Identification and analysis of volatiles released by different cowpea, Vigna unguiculata, and damage levels to this crop caused by thrips
英文摘要:
[Aim] To
identify volatile components of different cowpea Vigna sinensis (L.), assess and compare the degree of
thrip damage on different cultivars, and investigate potential ecological
control strategies for thrips. [Methods] Volatiles of four cowpea cultivars (Dama,
Rouma, Tianrui②,
Changma) were identified using SPME-GC-MS. The degree of thrip damage on each
of the four cultivars was assessed in a 5-point field investigation. [Results] The Rouma cultivar had the lowest number of
thrips, and the Dama cultivar the highest. The Changma cultivar had the
greatest species diversity of thrips. The most serious plant damage was caused
by Megalurothrips usitatus, followed
by Frankliniella intonsa.
Twenty-three kinds of volatiles were identified in the leaves (14 in Dama, 17
in Rouma, 16 in Tianrui②, 13
in Changma) and flowers (11 in Dama, 10 in Rouma, 12 in Tianrui②, 17
in Changma) of the four cultivars. Eight compounds in leaves and flowers were
shared by all four cultivars. Benzaldehyde and β-ionone content was relatively
high and stable in the leaves of the Dama, Rouma and Changma varieties,
significantly higher than was found in the Tianrui② variety (P<0.000 1). Among the
volatiles identified, fatty acid derivatives were the most abundant, followed
by benzene compounds. Fatty acid derivatives were the most abundant volatiles
of the Dama, Rouma, Tianrui② cultivars, followed by terpenes, which were the most abundant volatiles of the
Changma cultivar. [Conclusion] The dominant thrip species and primary
volatile compounds differed among four cowpea cultivars. Common volatiles, such
as benzaldehyde and β-ionone, were common in leaves, whereas linalool and
methyl palmitate were more common in flowers. Several cultivar-specific
volatiles were identified, such as cis-3-hexenyl acetate, which was
unique to leaves of the Tianrui② cultivar, hexadecanal, which was unique to
leaves of the Dama cultivar, 1-octene-3-ol, which was unique to the flowers of
the Dama cultivar, acetophenone, which was unique to the flowers of the Changma
cultivar, stearaldehyde, which was unique to flowers of the Rouma cultivar, and
phytone, which was unique to flowers of the Tianrui② cultivar.
Combined with the level of damage found on each cultivar and information in the
existing literature, it can be inferred that benzaldehyde, linalool, cis-3-hexenyl
acetate, β-ionone, 1-octene-3-ol, acetophenone, benzenepropanol,
3-phenyl-2-propenal, 2-amino-methyl ester benzoic acid and 2-hydroxy-methyl
ester benzoic acid, are potentially important compounds that influence the
relative preference of thrips for these cultivars.