Potato breeding with haploids and 2n gametes

Abstract

Potato breeding methods that utilize haploids of Solanum tuberosum group Tuberosum or group Andigena and 2n gametes exploit the genetic diversity, including both valuable traits and allelic diversity, available in exotic germ plasm. Three essential components are involved: (i) the wild and cultivated 2x relatives of the cultivated 4x potato are a valuable source of genetic diversity; (ii) haploids (2n = 2x = 24) of cultivars (2n = 4x = 48) are effective in capturing diversity (germ plasm enhancement); (iii) 2n gametes, resulting from first division restitution, are an efficient method of transmitting this genetic diversity to cultivated 4x potatoes. Heterosis for total and marketable tuber yield and specific gravity occurs in 4x families from crosses between 4x cultivars and 2x haploid Tuberosum × 'Phureja' hybrids. Selected 4x clones from relatively small 4x × 2x families have been released as cultivars based on their earliness and heat tolerance in the tropics. Other 4x clones from 4x × 2x crosses, where the 2x parents were haploid – wild species hybrids, have good yield, excellent tuber type, high specific gravity, low reducing sugars, storage quality, and stress tolerance. The seedling vigor, uniformity, and large tuber yields of progeny from 4x × 2x crosses also makes this an effective breeding method for producing potatoes from true potato seed. This breeding method is also being successfully exploited in alfalfa, red clover, sweet potatoes, yams and several species of grasses, fruits, and ornamentals.Key words: potato, haploids, 2n gametes, germ plasm, allelic diversity.

Hybridization between wild and cultivated potato species in the Peruvian Andes and biosafety implications for deployment of GM potatoes

“…However, the presence of 2n gametes may allow a species to overcome stylar, ploidy and EBN barriers. 2n gametes result from meiotic distortions affecting micro-or macro-sporogenesis (Peloquin et al 1989;Ramanna 1979). In potato, wild species are scrutinized for their contribution to variability in traditional farmer's fields and to current plant breeding efforts in the search for traits that make potato cultivars tolerant or resistant to diverse diseases (Chen et al 2003) and abiotic stresses such as drought and frost.…”

Phenotypic and Transcriptomic Changes Associated With Potato Autopolyploidization

“…Furthermore, the cultivated potato, Solanum tuberosum (2n ¼ 4x ¼ 48), has been defined as a classic autopolyploid on the basis of its tetrasomic inheritance (Grant 1981;Carputo et al 2003). Genetic manipulation via meiotic mutants associated with 2n gamete formation has played a more significant role in breeding of potato than in any other crops (Peloquin et al 1989(Peloquin et al , 1999. Thus, potato provides an excellent model system for autopolyploidy studies.…”

Genetic diversity of potato for nitrogen use efficiency under low input conditions in Ethiopia

“…On the other hand, these reproductive constraints can be compensated by other unique features of potato; namely the use of unreduced gametes (2n gametes) and the possibility of crossing diploids with tetraploids. These attributes contributed a lot to the evolution and genetic variation of potato (den Nijs and Peloquin, 1977;Peloquin et al, 1989;Carputo and Barone, 2005;Ortiz et al, 2005) A wide range of phenotypic variation in NUE has been reported in commercial potato cultivars, clonal selections, and accessions of wild potato species Martin et al, 1998, Errebhi et al, 1999;Zebarth et al, 2004a;Sharifi et al, 2007). This genetic variability within the cultivated potato and its wild relatives can be exploited by breeders to improve the NUE of the crop.…”