Mutation breeding in irish potatoes

The cultivated potato (Solanum tuberosum L.) originated from the Andean region of South America. Kenyan farmers started potato cultivation in 1920 and entered the export market in 1923. However, while average potato yields in North America and Western Europe often reach 40 t ha-1 yields in developing countries are usually below 20 t ha-1. The low yields have been attributed to poor agronomic practices, low use of inputs especially fertilizers, low soil fertility, limited access to quality seed, and diseases (especially bacterial wilt, late blight and viruses).Genetics of potato is limited because of its tetrasomic inheritance (2n=4x=48) and small chromosomes. Many cultivars show poor flowering and low fertility, high degree of heterozygosis and low heritability of many characters, therefore, cross breeding programmes conventionally are often disappointing. Alternatively, induced mutation breeding through radiation/chemical-induced mutagenesis has been recommended to improve cultivars of vegetative propagated crops. Occasionally potato plants may produce a spontaneous mutation but it doesn’t happen often enough to be useful as a breeding method with only 12 plants out of 100,000 plants and only 5 leaf mutants while examining more than 350,000 plants. Induced mutation techniques have been successfully used to improve yield, quality, and disease and pest resistance in many crops including potato. The use of In vitro cultures in mutation breeding offers several advantages over the In vivo techniques including, obtaining explants from pre-existing cultures and recovering mutants and rapidly micro-propagating them under controlled environmental conditions and depicts higher mutation frequencies. A research done on salt-tolerant mutants of potato (Solanum tuberosum L. ‘Marfona’) were obtained via gamma irradiation. On average the mutants were genetically 27.5% different from the control plants. The greatest difference encountered between the control and mutants was 47%, which was detected in mutant plants produced by20 or 30gy gamma irradiation and regenerated in selection medium containing 100mMNaCl.This review will try to address the need for mutation breeding.