Low technology tissue culture materials for initiation and multiplication of banana plants

Tissue culturing has become a routine method for propagating plants in high technology laboratories. The cost of production using conventional tissue culture is, however, high for most of the countries in the sub-Saharan Africa. In this study, we evaluated a micropropagating protocol for local banana ( Musa spp.) (Muunju landrace) in Kenya as an alternative to reduce the unit cost of tissue culture micropropagation. Matrices were satisfactory and comparable to the gelling agents. Glass beads were, however, the best matrix in shoot multiplication. Use of support matrices, locally available macronutrients, micronutrients, sugar, equipment and facility reduced the cost of consumable material for banana tissue culturing by about 94%. Putting into account energy, labour and capital investments, the cost dropped from approximately US 1.5 to 1.0 per plantlet. Contamination was not observed when the media and equipment were sterilised using a pressure cooker instead of an autoclave. Use of plastic syringes instead of glass cylinders and micropipettes, to measure volumes reduced the cost of the equipment by 96%. The risk of damage and loss due to breakage was eliminated compared to the use of glassware equipment. Shoots were rooted when they were transferred to Murashige and Skoog (MS) medium supplemented with 1 mg l-1 napthaleneacetic acid (NAA) or 1 mg l-1 Anatone. Acclimatised plants were successfully transplanted and established in the field. There is potential for use of locally available low cost resources as alternatives to the conventional costly laboratory resources.La culture des tissues est devenue une m\ue9thode de routine pour la propagation des plants dans des laboratoires de hautes technologies. Le co\ufbt de production utilisant la culture conventionnelle de tissues est par ailleurs \ue9lev\ue9 pour beaucoup des pays d'Afrique sub-Saharien. Dans cette \ue9tude, nous avons \ue9valu\ue9 un protocol de micropropagation de bananes locales (Muunju landrace) au Kenya comme un co\ufbt bas alternatif pour r\ue9duire le co\ufbt unitaire de la propagation de tissues cultiv\ue9es. Les matrices \ue9taient trouv\ue9es satisfaisants et comparables \ue0 l'agent g\ue9lant. Les Glass beads \ue9taitent par ailleurs la meilleure matrice dans la multiplication des bourgeons. L'utilisation des matrices de support, macronutriments localement disponibles, micronutriments, sucre, \ue9quipement et autre facilit\ue9s ont r\ue9duit le co\ufbt du mat\ue9riel consommable pour la culture d'environ 94% de tissues de banane. Consid\ue9rant l'\ue9nergie, la main d'oeuvre et le capital investi, le co\ufbt a approximativement baiss\ue9 de US 1.5 \ue0 1.0 par plantule. La contamination n'\ue9tait pas observ\ue9e lorsque le m\ue9dia et l'\ue9quipement n'\ue9taient pas st\ue9rilis\ue9s au pressure cooker \ue0 la place d'une autoclave. L'utilisation des syringues plastiques au lieu de cylindres en verre et micropipettes pour mesurer les volumes avaient r\ue9duit le co\ufbt de l'\ue9quipement de 96%. Le risque de damage et perte d\ufb \ue0 la casse \ue9tait \ue9limin\ue9 par comparaison \ue0 l'utilisation de l'\ue9quipement en verre. Les bourgeons \ue9taient enracin\ue9s lorsqu' elles \ue9taient transfer\ue9es au medium de Murashige et Skoog (MS) supplement\ue9 avec 1 mg l-1 de l' acid napthal\ue9n\ue9ac\ue9tique (NAA) ou 1 mg l-1 d' Anatone. Des plants acclimatis\ue9s \ue9taient transplant\ue9s avec succ\ue8s et \ue9tablis dans le champ. Il y a donc une possibilit\ue9 d'utiliser des resources locales \ue0 co\ufbt bas comme alternatives aux ressources de laboratoire \ue0 co\ufbt conventionnel

Low technology tissue culture materials for initiation and multiplication of banana plants

Tissue culturing has become a routine method for propagating plants in high technology laboratories. The cost of production using conventional tissue culture is, however, high for most of the countries in the sub-Saharan Africa. In this study, we evaluated a micropropagating protocol for local banana ( Musa spp.) (Muunju landrace) in Kenya as an alternative to reduce the unit cost of tissue culture micropropagation. Matrices were satisfactory and comparable to the gelling agents. Glass beads were, however, the best matrix in shoot multiplication. Use of support matrices, locally available macronutrients, micronutrients, sugar, equipment and facility reduced the cost of consumable material for banana tissue culturing by about 94%. Putting into account energy, labour and capital investments, the cost dropped from approximately US 1.5 to 1.0 per plantlet. Contamination was not observed when the media and equipment were sterilised using a pressure cooker instead of an autoclave. Use of plastic syringes instead of glass cylinders and micropipettes, to measure volumes reduced the cost of the equipment by 96%. The risk of damage and loss due to breakage was eliminated compared to the use of glassware equipment. Shoots were rooted when they were transferred to Murashige and Skoog (MS) medium supplemented with 1 mg l-1 napthaleneacetic acid (NAA) or 1 mg l-1 Anatone. Acclimatised plants were successfully transplanted and established in the field. There is potential for use of locally available low cost resources as alternatives to the conventional costly laboratory resources.La culture des tissues est devenue une méthode de routine pour la propagation des plants dans des laboratoires de hautes technologies. Le coût de production utilisant la culture conventionnelle de tissues est par ailleurs élevé pour beaucoup des pays d'Afrique sub-Saharien. Dans cette étude, nous avons évalué un protocol de micropropagation de bananes locales (Muunju landrace) au Kenya comme un coût bas alternatif pour réduire le coût unitaire de la propagation de tissues cultivées. Les matrices étaient trouvées satisfaisants et comparables à l'agent gélant. Les Glass beads étaitent par ailleurs la meilleure matrice dans la multiplication des bourgeons. L'utilisation des matrices de support, macronutriments localement disponibles, micronutriments, sucre, équipement et autre facilités ont réduit le coût du matériel consommable pour la culture d'environ 94% de tissues de banane. Considérant l'énergie, la main d'oeuvre et le capital investi, le coût a approximativement baissé de US 1.5 à 1.0 par plantule. La contamination n'était pas observée lorsque le média et l'équipement n'étaient pas stérilisés au pressure cooker à la place d'une autoclave. L'utilisation des syringues plastiques au lieu de cylindres en verre et micropipettes pour mesurer les volumes avaient réduit le coût de l'équipement de 96%. Le risque de damage et perte dû à la casse était éliminé par comparaison à l'utilisation de l'équipement en verre. Les bourgeons étaient enracinés lorsqu' elles étaient transferées au medium de Murashige et Skoog (MS) supplementé avec 1 mg l-1 de l' acid napthalénéacétique (NAA) ou 1 mg l-1 d' Anatone. Des plants acclimatisés étaient transplantés avec succès et établis dans le champ. Il y a donc une possibilité d'utiliser des resources locales à coût bas comme alternatives aux ressources de laboratoire à coût conventionnel

Effects of high temperature on survival, symbiotic performance and genomic modifications of bean nodulating Rhizobium strains Sobrevivência, fixação de nitrogênio e modificações genéticas em estirpes de Rhizobium sp. efetivas na nodulação do feijoeiro, expostas à altas temperaturas

High temperatures can affect the survival, establishment and symbiotic properties of Rhizobium strains. Bean nodulating Rhizobium strains are considered particularly sensitive because on this strains genetic recombinations and/or deletions occur frequently, thus compromising the use of these bacteria as inoculants. In this study R. tropici and R. leguminosarum bv. phaseoli strains isolated from Cerrado soils were exposed to thermal stress and the strains’ growth, survival and symbiotic relationships as well as alterations in their genotypic and phenotypic characteristics were analyzed. After successive thermal shocks at 45ºC for four hours, survival capacity appeared to be strain-specific, independent of thermo-tolerance and was more apparent in R. tropici strains. Certain R. leguminosarum bv. phaseoli strains had significant alterations in plant dry weight and DNA patterns obtained by AP-PCR method. R. tropici strains (with the exception of FJ2.21) were more stable than R. leguminosarum bv. phaseoli strains because no significant phenotypic alterations were observed following thermal treatments and they maintained their original genotypic pattern after inoculation in plants.<br>Altas temperaturas podem afetar a sobrevivência, estabelecimento e as propriedades simbióticas em estirpes de Rhizobium. As estirpes capazes de nodular o feijoeiro têm sido consideradas particularmente sensíveis, porque nessas estirpes é comum a ocorrência de recombinações e/ou deleções genômicas comprometendo, muitas vezes, a sua utilização como inoculantes. Neste trabalho, procurou-se avaliar a capacidade de crescimento e sobrevivência em temperaturas elevadas de estirpes de Rhizobium efetivas na fixação de nitrogênio no feijoeiro isoladas dos cerrados, bem como avaliar suas características fenotípicas e genotípicas após choque térmico. A capacidade de sobrevivência à temperaturas elevadas, avaliada após choques térmicos sucessivos (45ºC por 4 horas) mostrou ser uma característica própria de cada estirpe, independente de sua termotolerância, que aparentemente foi mais acentuada nas estirpes de R. tropici. Algumas estirpes de R. leguminosarum bv. phaseoli mostraram alterações significativas (Duncan 5% de probabilidade) nas suas características fenotípicas (produção de matéria seca) após choques térmicos e nos seus padrões genômicos evidenciados pela técnica de AP-PCR. As estirpes de R. tropici foram aparentemente mais estáveis não sendo detectadas alterações fenotípicas significativas e com exceção da estirpe FJ2.21, após choque térmico e inoculação na planta hospedeira, mantiveram o padrão genômico original