## 3 Results
### Molecular Network Expression  
F\({}_{9}\)-generation RILs of 309 lines constructed by crossing Gr 89-1 and Shuhui 527 were selected for eight agronomic traits (PH, PL, GPP, SSR, TGW, FLL, GL, and GW). Gene pools were established for ten extreme lines of the eight agronomic traits. From the 589 initially screened markers, 196 polymorphic markers (Table S1 for detailed primer information) were obtained, including 3 first-level markers, 6 second-level markers, 11 third-level markers, 17 fourth-level markers, 21 fifth-level markers, 28 sixth-level markers, 40 seventh-level markers, and 70 eighth-level markers (Table 3). The network expression relationship map was constructed to explain the correspondence between the agronomic traits and molecular markers. The three first-level markers showed polymorphism in all eight agronomic traits with corresponding network lines. As the level of markers increased, fewer agronomic traits showed polymorphism in each molecular marker. In the eighth-level markers, only one agronomic trait showed polymorphism in each molecular marker, and there was a single network line between markers and agronomic traits, which corresponded one to one (Figure 3). For the correlation between the eight grades of molecular markers and the eight agronomic traits, as can be seen in Table 4, the correlation degree between the first-level markers and the eight agronomic traits was 100%. Except for the correlation between the third-level markers and GW and GL, the correlations between molecular markers and agronomic traits decreased gradually with the increase of marker levels. Moreover, the correlations between the molecular markers and agronomic traits of the eighth-level markers were the lowest, and the correlation degrees with GW, SSR, TGW, PL, GPP, PH, GL, and FLL were 8.57%, 25.71%, 11.43%, 5.71%, 7.14%, 10.00%, 11.43%, and 20.00%, respectively. Three first-level markers were used to detect the 309 F\({}_{9}\)-generation RILs, and 76 resources were found to have molecular differences, from the first-level marker to the eighth-level marker, step-by-step and filter-by-level. Finally, 70 eighth-level markers were used to detect the RILs, and, as a result, 28 markers showed polymorphism, and only seven lines showed differences. Moreover, all of these showed differences in the level 1-8 grade markers and formed the first core group with a relatively distant genetic relationship. The 13 lines selected by the seventh-level markers constituted the second core group; the 17 lines selected by the sixth-level markers constituted the third core group; and the 76 lines selected by the first-level markers comprised the eighth core group (Table 5). The remaining 233 lines showed no difference in each level marker, belonged to an approximate group, and had a close genetic relationship. Figure 2: Main stem, panicle, flag leaf, and corresponding molecular markers of 14 different plant types in F\({}_{9}\) RILs of Gr 89-1 \(\times\) Shuhui 527; **(a)** main stem; **(b)** panicle; **(c)** flag leaf; P1 represents Gr 89-1; P2 represents Shuhui 527; the numbers (1–14) represent 14 different plant types in F\({}_{9}\) RILs of Gr 89-1 \(\times\) Shuhui 527.