为了研究西北地区气候条件正常年份下芝麻的天然异交率，以单花芝麻品种汾黑芝3号和三花芝麻品种晋芝3号为材料，以显性基因控制的单花芝麻为异源花粉，采用单花和三花芝麻混合播种、在三花芝麻中间单株播种三花芝麻、与单花芝麻不同距离播种3种试验设计，测定三花天然异交后代群体中的单花性状比率。结果表明，混合播种异交率较高，最高达到18.71%，是所有试验设计中最高的。单株播种设计异交率低于混合播种，但高于除第2行外所有不同行距离播种；三花芝麻种植在距离单花芝麻较近，且周边单花芝麻较多的环境下异交率较高，以第2行的异交率最高，达到11.56%；距离单花芝麻远且周边单花芝麻较少的环境下异交率较低，第42～69行的异交率仅有0～0.25%。

In order to study the nature outcrossing rate of sesame(normal year) in the northwest region of China， using a single-flower sesame Fenheizhi 3 and three-flower sesame Jinzhi 3 as materials， using single-flower sesame as heterogenous pollen controlled by dominant gene， three-flower sesame controlled by the recessive gene， three-flower trait became into single-flower trait after natural outcrossing， determining the principle of sesame natural outcrossing rate by measuring the rate of single-flower traits among the progenies (F1) of three-flower sesame； using the experiment design， namely， conducting the mixed seeding with single-flower& three-flower sesame， sowing one three-flower sesame(the spacing is different from the single-flower sesame)among three-flower sesames. The result shows that outcrossing rate of the mixed seeding is the highest of all trials， up to 18.71%. The outcrossing rate of seeds per plant is lower than mixed seeding and higher than different distance sowing； Three-flower sesame outcrossing rate is higher， when they nearing and surrounding of single flower sesame. Ju 2 outcrossing rate is highest， up to 11.56%， On the contrary， the outcrossing rate is lower. ju 42～ju 69 only 0～0.25%.

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国家现代农业产业技术体系“汾阳综合试验站”专项基金(CARS-15)；山西省科技自主创新能力提升工程项目“山西油料作物种质资源创制与利用研究”2015zzcx-07；山西省科技攻关项目“山西与我国主产区芝麻种质资源遗传多样性比较”(20140311010-3)；山西省农业科学院十二五育种工程“优质、高产、抗病芝麻新品种选育”(11yzgc013)