776 



Colchicine 



in treated plants of Kibes that remained diploid, aiitl thus meiotic ir- 

 regularities induced by colchicine would seem to be carried along, 

 not entirely explainable by tetraploidy.^^-^ 



Colchicuni autitmnale L. is a sterile plant in middle and southern 

 Japan. Cytological analysis showed many irregularities during meiosis 

 of these plants. ^-^^ In contrast to these figures, the root tip mitoses 



Fig. 4.5^Above. Untreated pollen mother cells and pollen. Below. The large multi- 

 cellular pollen mother cells and abnormal pollen grains of Corthamus tinctorius. Flowers 

 treated in an early stage of development. (After Krythe) 



were regular. The pollen grains from CoJdiicum were irregular, being 

 monosporic, disporic, trisporic, or tetrasporic. Many grains carried 

 fragments. The inter|jretation made from these studies was to the 

 effect that colchicine contained in the cells of Colchicum created an 

 autotoxicosis that led to sterility in this species. 



Irregular pollen anil jjoor germination were not reported for a 

 European representative of C. autuninalc L. usetl for pollen tube 

 germination.*'" In this instance the pollen tubes that formed did not 

 show a resistance to the {presence of colchicine added to the medium. 

 There was no evidence that the pollen of Colchicum carried the drug 

 within the protoplasm of the grains since responses obtained were 

 reportedly the same as pollen tubes of other species not known to 

 produce colcliicine, e.g., Polygo)i(il urn'''''' and A)ifnrhiniiiii.^-' 



