Full Length ArticleDevelopment and application of EST-SSR to evaluate the genetic diversity of Southeast Asian rice planthoppers

- A total of 97 and 25 pairs of EST-SSR markers were developed for BPH and WBPH, respectively.
- The developed EST-SSRs could detect the genetic diversity of the planthoppers population.
- Genetic diversity analysis was beneficial for rice planthoppers control strategy.

A total of 320 ESTs (Expressed Sequence Tags, 12.8%) of rice planthoppers were identified to carry SSR (Simple Sequence Repeat) motifs from 2491 ESTs downloaded from public database, and 397 pairs of brown planthopper (BPH; Nilaparvata lugens Stål) and 25 pairs of white-backed planthopper (WBPH; Sogatella furcifera) (Hemiptera: Delphacidae) EST-SSR were detected based on the motifs. The dinucleotide repeat was the dominant type with repeat motif AG/GA/TC/CT; and the trinucleotide repeat was the style of AAG/AGA/GAA/TTC/TCT/CTT among the BPH repeat motifs. A total of 20 EST-SSRs (16 developed in the present study and four from previous studies) were applied to survey the genetic diversity of the 15 rice planthoppers. Consequently, 18 pairs of primer amplifies clear, dominant and polymorphic gel bands among the collected planthoppers population; one EST-SSR amplified a single gel band; and one had no result. Furthermore, a total of 227 bands were produced by the selected 19 pairs of primers, of which 207 bands (91.2%) were polymorphic among the test insect populations. Genetic diversity analysis suggested that the BPH populations from Cuu Long, Thailand and Ho Chi Minh were clustered, respectively; and Hue and Long Xuyen were composed into one class; the others were clustered together when the similar coefficient was 0.76. The results show that it is an effective and available approach to develop SSR markers based on ESTs in rice planthoppers; and also the developed EST-SSR markers could detect the genetic diversity of the planthoppers population, which would be beneficial for rice planthoppers control strategy.

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