Reinventing potato breeding through true potato seed based technology

Abstract

Potato is the major staple food in many countries of the world. It has a long history of cultivation in its area of origin i.e. Andean region of Peru. It is propagated through tubers to maintain the purity of cultivars due to high heterozygosity and polyploid genome. The cultivated potatoes are auto-tetraploid and selfcompatible. But upon selfing they show high inbreeding depression due to high heterozygosity in parental lines and may be expression of lethal alleles on selfing. The homozygous lines therefore could not be developed in tetraploid potato and the varieties as well as advanced breeding material are maintained in the form of tubers only. Maintenance of varieties and other breeding lines through clonal propagation in the form of tubers lead to accumulation of pests and diseases particularly viruses, which keep on multiplying in each cycle of clonal propagation. This leads to diminution of varieties productivity and acceptance. Moreover, the potato breeding programme takes more than 12 years to develop a new variety and is based on clonal propagation of tubers. The seed of the variety is also multiplied clonally through tubers with a seed multiplication rate of approximately 1: 8 tubers per year. There are two approaches which have been envisioned at the global level for using TPS as the propagation material in potato.