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United States Department of Agriculture

Agricultural Research Service

Title: Aphid Resistance and Leaf Surface Chemistry of Sugar Ester Producing Tobaccos

Authors
item Johnson, A - CLEMSON UNIVERSITY
item Sisson, V - NORTH CAROLINA STATE UNIV
item Snook, M. - UNIVERSITY OF GEORGIA
item Fortnum, B. - CLEMSON UNIVERSITY
item Jackson, David

Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 5, 2001
Publication Date: April 1, 2002
Citation: Johnson, A.W., Sisson, V.A., Snook, M.E., Fortnum, B.A., Jackson, D.M. 2002. Aphid resistance and leaf surface chemistry of sugar ester producing tobaccos. J. Entomol. Sci. 37:154-165.

Interpretive Summary: Tobacco aphids are an important insect pest of commercial tobacco, however some tobacco types are resistant to aphids due to chemicals, such as sugar esters, that are exuded from their leaves. High sugar ester producing tobacco lines were evaluated for aphid resistance and surface chemicals in 1993-1995. There was a significant negative relationship between levels of sugar esters and aphid infestation ratings. A similar negative relationshi existed between another leaf-surface chemical, mono-ols, and aphid infestations. None of the other surface chemicals were statistically correlated with aphid resistance. However, not all tobacco entries with high levels of sugar esters, such as TI 1568, were resistant. This would suggest that there may be different types of sugar esters present in these tobaccos, and total sugar ester levels alone can not be used to predict aphid resistance. Also, some tobacco lines, like TI 1674 and TI 59 with lower sugar ester levels, were resistant in this study because of high mono-ol levels. The ten tobacco entries with the highest levels of sugar esters in this study were TI 698, TI 675, TI 704, TI 998, TI 193, JA 389, TI 722R, TI 1092, TI 711, and TI 1007. All of these lines exhibited high levels of aphid resistance, but some also had low-to-moderate levels of mono-ols that may have elevated the aphid resistance level. A number of these tobaccos could be used for production of natural sugar ester biorationals or used in a breeding program for development of aphid resistant cultivars.

Technical Abstract: High sugar ester producing tobacco lines were evaluated for aphid resistance and surface chemicals. The cembranoid and labdanoid diterpenes, docosanol, and sugar esters were quantified using high pressure liquid chromatography. Regression analysis of aphid infestation rating with leaf surface chemistry was statistically significant and showed that surface chemicals were important in explaining the observed variation in the aphid infestation ratings. A significant negative correlation was found between aphid ratings and sugar ester levels. Alpha and beta mono-ols (alpha and beta-4,8,13-duvatriene-1-ols) were also significantly correlated with aphid infestations in this study. None of the other surface chemicals were statistically correlated with aphid resistance. Although high sugar ester levels were correlated with aphid resistance, not all tobacco entries with high levels of sugar esters, such as TI 1568, were resistant. This would suggest that there may be different types of sugar esters present in these tobaccos, and total sugar ester levels alone can not be used to predict aphid resistance. Also, some tobacco lines, like TI 1674 and TI 59 with lower sugar ester levels, were resistant in this study because of high mono-ol levels. The ten tobacco entries with the highest levels of sugar esters in this study were TI 698, TI 675, TI 704, TI 998, TI 193, JA 389, TI 722R, TI 1092, TI 711, and TI 1007. All of these lines exhibited high levels of aphid resistance, but some also had low-to-moderate levels of mono-ols that may have elevated the aphid resistance level. A number of these tobaccos could be used for production of natural sugar ester biorationals or used in a breeding program for development of aphid resistant cultivars.

Last Modified: 9/2/2014
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