Name: Angélica Tomazeli da Silva
Type: MSc dissertation
Publication date: 28/02/2020
Advisor:
Name |
Role |
|---|---|
| Paulo Cezar Cavatte | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Diolina Moura Silva | Internal Examiner * |
| Elias Terra Werner | Internal Alternate * |
| José Francisco Teixeira do Amaral | Co advisor * |
| Josimar Aleixo da Silva | External Examiner * |
| Mário Luís Garbin | External Examiner * |
| Paulo Cezar Cavatte | Advisor * |
| Tatiana Tavares Carrijo | External Alternate * |
Summary: The selection of genotypes with superior photosynthetic performance is essential
to obtain significant gains in breeding programs, since understanding the
physiological aspects of coffee, reflected in photosynthetic performance, can
contribute to increasing crop productivity. However, for the characterization of the phenotypes (phenotyping), the main methodologies used are still carried out in a
destructive and laborious way, using high-cost equipment, which requires a lot of
time in the analysis, space and resources. Given the above, the objective of this
work was: i) to study the genetic diversity of the intensity of the color of the green
leaf in the genotypes of Coffea canephora, and ii) to relate the intensity of the
color of the green leaf with the photosynthetic performance in C. canephora
genotypes, as a way to enhance large-scale phenotyping of individuals with
superior photosynthetic capacity. For this purpose, 40 genotypes of C. canephora
cultivated under field conditions were initially evaluated. With the aid of the
portable chlorophyll meter, the indices of total chlorophyll, flavonoids,
anthocyanins and nitrogen balance were estimated non-destructive. The specific
and unitary leaf area was also determined. From the results obtained, a
significant difference was found between the genotypes for the evaluated
characteristics, except for specific leaf area, and genotypes were organized into
four distinct groups. The total chlorophyll index made the greatest contribution to
genetic diversity. The relationship between the intensity of green leaf color and
photosynthetic performance was studied in the six most divergent genotypes. For
this purpose, the pigment field was determined non-destructive using portable
chlorophyll meters. The transmittance of the leaves and the electron transport
rate were also determined in the same leaves. Subsequently, the leaves were
collected to determine the concentration of photosynthetic pigments, total soluble
phenols, nitrogen, phosphorus and specific leaf area. In C. canephora, the
determination of the total chlorophyll concentration, as well as the total nitrogen,
can be performed using portable chlorophyll meters. The transmittance of the leaf can also be determined using the ClorofiLOG. The intensity of the color of the green leaf, determined non-destructive with portable chlorophyll meters, showed a significant relationship with the concentration of pigments, nitrogen and leaf
transmittance. The use of portable chlorophyll meters can be used as a tool for
the selection of C. canephora genotypes that have superior photosynthetic
performance.
