陇草2号是由甘肃省农业科学院作物研究所以不育系B2A为母本、苏丹草恢复系F11为父本杂交选育的低氢氰酸饲草高粱新品种。2016 — 2017年参加甘肃省饲用高粱区域试验，2 a 10点(次)折合平均鲜草产量95 059.65 kg/hm2，较对照品种增产6.7%，2017年参加生产试验，鲜草平均产量94 359.60 kg/hm2，较对照增产5.8%。生育期132 d，株高317.1 cm，茎粗1.3 cm，平均分蘖数1.86个。抽穗期茎叶干物质含量184.0 g/kg，含粗蛋白110 g/kg、粗灰分116 g/kg、木质素52.6 g/kg、中性洗涤纤维(NDF)610 g/kg、酸性洗涤纤维(ADF)347 g/kg。茎中氢氰酸含量1.23 mg/kg，叶中氢氰酸含量2.34 mg/kg。高抗丝黑穗病。

Longcao 2 is a new forage sorghum cultivar， with parents combination of sterile line B2A and Sudangrass restorer line F11， bred by Institute of Crops， Gansu Academy of Agricultural Sciences. In 2016 — 2017， the average yield of green forage in 2 a 10 sites (times) was 95 059.65 kg/hm2， 6.7% higher than the control in the Gansu Forage Sorghum Regional Test. In 2017， the average yield of green forage was 94 359.60 kg/hm2， 5.8% higher than the control in the Production Test. Its growth period is 132 d， plant height is 317 cm， main stem diameter is 1.3 cm and average tiller number is 1.86. In heading period， the dry matter percentage， crude protein， crude ash， lignin， NDF and ADF of stalk and leaf are 184.0 g/kg， 110 g/kg， 116 g/kg， 52.6 g/kg， 610 g/kg and 347 g/kg， respectively. In addition， the HCN content was 1.23 mg/kg in stalk and 2.34 mg/kg in leaf. It is high resistant to sorghum head smut.

S544

甘肃省科技重大专项计划项目(1502NKDA005-1-1)部分内容；甘肃省农业科学院科技支撑计划项目(2017GAAS44)部分内容；甘肃省农业科学院院地科技合作项目(2017GAAS59)部分内容；兰州市科技支撑计划(2014-2-19)部分内容；甘肃省农业科学院中青年基金项目(2015GAAS33)部分内容。