Fig. 1From: Chromosomal Location of HWA1 and HWA2, Complementary Hybrid Weakness Genes in RiceHybrid weakness caused by two complementary genes: Hwa1-1 and Hwa2-1. Seedlings are shown 40Â days after sowing date: from left to right, P.T.B.10, F1 derived from the cross between P.T.B.10 and P.T.B.7, and P.T.B.7. The F1's developed leaves have turned yellow from the tip. Bar shows 10Â cm.Back to article page