Biotechnology and Nuclear Technology Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China.
Sichuan Academy of Agricultural Sciences, Chengdu 610066, China.
Genes (Basel). 2024 Oct 19;15(10):1340. doi: 10.3390/genes15101340.
Sweet potato ( (L.) Lam.), a key global root crop, faces challenges due to its narrow genetic background. This issue can be addressed by utilizing the diverse genetic resources of sweet potato's wild relatives, which are invaluable for its genetic improvement. The morphological differences in leaves, stems, and roots among 13 species were observed and compared. Chromosome numbers were determined by examining metaphase cells from root tips. Fluorescence in situ hybridization (FISH) was used to identify the number of 5S and 18S rDNA sites in these species. PCR amplification was performed for both 5S and 18S rDNA, and phylogenetic relationships among the species were analyzed based on the sequences of 18S rDNA. Three species were found to have enlarged roots among the 13 species. Chromosome analysis revealed that had 90 chromosomes, had 28 chromosomes, while the remaining species possessed 30 chromosomes. Detection of rDNA sites in the 13 species showed two distinct 5S rDNA site patterns and six 18S rDNA site patterns in the 12 diploid species. These rDNA sites occurred in pairs, except for the seven 18S rDNA sites observed in . PCR amplification of 5S rDNA identified four distinct patterns, while 18S rDNA showed only a single pattern across the species. Phylogenetic analysis divided the 13 species into two primary clades, with the closest relationships found between and , as well as between and . These results enhance our understanding of the diversity among species and provide valuable insights for breeders using these species to generate improved varieties.
甘薯（ (L.) Lam.）是一种重要的全球性块根作物，但由于其遗传背景狭窄，面临着挑战。这一问题可以通过利用甘薯野生近缘种的多样化遗传资源来解决，这些资源对于其遗传改良至关重要。观察并比较了 13 个种的叶片、茎和根的形态差异。通过检查根尖中期细胞来确定染色体数目。利用荧光原位杂交（FISH）鉴定这些物种中的 5S 和 18S rDNA 位点数量。对 5S 和 18S rDNA 进行 PCR 扩增，并根据 18S rDNA 序列分析种间的系统发育关系。在 13 个种中，发现有 3 个种的根较大。染色体分析表明， 有 90 条染色体， 有 28 条染色体，而其余种则有 30 条染色体。在 13 个种中检测 rDNA 位点显示，在 12 个二倍体种中存在两种不同的 5S rDNA 位点模式和六种 18S rDNA 位点模式。这些 rDNA 位点成双出现，除了在 中观察到的七个 18S rDNA 位点。5S rDNA 的 PCR 扩增鉴定出四种不同的模式，而 18S rDNA 在整个种间只显示出一种模式。系统发育分析将 13 个种分为两个主要分支，其中与 、 以及 与 之间的关系最为密切。这些结果增强了我们对种间多样性的理解，为利用这些种进行品种改良的育种者提供了有价值的信息。
