有关马铃薯正、反交各种差异的证据日益增多。已证明大量的质核互作造成马铃薯雄花育性在正、反交上的差异(Grun等,1962、1966)。栽培薯与富利亚薯的正、反交引起了种子休眠上的不同(Simmonds,1964)。Cubillos(1974)观察到栽培薯与安第斯薯正、反交的产量差异高达33％。最近有人指出富利亚薯与卡考恩斯薯(S.chacoense)在开花 There is increasing evidence of various differences between positive and negative resistance in potatoes. A large number of nucleus interactions have been shown to cause positive and negative crossings in potato male fertility (Grun et al., 1962, 1966). Positive and negative crosses between cultivated potato and Ficus yam caused differences in seed dormancy (Simmonds, 1964). Cubillos (1974) observed a 33% difference between positive and negative crosses between cultivated potato and Andean potato. Recently, it has been pointed out that the sweet potatoes and S. chacoense are blooming