Colchicine and amiprophos-methyl (APM) in polyploidy induction in banana plant

The objective was to assess the colchicine and amiprophos-methyl (APM) concentration and exposure period in the chromosome duplication of breed banana plants diploids. Banana stem tips were used from the following genotypes: breed diploids (1304-04 [Malaccensis x Madang (Musa acuminata spp. banksii)] and 8694-15 [0337-02 (Calcutta x Galeo) x SH32-63]). Colchicine was used at concentrations of 0 (control treatment), 1.25, 2.5 and 5.0 mM, while APM was used at 0 (control treatment), 40 and 80 μM, in solution under agitation (20 rpm), for 24 and 48 h periods. With the use of APM, 66.67% tetraploid plants were obtained in the 1304-04 genotype using 40 μM for 24 h and 18.18% in 80 μM for 48 h, while in the 8694-15 genotype using 40 and 80 μM colchicine for 48 h, 27.27 and 21.43% tetraploid plants were observed, respectively. For colchicine, in the 1304-04 genotype, only the 1.25 mM treatment for 48 h presented 25% tetraploid plants and in the 8694-15 genotype, the 5.0 mM concentration for 48 h produced 50% tetraploid plants. APM for 24 h enabled the tetraploid plant of the 1304-04 genotype to be obtained, while colchicine for 48 h resulted in tetraploid plants in the 8694-15 genotype.Key words: Musa acuminata, antimitotic, flow cytometry, tissue culture

Efeito de períodos de vernalização de alho (Allium sativum L.) sobre a cultivar Roxo Pérola de Caçador "in vitro".

Suplemento. Edição de Resumos expandidos e palestras do 43. Congresso Brasileiro de Olericultura, Recife, jul. 2003

Population pulsation resonances of excitons in monolayer MoSe2 with sub 1 {\mu}eV linewidth

Monolayer transition metal dichalcogenides, a new class of atomically thin semiconductors, possess optically coupled 2D valley excitons. The nature of exciton relaxation in these systems is currently poorly understood. Here, we investigate exciton relaxation in monolayer MoSe2 using polarization-resolved coherent nonlinear optical spectroscopy with high spectral resolution. We report strikingly narrow population pulsation resonances with two different characteristic linewidths of 1 {\mu}eV and <0.2 {\mu}eV at low-temperature. These linewidths are more than three orders of magnitude narrower than the photoluminescence and absorption linewidth, and indicate that a component of the exciton relaxation dynamics occurs on timescales longer than 1 ns. The ultra-narrow resonance (<0.2 {\mu}eV) emerges with increasing excitation intensity, and implies the existence of a long-lived state whose lifetime exceeds 6 ns.Comment: (PRL, in press

An approach on the in vitro maintenance of sugarcane with views for conservation and monitoring of plant nuclear DNA contents via flow cytometry.

In vitro conservation techniques can be utilized for germplasm maintenance. However, few reports on the in vitro conservation of sugarcane species are present in the literature. The objective of this study was to subject sugarcane plants to in vitro under minimal growth conditions and to evaluate the survival, regeneration, and the monitoring of nuclear DNA content levels of the plants. Shoots from 10 sugarcane varie-ties (Saccharum spp.) were introduced into two media: MC1, consisting of half-strength Murashige and Skoog (MS) salts and 3% sorbitol, or MC2, similar to the first formulation, but additionally supplemented with 3.8 ?Mabscisicacid(ABA)