Gametic culture in sweet orange [Citrus sinensis (L.) Osbeck].

• Grant number: 13/15637-4
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: October 01, 2013
• End date: June 30, 2017
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Rodrigo Rocha Latado
• Grantee: Karina Salomão
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

Production of homozygous lines in citrus traditional breeding program is difficult by some difficulties presented in citrus reproductive biology, such as: long juvenile stage, polyembrionic seeds, high heterozygosity and the presence of self-incompatibility in some species. The homozygous lines could be obtained more quickly using double-haploid technology, obtained by natural or induced diploidization of haploid plants, in order to generate completely homozygous lineages in only one cycle of cultivation. Anther culture, culture of isolated microspores and in situ or in vitro parthenogenesis are the most used methods to obtain haploid plants and / or double haploids. Anther and isolated microspore culture are affected by several factors, such as: genotypes, pre-treatments, the developmental stage of microspores and the composition of culture media. At the same way, the main effects for the success of parthenogenesis are the genotypes and radiation dose used for pollen grain inactivation before pollination. The aim of this project are the development of protocols for anther culture, isolated microspore culture and in situ parthenogenesis of sweet orange genotypes in order to obtain haploid and double-haploid plants. Thus, are being proposed several experiments, using these three techniques. All plants obtained will have the ploidy determined by flow cytometry using Cyflow Ploidy Analyzer (PARTEC), and the regenerated plants will be evaluated using molecular markers for determining the gametic, somatic or zygotic origin. If callus, embryos or haploid plants have been obtained, the diploidization of these materials will be made artificially by the use of colchicine in the culture medium.