Banca de QUALIFICAÇÃO: GABRIELE DIAS DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : GABRIELE DIAS DA SILVA
DATE: 06/10/2023
TIME: 14:00
LOCAL: Google Meet
TITLE:

Controlled crossings and selection in Cucurbita spp.aiming at fruit production and quality

KEY WORDS:

Genetic divergence; pollen viability; Cucurbita moschata; Cucurbita pepo.

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

Pumpkins and squash belong to the Cucurbitaceae family, and due to the great genetic variability of the family, they stand out for being widely consumed in Brazil and in the world. The exploitation of the culture takes place through the consumption of fruits, flowers, seeds and even for decorative purposes. Genetic divergence is expressed in characteristics such as: flavor, size, skin color, pulp color, skin and pulp texture, fruit weight. Based on this divergence, genetic improvement programs are dedicated to obtaining more productive cultivars that better meet the needs of the consumer market. In this sense, the present work aims to evaluate genotypes and carry out controlled crossings to obtain genotypes of the genus Cucurbita spp. with better performance in relation to production characteristics and fruit quality. The experiments will be conducted at the Federal Rural University of Rio de Janeiro, in the municipality of Seropédica, Rio de Janeiro, RJ, and will be divided into 3 experiments: the first experiment for genetic divergence, one carried out in 2023; a second experiment to carry out controlled crossing and pollen viability, in 2023; and another in 2024 for field evaluation of the best genotypes from the first experiment. The first experiment, in addition to selecting the genotypes with the best performance in relation to morphological characteristics and fruit quality, will evaluate the genetic divergence between 15 genotypes of Cucurbita spp. Analysis of variance will be performed and the means will be grouped by the Scott-Knott test (P<0.05). The Mean Euclidean distance will be used to obtain the dissimilarity matrix. The genotypes will be grouped using the Tocher Optimization method and the Hierarchical UPGMA (Unweighted Pair-Group Method using Arithmetic Avarages). In the second experiment, the pollen viability of two genotypes of Cucurbita moschata and two of Cucurbita pepo will be evaluated in five storage periods of pollen grain collected in pre-anthesis and in anthesis. Also in the second experiment, crosses will be performed between three genotypes of ‘menina brasileira’ (Cucurbita moschata), two genotypes used as female parents (better fruit quality) and another as male parent (better production). Characteristics of fruits obtained from crossings and random pollination will be evaluated. Means will be compared by non-parametric Kruskal-Wallis test at 5% probability. In the third experiment, four genotypes with the best performance in the first experiment will be evaluated in the field, in a randomized block design with five replications. Means compared by Tukey's test (P<0.05). At the end of this study it is expected to obtain information on the production and fruit quality of the evaluated genotypes, on the viability and to know the genetic divergence between genotypes of Cucurbita spp. This information will be useful for future work with the species Cucurbita moschata and Cucurbita pepo.

COMMITTEE MEMBERS:
Externo à Instituição - MARIA DO SOCORRO BEZERRA DE ARAÚJO
Externo à Instituição - VERÔNICA BRITO DA SILVA