Fig. 4
Analysis of additive and epistatic effects of QTLs for seed-set density and associated traits in S1-S5, D1-D3 and T1. a Sketch map of developed SSSLs (S1-S5), DSSLs (D1-D3) and TSSL (T1). N denotes recipient Nipponbare; X denotes donor Xihui18; S: SSSL, D: DSSL, T: TSSL. b Seed-set density (SSD); c panicle length (PL); d Spikelets per panicle (SPP); e Number of primary branches (NPB); f Number of secondary branches (NSB). Different lower-case letters indicate a significant difference (P < 0.05) as determined by Duncan’s multiple comparisons. µ is the mean value, ai denotes the additive effect of QTLs, I denotes the additive × additive epistatic effect between QTLs. The P-value for a SSSL indicates the probability of a significant difference between the SSSL and Nipponbare, and the SSSL carried a QTL (Student’s t-test, p < 0.05). The P-value for a DSSL and TSSL indicates the probability of an epitatic effect between QTLs in the DSSL or TSSL, i.e., (Nipponbare + DSSLij) and (SSSLi and SSSLj), and (Nipponbare + Nipponbare + TSSLijk) and (SSSLi and SSSLj + SSSLk) (Student’s t-test, p < 0.05). S1:RM5348–RM8207-RM3311–RM4455 (Chr.10); S2: RM8207–RM3311–RM4455 (Chr.10); S3: RM3321–RM3170–RM6015 (Chr.5); S4: RM152–RM1235–RM22617 (Chr.8); S5: RM21774–RM2715–RM22188 (Chr.7). D1: RM3321–RM3170–RM6015 (Chr.5), RM152–RM1235–RM22617 (Chr.8); D2: RM3321–RM3170–RM6015 (Chr.5), RM5348–RM8207-RM3311–RM4455 (Chr.10); D3: RM152–RM1235–RM22617 (Chr.8), RM5348–RM8207-RM3311–RM4455 (Chr.10); T1: RM3321–RM3170–RM6015 (Chr.5), RM152–RM1235–RM22617 (Chr.8), RM5348–RM8207-RM3311–RM4455 (Chr.10)