HS-SPME analysis of citrus blossoms

HS-SPME analysis of citrus blossoms revealed a diverse volatile
distribution between major citrus cultivars. Linalool, b-myrcene, amyrcene,
limonene, (E)-ocimene, methyl anthranilate and indole
were the major volatiles produced by citrus blossoms. The distribution
of citrus cultivar Eigenvector scores from PCA revealed
three widely separated, tight clusters consisting of pummelo, mandarins
and lemons–limes. Since PCA is a non-supervised learning
technique used to determine structure in data set, this widely separated
clustering indicated that these cultivars were the most different
amongst all the cultivars evaluated. This clustering of citrus
cultivars based on blossom volatile composition was found in good
agreement with recent phylogenic studies (Nicolosi et al., 2000).
Therefore, it appears that it may be possible to use blossom volatile
composition as a tool for classification in addition to other taxonomical/
phylogenetic methods. The biological significance of blossom
volatile production could be explained specifically for
pummelo blossoms. Survival of this citrus cultivar requires crosspollination
whereas the others in this study are self-pollinating.
Therefore, the pummelo’s production of the highest levels of total
blossom volatiles as well as highest levels of honeybee attracting
volatiles such as linalool and 1-hexanol serves to help perpetuate
the species.