Introgression of cold (4 C) chipping from 2x (2 endosperm balance number) potato species into 4x(4EBN) cultivated potato using sexual polyploidization

摘要

Cold-chipping cultivars could reduce microbial spoilage and chemical use due to cold storage of chipping potatoes. Sexual polyploidization breeding schemes that introgress cold chipping from diploid potato species may develop improved cultivars at an accelerated rate. The research objectives were (1) to determine the breeding behavior of cold chipping introgressed from 2x 2 Endosperm Balance Number (EBN) potato species into 4x(4EBN) progeny using sexual polyploidization, and (2) to determine if differences exist between 2n gametes and n tetrasomic gametes for transmission of cold chipping. Experimental families of 4x(4EBN) progeny were synthesized using sexual polyploidization (2x x 4x and 4x x 2x) and 4x x 4x matings using cold-chipping S. phureja and cultivated potato - wild species (C - W) hybrid parents. Control families from 4x x 4x matings using as parents current industry leading germplasm were also made. Progeny were field grown and evaluated for chip color (1 light - 10 dark, less than or equal to 4.0 is industry acceptable) after 3 and 6 months storage at 4 C. A larger percentage of progeny from experimental families had acceptable chip color compared to control families, likely due to introgression of cold-chipping alleles from diploid potato species. Out of experimental families, the best chip color means, highest phenotypic variance, and greatest percentage of acceptable chipping progeny resulted in 2x x 4x and 4x x 2x matings. The ability of 2n gametes to transmit dominant alleles to high frequencies of 4x progeny may contribute to the superiority of 4x - 2x crosses. Breeding schemes that use sexual polyploidization in conjunction with early generation selection should rapidly develop 4x cold-chipping germplasm.