CAROTENOIDS 



produced at the expense of lycopene for the total carotenoid concen- 

 tration of this fruit is normal. Typical varietal differences are recorded 

 in Table 11 for a fruit (mango) and in Table 12 a root (carrot) ; for 

 similar data for peas {see p. 44). Further details on other species will be 

 found in the Appendix (see p. 294). 



Table 12. — Carotene Content of different varieties of Carrots* 



■From Harper, R. H. & Zscheile, F. P. (1945). Food Res., 10, 84. 

 For further values see Appendix I (p. 290). 



PATHOLOGY 



No systematic study of the relationship between carotenoid production 

 and pathological conditions of plants has been reported, but a few 

 isolated statements are available. Sullivan and Chilton^^^ found that 

 rust-infected white clover leaves are lower in carotene than are rust-free 

 leaves by as much as 30 per cent. Leaf hopper (Empoasca fabae) 

 damage can reduce the carotene content of lucerne by more than one 

 half. 1 6 4, 1 5 6 According to Ham and Tysdal, ^ ^ ' the hoppers attack 

 leaves showing the least yellowing, that is, those with the highest 

 carotene content. Hamner^^' reaches the rather broad conclusion 

 that any condition producing chlorosis of leaves will decrease their 

 carotene content. 



It is claimed that yellowing of box (Buxus sempervivens) leaves owing 



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