Sexed propagation, vegetative and genetic diversity of Dalbergia nigra in miniclonal garden
Name: ALINE RAMALHO DOS SANTOS
Publication date: 26/02/2019
Examining board:
Name |
Role |
|---|---|
| TAÍS CRISTINA BASTOS SOARES | External Examiner * |
Summary: The demand for seedlings for establishment of forest plantations, whether for commercial or restoration purposes has grown rapidly, in parallel, there is the search for improvement of production techniques for low-cost seedlings and good performance in the field. Thus, the aim of this work was to evaluate the sexed propagation, vegetative and genetic diversity of Dalbergia nigra in miniclonal garden. The dissertation was structured in three chapters. In Chapter l, the objective of this study was to analyze the seedling growth of two D. nigra provenances grown on substrate plus different doses of controlled release fertilizer (FLC). The results indicated that the height of the seedlings at 120 days, dry mass of the root, shoot and total were significantly influenced by the interaction (p ≤ 0.05) between the FLC dose factors and D. nigra origins. The highest growth of the seedlings was observed for the Linhares origin in the dose 7.46 kg m-3 of FLC. The dose 5.99 kg m-3 is the most adequate for the production of seedlings from Viçosa. Chapter ll discusses the potential of cutting and minicutting technique as a vegetative propagation method for D. nigra. The miniclonal garden of D. nigra obtained 100% survival after 13 successive collections. The use of indole-3-butyric acid (IBA) in minicuttings of D. nigra is not a conditioning factor for rooting, although the addition of 6,000 mg Kg-1 IBA promoted a greater length and number of roots, minicut vigor and dry mass of the root of apical minicuttings. For intermediate minicuttings the addition of 6,000 mg Kg-1 of IBA anticipated the mean time of root emission and provided a higher number of adventitious roots. However, IBA concentrations linearly reduced shoot emission, shoot dry matter and total dry mass. The nutritional content of the matrix plant influenced in the rooting of minicuttings, being the origin of lineages more responsive to the addition of FLC. The geographical origins presented a set of responses and differential behavior in rooting. The cuttings adult showed high mortality and no rooting. The minicutting technique, using juvenile material, proved to be technically viable as a way of propagating D. nigra, and it is possible to use this methodology to produce large
scale seedlings. In chapter III, the objective was to characterize the genetic diversity in moniclonal garden of D. nigra. The ISSRs used for D. nigra were efficient in detecting polymorphism. The population showed consistent structure and high genetic diversity. The greatest wealth is found in the ministumps of the Linhares. The populations of D. nigra present moderate genetic differentiation, being verified that the greater proportion of the genetic diversity is within the populations. The ministumps present high diversity and, therefore, it reveals the potential to be used as matrices for the collection of propagules in the production of seedlings for conservation purposes.
Keywords: forest nutrition, native species, extinction, cloning, genetic conservation.
