## 4 Discussion  
Development of the resistance rice and study on the defense genes with determination of natural products and breeding for pest-resistant plants is a predominant focal point of agricultural research. Agricultural traditions have made necessary contributions to our knowledge and shaped our perceptions on plant resistance to pests for the duration of plant molecular breeding. Particularly, rice resistance to WBPH is well studied in the context of defense genes and natural management of these pests in agriculture. The most efficient and economical way of controlling WBPH is by developing resistance rice cultivars, resistant genes and natural products. The genetic alteration of secondary metabolites pathways during stress condition produces side products which are most significantly involved in mitigation of human disease. QTLs analysis is a basic tool to determine the gene and pathway involved in the specific stress inducing tool. In our study, we analyzed the genes and pathways involved in WBPH stress through QTLs analysis. We detected QTLs associated with cq-9 of the CNDH lines putatively on chromosomes 1, 2, 4, 6, 7, 8 and 12, respectively. The physical map of each chromosome was completed using a sequence database ([[http://www.gramene.org/](http://www.gramene.org/)]([http://www.gramene.org/](http://www.gramene.org/)), accessed on 11 October 2020). The vertical lines in the physical map indicate the advent of complete genetic linkage map consisting of codominant DNA marker typically SSR markers. QTL associated with rice resistance were identified the genes on the regions of map base genetic contribution. In the results, the additive effects of the QTL were positive with the additive coming fours QTL detected on chromosomes 1, 2, 4, 6, 7, 8 and 12, respectively. Regarding the additive effects, contribution of phenotype variation and genotype variation, a total of 21 QTLs identified by Windows QTL Cartographer 2.5, with one QTL (RM23191) detected  
Figure 6: Rice extract or cq-9 reduces vascular contraction in SD rats. Vasorelaxation induced by rice extract or cq-9 in the aorta from rats. Rice extract or cq-9 was added cumulatively to elicit relaxation when vascular contractions induced by U46619 reached a plateau in endothelium-intact (ET+) or –denuded (ET-) rat aortic rings. We investigated the relaxation response by treating endothelium-intact aortic rings with Apamin (500 nM), tetraethylammonium (TEA, 5 nM) and NG-nitro-L-arginine methylester (L-NAME, 100 nM) for 30 min. After U46619 treatment, Rice extract or cq-9 was cumulatively added to the aortic rings. Relaxation is expressed as the percentage of the maximal contraction. * \(p\) < 0.05, **_p_ < 0.01 vs. Rice extract (ET-) or cq-9 (ET-). # \(p\) < 0.05, **_p_ < 0.01 rice extract vs. cq-9. Data are expressed as the mean \(\pm\) SE (n = 4). Figure 7: Rice extract or cq-9 inhibits agonist-induced rat platelet aggregation. Collagen-, ADP-, or thrombin-stimulated washed platelets pre-treated with Rice extract or cq-9 extract concentrations in the presence of 1 mM CaCl\({}_{2}\). Platelet aggregation is expressed as the percentage of the maximal platelet aggregation by Collagen (0.625 ug/mL), ADP (5 uM), or thrombin (0.8 Unit). * \(p\) < 0.05, **_p_ < 0.01 Rice extract or cq-9. Data are expressed as the mean \(\pm\) SE (n = 4). on the same location. QTL mapping analyzes the interaction between genotype and phenotype and detects the sequence region most related to the phenotype [43]. In this research, we focused on the regions that are mapped identically every year through repeated experiments for 4 years. In this research, the newly discovered gene _OsCM_ was located on chromosome 8, and chromosome 8 showed a higher density than other chromosomes. Therefore, more accurate QTL could be obtained. From 2016 to 2019, there are 17 QTLs detected that show LOD of 2.5 or more when using the WBPH resistance score. Using the results of HPLC analysis, QTL mapping was carried out in 2020, and four QTLs were detected.