Detection and identification of Ephedra Herba seed pests based on X-rays and DNA barcodes

Abstract

As an important natural medicinal resource for humans, Ephedra sinica Stapf often suffers from various biological stresses during its growth process. One of the pests that pose a threat to Ephedra is the Ephedra seed pest. Its primary mode of damage is laying eggs inside the Ephedra seeds, where they develop and eventually emerge as adult wasps, causing significant damage to the seeds. This study aimed to investigate the effectiveness of X-ray for Ephedra seed pest detection, the impact on the use value of Ephedra seeds infested by pests, and the further confirmation of pest species information. The mature Ephedra seeds from the Inner Mongolia Autonomous Region were taken as the teste object. The results showed that the germination rates of three different batches of seeds were 46%, 40%, and 38%, while the seedling emergence rates were only 36%, 30%, and 32%, respectively, significantly lower than that of control healthy seeds 66% and 52%. The phylogenetic tree Neighbor-Joining (NJ) was constructed by extracting the COI sequences of the pest samples, and was identified as a new species of Eurytoma genus based on morphological characteristics. X-ray detection is a commonly used, non-invasive method. Based on non-destructive X-ray testing, the quality of Ephedra seeds could be classified into three types: healthy plump seeds, seeds infested by pests, and underdeveloped hollow seeds. In conclusion, the combined use of X-ray and DNA barcoding methods can achieve rapid and accurate detection and identification of E. sinica seed pests, which is of great significance for the management and control of Ephedra seed production.