Abstract: In the study， two oat varieties with significant difference in lodging resistance were taken as materials， the characteristics of lignin monomer synthesis in stem of lodging resistance varieties were determined by analyzing the change of fracture strength and lignin monomer content in basal section 2 at different growth stages.The results showed that： in the same stage， compared with the lodging sensitive varieties， the basal second internode of lodging resistant varieties had higher stem breaking strength and lower lodging index. The breaking strength of the basal second internode of lodging resistant varieties reached its maximum value at the milking stage. The lignin content of the basal second internode increased gradually with the progression of growth stage， and reached the maximum value at dough stage. The lodging resistant varieties increased by 2.90% on average. The total lignin monomer content of the basal second internode of lodging resistant cultivars was 32.84%， 20.22% and 8.78% higher than lodging sensitive cultivars at filling stage， milking stage and dough stage， respectively. The content of H type， S type and G type lignin monomer was higher than that of lodging sensitive cultivars at three stages， and the content of S type monomer was the highest by 121.53 μmol·g^-1， followed by G type and H type. The types of lignin synthesized monomers of the basal second internode were mainly S-type and G-type. S-type monomers were accumulated in large quantities at the filling stage， and G-type monomers were mainly accumulated from milking to dough stage， and the S/G ratio was higher at milking stage.

Key words: Oat, Stem inter-node, Lodging resistance, Lignin, Monomer characteristics

摘要： 本研究以2个抗倒性存在显著差异的饲用燕麦（Avena sativa L.）品种为材料，分析不同生育时期基部第2节茎秆折断强度与木质素合成单体含量的变化，明确不同抗倒性品种茎秆木质素单体合成特征。结果表明，同一时期，与易倒伏品种相比，抗倒伏品种基部第2节茎秆抗折强度大、倒伏指数小；抗倒伏品种茎秆基部第2节抗折强度在乳熟期达最大值。茎秆基部第2节间木质素含量随生育期推进逐渐增加，蜡熟期达最大值，抗倒伏品种平均增加2.90%。抗倒伏品种茎秆基部第2节间总木质素单体含量在灌浆期、乳熟期、蜡熟期分别较易倒伏品种高32.84%，20.22%和8.78%，H型、S型和G型木质素单体含量在3个时期均表现为抗倒伏品种>易倒伏品种，S型单体含量最高，为121.53μmol·g^-1，G型次之，H型最低。燕麦茎秆基部第2节间木质素合成单体类型主要为S型和G型，灌浆期大量积累S型单体，乳熟期至蜡熟期主要积累G型单体，S/G比率乳熟期较高。

关键词: 燕麦, 茎秆节间, 抗倒伏性, 木质素, 单体特征