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ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Publications at this Location » Publication #110622
Title: MODIFIED CONVENTIONAL BREEDING METHODS TO EFFICIENTLY TRANSFER UNIQUE LATE BLIGHT RESISTANCE FROM 2X(1EBN) SPECIES TO 2X(2EBN) AND 4X(4EBN) BREEDING LINES

Author
item Hanneman Jr, Robert

Submitted to: American Journal of Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: 4/13/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Several 2x(1EBN) Mexican species have been shown to be excellent sources of extreme resistance to late blight, but have not been used routinely in breeding because they do not readily cross with haploids or common cultivars due to Endosperm Balance Number differences. Two methods have been developed using sexual hybridization to transfer germplasm from the 2x(1EBN) species to the 2x(2EBN) and 4x(4EBN) levels. One uses double pollination techniques coupled with embryo rescue and has resulted in the formation of a S. pinnatisectum-Tuberosum haploid hybrid. This hybrid, though male sterile, has been successfully crossed as a female to 2x(2EBN) S. chacoense, S. phureja, S. sparispilum, Tuberosum haploids and 4x(4EBN) cultivars. A second method uses the Mexican species, 2x(2EBN) S. verrucosum, as a bridge species with 2x(1EBN) species. The 2x(1 1/2EBN) hybrids should segregate for EBN and therefore be crossable to 2x(1EBN) and 2x(2EBN) lines as well as to 4x(4EBN) parental material, if 2n gametes function. The 2x(1 1/2EBN) hybrids have been successfully crossed with 2x(2EBN) S. chacoense, S. phureja and a Tuberosum haploid; with 2x(1EBN) S. commersonii, S. pinnatisectum and S. trifidum, and with several 4x(4EBN) cultivars as predicted. Not only has extreme late blight resistance been characterized in the 2x(1EBN) Mexican genepool, but we now have demonstrated two modified conventional breeding methods to successfully transfer this resistance to the 2x(2EBN) or 4x(4EBN) level.