Banca de DEFESA: GESSICA TAIS ZANETTI

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : GESSICA TAIS ZANETTI
DATA : 28/02/2020
HORA: 13:00
LOCAL: Embrapa Agrossilvipastoril, Sinop, Mato Grosso
TÍTULO:

REPRODUCTIVE ASPECTS AND GENETIC DIVERSITY OF BALSA WOOD (OCHROMA PYRAMIDALE)

PALAVRAS-CHAVES:

Balsa wood tree; Genetic variability; ISSR; Palynology.

PÁGINAS: 110
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Melhoramento Vegetal
RESUMO:

The balsa tree (Ochroma pyramidale Cav. ex Lam. Urb) belongs to the Malvaceae family, and is a perennial tree species which is native to South and Central America. The species is widely used in the recovery of degraded areas and its harvesting has proved to be a productive activity of economic value for the production of low density wood. However, knowledge regarding the reproductive aspects and genetic diversity of this species is scarce. Therefore, this study aimed to analyze aspects of reproductive biology and evaluate the genetic diversity of populations of O. pyramidale cultivated in the state of Mato Grosso, Brazil. For analyses related to reproductive aspects, flower buds at different stages of development were collected in the municipalities of Sinop, Itaúba and Alta Floresta, Mato Grosso, and were used to study palynology, meiotic index, cytochemistry and pollen viability. For the genetic diversity investigation, PCR reactions were performed with 15 ISSR primers, using DNA extracted from young leaves of 60 individuals of O. pyramidale, which were collected from three populations in the municipality of Guarantã, Mato Grosso. The results demonstrate that the pollens of O. pyramidale are of the suboblat type, triporate, large, have a large polar area and sexine with reticulated ornamentation. The species has a high percentage of viable pollen, regular meiotic index and has starch and lipid as storage substances in pollen. ISSR primers amplified a total of 111 loci, of which 97.3% were polymorphic. The values of genetic dissimilarity obtained from the complement of the Jaccard index ranged from 0.17 to 0.79, not showing identical individuals in genetic terms. The genetic diversity of Nei (0.32) and Shannon Index (0.48) for the species is indicative that there is genetic diversity among the 60 individuals studied. AMOVA revealed that 71% of the total genetic variation is found in populations while 29% among the evaluated populations. The ISSR molecular markers were efficient in analyzing the genetic diversity of the 60 individuals of O. pyramidale, and can be considered promising sources of genetic resources for selection and use in breeding programs. Furthermore, the study enabled the expansion of knowledge regarding the reproductive aspects and the genetic diversity of O. pyramidale, which is useful information both for conservation of this species, as well as for breeding programs.

MEMBROS DA BANCA:
Presidente - 32143004 - ANA APARECIDA BANDINI ROSSI
Interno - 607.835.671-20 - EULÁLIA SOLER SOBREIRA HOOGERHEIDE - USP
Externo à Instituição - MÁRCIA FABIANA BARBOSA DE PAULA - UFMT
Externo à Instituição - JOYCE MENDES ANDRADE PINTO - EMBRAPA