Banca de QUALIFICAÇÃO: EULINA BRITO MARINHO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : EULINA BRITO MARINHO
DATE: 06/09/2024
TIME: 14:00
LOCAL: Link: https://meet.google.com/zdj-gtjc-vgb
TITLE:

COMBINATORY CAPACITY IN SPECIAL TYPES OF RICE

KEY WORDS:

Allelic interaction; Hybrids; Polymorphism; Heterozygosity; DNA extraction.

PAGES: 34
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitotecnia
SPECIALTY: Melhoramento Vegetal
SUMMARY:

Rice (Oryza sativa L.) is a crop of great importance in the world economy due to its socioeconomic attributes that enhance its value from production to consumption. Special types of rice have been gaining more and more space in the market due to their advantages, such as differentiated organoleptic properties, high nutritional value, resistance to pests and diseases, and socio-environmental benefits. However, it is important to develop hybrids that present high productivity, quality, and resistance in order to meet market criteria and foster the economy. This study aims to evaluate and estimate the combining capacity between white rice parents and previously selected red rice genotypes. The experiment will be conducted in a greenhouse covered with shade cloth and in a laboratory at the Federal Rural University of Rio de Janeiro (UFRRJ), and will be divided into two stages. The first stage consists of crossing the parents in a 4x4 partial diallel scheme. The parents will be the white rice cultivars BRS Esmeralda and Escrevi (Cateto) and red rice genotypes ENA AR1601 and ENA AR1602 (Virginia). Five 5-L pots with five seeds in each will be used for sowing. Thinning will be carried out 15 days after sowing (DAS), leaving two plants per pot. To emasculate the female parents, the flower will be cut before it opens and the anthers will be removed using a vacuum system produced by a motor pump. This process will be carried out in the central third of the panicle, which will be protected with paper bags for up to 5 days. The collection and pollination will be carried out on the same day after the flower opening and pollen grain release. After the maturation period, the hybrid seeds will be collected, dried and stored at refrigerated temperature (6ºC). In the second stage, the hybrid combinations and parents will be sown as in the first stage. After this period, DNA extraction will be performed to confirm the crosses. The DNA of each sample will be obtained in a stock solution and stored at 20°C. It will then be diluted at a concentration of 5ng μL-1 to compose the working solution. PCR (Polymerase Chain Reaction) will be performed in 0.2mL microtubes and DNA amplification and primer selection will be performed using 25ng of DNA from three samples, with 2.0mL of 10X reaction buffer, 2.5mM MgCl2, 0.8mM of each dNTP, 1U of Taq-DNA Polymerase (Invitrogen), and 0.4mM of specific primers for a final volume of 20L. In the selection of microsatellites, which will be obtained from SSR (Simple Sequence Repeats) marker sites for rice, three DNA samples from the hybrids, chosen at random, will be used and analyzed in agarose gel to verify the complementarity and reproducibility of the primers. The gels will be visualized and photographed. The selection of hybrids will be done by excluding those that do not present an allele of the genotype. In parallel, the second stage of the experiment will be carried out, which will consist of planting the four parents together with the six hybrid combinations to evaluate the general and specific combining capacity according to the methodology of Griffing (1956). Planting will be done in 5-L pots, in a greenhouse, in a completely randomized design, with three replicates. The characteristics evaluated in the second stage will be: flag leaf length (CFB, in cm); flag leaf thickness (EFB in mm); flag leaf angle (ANG); plant height (ALT, in cm); number of viable tillers (NPV); percentage of fertile spikelets (%EF); hundred-grain weight (MCG, in g); production (PROD, in g.plant-1); full flowering (FP); and crop cycle (CC, maturation). The means will be compared by Tukey's test at 5% probability. Overall, it is expected to confirm the hypothesis that it is possible to obtain potential hybrids from combinations between previously selected parents (white rice cultivars and red rice genotypes).

COMMITTEE MEMBERS:
Presidente - 2271445 - BRUNA RAFAELA DA SILVA MENEZES
Externa ao Programa - 2147409 - MARILENE HILMA DOS SANTOS - UFRRJExterno à Instituição - MARIA DO SOCORRO BEZERRA DE ARAÚJO