY1 expression was significantly higher in the yellow cultivars, but PSY protein amount did not vary. Furthermore, we evaluated whether expression of one of the variants, MeOR_X1, affected carotenoid accumulation in cassava Friable Embryogenic Callus (FEC). Overexpression of maize PSY1 alone resulted in carotenoids accumulation and induced crystal formation. Co-expression with MeOR_X1 led to greatly increase of carotenoids although PSY1 expression was high in the co-expressed FEC. Our data suggest that posttranslational mechanisms controlling OR and PSY protein stability contribute to higher carotenoid levels in yellow cassava. Moreover, we showed that cassava FEC can be used to study the efficiency of single and combinatorial gene expression in increasing the carotenoid content prior to its application for the generation of biofortified cassava with enhanced carotenoids levels.