甜荞与野生近缘种杂交优势利用研究

为了提高甜荞单产水平，参照玉米杂种优势利用的技术路线，育成了甜荞‘矮B近交系’和‘野生自交系Ⅰ’、‘野生自交系Ⅱ’3个亲本系，配制成2个组合进行杂交制种及生产利用。对田间花朵雌蕊花粉载量、正交、反交杂种率进行了观察统计，其结果是：在盛花期午后2点采样，显微镜观察，每朵花三列柱头载花粉粒量15~55粒不等，平均23粒;正交（矮B系×野生系），杂交率60%~65%;反交（野生系×矮B系），杂交率30%;生产表现：在穴播生产田中，一穴中既有F₁植株，也有亲本植株，二者差别明显，F₁植株强壮、繁茂，产量是亲本3倍以上，表明F₁代杂种优势强，区试结果比亲本增产11.7%，比其他品种平均增产29%。本研究认为，野生近缘种是珍贵的种质资源;甜荞与野生近缘种杂种优势强，有望提高甜荞的单产水平;还存在花期不遇等原因，造成杂交率远未达到2/3的理论数值。

Utilization of Heterosis in Common Buckwheat and Its Wild Relatives

In order to increase the per unit area yield of common buckwheat (F. esculentum), according to the technical way of corn heterosis utilization, we have cultivated 3 parent lines: common buckwheat ‘dwarf B inbred line’, ‘wild relative self-bred line I’ and ‘wild relative self-bred line II’, and made two combinations for hybrid seed production and utilization. Through observing and counting the pistil pollen loads and the rate of positive hybridization and negative hybridization in field, it was found that: taking a sample at 2:00pm at full-bloom stage and observing with a microscope, pollen grains of 3 columns of stigma in each flower varied from 15 to 55 with the average of 23. The rate of the positive hybridization (dwarf B line × wild relative line) was 60%-65%; the rate of the negative hybridization (wild relative line × dwarf B line) was 30%. In production, the difference was significant between the F₁ plant and the parent plant in the same hole in bunch planting field. The F₁ plant was strong and lush, and its yield was more than 3 times that of the parent plant, indicating that the F₁ generation had strong heterosis. Its yield increase in the regional test was 11.7% compared with the parent plant and 29% compared with other varieties. The study proposed that wild relatives are a kind of precious germplasm resource, and the strong heterosis in common buckwheat and wild relatives could be used to improve the per unit area yield of common buckwheat. The study also found that the hybridization rate could not achieve 2/3 of the theoretical value because of the poor flower synchronization.