Mimosine content in the sap of leucaena species resistant and susceptible to Heteropsylla cubana Crawford

Abstract

Resistance of leucaena species and hybrids has been observed during an epidemic of leucaena psyllids (Heteropsylla cubana Crawford). Since leucaena contains mimosine which may confer resistance against the onset of these sap‐feeding insects, mimosine content in the sap of some leucaena accessions was compared. Mimosine concentration found in 7 resistant leucaena accessions with 5 replicates ranged between 3.64 to 12.16% (fresh weight) whilst 6 accessions in the susceptible group ranged between 5.38 to 12.53%. Mean value from the resistant accessions (6.82 + 2.05%) was lower than the susceptible leucaenas (8.60 ± 1.55%), but this difference was not significant (P = 0.01). Since higher mimosine level was not found among the resistant leucaenas, the basis of resistance is not due to the presence of this toxic compound.