Abstract:

To increase the yield of cultivated common buckwheat, the traditional common buckwheat varieties with high yield were improved by using the superior related wild resources of buckwheat. According to the observation and statistics, the external morphology of wild relatives and cultivated common buckwheat were identical, while the floral structures were different. Among them, the stems of wild relatives were hard and the growth period was moderate, and wild relatives of buckwheat also had the advantages of equal length of pistils and stamens, self-fertility (the seed setting rate was as high as 41.9%-62.6%, and the bagging self-crossing seed setting rate was 21.2%) and fertility after hybridizing with common buckwheat. However, there were also some disadvantages in the wild relatives, such as strong seed shattering and easy panicle germination. The common buckwheat had extremely long stamens (cross-pollination) and the setting rate of crossing and bagging self-crossing (indicating self-crossing sterility) were only 12.9% and 0.9%, respectively. F₁ (wild relatives used as the female parent and common buckwheat as the male parent) showed the genetic markers of male parent’s red wings, which indicated that it was a hybrid definitely. The yield results showed that the average yield per plant of female parent was 6.3 gram and the thousand-grain weight was 20.4 g, while the average yield of F₁ was 23.4 g per plant and the thousand-grain weight was 27.1 g. The yield of F₁ was 3.7 times that of the female parent plant, showing significant heterosis in F₁. The results of experimentⅡshowed that F₁ had the middle color of parental corolla, which was incomplete dominant. Besides, the plant height was relatively low and its pistils and stamens in floral structure were with equal length. In F₂ generation, five dark red plants, the same color of corolla as their male parent, were isolated; among which, 2 plants had the same flower structure as their female parent (the equal length of pistils and stamens). The seed setting rate of these five plants was 47%. Another three plants were heterogony, which was the same as their male parent, and the seed setting rate was less than 10%. The study indicates that the wild relatives of buckwheat have cross compatibility with common buckwheat, and they possess strong heterosis, self-fertility and high seed setting rate, so they could be considered to be a quite precious germplasm resource to improve the low-yield situation of common buckwheat.

Key words: buckwheat, wild relatives, self-pollination, high seed setting rate, cross compatibility, hybridization