Banca de DEFESA: ADRIELE NUNES RODRIGUES SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ADRIELE NUNES RODRIGUES SILVA
DATE: 28/06/2025
TIME: 14:00
LOCAL: Google Meet
TITLE:

Genetic Diversity of cultivated Coffea canephora Genotypes in the Western Amazon: Yield, Compatibility, and Leaf Stomatal Characteristics

KEY WORDS:

Self-incompatibility. Stomata. Conilon. Robusta.

PAGES: 61
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitotecnia
SPECIALTY: Melhoramento Vegetal
SUMMARY:

Coffee is widely cultivated and consumed globally, with its economic importance being a major driver of breeding studies and selection improvements. The development of coffee cultivation in the Amazon region is exemplified by the state of Rondonia, where a significant reduction in cultivated area has been accompanied by a notable increase in productivity. In this context, the aim of this study was to assess the genetic diversity of major Coffea canephora genotypes cultivated in the Western Amazon. The experiments were conducted at Embrapa Rondonia's experimental field from 2021 to 2023, involving 64 genotypes, including commercial cultivars and publicly available clones. To assess grain yield, the cherry fruits of the genotypes were dried and hulled. Compatibility tests between clones were performed using in vitro pollination and fluorescence microscopy. Additionally, leaf stomatal characteristics were analyzed by creating epidermal impressions on slides, which were photographed under an optical microscope, with measurements performed virtually using ImageJ software. Data analysis was carried out using the GENES software to determine variance, genetic parameters, mean clustering, and correlations between variables. High-yielding clones, such as LB30, BRS1216, LB12, N7, LB10, LB20, BRS3220, and AS5, exhibited an average yield of 25.51%, reflecting a 12.17% increase. In contrast, low-yielding clones, including BG180, GJ30, GJ20, AS7, AS10, P42, N1, and P60, averaged 19.15%, indicating a 14.02% reduction compared to the overall average. Yield distribution classified 19.4%, 62.7%, and 17.9% of the genotypes as high, medium, and low yield, respectively, offering valuable insights for optimizing cultivation strategies. Based on compatibility responses, the genotypes were grouped into six categories: group I (24.4%), group II (31.1%), group III (24.4%), group IV (2.2%), group V (2.2%), and group VI (15.6%). The lower frequencies in groups IV, V, and VI were linked to the lower occurrence of rarer allelic forms in this breeding population (p = 0.36; q = 0.26; r = 0.29; s = 0.10). The alignment between allelic and genotypic frequencies indicates that this population is in Hardy-Weinberg equilibrium (HWE) for this trait. Considering the cultivation of 2 to 10 clones, the studied population showed intermediate pollination efficiency, between an ideal HWE population (p = q = r = s = 0.25) and a population with rarer allelic forms (p = 0.48; q = 0.32; r = 0.19; s = 0.01). Stomatal density separated the genotypes into four groups, ranging from 486.3 stomata mm-2 (genotype WP6) to 206.3 stomata mm-2 (genotype 38E). Higher partial correlations were observed between stomatal index and stomatal density (0.74), as well as between polar diameter and pore length (0.74). Negative correlations were noted between leaf area and polar diameter (-0.27) and between stomatal index and equatorial diameter (-0.20), in line with findings from other recent studies evaluating similar traits in C. canephora. These results indicate that genetic diversity enables the selection of plants with distinct productive and anatomical characteristics, aiding in the understanding of their field performance. The findings also underscore the recommendation that the selection of clones for C. canephora cultivation should consider a combination of traits rather than focusing on a single characteristic to enhance cultivation efficiency.

COMMITTEE MEMBERS:
Externo à Instituição - ALEXSANDRO LARA TEIXEIRA
Interno - 1632974 - ANGELO GILBERTO MANZATTO
Externo à Instituição - ENRIQUE ANASTACIO ALVES
Interna - 2363379 - GLEIMIRIA BATISTA DA COSTA MATOS
Interno - 1545801 - JAIRO ANDRE SCHLINDWEIN
Externo à Instituição - MARCELO CURITIBA ESPINDULA
Presidente - ***.879.256-** - RODRIGO BARROS ROCHA - EMBRAPA