Banca de DEFESA: EWERTON LÉLYS RESENDE

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE: EWERTON LÉLYS RESENDE
DATA: 26/03/2024
HORA: 08:00
LOCAL: Sala DBI 02
TÍTULO:

PHENOTYPIC AND GENOTYPIC VARIATION WITHIN SOYBEAN CULTIVARS

PALAVRAS-CHAVES:

Glycine max L. Merril., Intracultivar Variability, Conservation Breeding

 

PÁGINAS: 94
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Melhoramento Vegetal
RESUMO:

Soybean plays a fundamental role in Brazil's agribusiness, particularly as the country is the world's largest producer of the crop. There is a constant pursuit of homozygous and pure genotypes in commercial soybean breeding programs. However, it is important to recognize that genetic homogeneity and purity do not remain stable over medium and long terms due to the notable instability and flexibility of the genome, which leads to intracultivar variability. Consequently, the objective was to investigate intracultivar variability in soybean lines, bothphenotypically and genotypically. Efforts were also made to compare different strategies for ranking soybean progenies and to select the most promising lines for traits exhibiting variability. During the 2017/2018 growing season, plants from six soybean cultivars—SYN1359S IPRO, P98Y11, BMX6160, 97R73 RR, NS7000 IPRO, and NA5909—were selected to establish genetic treatments. For each cultivar, a population of 500 plants was initially sown. From this population, 80 plants per cultivar were chosen for further evaluation based on their yield, which was measured in grams.Subsequently, 47 plants were selected to create progenies. These progenies, along with control samples, underwent assessment in the two following growing seasons, 2018/2019 and 2019/2020. The evaluated traits included Grain Yield (YIELD), Absolute Maturity (AM), Days to Flowering (DF), and Plant Height (PH). Besides that, the genotyping of the 288 genotypes was performed using the Genotyping by Sequencing (GBS) technique, which encompassed 1329 markers (SNPs). Sequencing was carried out using the ION S5 sequencer from Thermo Fisher Scientific in collaboration with GDM Seeds Inc., located in Cambé-PR. The phenotypic data were analyzed using R software, specifically utilizing the mixed models approach, to assess variance, heritability, accuracy, and coefficient of variation. Spearman's rank correlation (ρ) was calculated using the predicted genetic values between the different analysis strategies, BLUP and GBLUP. The coincidence index (IC), proposed by Hamblin and Zimmermann (1986), was also determined. For genotypic analysis, quality control (QC) for markers and imputation for missing data were employed. Subsequently, various analyses were conducted, including the construction of a dendrogram, Principal Component Analysis (PCA), STRUCTURE analysis, and Genomic Best Linear Unbiased Prediction (GBLUP). Expected Heterozygosity (HE) and Observed Heterozygosity (HO) were also calculated. Variation was detected for Plant Height in the joint analysis of variance, indicating good experimental quality. Regarding genetic parameters, the populations with more variation were P98Y11 and NA5909, while BMX6160 and 97R73 showed low variation. The coincidence index varied among populations, with the highest value observed for 97R73.

MEMBROS DA BANCA:
Externo à Instituição - JOSE BALDIN PINHEIRO - USP (Membro)
Externo ao Programa - HELOISA OLIVEIRA DOS SANTOS - DAG/ESAL (Membro)
Interno - EVANDRO NOVAES (Membro)
Externo à Instituição - CRISTIAN RAFAEL BRZEZINSKI - GDM (Suplente)
Externo à Instituição - CARLOS EDUARDO PULCINELLI - AOI (Suplente)
Externo à Instituição - ARTHUR TAVARES DE OLIVEIRA MELO - ND (Membro)
Presidente - ADRIANO TEODORO BRUZI (Membro)