Breeding potential of Solanum tuberosum–S. commersonii pentaploid hybrids: fertility studies and tuber evaluation
- 106 Downloads
Twenty-one (near) pentaploid hybrids between sexually incompatible Solanum commersonii [2x(1EBN)] and cultivated S. tuberosum [4x(4EBN)] were characterized for tuber traits and fertility. A number of genotypes resembled the S. tuberosum type in terms of stolon length and eye depth and produced tubers under long day conditions. Tuber yields were not as high as expected, probably due to lack of adaptation of the S. commersonii genome to the environmental conditions in southern Italy (on average 325 g·pt−1 and 285 g·pt−1 in 2003 and in 2004, respectively). Compared to 2004, in the summer of 2003, characterized by extremely high temperatures, hybrids gave a higher tuber yield than the S. tuberosum control, suggesting that in our environmental conditions the wild S. commersonii genome, rather than resulting in heterosis for tuber yield, provides better adaptation to harsh environments. Although aneuploidy has often been associated with reduced fertility, several hybrids were fertile in crosses with S. tuberosum when used as female parents. In particular, the average berry set and number of seeds per berry were 38.2% and 31.8%, respectively. Based on significant relationships between ploidy levels and all yield and fertility data measured, the presence of extra chromosome affected the parameters considered: tuber yield in 2003 and 2004, percentage of fruit set, number of seeds per berry and number of seeds per pollinated flower. Regression analysis also indicated that “Residuals” were significant for all parameters measured. Therefore, additional factors (e.g. the genetic makeup of hybrids) may be key to fertility and yield.
KeywordsEndosperm balance number Interspecific hybridization Pentaploids S. commersonii Solanum tuberosum Tuber traits
Contribution no. 161 from Dept. Soil, Plant, Environmental and Animal Production Sciences. The authors thank Mr. R. Garramone for his technical help.
- Bani-Ameur F, Lauer FI, Veilleux RE, Filali A (1991) Genomic composition of 4x–2x potato hybrids: influence of Solanum chacoense. Genome 34:413–420Google Scholar
- Ehlenfeldt MK, Hanneman RE Jr (1988) Genetic control of endosperm balance number (EBN): three additive loci in a threshold-like system. Theor Appl Genet 75:825–832Google Scholar
- Hanneman RE Jr, Bamberg JB (1986) Inventory of tuber-bearing Solonum species. Research Bullettin 533, University of Wisconsin, Madison, Wisconsin, p 216Google Scholar
- Jansky S (2000) Breeding for disease resistance in potato. Plant Breed Rev 19:69–155Google Scholar
- Johnston SA, den Nijs TPM, Peloquin SJ, Hanneman RE Jr (1980) The significance of genic balance to endosperm development in interspecific crosses. Theor Appl Genet 57:5–9Google Scholar
- Khush GS (1973) Transmission of extra chromosome in trisomics. In: Cytogenetics of aneuploids. Academic, New York, pp 60–86Google Scholar
- Laverty T, Vorsa N (1991) Fertility of aneuploids between the 5x and 6x levels in blueberry: the potential for gene transfer from 4x to 6x levels. J Am Soc Hort Sci 116:330–335Google Scholar
- Lee HK, Kessel R, Rowen PR (1972) Multiple aneuploids from interspecific crosses in Solonum: fertility and cytology. Can J Genet Cytol 14:533–543Google Scholar
- Vorsa N, Jelenkovic G, Draper AD, Welker WV (1987) Fertility of 4x × 5x progenies derived from Vaccinium ashei/corymbosum pentaploid hybrids. J Am Soc Hort Sci 112(6):993–997Google Scholar