RNAi介导的有害生物防控策略是农业生物技术领域的最新突破之一。但是，目前对RNAi防控策略可能产生的脱靶效应仍未完全了解。本文中，我们研究了两种昆虫致死基因siRNA在靶标和非标靶昆虫中的脱靶效应。结果表明，致死基因siRNA的脱靶效应广泛存在于靶标昆虫和非靶标昆虫中。我们根据基因的同源性、相关KEGG途径以及与siRNA序列的连续匹配度，对所有表达量受影响的基因进行了分类。出人意料的是，非靶标基因表达量受影响的程度与序列的连续匹配度并不一直。而少部分同源基因和KEGG相关基因的表达量正如预期的一样发生了显著变化。通过计算转录组熵值，结果表明尽管在siRNA处理后数百个基因的表达受到影响，但转录组的熵值保持不变，这表明转录组的表达模式在整体上是平衡的。本文的结果表明，siRNA与非靶标生物中的单个基因发生交叉反应，但在基因组水平上对靶标和非靶标生物中转录组完整性并没有显着影响。同时，本文提出了一种评估昆虫致死基因siRNA脱靶效应的体系，将有助于评估RNAi害虫防控策略的安全性。

The normalization of quantitative real-time PCR (qPCR) is important to obtain accurate gene expression data, and the most common method for qPCR normalization is to use reference genes. However, reference genes can be regulated under different conditions. qPCR has recently been used for gene expression study in Laodelphax striatellus, but there is no study on validation of the reference genes. In this study, five new housekeeping genes (LstrTUB1, LstrTUB2, LstrTUB3, LstrARF and LstrRPL9) in L. striatellus were cloned and deposited in the GenBank with accession numbers of JF728809, JF728810, JF728811, JF728807 and JF728806, respectively. Furthermore, mRNA expressions of the five genes and β-actin were measured by qPCR with insect samples of different instar at nymph stage, and the expression stabilities were determined by the software geNorm and NormFinder. As a result, ARF and RPL9 were consistently more stable than β-actin, while three TUB genes were less stable than β-actin. To determine the optimal number of reference genes used in qPCR, a pairwise variations analysis by geNorm indicated that two references ARF and RPL9 were required to obtain the accurate quantification. These results were further confirmed by the validation qPCR experiment with chitinase gene as the target gene, in which the standard error of the mRNA quantification by using binary reference ARF-RPL9 was much lower than those by ARF, RPL9 or β-actin alone. Taken together, our study suggested that the combination of ARF-RPL9 could replace β-actin as the reference genes for qPCR in L. striatellus.