杨树与柳树属间杂交、杨树与榆树科间杂交均属远缘杂交,由于亲本间的遗传和生理机制差异,造成生殖隔离,产生杂交不育现象。但这种不育的程度是不相同的,通常是杂合子不能形成健全的种子,半途天亡。表现在种子未成熟前整个果穗脱落,很难获得杂种苗木。国内曾有过青、黑杨派与柳属杂交获得苗木的先例,但对难成功的白杨派与柳属杂交,杨榆杂交迄今未见报道。为了改良杨树的生长与适应性,我们于1978—1979年先后开展了银白杨×旱柳、银白杨×白榆、旱柳×钻天杨、旱柳×美洲黑杨的杨与柳、榆的远缘杂交试 Poplar and willow hybrids between poplar and elm cross hybrids are distant hybrids, due to differences in genetic and physiological mechanisms between parents, resulting in reproductive isolation, resulting in hybrid sterility. However, this degree of infertility is not the same, usually heterozygotes can not form a sound seed, half-dead. The performance of the whole ear before the immature seeds fall off, it is difficult to obtain hybrid seedlings. There was a precedent for crossbreeding between Populus nigra and Salix in China. However, there was no report on hybridization between Populus and Salix which is difficult to succeed. In order to improve the growth and adaptability of poplar, in 1978-1979, we carried out Poplar × Salix matsutake, Populus × white elm, Aconitum × Salix psammophila × Salix psammophila Edge hybrid test