## 1 Introduction  
The Green Revolution of the 1960s led to a notable acceleration in grain production in developing countries, mainly due to the development of high-yielding hybrid strains of rice (_Oryza sativa_ L.), wheat and maize, and the introduction of chemical fertilizers, pesticides and irrigation. However, because of their genetic homogeneity, the cultivars were more susceptible to pests, weeds and diseases than the traditional varieties. Approximately half of the world population uses rice as a staple food. Pests are the main culprits for the rice productivity reduction. White backed planthopper (WBPH; _Sogatella furcifera_ [PERSON]) and brown planthopper (_Nilaparata lugens_ Stal, BPH) are among the major pests causing the greatest damage to rice crops worldwide. Both the pests transmitting southern rice black-streaked dwarf virus (SRBSDV), but WBPH is a strong persistent-transmitting vector for SRBSDV. In the near past, SRBSDV was discovered in Guangdong province China and rapidly spread in Southern China and Vietnam [1; 2]. SRBSDV belongs to the Fijivirus genus which also includes _Oat Sterile Dwarf Virus_ (OSDV), _Garlic Dwarf Virus_ (GDV), _Fiji Disease Virus_ (FDV), _Mal de Rio Cuurto virus_ (MRCV), _Maize rough dwarf virus_ (MRDV), _Pangola stunt virus_ (PaSV) and _Nilaparata lugens reovirus_ (NLRV). These are all viruses that propagate in vivo through a hopper vector in a sophisticated way except GDV whose vector is still unknown [3]. A distinctive feature of plants and other sessile organisms, which cannot run away in case of hazard and lack an immune system to contest pathogens, is their capacity to produce a massive variety of compounds, the so-called secondary metabolites [4]. The biosynthesis of numerous secondary metabolites is constitutive, whereas in various plants it can be induced and enhanced by biological stress conditions, such as wounding or infection [5]. Over 2000 plant species are known to have pesticidal properties, and many of these plants are used by farmers in developing countries [6; 7]. However, it is assessed that only 20-30% of higher plants have been studied so far [4]. Only a small percentage of plants has been screened for pesticidal activity, and, in addition, many such studies are not complete and often bioassay procedures used have been insufficient or inappropriate [8; 9]. The plant kingdom represents a huge pool of new molecules to be discovered; as potentially useful biological compounds remain undiscovered, unexplored, undeveloped or underutilized from this reservoir of plant material [10; 11]. To properly investigate the new compound, require separation techniques, structural elucidation and bioassay. Because plants are sessile organisms that cannot move they face a variety of stress conditions during their growing life. Moreover, in order to survive this stress condition, numerous changes occurring in the growth stage and numerous mechanisms that can grow and develop by resisting stress have evolved [12]. Plant secondary metabolites are derivatives of primary metabolites made directly from plants due to a variety of physiological changes [13]. In addition, secondary metabolites play a key role in plant growth and survival under stress conditions and have a long-term effect [14]. In plants, about 100,000 secondary metabolites exist in three main groups [15]. In particular, plants synthesize aromatic amino acids such as tryptophan, phenylalanine and tyrosine, which are aromatic amino acids through the shikimate pathway. Aromatic amino acids are precursors to secondary metabolites that play a critical role in plant growth, development and defense reactions. In addition, chorismate, a precursor of aromatic amino acids, is used as a precursor of salicylic acid, a representative plant defense material. QTL is a technique that is effectively used to analyze the relationship between phenotype and genotype [16]. So far, resistance genes and major QTLs that can be usefully used in agriculture have been reported [17].