为探究芦头繁殖代数与怀山药农艺性状和品质的关系，明确怀山药芦头更新的时间节点，以怀山药繁殖第1、2、3、4代的芦头为材料，采用随机区组试验，测定其出苗时间、出苗率、根茎长度、根茎直径、单支根茎鲜质量和干质量，采用分光光度法测定淀粉、可溶性糖、蛋白质含量，高效液相色谱法测定山药薯蓣皂苷、尿囊素含量。结果表明，怀山药的根茎长度、根茎直径、单支鲜质量、单支干质量、尿囊素含量均随着芦头繁殖代数的增加表现为先上升后下降，且在第3代达到最大值，分别为109.77 cm、31.58 mm、324.78 g、92.38 g、21.79 mg/g；而蛋白质含量变化与以上指标相反，且第3代最低，为152.89 mg/g；可溶性糖含量总体呈下降趋势，第4代最低，为34.23 mg/g；淀粉和薯蓣皂苷含量亦在第3代最高，分别为218.00、0.177 3 mg/g。可见，芦头繁殖第3代的怀山药农艺性状及品质最佳，第4代芦头所产山药的农艺性状和品质性状均开始衰退，因此，怀山药生产中需要定期更新种栽，以保障药材的产量和品质。

To explore the relationship between propagation generation? and agronomic characters and quality of Chinese yam and clarify the time to update basal part of stem,the first,second,third and fourth generations of Chinese yam basal part of stem were used as materials,and the emergence time,seedling rate,rhizome length,rhizome diameter,fresh weight and dry weight of single rhizome were studied with random block test.The contents of starch,soluble sugar and protein were determined by spectrophotometry,and the diosgenin and allantoin by HPLC.The results showed that rhizome length,rhizome diameter,single branch fresh weight,single branch dry weight and allantoin content all increased firstly and then decreased with the increase of propagation generations,and reached the maximum value in the third generation,which were 109.77 cm,31.58 mm,324.78 g,92.38 g,21.79 mg/g,respectively;While the protein content change was contrary to the above indexes,and the third generation was the lowest,which was152.89 mg/g.The content of soluble sugar decreased with the increase of generations,and reached the minimum in the fourth generation,which was 34.23 mg/g;the contents of starch and diosgenin were the highest in the third generation,which were 218.00 mg/g and 0.177 3 mg/g,respectively.We conclude that the third generation of Chinese yam has the best agronomic and quality characters,while the fourth generation has begun to decline. Therefore,it is necessary to update the basal part of stem regularly to en sure the yield and quality of Chinese yam.