Clonagem de Tectona grandis Linn f. por estaquia e miniestaquia

• Autor(a) principal: Valverde, Yorleny Badilla
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3158
• topic: Teca (árvore); Tectona grandis; Plantas - Melhoramento genético; Propagação vegetativa; Teak (tree); Tectona grandis; Plants - Breeding; Vegetative propagation; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::SILVICULTURA

Tectona grandis belongs to Lamiaceae family, original from southestern Asean tropical forests, and introduced commercially to tropical Africa, Australia, Pacific islands, and to Central and South America. Observed expression in growth differences in commercially planted teak trees, was the most important factor as part of genetic differences due to origin. Therefore, productivity could be substantially improved through cautiously provenance and superior genotypes selections. Today, there are breeding programs based on the selection of superior trees, where vegetative propagation research plays an important role due to clonal forestry advantanges. In this context, this study evaluated clonal propagation issues on cuttings and mini-cuttings of four Tectona grandis clones. As specific objectives there were the evaluation of: 1) mini-clonal hegde density influence on mini-stumps survivance and its mini-cuttings productivity; 2) AIB growth regulator influence on mini-cuttings rooting; 3) Foliar reduction and harvest/preparation time-interval effect on survival and mini-cuttings rooting; 4) plus trees vegetative capture techniques through cuttings rooting. The study was developed at clonal nursery in Agrícola Verde Novo Ldta. company, located in Colíder County, Mato Grosso, Brasil, based on four Tectona grandis clones (Carapá, Ipê, GU5 and TB7), established in hydroponic miniclonal hedge, as well as on randomly selected 5, 10 and 15 years-old trees from comercial plantations from Bacaeri company, located in Alta Floresta County, Mato Grosso. Results indicate high survival percentages and rooting rates in greenhouse as well as after acclimatization, independently from AIB dosages (95, 92 and 90% respectively). Similar high values results were also obtained in the study of time intervals between harvest and cutting preparation effect on survivance (92.71%) and rooting (90.03%) after greenhouse conditions, as well as survival after acclimatization (88.09%). No influence of storage periods effects was observed, however, it was registered differences among clones in relation to mini-cuttings rooting rates. In terms of experiments related to cuttings-foliage reduction area, it was observed that there is an influence on its rooting and survival rates, as well as in its height and collar diameter. It was concluded that 25% foliage area utilization in mini-cuttings is recommended, due to its higher values in evaluated characteristics (rooting: 97.4%; survival: 94.27%; height: 10.94 cm and collor diameter: 4.39 mm). Basically due to the absence of limitations in relation to differences in irrigation regimes during rooting and acclimatization stages, which minimized guarda-chuva effect. With respect to density effect on mini-clonal hedge productivity, 10 x 10 cm spacing (100 miniplantas m 2 ) registered highest mini-cutting production per mother plant (0.63). 5 x 5 cm was the highest density in mini-stump per area (m 2 ), which registered the lowest mini-cuttings production per plant (0.48) but highest mini-cutting production per square meter (191 m 2 ). However, it was observed that mini-cutting production varied significantly along the different harvests in the experiment, which is an evidence of environmental effects in teak mini-clonal hedge sprouting. In relation to Tectona grandis plus trees capture, felling down trees registered best results in sprouting (86.7%), number of sprouts per tree (6.5) and the best rooting rate in harvested cuttings (43.1%). Felling down tress as well as in promoting sprouting through half-ringing, best capture results were obtained in trees at lower age.