Multiplicação in vitro de gemas axilares de acácia-negra (Acacia mearnsii De Wild.) In vitro multiplication of black watlle (Acacia mearnsii De Wild.) axillary buds

A acácia-negra (Acacia mearnsii De Wild.) é uma espécie de difícil micropropagação devido à pequena capacidade de multiplicação e desenvolvimento de gemas. O presente estudo visou determinar a influência de diferentes citocininas na proliferação de gemas axilares em segmentos nodais de A. mearnsii. Plântulas germinadas in vitro forneceram explantes que foram inoculadas em meio básico B5 (GAMBORG et al., 1968). Testaram-se as citocininas: BAP (6-benzilaminopurina), BA (6-benziladenosina), 2iP (gama,gama-isopenteniladenina) e cinetina (6-furfuralamino-purina). Diferentes concentrações desses reguladores de crescimento foram empregadas: 1 mgL-1, 2 mgL-1 e 3 mgL-1. Utilizou-se o delineamento de blocos casualizados, em arranjo fatorial, com seis repetições e cinco plantas por parcela. As avaliações foram feitas aos 30 dias, através da contagem de gemas alongadas e da presença de calos. A utilização de BAP a 2 mgL-1 promoveu a maior taxa de multiplicação de gemas (3,5 brotos/explante).<br>Black wattle (Acacia mearnsii de Wild.) is difficult to micropropagate due to the low ability of multiplication and development of shoots. Thus, the present study aimed at determining the influence of various cytokinins on axillary bud proliferation in nodal segments of A. mearnsii. Explants from in vitro germinated seedlings were inoculated on B5 (Gamborg et al., 1968) basal medium. BAP (6-benzylaminopurine), BA (6-benzyladenine), 2iP (gamma,gamma-dimethylallylamino-purine) and Kinetin (6-furfurylaminopurine) were tested at the concentrations 1 mgL-1, 2 mgL-1, and 3 mgL-1. A randomized block design, in factorial arrangement with 6 replications, and 5 plants per plot was used. The assessments were made after 30 days, by counting the elongated shoots and the presence of callus. The use of BAP at 2 mgL-1 promoted the highest rate of bud multiplication (3,5 shoots/explant)

COSINE-100 and DAMA/LIBRA-phase2 in WIMP effective models

Assuming a standard Maxwellian for the WIMP velocity distribution, we obtain the bounds from null WIMP search results of 59.5 days of COSINE-100 data on the DAMA/LIBRA-phase2 modulation effect within the context of the non-relativistic effective theory of WIMP-nucleus scattering. Here, we systematically assume that one of the effective operators allowed by Galilean invariance dominates in the effective Hamiltonian of a spin-1/2 dark matter (DM) particle. We find that, although DAMA/LIBRA and COSINE-100 use the same sodium-iodide target, the comparison of the two results still depends on the particle-physics model. This is mainly due to two reasons: i) the WIMP signal spectral shape; ii) the expected modulation fractions, when the upper bound on the time-averaged rate in COSINE-100 is converted into a constraint on the annual modulation component in DAMA/LIBRA. We find that the latter effect is the dominant one. For several effective operators the expected modulation fractions are larger than in the standard spin-independent or spin-dependent interaction cases. As a consequence, compatibility between the modulation effect observed in DAMA/LIBRA and the null result from COSINE-100 is still possible for several non-relativistic operators. At low WIMP masses such relatively high values of the modulation fractions arise because COSINE-100 is mainly sensitive to WIMP-sodium scattering events, due to the higher threshold compared to DAMA/LIBRA. A next COSINE analysis is expected to have a full sensitivity for the 5 a region of DAMA/LIBRA.Peer reviewe