No Effect of Bt-transgenic Rice on the Tritrophic Interaction of the Stored Rice, the Maize Weevil Sitophilus Zeamais and the Parasitoid Wasp Theocolax elegans

Qingfeng Tang,Ying Zhang,Zhipeng Yang,Chen Shen,Jian Wang,Rongrong Han

doi:10.1038/s41598-019-40836-8

Qingfeng Tang, Ying Zhang + Show 4 more

Open Access

https://doi.org/10.1038/s41598-019-40836-8

Copy DOI

Abstract

During Bt transgenic rice storage, Bt Cry1Ab/Cry1Ac fused protein is exposed to the maize weevil Sitophilus zeamais and the parasitoid wasp Theocolax elegans. We have carried out a long-term risk assessment for Bt rice to these non-target organisms in the storehouse. Effects of Bt rice on S. zeamais and T. elegans have been carefully detected in a laboratory experiment of over 5 years. The survival, development, fecundity, and longevity of the maize weevil were compared between Bt rice and non-Bt rice treatments for every 5 generations from generation 1 to 25. Moreover, the development, adult body size and sex ratio of T. elegans were compared between them parasitizing S. zeamais feeding on Bt rice or non-Bt rice. We found that although Bt Cry1Ab/Cry1Ac fused protein exists in the Bt rice grains and S. zeamais digestive tracts, Bt rice is not harmful to the maize weevil S. zeamais and its parasitoid T. elegans.

Highlights

Rice (Oryza sativa L) is one of the most important grain crops
When S. zeamais were reared on non-genetically modified (GM) rice under the conditions of 28 ± 1 °C, 80% relative humidity, and total darkness, the final survival rate during the developmental stages from egg to nonage was about 82% and the developmental time for this period was about 73 days. These numbers were stable from the 1st to 25th generation and no significant difference was detected when comparing the beetles feeding on non-GM rice or Bt rice (Table 1, p > 0.05), indicating that Bt rice does not affect S. zeamais development
We examined the effects of Bt rice on the longevity and fecundity of S. zeamais adults

Summary

Introduction

Rice (Oryza sativa L) is one of the most important grain crops. It serves as a staple diet for more than half of the world’s population[1]. Before a Bt rice line can be cultivated, the risks to the environment and human health must be assessed This includes the evaluation of potential adverse effects on non-target invertebrate and vertebrate animals, as well as the ecosystem services they provide[9,10,11,12]. For this purpose, extensive investigations have been conducted in the rice field. We studied the effects of transgenic Bt stored rice (Bt cry1Ab/cry1Ac) on the non-target coleopteran storage pest S. zeamais and its natural enemy T. elegans

Methods

Results

Conclusion