Genetic Improvement of Crops by Mutation Techniques in Brazil

Agriculture in Brazil has a prominent position in the country's economy due to its large spread under diverse but suitable climatic conditions which are indispensable for higher performance of many crops. Therefore, constant efforts in plant breeding by traditional methods have led Brazil to be internationally recognized as a tropical agricultural country. Spontaneous mutations constitute the source of genetic variability and have been long utilized by breeders. In Brazil, various cultivars of seed propagated, as well as vegetatively propagated plants, were obtained from spontaneous mutation, such as cultivar 'Carioca' (Phaseolus vulgaris L.) and cultivar 'Bahianinha' (Citrus sinensis L.). After introduction of mutation induction in Brazil, several breeding programmes using mutagens, such as nuclear radiation, alkylating and non-alkylating chemical compounds, have been carried out to increase crop production. As will be reported, various mutants were selected or are in the process of selection. (author)