Abstract: In this study， the forage oat （Avena sativa L.） cultivar ‘Zhongtian No. 4’ was used as the experimental material to establish an optimized ethyl methanesulfonate （EMS） mutagenesis system. A series of pretreatments steps were employed， including husk removal and a 30-hour seed moisture conditioning period， followed by EMS mutagenesis treatments at different concentrations and durations， and a post-treatment involving exogenous gibberellin application. An M₂ mutant population was constructed. Agronomic traits were investigated at the milk stage to evaluate the mutagenic effects and to screen the high-yielding germplasm. The results indicated that soaking seeds in 98% concentrated sulfuric acid for 6 minutes effectively removed the husk barrier of forage oat seeds. Adjusting seed moisture content to 50% via a 4-hour soaking facilitated efficient penetration of EMS into the seed. The optimal EMS mutagenesis conditions for forage oat were determined to be 1.0% EMS treatment for 16 hours. Treatment of mutagenized seeds with 50 mg·L^-1 exogenous gibberellin significantly improved seedling growth. Compared with the control without added gibberellin， the germination rate increased by 8.5%， and the seedling length also recovered to the level of the non-mutagenized seedlings. This EMS mutagenesis technique systematically addressed key limiting factors in forage oat， including seed permeability barriers， inconsistent physiological states， and mutagen-induced damage. In the M₂ generation， the mutagenic efficiency for obtaining high-yield potential germplasm reached 1.92%， and 13 elite high-yield potential germplasms were successfully identified.

Key words: Forage oat, EMS, Mutagenesis system, Exogenous gibberellin, Moisture content, High-yield germplasm

摘要： 本研究以‘中天4号’饲用燕麦（Avena sativa L.）种子为材料，通过去除稃皮和连续30 h种子含水量调节的前处理，不同浓度和时间的EMS诱变处理，以及赤霉素外源施加的后处理，优化饲用燕麦EMS诱变技术体系。构建M₂代突变群体，于乳熟期调查其农艺性状，评估诱变效率并筛选高产种质。结果表明：98%浓硫酸浸泡6 min可有效去除饲用燕麦稃皮障碍，调节种子含水量至50%（4 h浸泡）可促进EMS高效地进入种子，筛选出饲用燕麦EMS最佳诱变条件为1.0% EMS处理16 h，采用50 mg·L^-1外源赤霉素处理诱变种子可显著促进诱变后幼苗生长（P<0.05），与未添加赤霉素的对照相比，发芽率显著提高8.5%，苗长也恢复至未诱变幼苗水平。该EMS诱变技术系统性地克服了饲用燕麦种子渗透障碍、生理状态不一及诱变损伤等关键限制因素。M₂代获得高产潜力种质的诱变效率达到1.92%，筛选到13份表现优异的高产潜力种质。

关键词: 饲用燕麦, EMS, 诱变体系, 赤霉素, 含水量, 高产种质