新疆野生樱桃李扦插繁殖不定根的形成及生长调节剂对扦插成活率的影响

Formation of adventitious roots and effect of plant growth regulator on the survival rate of Xinjiang wild Myrobalan plum cuttings

利用扦插繁殖研究新疆野生樱桃李绿枝扦插的生根机制及不同生长调节剂处理对硬枝扦插生根的影响。结果显示:扦插前,新疆野生樱桃李的茎中没有根原始体细胞,属于诱导型生根。其生根形式主要是愈伤组织生根和皮部生根。绿枝扦插生根包括切口处愈伤组织的形成、根原基的形成和不定根的发育3个过程。愈伤组织由形成层细胞分裂形成,并对不定根的形成起诱导和促进作用;不定根原基起源于形成层,发生部位是形成层与韧皮部射线相交叉的区域。外源生长素类生长调节剂能够促进硬枝扦插的成活率,其中IBA+NAA(1∶1)2 000mg/L蘸根处理插条成活率为30.2%,并且蘸根处理时间以20s为宜。生长调节剂处理后平均根数、平均根长和平均根径变化不大,但平均生根率与成活率的关系密切,说明生长调节剂主要诱导不定根的形成,对根后期发育影响不大。

This paper concerned with the mechanism of the initiation and development of adventitious roots and investigate the effect of plant hormones on the survival rate and the development of those roots.The results showed that none primordium cells existed in stems,which belonged to inducible rooting.The adventitious roots originated from the callus and the cortex.The initiation and growth of adventitious roots in greenwood cutting included three phases of the formation of callus,the initiation of root primordium and the development of adventitious roots.The callus originated from the cell division of vascular cambium,which induced and promoted the formation of adventitious roots.The adventitious roots were developed from the cambium located at the vascular bundle of the phloem.Plant growth regulator could promote the survival rate of hardwood cuttings soaked in IBA+NAA(1∶1)2 000mg/L for 20 s.The survival rate was up to 30.2%.The variation of average root number,root length and root diameter were not obvious after plant hormones treatment.But the average rooting rate was closely related to the survival rate,which suggested that plant hormones could promote the initiation of the adventitious roots and had little effect on root development after the formation.