自然单倍体川桑的发现与研究

THE DISCOVEKY AND STUDY ON A NATURAL HAPLOID MORUS NOT ABILIS SCHNEID

经对川桑（Ｍ．ｎｏｔａｂｉｌｉｓＳ．）作体细胞染色体倍数性鉴定，发现体细胞染色体数为１４条，是通常二倍体桑的一半，初步认为是自然单倍体桑。对川桑的组织构造、同工酶谱等作了调查，并与二倍体纳溪桑、小官桑作了比较，经对川桑和多个其它桑种初步作ＲＡＰＤ研究，川桑与其它桑种亲缘关系都很远，推测它可能是桑属中分化最早的种。

Bymeans ofChromosome ploidy identification,we have discovered that M.notabilis Scneid has 14 chron1osomes in one somEitic cell,a half of the normaldiploidy mulberries.Thus it is preliminarily regarded as a natural haploid.Its morphological structures and bands of isozymes were investigated and compared with two diploidy mulberries,i.e.Naxi Sang and Xiaoguan Sang,Additionally,RAPD of M.notabilis S.and other mulber-ry species were studied.The results showed that the consanguinity relationship between M. notabilis S.and all other mulberry species is very far,implying that M. notabilis S.is possibly a species that differentiated the earliest in the genus of Morus.