Genome. 1994 Oct;37(5):866-70. doi: 10.1139/g94-122.
The cultivated potato Solanum tuberosum Dunal has many wild related species with desirable traits. Some of these wild tetraploids have disomic chromosome pairing, ready selfing with little inbreeding depression, but have strong crossing barriers with cultivars. They hybridize most easily with 2EBN forms (which include most diploid species). Chromosome doubling to the 8x level, use of 2n gametes, use of 2n gametes of 4x-2x triploid hybrids, and embryo rescue have been proposed to overcome the crossability barrier of these species with S. tuberosum. In this study, 2x S. commersonii (cmm) was used as a bridge species with S. acaule and series Longipedicellata species. Synthetic tetraploid 4x-cmm crossed readily to disomic 4x species, resulting in fertile F1 and F2 hybrids. Some of these had 2n gametes, which enabled direct crossing to tuberosum, resulting in 6x hybrids. The benefits of this scheme are (i) hybrids are relatively fertile, so many progeny may be produced for selection at each step, (ii) hybridization with cmm results in 2n gametes needed for crossing to tuberosum, and breaks up restricted recombination within disomic genomes, and (iii) simple techniques and tools are employed.
栽培马铃薯 Solanum tuberosum Dunal 有许多具有理想特性的野生近缘种。其中一些野生四倍体具有二体染色体配对，可自交且很少出现近交衰退，但与品种的杂交障碍较强。它们与 2EBN 形式（包括大多数二倍体物种）杂交最为容易。染色体加倍到 8x 水平、使用 2n 配子、使用 4x-2x 三倍体杂种的 2n 配子以及胚胎拯救已被提议用于克服这些物种与 S. tuberosum 的可杂交性障碍。在这项研究中，2x S. commersonii (cmm) 被用作与 S. acaule 和系列 Longipedicellata 物种的桥梁物种。合成的四倍体 4x-cmm 与二倍体物种易交配，产生可育的 F1 和 F2 杂种。其中一些杂种具有 2n 配子，可直接与 tuberosum 杂交，产生 6x 杂种。该方案的好处是：(i) 杂种相对可育，因此每个步骤都可以产生大量后代进行选择；(ii) 与 cmm 的杂交产生了与 tuberosum 杂交所需的 2n 配子，并打破了二倍体基因组内的受限重组；(iii) 采用了简单的技术和工具。
