Name: Erika Belotti Merisio
Type: MSc dissertation
Publication date: 25/08/2022
Advisor:
Name |
Role |
|---|---|
| Camilla Rozindo Dias Milanez | Advisor * |
| LEONARDO VALANDRO ZANETTI | Co-advisor * |
Examining board:
| Name |
Role |
|---|---|
| Antelmo Ralph Falqueto | Internal Examiner * |
| Camilla Rozindo Dias Milanez | Advisor * |
| Geraldo Rogério Faustini Cuzzuol | Internal Alternate * |
| Gloria Maria de Farias Viégas Aquije | External Alternate * |
| LEONARDO VALANDRO ZANETTI | Co advisor * |
| LUIZ FERNANDO GANASSALI DE OLIVEIRA JUNIOR | External Examiner * |
Summary: The `Mascot` grape tomato is a minitomato hibryd strain, much appreciated by the consumer for its sweet taste and culinary versatility. Firmness is an important parameter of tomato quality, being crucial for its commercialization and post-harvest life. One of the main problems related to low firmness is fruit cracking, which can be prevented through specific nutritional calcium and boron manegment. The tomato crack it´s a pericarp fissure that can be healing at injury site through scar tissue development. Specialized literature considers firmness a multifactorial property, which is influenced by a set of phenotypic variables. Therefore, this work evaluated the effects of the interrelationships between 15 physicochemical, anatomical and morphological fruits attributes (predictor variables) and Mascot grape tomato´s firmness (response variable). The following characteristics were assessed: diameter (d1, d2), fresh mass (Massafresca), total soluble solids (TSS), total titratable acidity (TTA), calcium and boron contents (Ca and B), structural carbohydrates (Cellulose, Hemicellulose, Lignin) and exocarp tissue thickness. Calcium and boron nutritional supplementation treatments (group Ca, 3 mmol/L; group B, 2.5 µmol/L; and control) were applied through substrate and the efects on phenotypic attributes of the fruits were evaluate. The anatomy of the intact and cracked prericarp was described, and the healing tissue chemical containment was verified by histochemical tests. The interrelationships among firmness and phenotypic variables showed that Ca and TSS are the most influential variables, but they have antagonistic effects in firmness. Positive changes in Ca are directly associated with increased firmness; while TSS promotes the oposite. Ca positively influences exocarp thickness and cuticle thickness, but does not promotes the firmness through anatomical variables. Also, Ca does not promote firmness through effects on structural carbohydrate contents. Among the morphological variables, equatorial diameter stood out for its direct and negative effect on firmness. It was also verified that the increase in the epidermis thickness is related to low firmness; but the exocarp (set of exocarpo tissues) has a positive effect. Nutritional supplementation treatments did increase fruit firmness, possibly due to via substrate intake and low nutrient mobility. The `Mascot` grape tomato´s cracks has longitudinal pattern, and the lesion is local contained through a tenuous healing tissue, which consists in cell wall thickening process developed by injured cell. The chemical contend of healing tissue is lipid, verified by the sudan IV test.
