Nucleosides are active components in Ophiocordyceps sinensis. All individual nucleoside contents in both fruiting and caterpillar bodies were significantly different among the 24 O. sinensis populations that are distributed across the Qinghai-Tibet Plateau of China. The nucleoside contents of the fruiting and caterpillar bodies show significant positive correlations with the geographical distances of O. sinensis populations, and the nucleoside contents in the O. sinensis populations with the non-dominant fungus-host haplotype associations from isolated geographical areas show significant positive correlations with the genetic distances among those populations based on nrDNA ITS and COI sequences, respectively. The fungus-host associations play important roles in the nucleoside differences of O. sinensis populations.
Keywords: Fungus–host haplotype association; Host insects; Nucleosides; Ophiocordyceps sinensis.