Abstract: In order to improve the yield and ethanol production capacity of ‘Reyan No.4’ king grass （Pennisetum purpureum×P. americanum cv. ‘Reyan No.4’）， the optimum cutting intervals were studied. In this paper， king grass was used as the experimental material to study the effects of different cutting intervals （2， 3， 4， 6 and 12 months） on agronomic traits and cellulosic ethanol production. The results showed that the total yields of fresh matter （FM）， dry matter （DM）， and ethanol of king grass at the 6-month cutting interval was significantly higher than those at other cutting intervals （P<0.05）， reached 328.29 t·hm^-2 FM， 86.08 t·hm^-2 DM， and 15.18 t·hm^-2， respectively. The longer the cutting interval， the larger the dry matter rate， average plant height and stem diameter， the more the cellulose， hemicellulose， and lignin content， while the average tillering number， ash content， adsorbed water content， lignin removal rate， dry base weight loss rate of enzymatic hydrolysis， enzymatic hydrolysis rate， ethanol concentration， and ethanol conversion rate decreased gradually. In summary， the yields of king grass and ethanol with a 6-month cutting interval were the best， which provides a reference for the industrial application of king grass in producing cellulosic ethanol.

Key words: King grass, Cutting intervals, Agronomic traits, Cellulosic ethanol

摘要： 为了提高‘热研4号’王草产量和乙醇生产能力，探究其最佳刈割间隔。本论文以‘热研4号’王草（Pennisetum purpureum×P.americanum cv.‘Reyan No.4’）为试验材料，研究了不同刈割间隔（2，3，4，6和12个月）对其农艺性状和纤维素乙醇生产的影响。结果显示，刈割间隔为6个月时，王草鲜草、干草和乙醇总产量显著高于其他刈割间隔（P<0.05），分别达到了328.29 t·hm^-2 FM，86.08 t·hm^-2 DM和15.18 t·hm^-2。刈割间隔越长，干物质含量、平均株高和茎粗越大，纤维素、半纤维素和木质素含量越高；平均分蘖数、灰分和绝对含水量及木质素移除率、酶解干基失重率、酶解率、乙醇浓度和乙醇转化率逐渐减少。综上所述，刈割间隔6个月的王草产量和乙醇产量最高，研究结果为王草生产纤维素乙醇的工业化应用提供参考。

关键词: 王草, 刈割间隔, 农艺性状, 纤维素乙醇