Problems in breeding low-mimosine types in the genus Leucaena.
In L. leucocephala cv. Cunningham, the mimosine content varied little about the mean of 11.34%, either within or between years. Among lines of 4 other Leucaena species, low mimosine content was found solely in L. pulverulenta. In the F2, F3 and F4 from the cross L. pulverulenta × Cunningham, the ranges of mimosine content in vigorous trees were 4.6-14.4%, 4.5-15.8% and 5.8-11.6% respectively. By the F4, the number of vigorous trees with low mimosine content had fallen to 2. This change was associated with the tendency for the chromosome number to fall, in successive hybrid generations, towards that of Cunningham.