Differences in thermal tolerance and the expression of Hsp64.9 between geographical populations of Liriomyza trifolii
Author of the article:CHANG Ya-Wen1 ZHONG Ling1 YAN Yu-Qing1 ZHAO Jing-Ya1 GONG Wei-Rong1, 2 DU Yu-Zhou1, 3
Author's Workplace：1. College of Plant Protection & Institute of Applied Entomology, Yangzhou University; 2. Plant Protection and Quarantine Station of Jiangsu Province; 3. Joint Laboratory of International Cooperation in Agriculture and Agricultural Products Safety, Ministry of Education
Key Words：Liriomyza trifolii; geographical population; high temperature; heat tolerance; Hsp64.9
Abstract：
[Aim] To investigate differences in the
high temperature tolerance and expression of the heat shock protein gene Hsp64.9 between different geographical
populations of Liriomyza trifolii,
and investigate the mechanism of temperature adaptation in this species. [Methods] Adults and pupae from the Hainan and Jiangsu
populations of L. trifolii were
exposed to different high temperatures for different periods. Differences in
heat tolerance between these geographical populations were then assessed by
comparing adult survival rates and pupal emergence rates. The expression of Hsp64.9 in adults and pupae from each
population were also measured and compared. [Results] The survival rate of both the Jiangsu and
Hainan populations began to decrease significantly at 42 and 43 ℃ (Jiangsu population: F6,14=296.459, P<0.001; Hainan population: F6,14=255.810, P<0.001), respectively, but the
survival rate of the Hainan population was significantly higher than that of
the Jiangsu population (P<0.05).
There was no significant difference in survival rate between the two
populations following exposure to 39 ℃ for
less than 4 h, or exposure to 42 or 45 ℃ for
less than 1 h (P>0.05). The
survival rate of adults from the Hainan population was significantly higher
than that of those from the Jiangsu population following longer durations of
exposure to high temperatures (P<0.05).
The emergence rate of the Hainan population was also significantly higher than
that of Jiangsu population after exposure to 42, 44
and 46 ℃ for 1 h (42 ℃: t=﹣4.234, P=0.013;
44 ℃: t=﹣5.567, P=0.005;
46 ℃: t=﹣4.000, P=0.016),
but duration of exposure to high temperature had no significant effect on the
emergence rate of pupae from these populations (P>0.05). The expression of Hsp64.9 in adults and pupae from the Hainan population was significantly higher
than that of those from the Jiangsu population under all treatment combinations
(P<0.05). [Conclusion] The Hainan population of L. trifolii is significantly more tolerant to high temperatures
than the Jiangsu population, an adaptation that, at least in part, could be due
to greater expression of the Hsp64.9 gene.