Tomato doubled haploids

Tomato, belonging to the Solanaceae family, is one of the most important world vegetable crops. According to FAO data, in 2002 global tomato production (processing and fresh) and global trade of tomatoes and tomato products have reached 108 million tons and $4.2 billion, respectively. Modern plant breeding and genetic technologies are used nowadays for breeding of hundreds of tomato varieties, including F1-hybrids, which offer various advantages to vegetable companies. However, breeding of F1 hybrids depends solely on the commercial availability of homogenous genetic resources with guaranteed levels of identity. To generate these materials, companies usually use time-consuming and very costly procedures such as conventional selfing and back-crossing. Establishing new efficient technologies such as doubled haploid production can provide a breakthrough for the production of homogenous genetic resources.Specifically, the major advantage of doubled haploids in plant breeding is the immediate achievement of complete homozygosity leading to the fixation of desired genotypes in one generation. Despite the great importance of doubled haploid plants for F1 hybrid breeding, no technology for obtaining doubled haploids in tomato has been developed yet. Some attempts published by academic research groups appeared to be very inefficient, not reproducible, or highly genotype-dependent. Our laboratory has achieved a significant progress in regenerating doubled haploids from in vitro cultured tomato microspores. The efficiency of initial microspore divisions and formation of multi-cellular structures is comparable to other well-developed systems such as tobacco or wheat. These results have been achieved with the help of internal resources and financial support from such funding organizations as ÖAD. The main objective of the project is to establish an efficient and reproducible doubled haploid production technology for tomato and to build up intellectual property assets (IP), which will enable collaboration with the industry. Specific aims of the project are: - establishing optimal culture conditions for embryo formation in tomato microspores; - discovery of factors for efficient regeneration of microspore-derived tomato embryos; - establishing a method for efficient spontaneous or induced chromosome doubling of haploid microspores, embryos, and plants; - transfer of doubled haploid technology to other tomato varieties and lines; - IP protection of the method for obtaining doubled haploids in tomato.