The process and lessons of exchanging and managing in-vitro elite germplasm to combat CBSD and CMD in Eastern and Southern Africa

Varieties with resistance to both cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) can reverse food and income security threats affecting the rural poor in Eastern and Southern Africa. The International Institute of Tropical Agriculture is leading a partnership of five national (Malawi, Mozambique, Kenya, Tanzania and Uganda) cassava breeding programs to exchange the most elite germplasm resistant to both CMD and CBSD. This poster documents the process and the key learning lessons. Twenty to 25 stem cuttings of 31 clones comprising of 25 elite clones (5 per country), two standard checks (Kibandameno from Kenya and Albert from Tanzania), and four national checks (Kiroba and Mkombozi from Tanzania, Mbundumali from Malawi, and Tomo from Mozambique) were cleaned and indexed for cassava viruses at both the Natural Resources Institute in the United Kingdom and Kenya Plant Health Inspectorate Services, in Kenya. About 75 in-vitro plantlets per clone were sent to Genetic Technologies International Limited, a private tissue culture lab in Kenya, and micro-propagated to ≥1500 plantlets. Formal procedures of material transfer between countries including agreements, import permission and phytosanitary certification were all ensured for germplasm exchange. At least 300 plantlets of each elite and standard check clones were sent to all partner countries, while the national checks were only sent to their respective countries of origin. In each country, the in-vitro plantlets were acclimatized under screen house conditions and transplanted for field multiplication as a basis for multi-site testing. Except for Tomo, a susceptible clone, all the clones were cleaned of the viruses. However, there was varied response to the cleaning process between clones, e.g. FN-19NL, NASE1 and Kibandameno responded slowly. Also, clones responded differently to micro-propagation protocols at GTIL, e.g. Pwani, Tajirika, NASE1, TME204 and Okhumelela responded slowly. Materials are currently being bulked at low disease pressure field sites in preparation for planting at 5-8 evaluation sites per country. The process of cleaning, tissue culture mass propagation, exchange and local hardening off/bulking has been successful for the majority of target varieties. Two key lessons derived from the process are that adequate preparations of infrastructure and trained personnel are required to manage the task, and that a small proportion of varieties are recalcitrant to tissue culture propagation

Using optical characteristics to estimate the oil content and volume of mesocarp in Macaw palm fruits

A macaúba [Acrocomia aculeata (Jacq.) Lodd. Ex Mart.] é uma oleaginosa rústica, de alta produtividade e múltiplas potencialidades, com grande demanda nas indústrias alimentícia, cosmética e, principalmente, a energética, em função da adequação para produção do biodiesel. Contudo, apesar do enorme potencial, a exploração da macaúba ainda resume-se ao extrativismo. Os estudos visando a sua domesticação e o consequente uso sustentável da espécie são insipientes, em função da falta de métodos práticos e eficientes que possam subsidiar os programas de melhoramento na seleção de genótipos de interesse. Assim, o objetivo deste trabalho foi desenvolver e propor métodos para estimar o teor de óleo e volume do mesocarpo no fruto da macaúba utilizando características ópticas. Para avaliação das metodologias foram conduzidos dois ensaios. No primeiro foram utilizadas 420 amostras para desenvolver um modelo de predição do teor de óleo do mesocarpo usando a espectrometria do visível e infravermelho próximo. Como referência foi usado o método soxhlet. No segundo, composto por 20 amostras, foram desenvolvidos algoritmos do processamento de imagens digitais para estimar o volume do mesocarpo, e como referência empregou-se o método do deslocamento da coluna da água. No primeiro ensaio, o modelo desenvolvido apresentou resultados consistentes na calibração e validação, sendo potencialmente viável para a caracterização e pré-seleção de genótipos visando o melhoramento da macaúba. No segundo ensaio, foram desenvolvidos dois algoritmos, um considerando cada fruto como uma esfera e outro por aproximação a um elipsóide. Os resultados permitem concluir que os algoritmos podem ser usados nas áreas da pré e pós-colheita e na seleção de genótipos em programas do melhoramento da macaúba.The macaúba [Acrocomia aculeata (Jacq.) Lodd. Ex Mart.] is a rustic oilseed, with high productivity and multiple potential, which is strongly demanded in the food, cosmetic, and especially the energy industries, due of its suitability for biodiesel production. However, despite the enormous potential, the exploitation of macaw palm still boils down to foraging. Studies aiming at their sustainable use and the resulting domestication of the species are ignorant, because of the lack of practical and efficient methods to support breeding programs on genotypes selections. The main objective of this study was to develop and propose methods to estimate the oil content and volume of the mesocarp in macaw palm fruit using optical characteristics. For methodologies evaluation two assays were carried out. In the first, 420 samples were used to develop calibration model to predict oil content of mesocarp using visible and near infrared spectrometry. The soxhlet method was used as reference. In the second, consisted of 20 samples, were developed imaging algorithms to estimate the mesocarp volume, and as a reference was used water displacement method. In the first assay the developed model showed consistent results in the calibration and validation sets, and it s potentially feasible for preliminary selections and characterization of genotypes intended macaw palm improvement. In the second, were developed two algorithms, one considering each fruit as sphere and another one using ellipsoid approximation. The results show that the algorithms can be used in the pre and post-harvest sector and to make genotypes selection in macaw palm breeding programs.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Prediction of oil content in the mesocarp of fruit from the macauba palm using spectrometry1

In the present work a model was developed for the prediction of the oil content of the mesocarp of fruit from the macauba palm, using visible and near infrared spectrometry. Reference values were determined the by Soxhlet method. The model was calibrated using spectral data from the mesocarp of macauba fruit by partial least squares regression, considering nine latent variables. The results of the calibration series were consistent with those of the validation series, registering an The coefficient of determination between the reference method and the developed model, systematic error between the predicted values and the measured values and root mean square error, for calibration and validation with independent data, respectively, equal to 0.8223, -9.2-14 and 5.917 and 0.7760, 7.081 and -0.064. VIS-NIR spectroscopy is a viable tool in the evaluation of genotypes in breeding programs for the macauba palm