无根藤吸器发育过程的解剖及组织化学研究

ANATOMICAL AND HISTOCHEMICAL STUDIES OF HAUSTRIAL DEVELOPMENT OF CASSYTHA FILIFORMIS L.

对樟科寄生植物无根藤(Cassytha filiformis L.)吸器侵染杞柳(Salix parpurea L.)的过程进行了解剖研究,并对吸器发育过程的组织化学进行了观察。吸器的发育过程包括:极性的发生、垫状吸盘的形成,吸器原基的发生、生长、穿透皮层及侵入寄主。吸器中分化出管状分子,始于吸器基部。未观察到筛管的分化。组织化学观察发现:正常茎的皮层中含有淀粉粒;缠绕寄主后,近寄主端的皮层细胞中淀粉粒逐渐增多;吸盘形成后,中央一团细胞大量积累淀粉,预示吸器即将形成;吸器分生组织细胞团无淀粉积累,但含有丰富的蛋白质。蛋白质的分布和积累动态与淀粉粒的相反。对吸器结构、寄生机制以及淀粉和蛋白质的变化动态进行了讨论。

This paper deals with the haustorium development of parasitic plant (Cassytha filiformis L.) parasitized on purple willow (Salix purpurea L.).The polarity occurred in the portion near the host;and the cushion-shaped haustorial plate formed,and then the haustorial primordium initiated in the cortex.Finally,the haustoria reached the cortex of pith of the host, penetrating through its own cortex and epidermis.Tracheary elements were differentiated from the base of the haustoria and the sieve elements were not observed in the haustoria.Histochemical studies revealed that there were starch grains in normal stem cortex.The starch grains were increased in the portion near the axis after twisting on host.After the haustorial plate was formed,the starch grains were richly accumulated in the central group of cells,which were followed by the haustorial development;The starch disappeared in the meristem,in which protein stained deeply;The dynamic change of protein turned out to be contrary to the tendency of starch accumulation.The structure and parasitic mechanism and the dynamic change of starch and protein are discussed.