Regulation of the vegetative-to-reproductive balance through the semideterminate growth habit in tomato (Solanum lycopersicum L. cv Micro-Tom) and its impact in the productivity and water use efficiency

Author(s)

Mateus Henrique Vicente

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2013-08-29

Examining board members

Lazaro Eustaquio Pereira Peres; Marcel Giovanni Costa França

• Advisor: Lazaro Eustaquio Pereira Peres

Abstract

Growth habit influences the balance between vegetative and reproductive development of plants. This, in turn, is directly linked to several variables of agronomic interest, such as yield and water-use efficiency (WUE). In tomato, there are three growth habits: determinate, indeterminate and semi-determinate, the latter being actually determinate, but with an extension of the vegetative cycle. Cultivars of determinate growth are widely used for processing-tomato industry (sauces and ketchups), and indeterminate for in natura consumption (production to salads). On the other hand, semi-determinate growth genotypes, although are still poorly explored, they present an excellent option for both the industry and in natura consumption. Thus, the aim of the present study was to evaluate the implication of the semi-determinate growth habit in productive performance and in WUE of tomato plants. For this reason, genotypes with different growth habits were produced through introgression of allelic variations that affect the plants growth habit, in the genetic background of the tomato cultivar Micro-Tom (MT). The characterization of these genotypes showed that the semi-determinate growth materials exhibit a delay in flowering, producing on average one extra leaf before the first inflorescence formation. In addition, this architecture presents an intermediate height between determinate and indeterminate growth genotypes, 50 days after sowing. As for agronomic traits, we found a significant increase in yield and total soluble solids content (brix) in the fruits of semi-determinate growth genotypes compared with determinate growth. Our data suggest this effect is resulting from a more balanced vegetative and reproductive development, evidenced by the absence of significant difference on the dry matter partition derived from the vegetative and reproductive development in these genotypes, when compared to determinate and indeterminate growth genotypes. WUE was evaluated both gravimetrically (dry mass produced per amount of water transpired), and through isotopic discrimination. The semideterminate growth genotypes showed higher WUE than determinate and indeterminate genotypes at 50 days after sowing. Interestingly, the plants of semideterminate growth were more resistant than determinate growth genotype used as control, when exposed to drought stress. However, studies are needed to elucidate the mechanism involved in this resistance. In conclusion, the results presented here suggest that the genotypes of semi-determinate growth reached the optimal balance between vegetative and reproductive development, in order to increase concomitantly, productivity, brix content in the fruits, and WUE. (AU)

• FAPESP's process: 11/16554-0 - Regulation of the vegetative-to-reproductive balance through the semi-determinate growth habit in Tomato (Solanum lycopersicum L. cv Micro-Tom) and its impact in the productivity and water use efficiency
• Grantee: Mateus Henrique Vicente
• Support Opportunities: Scholarships in Brazil - Master