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| Author(s): |
Aline Galdino do Nascimento
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2010-08-09 |
| Examining board members: |
Paulo Yoshio Kageyama;
Antonio Aparecido Carpanezzi;
Isaias Olivio Geraldi
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| Advisor: | Paulo Yoshio Kageyama |
| Abstract | |
The bracatinga (Mimosa scabrella Bentham) is a leguminous tree naturally occurring in Brazil, between latitudes 21°30\'S (state of Minas Gerais) and 29°40\'S (state of Rio Grande do Sul) at low temperatures. Being a perennial tree species, pioneer of rapid growth and meliferous, is commercially used for multiple purposes (sawmill, firewood, coal, construction) in monoculture and in agroforestry systems. Their culture release aggressive techniques of soil tillage and mechanized harvesting, resulting in the maintenance of the structure and conditioning of the soil, but also promotes the recovery of degraded soils by nitrogen fixation by Rhizobium sp associated with their roots. Due to the economic and productive potential of bracatinga, it was implemented a progenies and provenances test of bracatinga in the Itatinga Experimental Station (EECFA/USP) in Itatinga/SP. In this experiment, they were studied the genetic parameters and the potentiality for genetic improvement of this species for the characteristics associated with productivity, wood quality and adaptation to an environment with temperatures slightly above its region of origin. The trial was designed in a compact family block, with nine provenances, 10-20 progenies per provenance. The survival rate of plants (84%) and the high seed germination (95%), besides the flowering and fruiting in all progenies of the test, are indicative of the adaptability of these materials to the local soil and climatic conditions. Among the traits, the straightness of the stem, the circumference at breast height and flowering potential were shown to be most promising in the selection practice. These results demonstrate the possibility of genetic improvement of bracatinga to enable their cultivation by small farmers, increasing their income and encouraging the recovery of marginal areas. (AU) | |