Advances in the application of in vitro radiomutagenesis for the genetic improvement of Citrus rootstocks

Abstract

Since the 80’s of the last century, the Radiobiology Department at CEADEN has collaborated with impor-tant genetic breeding groups in the country in obtaining mutants of rice, tomato, sugar cane, soybean, among others; not only with the irradiation of materials, but also in the biochemical and molecular characterization of the mutants generated, mainly in rice. Starting in 2000, radiomutagenesis projects began in fruit crops (Citrus and avocado) in collaboration with the Tropical Fruit Growing Research Ins-titute (IIFT) and the International Atomic Energy Agency (IAEA). This work presents the advances in es-tablishing an in vitro radiomutagenesis methodology for rootstocks of interest for the Cuban citriculture (Swingle citrumelo, Citrus macrophylla, Citrus aurantium, Cleopatra mandarin and Carrizo citrange). An in vitro selection protocol for lines with possible tolerance to drought was developed, the selective do-ses against PEG-6000 were determined and putative descriptors of the response to in vitro water stress were identified. An alkalinity tolerance selection potocol, based on an iron deficient selective medium was evaluated on Swingle citrumelo. Three lots of mutant lines selected against water stress were deve-loped which are currently under evaluation. At the moment, two mutant lines with higher diameter/height ratio, four lines with shorter internodes (one of them with reduced height) and five lines with higher vigo and better phytopathological behavior have been identified.