答:无籽西瓜制种时不需要每年都用化学药剂(一般用秋水仙素)来处理二倍体西瓜获得四倍体西瓜。在通过人工诱变获得四倍体种子后,根据四倍体西瓜有较高育性的特点,可以用它来继续播种繁殖,以获得四倍体种子,但一定要注意四倍体西瓜的保纯。其方法如下:少量栽培时可用人工套袋进行自交,对次日可能开 A: seedless watermelon seed production does not require every year with chemicals (usually colchicine) to deal with diploid watermelon tetraploid watermelon. Tetraploid seeds obtained by artificial mutagenesis, according to tetraploid watermelon has a higher fertility characteristics, you can use it to continue sowing and breeding to obtain tetraploid seeds, but we must pay attention to tetraploid watermelon Paul pure. The method is as follows: a small amount of artificial bagging can be used for selfing, the next day may open