Abstract
The Asian citrus psyllid Diaphorina citri Kuwayama is a major pest in citrus production, transmitting Candidatus Liberibacter asiaticus. It has spread widely across eastern and southern China. Unfortunately, little is known about the genetic diversity and population structure of D. citri, making pest control difficult. In this study, nine specifically developed SSR markers and three known mitochondrial DNA were used for population genetics study of D. citri using 225 samples collected from all 7 distribution regions in China. Based on the SSR data, D. citri was found highly diverse with a mean observed heterozygosity of 0.50, and three subgroups were structured by host plant: (i) Shatangju, NF mandarin and Ponkan; (ii) Murraya paniculata and Lemon; (iii) Citrus unshiu, Bingtangcheng, Summer orange and Navel. No significant genetic differences were found with mtDNA data. We suggested the host-associated divergence is likely to have occurred very recently. A unimodal distribution of paired differences, the negative and significant Tajima’s D and Fu’s FS parameters among mtDNA suggested a recent demographic expansion. The extensive citrus cultivation and increased suitable living habitat was recommended as a key for this expansion event.
Highlights
The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is the most serious pest of citrus worldwide, primarily due to its role as a vector for “Candidatus Liberibacter asiaticus”, the bacterium that causes the highly destructive Asian huanglongbing (HLB)[1]
Thirteen primer pairs were validated on a panel of samples, i.e., production of specific polymerase chain reaction (PCR) products of the expected size, and tested for polymorphism
Our present study explores nine polymorphic Short Simple Repeats (SSR) loci and demonstrates that host-associated differentiation exists among D. citri populations in China
Summary
The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is the most serious pest of citrus worldwide, primarily due to its role as a vector for “Candidatus Liberibacter asiaticus”, the bacterium that causes the highly destructive Asian huanglongbing (HLB) (citrus greening)[1]. The use of only mtDNA for phylogeographic and population genetic studies is questioned, because within-species diversity does not reflect population size or ecology, and it is difficult to investigate evolutionary questions[23] Utilizing both slow evolving and fast evolving molecular markers together can generate a comprehensive picture of both ancient and recent population histories and becomes necessary 24,25. Owing to their rapid evolution, extensive genome distribution and high level of polymorphism, as well as apparent neutrality and co-dominant behavior, Short Simple Repeats (SSR) or microsatellite markers have become a useful marker in studies of ecology, evolution, conservation, and population biology of many insect species[26,27]. No researcher has tested if mtDNA genes are neutral before using them
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
