高粱是最早使用“三系”配套生产杂交种子的作物 ,杂效种子纯度很大程度取决于制种亲本的纯度。因此 ,亲本防杂保纯 ,特别是不育系的纯度历来备受关注。经过多年的摸索和总结 ,我认为不育系 A的防杂保纯应重点抓好以下几个技术环节 :1　采取循环法进行原种生产由于不育系 A本身 Sorghum is the earliest crop that uses the “three lines” to produce hybrid seeds. The purity of the hybrid seeds depends largely on the purity of the parents. Therefore, the purity of the parental hybrids, especially the sterile lines, has always drawn much attention. After many years of groping and summarizing, I think that A sterile hybrid sterile should focus on the following aspects of technology: 1 to take the original production of the cycle method because of sterile line A itself