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Recent Submissions

Novel Technological and Management Options for Accelerating Transformational Changes in Rice and Livestock Systems

Date: 2017-10-27

Type: Journal Article

Status: Open access

Agricultural producers grapple with low farm yields and declining ecosystem services within their landscapes. In several instances, agricultural production systems may be considered largely unsustainable in socioeconomic and ecological (resource conservation and use and impact on nature) terms. Novel technological and management options that can serve as vehicles to promote the provision of multiple benefits, including the improvement of smallholder livelihoods, are needed. We call for a paradigm shift to allow designing and implementing agricultural systems that are not only efficient (serving as a means to promote development based on the concept of creating more goods and services while using fewer resources and creating less waste) but can also be considered synergistic (symbiotic relationship between socio-ecological systems) by simultaneously contributing to major objectives of economic, ecological, and social (equity) improvement of agro-ecosystems. These transformations require strategic approaches that are supported by participatory system-level research, experimentation, and innovation. Using data from several studies, we here provide evidence for technological and management options that could be optimized, promoted, and adopted to enable agricultural systems to be efficient, effective, and, indeed, sustainable. Specifically, we present results from a study conducted in Colombia, which demonstrated that, in rice systems, improved water management practices such as Alternate Wetting and Drying (AWD) reduce methane emissions (~70%). We also show how women can play a key role in AWD adoption. For livestock systems, we present in vitro evidence showing that the use of alternative feed options such as cassava leaves contributes to livestock feed supplementation and could represent a cost-effective approach for reducing enteric methane emissions (22% to 55%). We argue that to design and benefit from sustainable agricultural systems, there is a need for better targeting of interventions that are co-designed, co-evaluated, and co-promoted, with farmers as allies of transformational change (as done in the climate-smart villages), not as recipients of external knowledge. Moreover, for inclusive sustainability that harnesses existing knowledge and influences decision-making processes across scales, there is a need for constant, efficient, effective, and real trans-disciplinary communication and collaboration.

First report of a ‘Candidatus Phytoplasma asteris’ isolate associated with banana elephantiasis disease in Colombia

Author(s): Aliaga, Flavio; Hopp, E.; Alvarez, Elizabeth; Becerra, Augusto (British Society for Plant Pathology (BSPP), 2018-06-01)

Date: 2018-03-01

Type: Journal Article

Status: Open access

First report of a ‘Candidatus Phytoplasma asteris’ isolate associated with banana elephantiasis disease in Colombia

An optimized isolation protocol yields high-quality RNA from cassava tissues (Manihot esculenta Crantz)

Author(s): Behnam, Babak; Bohorquez-Chaux, Adriana; Castañeda, Oscar; Tsuji, Hiroyuki; Ishitani, Manabu; Becerra, Augusto (Wiley Open Access, 2018-11-24)

Date: 2018-11-24

Type: Journal Article

Status: Open access

We developed and modified a precise, rapid, and reproducible protocol isolating high-quality RNA from tissues of multiple varieties of cassava plants (Manihot esculenta Crantz). The resulting method is suitable for use in mini, midi, and maxi preparations and rapidly achieves high total RNA yields (170–600 μg·g−1) using low-cost chemicals and consumables and with minimal contamination from polysaccharides, polyphenols, proteins, and other secondary metabolites. In particular, A260 : A280 ratios were > 2.0 for RNA from various tissues, and all of the present RNA samples yielded ribosomal integrity number values of greater than six. The resulting high purity and quality of isolated RNA will facilitate downstream applications (quantitative reverse transcriptase-polymerase chain reaction or RNA sequencing) in cassava molecular breeding.

A metabolomics characterisation of natural variation in the resistance of cassava to whitefly

Author(s): Perez-Fons, Laura; Bohorquez-Chaux, Adriana; Irigoyen, Maria; Garceau, Danielle; Morreel, Kris; Boerjan, Wout; Walling, Linda; Becerra, Augusto; Paul, Fraser (BioMed Central, 2019-11-27)

Date: 2019-11-27

Type: Journal Article

Status: Open access

Background Cassava whitefly outbreaks were initially reported in East and Central Africa cassava (Manihot esculenta Crantz) growing regions in the 1990’s and have now spread to other geographical locations, becoming a global pest severely affecting farmers and smallholder income. Whiteflies impact plant yield via feeding and vectoring cassava mosaic and brown streak viruses, making roots unsuitable for food or trading. Deployment of virus resistant varieties has had little impact on whitefly populations and therefore development of whitefly resistant varieties is also necessary as part of integrated pest management strategies. Suitable sources of whitefly resistance exist in germplasm collections that require further characterization to facilitate and assist breeding programs. Results In the present work, a hierarchical metabolomics approach has been employed to investigate the underlying biochemical mechanisms associated with whitefly resistance by comparing two naturally occurring accessions of cassava, one susceptible and one resistant to whitefly. Quantitative differences between genotypes detected at pre-infestation stages were consistently observed at each time point throughout the course of the whitefly infestation. This prevalent differential feature suggests that inherent genotypic differences override the response induced by the presence of whitefly and that they are directly linked with the phenotype observed. The most significant quantitative changes relating to whitefly susceptibility were linked to the phenylpropanoid super-pathway and its linked sub-pathways: monolignol, flavonoid and lignan biosynthesis. These findings suggest that the lignification process in the susceptible variety is less active, as the susceptible accession deposits less lignin and accumulates monolignol intermediates and derivatives thereof, differences that are maintained during the time-course of the infestation. Conclusions Resistance mechanism associated to the cassava whitefly-resistant accession ECU72 is an antixenosis strategy based on reinforcement of cell walls. Both resistant and susceptible accessions respond differently to whitefly attack at biochemical level, but the inherent metabolic differences are directly linked to the resistance phenotype rather than an induced response in the plant.

Metabolite database for root, tuber, and banana crops to facilitate modern breeding in understudied crops

Author(s): Price, Elliot; Drapal, Margit; Perez-Fons, Laura; Amah, Delphine; Bhattacharjee, Ranjana; Heider, Bettina; Rouard, Mathieu; Swennen, Rony; Becerra, Augusto; Paul, Fraser (Wiley, 2021-03-01)

Date: 2019-12-19

Type: Journal Article

Status: Open access

Roots, tubers, and bananas (RTB) are vital staples for food security in the world’s poorest nations. A majorconstraint to current RTB breeding programmes is limited knowledge on the available diversity due to lackof efficient germplasm characterization and structure. In recent years large-scale efforts have begun to eluci-date the genetic and phenotypic diversity of germplasm collections and populations and, yet, biochemicalmeasurements have often been overlooked despite metabolite composition being directly associated withagronomic and consumer traits. Here we present a compound database and concentration range formetabolites detected in the major RTB crops: banana (Musaspp.), cassava (Manihot esculenta), potato(Solanum tuberosum), sweet potato (Ipomoea batatas), and yam (Dioscoreaspp.), following metabolomics-based diversity screening of global collections held within the CGIAR institutes. The dataset including 711chemical features provides a valuable resource regarding the comparative biochemical composition of eachRTB crop and highlights the potential diversity available for incorporation into crop improvement pro-grammes. Particularly, the tropical crops cassava, sweet potato and banana displayed more complex com-positional metabolite profiles with representations of up to 22 chemical classes (unknowns excluded) thanthat of potato, for which only metabolites from 10 chemical classes were detected. Additionally, over 20%of biochemical signatures remained unidentified for every crop analyzed. Integration of metabolomics withthe on-going genomic and phenotypic studies will enhance ’omics-wide associations of molecular signa-tures with agronomic and consumer traits via easily quantifiable biochemical markers to aid gene discoveryand functional characterization.