马铃薯和甘薯是无性繁殖作物,来自同一个单株的无性繁殖后代遗传基础相同,生长整齐一致,不存在分离现象,也不存在天然杂交引起退化。但栽培不当,不注意选留种薯,也会丧失原品种的优良特性,造成退化减产。其防杂保纯方法为:在留种地选择具有原品种典型性状的优良植株,作上标记,收获时分窝挖起,再根据结薯性、薯形、薯色等特点,淘汰杂、劣株,其余混收作种。 Potato and sweet potato are vegetatively propagated. The cloned offspring from the same plant have the same genetic basis, grow neatly, have no segregation phenomenon, and do not degenerate by natural hybridization. However, improper cultivation, do not pay attention to choose to stay seed, will also lose the fine characteristics of the original breed, resulting in reduced yield. The method for preventing and protecting impurities is as follows: selecting fine plants with the typical characters of the original varieties to stay on the ground, marking them and digging them up at the time of harvesting, and eliminating the miscellaneous and inferior plants according to the characteristics of tuber, potato and potato , The rest mixed for planting.