Fu Yong-Bi, Horbach Carolee
Plant Gene Resources of Canada, Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7N 0X2, Canada.
Cells. 2025 Jun 4;14(11):844. doi: 10.3390/cells14110844.
Modern high-yielding crop cultivars are known to have narrow genetic bases, making them vulnerable to biotic and abiotic stresses. However, little is known about the extent of deleterious genetic variants (or mutation burden) present in these cultivars. An attempt was made using RNA-Seq to screen genome-wide deleterious genetic variants in 141 oat and 142 wheat cultivars released through Canadian breeding programs over the past century. The screening identified 5726 and 3022 deleterious genetic variants across all 21 chromosomes of both the oat and wheat genomes, respectively. These deleterious variants were largely harbored in a few cultivars and were involved with diverse biological processes, cellular components, and molecular functions. More highly deleterious variants were predicted in oat, than in wheat, cultivars, and different gene expression profiles at the early seedling stage were observed between oat and wheat cultivars, illustrating different genetic impacts of the oat and wheat breeding programs. Estimating mutation burdens for each cultivar revealed large variations among both the oat and wheat cultivars. These mutation burdens were found to increase from early to recent oat and wheat cultivars and were associated with higher cultivar yields. Genetic analyses also revealed genetic shifts and expansions from early to recent oat and wheat cultivars. These findings provide the first empirical evidence of elevated mutation burdens in Canadian oat and wheat cultivars and are useful for advancing plant breeding programs to minimize genetic risk.
现代高产作物品种的遗传基础狭窄，这使得它们易受生物和非生物胁迫的影响。然而，对于这些品种中存在的有害遗传变异（或突变负荷）的程度却知之甚少。研究人员尝试利用RNA测序技术，对过去一个世纪通过加拿大育种计划发布的141个燕麦品种和142个小麦品种进行全基因组有害遗传变异筛选。筛选结果分别在燕麦和小麦基因组的所有21条染色体上鉴定出5726个和3022个有害遗传变异。这些有害变异大多集中在少数几个品种中，并涉及多种生物学过程、细胞成分和分子功能。预测燕麦品种中的有害变异比小麦品种中的更多，并且在燕麦和小麦品种的幼苗早期观察到不同的基因表达谱，这说明了燕麦和小麦育种计划对遗传的不同影响。对每个品种的突变负荷进行估计后发现，燕麦和小麦品种之间存在很大差异。这些突变负荷从早期到近期的燕麦和小麦品种呈增加趋势，并且与更高的品种产量相关。遗传分析还揭示了从早期到近期燕麦和小麦品种的遗传变化和扩展。这些发现首次提供了加拿大燕麦和小麦品种中突变负荷增加的实证证据，有助于推进植物育种计划，以将遗传风险降至最低。
