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| Author(s): |
Cecília Luzia Dourado
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Ilha Solteira. 2017-05-23. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Engenharia. Ilha Solteira |
| Defense date: | 2016-11-10 |
| Advisor: | Mario Luiz Teixeira de Moraes; Marcela Aparecida de Moraes |
| Abstract | |
The main objective of this work is to quantify the genetic variability in progenies of rubber tree, based on the quantitative characterization and the molecular characterization of the microsatellite type (SSR). The first population of the study originated in the primary forest of Rio Branco-Acre (wild population-PS), and the other population is a population originated from clonal matrices (improved population-PM). They are installed as progeny tests at the Teaching, Research and Extension Farm, That belongs to Engeneering College of the Julio Mesquita Filho State University of São Paulo, In Selvira, State of South Mato Grosso Brazil. For the two populations, the following silvicultural characteristics of growth, height (ALT), commercial height (AC), average crown diameter (DMC), stem shape (FOR), stem perimeter (PAP and P50) and dry rubber yield (PBS) at eight (PM) and 23 (PS) years old. The experimental design consisted of randomized blocks, composed of 31 families, four replications and linear plots of 10 plants, spaced 3 x 3 m (MP). For PS the experimental design was of causalized blocks with 37 families distributed in three replications, unbalanced with a maximum of 10 plants per progeny in the spacing of 5 x 3 m (PS). Estimates of the genetic parameters were made using the mixed linear univariate model (REML / BLUP) methodology and gains in selection by multi-effects index (MEI). Genomic DNA was extracted, quantified and genotyped for the two study populations. The analyzes of the breeding and diversity system were based on the mixed breeding model and correlated crosses model. Significant differences were detected by the likelihood ratio test in the deviance analysis for the characters, mean crown diameter (DMC), stem perimeter at 50 cm from soil (P50), stem perimeter at 1,30m from soil (PAP) and dry rubber yield (PBS) for PM. For wild populations were significant, the characters ALT, DMC, P50 and PAP. The characters that presented the greatest magnitude for the heritabilities were PBS, for improved population and PAP, PBS for the wild population, with heritabilities above 60%. The selection strategies of 50%, 40% and 22% of individuals for the PBS and PAP using the multi-effects index revealed high and low gains in the selection of the two populations. For PM it was more indicated the strategy of selection between and within and for PS the individual selection. The gains obtained in the selection were 54% for the PBS character in the improved population and 0,46% for the PAP character for the wild population. The observed heterozygosity was 0,839 to 0,747 for adults and 0,425 to 0,399 for the progenies, for the two populations studied. The multilocus crossing rate ( ) varied from 0,726 (MP) to 0,798 (PS), indicating that most of the seeds originated by crosses, but there was a presence of self-fertilization, characterized by a mixed mating system.The presented inbreeding was generated by correlated crosses and not by self-fertilization. Due to the effective size (Ne) of less than 4, it resulted in the need to collect seeds for purposes of genetic conservation, environmental recovery and forest improvement of at least 94 and 89 trees, for PM and PS respectively. (AU) | |
| FAPESP's process: | 13/03074-5 - Improvement in rubber tree progenies [Hevea brasiliensis (Willd. ex Adr. than Juss.) Muell. - Arg.] by characters and molecular markers quantitative SSR type in two populations of different origin |
| Grantee: | Cecília Luzia Dourado |
| Support Opportunities: | Scholarships in Brazil - Doctorate |