ABSTRACT

Understanding and improving water-use efficiency and drought resistance in tomato A. Zsögön, Universidade Federal de Viçosa, Brazil; and M. H. Vicente, D. S. Reartes and L. E. P. Peres, Universidade de São Paulo, Brazil

1 Introduction

2 Tomato as a genetic model in plant biology

3 Patterns in tomato plant development

4 Water relations in tomato

5 Natural genetic variations in tomato

6 Case study: Solanum pennellii as a source of drought-resistance

7 Plant development and water relations

8 Future trends and conclusion

9 Where to look for further information

10 References

Plant physiology is a broad sub-field of botany concerned with how plants function. It is customary to divide plant physiology in disciplines dealing specifically with water relations, photosynthesis and respiration, biotic and abiotic stress and mineral nutrition. As sessile organisms, plants need to adapt their functioning to contingent environmental conditions, which can vary broadly over time. Thus, plant development and physiology are intimately linked throughout a plant’s life cycle. The tomato (Solanum lycopersicum L.) is both a well-established genetic model for plant biology and a horticultural cash crop with an increasing importance for human nutrition. Research in tomato physiology has a rich history which includes many conceptual breakthroughs. On the applied side, production of cultivated tomatoes is divided broadly into two categories: greenhousegrown tomato for fresh consumption and field-grown processing tomato for industrial use. The latter attracts the largest share of the research and breeding effort. Tomato is mainly cultivated under irrigated conditions, so water use is of considerable relevance for healthy plant growth and adequate yield. The coming years will see a growing competition for the use of freshwater between agriculture and industrial/residential consumption. It is therefore desirable to increase our understanding of water relations in

tomato. Our goal in this chapter is to review recent advances in tomato physiology, with particular emphasis on the promising convergence between developmental physiology and water relations. We also endeavour to integrate recent findings with selected earlier studies.