Tetraploids potatoes

Male sterility due to deleterious nuelear genes is common in the cultivated potato (Howard, 1970). Because the marketable product is not seed, there is no selection pressure for high fertility in breeding programs. In fact, fruit development may partition resources away from tuber deld, so breeders may inadvertently select against high fertility (Jansky and Thompson, 1990). In addition, deleterious recessive alleles can accumulate in tetraploid potato cultivars because they are more easily masked than in diploids. 

Haploids are sporophytes with the gametophytic chromosome number. Haploids (2x) of tetraploid potato cultivars provide a mechanism for direct gene transfer from wild 2x relatives and allow breeders to work at the diploid level. As discussed below, selection progress is more rapid with diploids than tetraploids. Haploids can also be used to measure the genetic load in the tetraploids from which they are derived, since deleterious alleles hidden in tetraploids are often expressed in haploids. 

Johnson, A. A. T., Nault, B. A., Veilleux, R. E. (2003). Transmission of a Bacillus thuringiensis eiy3Aa transgene from diploid to tetraploid potato using 4x-2x hybridization effeet of ploidy inerease on transgene expression and implieations for TPS hybrid produetion. Plant Breeding, 122,223-228. 

Maris, B. (1990). Comparison of diploid and tetraploid potato families derived from Solanum phureja x dihaploid... 

Simko, L, Costanzo, C., Haynes, K. G., Christ, B. J., Jones, R. W. (2004a). Linkage disequilibrium mapping of a Verticillium dahliae resistanee quantitative trait locus in tetraploid potato (Solanum tuberosum) through a candidate gene approach. Theoretical and Applied Genetics, 108,2X1-224. 

Raker, C. M., Spooner, D. M. (2002). Chilean tetraploid cultivated potato, Solanum tuberosum, is distinct from the Andean populations microsatellite data. Crop ScL, 42, 1451-1458. 

De Jong, H., Tai, G. C. C. (1977). Analysis of tetraploid-diploid hybrids in eultivated potatoes. Potato Research, 20, 111-121. 

Ortiz, R., Iwanaga, M., Peloquin, S. J. (1997). Evaluation of FDR diploid and tetraploid parents in potato under two different day-length environments. Plant Breeding, 116,353-358. 

Przetakiewicz, J., Nadolska-Orczyk, A. N., Kuc, D., Orczyk, W. (2007). Tetraploid somatic hybrids of potato Solanum tuberosum L.) obtained from diploid breeding lines. Cellular and Molecular Biology Letters, 12, 253-267. 

Kozukue, N., Misoo, S., Yamada, E, Kamijima, O., Friedman, M. (1999). Inheritance of morphological characters and glycoalkaloids in potatoes of somatic hybrids between dihaploid Solanum acaule and tetraploid Solanum tuberosum. J. Agric. Food Chem., 47, 4478 483. 

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