Micropropagación de Calibanus hookeri (lem.) trel (1911). Una especie amenazada / Micropropagation of Calibanus hookeri (lem.) trel (1911). A threatened species

RESUMEN La especie Calibanus hookerii perteneciente a la familia Asparagaceae, está registrada en la NOM-059-SEMARNAT-2010 catalogada como planta amenazada. Sus poblaciones naturales se han visto reducidas de manera importante debido a una explotación excesiva y destrucción de su hábitat, por lo que se requiere de métodos de propagación eficaz que aseguren su conservación. La propagación in vitro es una alternativa viable para especies vegetales amenazadas. En la presente investigación se reporta el protocolo para la micropropagación de Calibanus hookerii mediante la germinación de semilla sin testa inoculada en medio MS complementado con 2.5, 5.0 y 7.0 mg L-1 de 6 benciladenina (BA), cinetina (K), 2-isopentil-adenina (2iP) y tidiazuron (TDZ). Las variables a medir fueron porcentaje de germinación, número y longitud de brotes producidos por semilla. El tratamiento más eficiente fue de 5.0 mg L-1 de BA produciéndose un promedio de 26 brotes por semilla; el tratamiento menos eficaz fue con 2.5 mg L-1 K en el cual solamente se obtuvieron dos brotes por semilla. De las tres concentraciones de 2iP solamente en la concentración de 7 mg. L-1 mostró resultados produciendo 6 brotes por semilla. En lo que respecta a la longitud del brote ningún tratamiento superó al testigo (8.07cm). La eficiencia la germinación in vitro fue de 56-97%.

ABSTRACT The species Calibanus hookerii belonging to the family Aspagaceae is registered in the NOM-059-SEMARNAT-2010 cataloged in danger of extinction and therefore is necessary of propagation methods that assure its conservation and its propagation. In vitro propagation is a viable alternative for endangered plant species. The present investigation reports the protocol for the micropropagation of Calibanus hookerii. This was achieved by seed germination without test in MS medium supplemented with 2.5, 5.0 and 7.0 mg L-1 of 6-benzyladenine (BA), kinetin (K), 2-isopentyl-adenine (2iP) and tidiazuron (TDZ). The variables to be measured were percentage of germination, number and length of shoots produced by seed. The most efficient treatment was 5 mg L-1 of BA producing an average of 26 shoots per seed, the worst treatment was with 2.5 K only produced 2 shoots per seed, of the four cytokinins used 2ip treatment in only one study of the Performed showed results (7 mg L-1) producing 6 shoots per seed. Regarding the length of the shoot, no treatment exceeded the control (8.07cm). Finally, in vitro germination was high (56-97%) in all treatments.

Efficient regeneration and genetic transformation platform applicable to five Musa varieties

Background: Banana (Musa spp.) is an important staple food, economic crop, and nutritional fruit worldwide. Conventional breeding has been seriously hampered by their long generation time, polyploidy, and sterility of most cultivated varieties. Establishment of an efficient regeneration and transformation system for banana is critical to its genetic improvement and functional genomics. Results: In this study, a vigorous and repeatable transformation system for banana using direct organogenesis was developed. The greatest number of shoots per explant for all five Musa varieties was obtained using Murashige and Skoog medium supplemented with 8.9 µM benzylaminopurine and 9.1 µM thidiazuron. One immature male flower could regenerate 380­456, 310­372, 200­240, 130­156, and 100­130 well-developed shoots in only 240­270 d for Gongjiao, Red banana, Rose banana, Baxi, and Xinglongnaijiao, respectively. Longitudinal sections of buds were transformed through particle bombardment combined with Agrobacterium-mediated transformation using a promoterless ß-glucuronidase (GUS) reporter gene; the highest transformation efficiency was 9.81% in regenerated Gongjiao plantlets in an optimized selection medium. Transgenic plants were confirmed by a histochemical assay of GUS, polymerase chain reaction, and Southern blot. Conclusions: Our robust transformation platform successfully generated hundreds of transgenic plants. Such a platform will facilitate molecular breeding and functional genomics of banana.

Somaclones em batata identificados pelos descritores mínimos de broto / Potato somaclones identified by minimum descriptors sprout

Este estudo objetivou verificar a estabilidade fenotípica das cultivares de batata 'Asterix' e 'Macaca', avaliar o efeito do tipo de explante (organogênese direta e indireta) e do tempo de subcultivo (12 e 70 meses) em meio nutritivo MS sobre a ocorrência de somaclones nas duas cultivares na produção de batata semente, mediante o emprego de sete descritores mínimos de broto. Em 'Asterix' e 'Macaca' ocorreram somaclones em quatro dos sete descritores, contudo, apenas no formato e pubescência da base do broto houve variação, simultaneamente, em ambas. Os dois genótipos são suscetíveis à ocorrência de variação somaclonal. Registrou-se somaclonesnos dois tempos de subcultivo nas duas cultivares. Diferente do amplamente registrado, identificaram-se somaclones em segmentos apicais caulinares e nodais originados de organogênese direta em 'Asterix' e 'Macaca'.(AU)

It was examined the phenotypic stability of potato cultivars 'Asterix' and 'Macaca', evaluated the effect of explant type (direct and indirect organogenesis) and subculture time (12 and 70 months) in MS nutrient medium on the occurrence of somaclonal variation in both cultivars in seed potato production through the use of seven minimum descriptors sprout. In 'Asterix' and 'Macaca' somaclones have occurred in four of the seven descriptors, however, only in the shape and in the base of the bud pubescence that somaclonal variation occurred simultaneously in both cultivars. Both genotypes are susceptible to the occurrence of somaclonal variation. It was identify the occurrence of somaclones both at 12 months and 70 months of subculture in both genotypes. Unlike the widely recorded, somaclones were identified in shoot apical segments and nodal segments derived from direct organogenesis in 'Asterix' and 'Macaca'.(AU)

Somaclones em batata identificados pelos descritores mínimos de broto / Potato somaclones identified by minimum descriptors sprout

Este estudo objetivou verificar a estabilidade fenotípica das cultivares de batata 'Asterix' e 'Macaca', avaliar o efeito do tipo de explante (organogênese direta e indireta) e do tempo de subcultivo (12 e 70 meses) em meio nutritivo MS sobre a ocorrência de somaclones nas duas cultivares na produção de batata semente, mediante o emprego de sete descritores mínimos de broto. Em 'Asterix' e 'Macaca' ocorreram somaclones em quatro dos sete descritores, contudo, apenas no formato e pubescência da base do broto houve variação, simultaneamente, em ambas. Os dois genótipos são suscetíveis à ocorrência de variação somaclonal. Registrou-se somaclonesnos dois tempos de subcultivo nas duas cultivares. Diferente do amplamente registrado, identificaram-se somaclones em segmentos apicais caulinares e nodais originados de organogênese direta em 'Asterix' e 'Macaca'.

It was examined the phenotypic stability of potato cultivars 'Asterix' and 'Macaca', evaluated the effect of explant type (direct and indirect organogenesis) and subculture time (12 and 70 months) in MS nutrient medium on the occurrence of somaclonal variation in both cultivars in seed potato production through the use of seven minimum descriptors sprout. In 'Asterix' and 'Macaca' somaclones have occurred in four of the seven descriptors, however, only in the shape and in the base of the bud pubescence that somaclonal variation occurred simultaneously in both cultivars. Both genotypes are susceptible to the occurrence of somaclonal variation. It was identify the occurrence of somaclones both at 12 months and 70 months of subculture in both genotypes. Unlike the widely recorded, somaclones were identified in shoot apical segments and nodal segments derived from direct organogenesis in 'Asterix' and 'Macaca'.

Meios de cultura no desenvolvimento de ápices caulinares de mamoneira (Ricinus communis L.) in vitro / Culture media on in vitro development of castor bean (Ricinus communis l.) stem tips

A pesquisa da composição do meio de cultura mais adequado à espécie vegetal e ao tipo de explante empregado é o fator de maior relevância da cultura de tecidos. O cultivo de ápice caulinar com recuperação da planta matriz é uma técnica de grande impacto para a propagação de plantas in vitro, regeneração de plantas livres de vírus, conservação de germoplasma e modificação genética. Objetivou-se, neste trabalho, avaliar composições do meio de cultivo para organogênese direta in vitro a partir de ápices caulinares pertencentes à população FCA-UNESP-PB de mamoneira (Ricinus communis L.), com vistas à propagação clonal de genótipos elite. Foram testadas quatro formulações: MS básico (T1), MS modificado 1 (T2), MS modificado 2 (T3) e WPM (T4), em delineamento experimental inteiramente casualizado, com 20 repetições em cada tratamento, sendo a repetição 1 ápice caulinar/frasco. O T3 apresentou-se superior e diferiu significativamente dos outros tratamentos apresentando 35 por cento dos ápices caulinares diferenciados e desenvolvidos; seguiu-se o T2 com 10 por cento e os tratamentos T1 e T4 não apresentaram diferenciação de tecidos. Os resultados permitiram concluir que os balanceamentos de sais minerais nos meios de cultura avaliados, especialmente a relação NO3 / NH4 e ausência de FeSO4.7H2O, indicaram grande influência no desenvolvimento de ápices caulinares de mamoneira.

The research of the culture medium composition suitable for plant species and the type of explant to be used is the most significant factor in plant tissue culture. The culture of stem tips with plant donor recovery is a technique of great impact for the in vitro plant production, regeneration of virus-free plants, germoplasm conservation and genetic modification. The objective of this study was to evaluate culture media composition in vitro on direct organogenesis of the FCA-UNESP-PB population of castor bean (Ricinus communis L.), from stem tips for clonal propagation of elite genotypes. Four formulations were tested: basic MS (T1), modified MS 1 (T2), modified MS 2 (T3) and WPM (T4) in a completely randomized experimental design with 20 replicates pertreatment with 1stem tip/flask. The treatment T3was superior, and differed significantly from the other treatments, with 35 percent of stem tips developed, followed by 10 percent in T2. T1 and T4 showed no plant tissue differentiation. The results allowed to conclude that the balance of mineral salts and culture media evaluated especially the rate NO3 / NH4 and the absence of FeSO4.7H2O showed nigh influence on the development of stem tips of castor bean.