甘薯采用有性杂交育种方法,在国内、外已选育出大量的优良品种,至今仍然是一个最有效的育种途径。进行杂交育种,首先要采取简易有效的办法制取大量的杂交种子。这是甘薯杂交育种中选种材料的基础,本环节工作的好坏,影响到整个育种工作进程。一、诱导开花甘薯在我国北部地区的自然条件下,一般品种不能开花,而在南方诸省如广东、福建等省甘薯开花较普遍,但也不是所有的品种均能开花。因此,进行甘薯有性杂交育种,首先要诱导甘薯开花。促进甘薯开花的方法种类繁多,如环状剥皮、倒割、嫁接、短日照处理、药剂处理等法均有一定效果。国内、外长期实践证明,以嫁接与短日照处理相结合的“重复法”效果优良。对于难开花的品种如夹沟大紫,即使用“重复法”也属无效,可采用笔者曾推荐过的“应用自然开花品种诱导甘薯开花”的方法(详见《农业科技通讯》1982年第12期)。(一)砧木准备目前采用的砧木有牵牛花、东 The method of sexual hybrid breeding is adopted in sweet potato, and a large number of fine varieties have been bred at home and abroad, which is still one of the most effective breeding methods. For hybrid breeding, we must first take a simple and effective way to produce a large number of hybrid seeds. This is the basis of sweet potato hybrid breeding materials, the quality of work in this session, affecting the entire breeding process. First, the induction of flowering sweet potatoes in northern China under natural conditions, the general species can not flowering, but in southern provinces such as Guangdong, Fujian and other provinces sweet potato flowering is more common, but not all varieties can flowering. Therefore, sexual hybrid sweet potato breeding, we must first induce sweet potato flowering. A wide range of ways to promote the flowering of sweet potato, such as ring peeling, cutting, grafting, short-day treatment, pharmaceutical treatment and other methods have some effect. Long-term domestic and foreign practice has proved that the “replicate method” combining grafting with short-day treatment has a good effect. For difficult to flowering varieties such as Jiaogou purple, even the use of “duplicate method” is invalid, can I have recommended “the use of natural flowering varieties to induce sweet potato blossom” method (see “Agricultural Science and Technology Newsletter” in 1982 12 issues). (A) rootstock preparation Currently used rootstock has morning glory, east