Madina Rasulova Molecular Systematics of Nematodes Page 1

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Restriction patterns of the Belonolaimus ITS1 region done by Cherry et al. (1997) illustrate that this region differs from one individual nematode to another. For example, Hinc II digestion of ITS1 from the Arkansas population (Figure 3, A) displayed three fragments between 300 and 400 bp, while in Kansas population there are two bands in one case and one band in two cases (Figure 3, B). The populations from other areas displayed only one fragment in the same range. Despite of very similar morphologies the studied isolates gave a unique restriction profile. This may be explained by evolutionary divergence that has occurred in allopatry, since Belonolaimus populations live in sandy soils that are often geographically isolated. ITS1 heterogeneity within individuals has been observed in Meloidogyne (Zijlstra et al., 1995) because of mitotically parthenogenetic polyploidy, but the structural nature of this heterogeneity in Belonolaimus is unclear since Belonolaimus is a taxon of diploid, amphimictic species (Cherry et al., 1997). According to Gozel et al. (2006), the phylogeny inferred from the DNA sequences of the sting nematode populations indeed support the likelihood that B. longicaudatus and B. euthychilus are species complexes (Adams, 1998). Robbins and Hirschmann (1974) propose that populations of B. longicaudatus Figure 3. A) Hinc II digestion patterns of representative Belonolaimus longicaudatus from different isolates. KS = Kansas, AR = Arkansas, CA = California, SC = South Carolina, FL = Florida. Figure 3. B) Nucleotide base pair fragment length patterns of various digested Belonolaimus isolates. Madina Rasulova Molecular Systematics of Nematodes Page 14
outside of Florida are reproductively isolated. Besides, several studies report that B. longicaudatus populations differ within each other showing various host range and wide morphometric variations (Abu- Gharbieh and Perry, 1970; Robbins and Hirschmann, 1974; Duncan et al., 1996). All of the above mentioned prove, that indeed B. longicaudatus populations are very complex and require additional studies of reproductive compatibility, behavior and morphology of specific genotypes (Gozel et al., 2006) in order to be able to distinguish it from other species as well as have the complete picture of phylogeny of this genus. CONCLUSION Polymorphism within populations of the same species makes it an ideal tool for application in many aspects such as phylogeny in order to distinguish individuals among populations (in this case B.longicaudatus). These genetic differences, on one hand serve as convenient diagnostic markers; on the other hand proves that the genus Belonolaimus is far more complex than currently recognized. ACKNOWLEDGEMENTS Many thanks to Professor Sergei A. Subbotin for providing us with necessary skills, so we are able to work with a number of phylogeny programs ourselves without any assistance. I believe that this acquired knowledge would be valuable in our further research activities as well as future career. REFERENCES Abu-Gharbieh, W. L., and V. G. Perry. (1970) Host differences among Florida population of Belonolaimus longicaudatus. Journal of Nematology 2:209-216. Madina Rasulova Molecular Systematics of Nematodes Page 15
Page 1 and 2: Madina Rasulova Molecular Systemati
Page 3 and 4: very sandy soils and are active whe
Page 5 and 6: level analyses because of appreciab
Page 7 and 8: constraining, rooting and testing h
Page 9 and 10: 2 DQ672373 Belonolaimus longicaudat
Page 11 and 12: of other species of the same genus
Page 13: ermudagrass (Poteet) isolates were
Page 17 and 18: Han H-R., Jeyaprakash A., Weingarth
Page 19 and 20: APPENDIX Figure 4. Results of BLAST
Page 21 and 22: Figure 7. NJ, MP and ML trees with
Page 23 and 24: Figure 9. Phylogenetic tree MP. Max
Page 25: Figure 11. Phylogenetic tree MrB. B

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