Abstract
This research focuses on the study of genetic differences among eight greenbug biotypes revealed by AFLP analyses and isolation of mega-base DNA for BAC library construction. Genetic relationship among greenbug biotypes is an old, but interesting topic. Understanding of genetic differences could help in elucidating roles of greenbug-host interaction in plant resistance and assist in development of new resistant cultivars. In addition, constructing a BAC library for greenbug will provide a powerful tool for molecular dissection of counter-defense mechanisms. Genetic relationship analyses based on 3341 AFLP markers showed that biotypes damaging sorghum cultivars and hybrids (biotypes C, E, I and K) shared higher genetic similarity as compared to non-sorghum biotypes. This result may provide a way of using AFLP fingerprinting for prediction of potential sorghum greenbugs and may lead to more effective and longer lasting plant resistance. An efficient protocol suitable for mega-base DNA isolation from greenbug (Schizaphis graminum) (Rondani) was developed. The resulting high quality mega-base DNA from greenbug was used to construct a BAC library. The average insert size of the library was estimated to be 96kb, with an average frequency of false positive clones of 19%.
Li, Haiwen (2002). AFLP-based study of genetic difference and mega-base DNA isolation for BAC library construction from greenbug Schizaphis graminum (Rondani) (Homoptera:Aphididae). Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2002 -THESIS -L48.