African Journal of Biotechnology Vol. 6 (21), pp. 2458-2466, 5 November 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Comparative d2/d3 LSU–rDNA sequence study of some Iranian Pratylenchus loosi populations

Behzad Hajieghrari^1*, Mousa Torabi-Giglou¹ and Lieven Waeyenberge²

¹Department of Plant Production, Moghan Junior College of Agriculture, University of Mohaghegh – Ardabili, Ardabil, Iran.

²Agricultural Research Centre, Burg. Van Gansberghelaan96, 9820 Merelbeke, Belgium.

*Corresponding author. E-mail: bhajieghrari@uma.ac.ir. Tel : +989143186861. Fax : +984527463417

Abbreviations: LSU, Large subunit; SSU, Small subunit; ITS, Internal transcribed spacer; UC, Uncorrected distance; JC, Jukes-Cantor; K Kimura distance; JNG, Jin-Neigamma distance; NJ, Neighbor-joining; UPGMA, Unweighted Pair Group Method with Arithmetic Mean.

Accepted 16 March, 2007

The D₂/D₃ LSU rDNA expansion segment of 13 isolates attaching tea shrubs roots in tea gardens that verified by morphological and morphometrical studies as Pratylenchus loosi Loof, 1960 from Guilan province, North of Iran, were amplified and sequenced. Amplification of the D₂/D₃ LSU rDNA expansion segments yielded one fragment at over all sequenced isolates as 787 bp in size. The DNA sequences were aligned using Clustral X1.81 together and with three sequences of similar region of P. loosi isolates available in Genbank database (Isolate T from Serilanka and Isolates N1 and N2 from Florida, USA). Also the genetic distance between sequences data were calculated through four methods as following; Uncorrected distance (UC), Jukes-Cantor (JC) Kimura distance (K) and Jin-Neigamma distance (JNG). For generating phyllogenetic trees both Neighbor-joining (NJ) and Unweighted Pair Group Method with Arithmetic Mean (UPGMA) were used. The results indicated that very short genetic distance exist among the Iranian isolates and between the Iranian isolates and isolate T from Serilanka whereas the Iranian isolates and isolate T were genetically distinct from isolates N₁ and N₂. The phyllogenetic analyses revealed relationship not only among Iranian isolates but also between Iranian isolates and isolate T. 

Key words: Tea, Pratylenchus loosi, D₂/D₃ LSU rDNA, sequencing, Iran