Induced Mutagenesis and Natural Genetic Variation in Tomato 'Micro-Tom'

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Pino-Nunes, L. E. ; Figueira, A. V. de O. ; Tulmann Neto, A. ; Zsoegoen, A. ; Piotto, F. A. ; Silva, J. A. ; Bernardi, W. F. ; Peres, L. E. P. ; Fischer, G ; Magnitskiy, S ; Nicola, S

• Document type: Journal article
• Source: INTERNATIONAL SYMPOSIUM ON TOMATO IN THE TROPICS; v. 821, p. 9-pg., 2009-01-01.

Abstract

Tomato is a good example of a successful use of mutations affecting major genes for plant breeding, which are also valuable for gene discovery and physiological studies. However, mutant alleles are only currently known for an insignificant fraction of the about 35,000 genes in the tomato genome. Large scale mutagenesis and introgression of natural genetic variation from the wild ycopersicon species into a genetic model system, such as 'Micro-Tom' (MT), can be useful to fill this gap. MT has the advantages of little space requirements and rapid cycle. Here we present the use of MT to explore natural genetic variation in tomato as well as a reassessment of the methodology for large scale tomato mutagenesis based on different agents (chemical and physical) and targets (seeds and pollen). The best parameter for dose adjustment of mutagen was the fertility of M1 plants, whereas the germination of treated-seed and that of pollen were found to be poor indicators of mutagenic efficiency. Using seeds treated with 0.7% EMS and pollen treated with 80 Gy gamma-ray it was possible to isolate a large number of mutants, including some dominant non-chimeric ones in the M1 generation derived from mutagenized pollen. Some mutations were allelic to previously known ones, but many others are novel and could be use for tomato breeding (e.g. high Brix) and basic studies. Furthermore, natural genetic variation affecting diverse developmental process and metabolic pathways was introgressed into MT from wild species. MT was a suitable model for a fast an inexpensive screening and characterization of advantageous mutations and natural genetic variation, which could be further transferred to elite cultivars or hybrids. (AU)

• FAPESP's process: 07/07175-0 - Genetic analysis of Theobroma cacao defense response against Moniliophthora perniciosa, the causal agent of witches broom
• Grantee: Antonio Vargas de Oliveira Figueira
• Support Opportunities: Research Projects - Thematic Grants