Creation of a highly homozygous diploid potato using the S locus inhibitor ( Sli ) gene
- PDF / 2,579,525 Bytes
- 16 Pages / 547.087 x 737.008 pts Page_size
- 94 Downloads / 157 Views
(0123456789().,-volV) ( 01234567 89().,-volV)
Creation of a highly homozygous diploid potato using the S locus inhibitor (Sli) gene Kazuyoshi Hosaka
. Rena Sanetomo
Received: 13 August 2020 / Accepted: 19 September 2020 Ó Springer Nature B.V. 2020
Abstract Potato is a heterozygous autotetraploid crop propagated as tubers. Diploid potatoes, which are mostly self-incompatible due to gametophytic selfincompatibility, are often used to reduce genetic complexity. The discovery of the S locus inhibitor (Sli) gene has created a way to develop diploid inbred lines and perform F1 hybrid breeding in potato. However, residual heterozygosity found in advancedgeneration selfed progenies has posed the question of whether a minimum level of heterozygosity is necessary to maintain self-fertility. We continued selfing and finally identified a highly homozygous diploid potato among tenth-generation selfed progeny, which was homozygous at all 18,579 genome-wide single nucleotide polymorphism (SNP) markers surveyed. The S10 plants suffered severe inbreeding depression in terms of fertility and vigor, showing a small number of mature flowers and extremely slow growth. Although asexual techniques such as anther culture followed by chromosome doubling can result in completely homozygous diploid potatoes, all previously derived
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10681-020-02699-3) contains supplementary material, which is available to authorized users. K. Hosaka (&) R. Sanetomo Potato Germplasm Enhancement Laboratory, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan e-mail: [email protected]
plants were male sterile. In contrast, continuous selfing using Sli swept out all lethal alleles and selected for self-fertility, which generated a highly homozygous diploid potato retaining male and female fertility and tuberization ability under long days. Keywords S locus inhibitor (Sli) gene Highly homozygous diploid potato Inbreeding depression Genome-wide SNPs Selfing Introduction Potato (tetraploid form of Solanum tuberosum L.) is a heterozygous tuber crop. Heterotic effects on vigor and yield are maintained and used for clonal propagation via tubers. However, genetic analyses are difficult due to autotetraploidy and heterozygosity. It is thought that many deleterious or lethal genes exist as heterozygotes in the potato genome which would be expressed by selfing. Thus, inbreeding depression in terms of viability and fertility has limited continuous selfing in potato (Krantz 1924; De Jong and Rowe 1971). The majority of the diploid potatoes of cultivated and wild species are self-incompatible due to the gametophytic self-incompatibility system controlled by the S locus (Pushkarnath 1942; Pandey 1962; Cipar et al. 1964a). However, exceptional self-compatible diploid variants have often been reported (Pushkarnath 1942; Cipar et al. 1964b; De Jong and Rowe 1971; Olsder and Hermsen 1976; De Jong 1977; Cappadocia
123
169
Pag
Data Loading...
