Banca de QUALIFICAÇÃO: PEDRO PAULO FARIA CONDE

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : PEDRO PAULO FARIA CONDE
DATE: 06/05/2025
TIME: 13:30
LOCAL: PPGF
TITLE:

GENETIC DIVERSITY IN BRAZILIAN PEPPER TREE (Schinus terebinthifolius Raddi) BASED ON LEAF CHARACTERISTICS AND ISSR MARKERS

KEY WORDS:

Morphological aspects of the leaf; Image analysis; ISSR markers; Multivariate statistics; Cultivar.

PAGES: 31
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitotecnia
SPECIALTY: Melhoramento Vegetal
SUMMARY:

The Brazilian pepper tree (Schinus terebinthifolius Raddi) stands out mainly for its important medicinal properties and for producing fruits known as pink pepper, a condiment highly appreciated in European countries. Despite its agronomic potential, to date, breeding programs for the species and cultivars indicated for planting in Brazil are practically scarce. Therefore, the objective of this research is to understand the genetic diversity among 20 genotypes of the Brazilian pepper tree (Schinus terebinthifolius Raddi.) based on morphological characteristics of the leaves and DNA markers of the ISSR type. In addition, to observe whether the variables used will be useful in distinguishing five genotypes of agronomic interest, with a view to requesting registration of these materials with MAPA. To this end, 20 fully developed leaves per genotype will be collected and identified. After drying at room temperature, the leaves will have their adaxial portion scanned on a flatbed scanner. Images will be obtained in jpg format with a known scale. The images will be analyzed using the ImageJ program to obtain the following quantitative variables: length, width and average area of the leaf, average length of the leaf stalk, average length of the space between leaflets, length, width and average area of the leaflets, number of leaflets, average angle of the base and apex of the leaflets. All genotypes will undergo DNA extraction. Then, after DNA quantification, ISSR primers will be tested. The 15 most polymorphic primers will be used. After PCR analysis, the amplified products will be subjected to agarose gel electrophoresis. All gels will be photodocumented. In the images, present ISSR bands will be annotated with a value of 1, and absent ones, as zero. For the leaf variables, the Euclidean distance between the genotypes will be estimated. For the ISRR variables, the Jaccard dissimilarity will be estimated. The two spreadsheets will be subjected to cluster analysis using the UPGMA method. Cophenetic correlations will be estimated for both situations. The two clustering matrices will be subjected to bottleneck estimation. If bottleneck is greater than or close to 1.0, diversity will be analyzed individually in the dendrograms mentioned above. However, if bottleneck is estimated at zero, diversity will be analyzed in a single UPGMA dendrogram containing both leaf variables and DNA variables. For this, a new genetic distance will be obtained using the Gower algorithm. Genetic distances greater than 0.7 and a high number of statistically distinct groups will indicate high genetic diversity. The variables used here will be efficient in distinguishing the genotypes of interest if at least one genotype forms a unique group in the dendrogram.

COMMITTEE MEMBERS:
Presidente - 1712769 - PEDRO CORREA DAMASCENO JUNIOR
Interna - 2271445 - BRUNA RAFAELA DA SILVA MENEZES
Externo ao Programa - 2582213 - MARCO ANDRE ALVES DE SOUZA - UFRRJ