mac key: induced mutation in crop improvement 363 



Judging from other crops, the genetic control of photoperiodism is 

 likely to be rather simple. Thus, it would seem worth trying this experi- 

 ment in cotton. 



Patterson: The pleiotropic effects of the erectoides mutations on straw 

 strength are of special value for use in cross breeding for straw strength 

 in barley. Selection for the erectoid type results in selection for straw 

 strength, a character usually difficult to obtain. 



MacKey: I think that the Swedish barley breeding along conventional 

 lines, with results like Rika, Herta, and Ingrid, proves that straw strength 

 can be achieved also in other ways than through inducing erectoides 

 mutations. The important thing is that the two ways are different with 

 possibilities for transgression when combined. 



Konzak: Since terminology in this new field has an important bearing 

 on the understanding of methods and treatments, I wish to recom- 

 mend that we utilize a standard designation system for describing the 

 generation following mutagen treatment as the M x , M 2 , etc., designa- 

 tion system. In addition, I would suggest that we consider an idea 

 expressed to me by Doctor Wellensiek recently — this is to use a super- 

 script to denote the mutagen and the treatment used, as M^ms 4hr02 

 for the first generation following ethyl methane sulfonate treatment 

 or to designate the first generation from a 15 Kr gamma radiation treat- 

 ment as Mj 15 Kr G . 



In a case where repeated treatments are studied, the designation might 

 be modified thus: 



M x i_ 2 first generation, x = kind of treatment and dose, if desired 



second cycle M = mutagen treatment 



M x 2 _2 second generation, 1 = 1st generation 



second cycle 2 = 2nd generation treatment 



MacKey: I think it is highly desirable to agree upon a standard desig- 

 nation system, but the abbreviations should not be so exclusively used 

 that people outside our group will not be able to understand our pub- 

 lications. 



Konzak: It should be recorded here for the benefit of those interested 

 that we put into use two additional microanalyses techniques in our 

 mutation and plant breeding programs with wheat. 



One of these involves a rapid microtest for protein analyses. The 

 equipment used is an Udy protein analyzer which, using a dye bind- 



