The role of biotechnology in animal agriculture to address poverty in Africa: The need for appropriate policies

Livestock production currently accounts for about 30% of the gross value of agricultural production in Africa. Seventy per cent of the rural poor in Africa own livestock, including pastoralists living in arid and semi-arid zones. Of these, over 200 million rely on their livestock for income (sales of milk, meat and skins) and manure for growing crop. The livestock sector in Africa, characterised by low productivity, is struggling to keep up with the demand for food from animal sources by the expanding human population. Conventional methods of livestock improvement and agricultural research and development have in the past served the purpose of increasing livestock productivity. However, these options can no longer sustain production hence new intensive techniques including biotechnology are now required to augment productivity. Modern biotechnology has the potential to provide new opportunities for achieving enhanced livestock productivity in a way that alleviates poverty, improves food security and nutrition and promotes sustainable use of natural resources. While modern biotechnology is and will not be a panacea for solving all the problems of food insecurity and poverty, it could provide a critical component to the solution if it is guided by appropriate policies. This proposition forms the basis of this paper

Creation and selection of Coffea arabica hybrids in Tanzania

L'amélioration de Coffea arabica débuta en Tanzanie dans les années 1930 par des essais d'homogénéité dans les variétés Bourbon et Kent. La sélection était basée sur la valeur individuelle des arbres, le rendement à l'usinage, et les qualités physiques et organoleptiques. Il en résulta la distribution des variétés N39, KP162 et 423, H66 à partir de 1960. Ces variétés sont sensibles à la rouille orangée (CLR) et l'anthracnose des baies (CBD). Le programme d'amélioration s'est donc attaché à introduire des résistances dans ces variétés. Le programme de croisement utilise les variétés Geisha, Rume Sudan et l'hybride de Timor CIFC 1343 pour introgresser plusieurs facteurs de résistance. Un grand nombre d'hybrides plus ou moins complexes ont ainsi été créés. Ils présentent des niveaux de résistance aux maladies appréciables. Après une sélection sur les moyennes, seize hybrides ont été multipliés par boutures et implantés dans un essai multilocal de 24 sites, dans les principales régions caféières du pays. On a tenu compte, dans la sélection, de la résistance aux maladies, de la productivité et de la qualité à la tasse. La distribution de ces hybrides est envisagée à partir de 2001. Les principaux résultats de ce programme sont présentés et discutés. (Résumé d'auteur

Techniques for screening resistance to coffee berry disease (Colletotrichum kahawae Waller & Bridge)

En Tanzanie, l'anthracnose des baies du caféier est un problème important. Aussi l'évaluation d'hybrides de caféiers résistants à la maladie est essentielle. Différentes méthodes d'évaluation sont présentées : pré-sélection sur plantules et test sur cerises matures provenant de différents hybrides, inoculation artificielle, infection naturell

Effect of 6-BA on nodal explant bud sproutings of Coffea arabica cv. Mundo Novo Efeito de 6-BA na brotação de gemas de explantes nodais de Coffea arabica cv. Mundo Novo

Coffee plants can be micropropagated by nodal bud sprouting using the 6-benzylaminopurine (6-BA) hormone. However, literature reports the use of a wide range of 6-BA, from 0.5 to 88.8 µM L-1. So, this study was performed to narrow that range. Nodal explants of Coffea arabica cv Mundo Novo obtained from in vitro plantlets were inoculated on gelled-MS medium supplemented with different concentrations of 6-BA. Two assays were carried out: in the first one, 6-BA was used at concentrations of 0, 5, 25, 50, and 100 µM L-1, being evaluated at 43 and 123 days. In the second experiment, dosis of 10, 20 and 30 µM L-1, have evaluated at 65 and 100 days. Treatments with 6-BA induced multiple sprouting from the nodal explants, which were best characterized around 100 days after inoculation. The nodal explants grew taller and showed multiple shoots, whereas the effect of 6-BA at 5 to 25 µM L-1 was similar to that with higher concentrations (50 and 100 µM L-1). Nodal explants yielded from 2.9 to 6.0 buds per node, achieving height of 1.3 to 1.5 cm at 5 to 25 µM L-1 of 6-BA, whereas they yielded from 4.3 to 4.9 buds per node but the sprouting grew about 0.8 cm at 50 and 100 µM L-1 of 6-BA. This study indicated that multiple sprouting of lateral buds can be induced by lower concentrations of 6-BA, for example, from 10 to 30 µM L-1, diminishing possible risks of somaclonal variation due to high levels of hormone concentration.<br>O cafeeiro pode ser micropropagado via brotação de gemas laterais, aplicando o regulador de crescimento 6-benzilaminopurina (6-BA). Entretanto, a literatura apresenta ampla variação da dose empregada, desde 0.5 a 88.8 µM L-1. Assim, este estudo visou otimizar doses para explantes nodais do cafeeiro C. arabica cv Mundo Novo. Explantes nodais, obtidos de plântulas cultivadas in vitro, foram inoculados em meio MS geleificado, com adição de diferentes concentrações de 6-BA. Foram feitos dois experimentos: no primeiro, 6-BA foi usado nas doses de 0, 5, 10, 25, 50 e 100 µM L-1 e avaliado aos 43 e 123 dias; no segundo, 10, 20 e 30 µM L-1, avaliado aos 65 e 100 dias após a inoculação dos explantes. Os tratamentos com 6-BA induziram a multibrotação dos explantes nodais, e os resultados foram mais bem caracterizados aos cem dias. Os explantes nodais tratados formaram multibrotações que também atingiram maior altura; todavia, o efeito de 6-BA nas concentrações entre 5 a 25 µM L-1 foi semelhante ao das doses mais elevadas, 50 e 100 µM L-1. As doses de 5 a 25 µM L-1 de 6-BA induziram a brotação de 2,9 a 6,0 gemas por nó, atingindo de 1,3 a 1,5 cm, enquanto os tratamentos de 50 a 100 µM L-1 formaram 3,0 a 4,9 gemas por nó e as suas brotações atingiram cerca de 0,8 cm de altura. Observou-se neste estudo que a multibrotação de explantes nodais de C. arabica cv Mundo Novo pode ser induzida por concentrações menores de 6-BA, entre 10 a 30 µM L-1, diminuindo os riscos de variação somaclonal devido às altas concentrações de hormônio