52 



FERTILIZATION 

 TABLE ID 



that the different flavonol glycosides are found. These observa- 

 tions, if they are correct, are important in that, for the first time, 

 self-sterility and the specificity of fertihzation can be related to 



rhamnose 



HO. 



Rutinose 

 Rutin (long stamens) 



O. 



Qit Q rhamnose 



Quercitrin (short stamens) 



specific chemicals occurring in the sexual organs. The produc- 

 tion of quercetin, the aglucone of rutin or quercitrin, following 

 the interaction of the 'right' sort of pollen with the 'right' sort of 

 stigma, is achieved by hydrolysing enzymes, presumably acting in 

 a similar way to rhamnodiastase, which is obtained from Chinese 

 buckthorn. These hydrolysing enzymes are said to be located in a 

 thin layer of cells covering the top of the stigma. The two types of 

 enzyme are specific, the one in 'short' stigmata hydrolysing quer- 

 citrin to quercetin, while that in 'long' stigmata hydrolyses rutin 

 to quercetin. 



Moewus' biological identification of quercetin has been men- 

 tioned. Three clones of the alga Chlainydomonas eugametos Moewus 

 are used: Clone i, which is obtained by subjecting female cells to 

 temperature shock, consists of mutants which, unlike the original 

 organisms, do not produce wo-rhamnetin. The inability of these 



