Development of an embryogenic suspension culture of bitter melon (Momordica charantia L.)

We have optimized a system for the somatic embryogenesis via embryogenic suspension cultures in bitter melon (Momordica charantia L.). Friable calli could be induced in 30-day-old leaves on semi-solid MS [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15, 473–497.] medium supplemented with 1.0 mg/l 2,4-D. Large number of globular embryos (24.6%) were noticed when the calli was subcultured in liquid medium containing 1.5 mg/l 2,4-D. The complete removal of 2,4-D in the later stages of culture, stimulated their further development to heart and torpedo stages. Microscopic examination revealed the ontogeny of somatic cell development via the formation of cell clusters, which then enlarged to pro-embryos, and gave rise to heart and torpedo stages within a period of 2 weeks. Somatic embryos successfully germinated on agarified MS medium with no additional growth regulators. An effect of media, other components and stimulating factors such as carbohydrates, amino acids has also been evaluated for somatic embryogenesis. The full strength MS medium containing 50 mg/l PVP and 40 mg/l glutamine was effective to achieve a high frequency of somatic embryo induction, maturation and further development. An average of 6.2% young plants was achieved from friable callus and was phenotypically normal. To our knowledge, there is no published report on somatic embryogenesis of bitter melon (M. charantia L.) via embryogenic callus or cell suspension cultures. These results are likely to facilitate genetic transformation of bitter melon

Micropropagação de Cabralea canjerana Micropropagation of Cabralea canjerana

A Cabralea canjerana (Vell.) Mart. (Meliaceae) (canjarana) é uma espécie arbórea nativa brasileira importante para fornecimento de madeira de boa qualidade. As sementes desta espécie não podem ser armazenadas por muito tempo e, por tanto, existe a necessidade do desenvolvimento de técnicas alternativas de propagação como a micropropagação. Neste trabalho, foram realizados experimentos de multiplicação utilizando segmentos nodais, retirados de plantas germinadas in vitro. Os segmentos foram inoculados em meio de cultura MS ou WPM, adicionado de 6-benzilaminopurina (BAP) e, ou, 2-isopenteniladenina (2-iP) nas concentrações de 2,5 ou 5 &micro;M. Microestacas de rebrotas foram colocadas em meio de cultura MS/2, com a metade da concentração dos sais do meio MS, adicionado de ácido indol 3-butírico (AIB) (0, 2,5 e 5 &micro;M). Após sete dias, foram transferidas para meio MS/2 sem auxina e na luz. Na fase de multiplicação, o meio de cultura MS foi mais adequado que o meio WPM. O segmento nodal, em presença de 2,5 &micro;M de BAP, propiciou um dos melhores resultados, com uma taxa de multiplicação de 1,77 por mês, em meio de cultura MS. O enraizamento das microestacas oriundas de rebrotas foi de 87,5% em presença de 5 &micro;M de AIB durante sete dias. A aclimatização foi realizada em casa de vegetação e proporcionou 90% de sobrevivência das mudas após 30 dias. A micropropagação da canjarana a partir de segmentos nodais de mudas cultivadas in vitro é viável para a multiplicação dessa espécie.<br>Cabralea canjerana (Vell.) Mart. (Meliaceae) ("canjarana") is a native tree of economic importance in Brazil. The storage of seeds is of short duration and it is therefore necessary to establish a protocol for micropropagation of this species. In this work, multiplication experiments were carried out using nodal segments, excised from in vitro germinated plants. The segments were inoculated in MS or WPM culture medium, supplemented with 6-benzylaminopurine (BAP) and/or 2-isopentenyladenine (2-iP) at 2.5 or 5 &micro;M. Micro-cuttings were taken from new shoots developed from the seeds and used in a rooting experiment using a culture medium with half-strength MS medium (MS/2) supplemented with indolbutyric acid (IBA) (0, 2.5 and 5 &micro;M). After 7 days in this medium, they were transferred to MS/2 medium without auxin under light. During the multiplication phase, the MS culture medium was more suitable for the multiplication of C. canjerana than WPM medium. The nodal segments cultured in the presence of 2.5 &micro;M BAP showed the best result, with a multiplication rate of 1.77 per month on MS medium. The rooting of the microcuttings was 87.5% when they were kept in the presence of 5 &micro;M IBA for 7 days. An acclimatization rate of 90% was achieved after 30 days in the greenhouse. In conclusion, the micropropagation of C. canjerana from nodal segments of plantlets is possible for this species