BIOCHEMICAL STUDIES OF HYBRIDS 



309 



Jack pine contains a mixture of dextro- and levo-pinene with 

 an admixture of levo-;8-pinene. 



CH3 



HoC 



CH 



CHs 



HoC 



H.,C 



a-pmene 



^-pinene 



Optical rotation varies somewhat, apparently because of vary- 

 ing proportions of the three compounds. Although some jack pine 

 samples are levorotatory, those from Alberta were all dextrorotatory. 



Analysis of the turpentine from an artificial Fi hybrid from 

 California indicated 75 to 78 per cent pinenes and 20 to 22 per cent 

 phellandrene. The conclusion, then, was that the turpentine of the 

 hybrid was of a mixed nature. From the natural hybrid swarm Mirov 

 collected turpentine from seventy-three individuals, including trees of 

 an intermediate character, and those typical of the parental species. 

 Additional samples of lodgepole and jack pine were included, presum- 

 ably from regions more remote from the hybrid swarm. Analyses of 

 the turpentine from individual trees showed extensive variation. 



Estimation of the per cent of phellandrene in hybrids ranged 

 from about 13 per cent in the artificial hybrid (data from one figure 

 of the text give a figure of 20 to 22 per cent) to slightly above 40 per 

 cent among certain individuals of the natural hybrid groups. Pure 

 lodgepole gave 73 per cent phellandrene and only one morphological 

 "hybrid" gave little or no phellandrene. A more comprehensive 

 presentation of the biochemical and morphological data is given in 

 the table below, adapted from Mirov (1956). 



