Using a transgenic Bacillus thuringiensis (Bt) crop is reportedly one of the most effective ways to improve
insect resistance; however, the insertion of external Bt genes may affect the non-target growth characteristics
of crop. Field experiments were conducted to investigate the yield performance and physiological
traits in an elite restorer rice line, Minghui63 (MH63) with Cry1C*, Cry2A* or Cry1Ab/Ac genes under three
fertilizer applications [zero nitrogen fertilizer (N0), zero potassium fertilizer (K0) and recommended
nitrogen and potassium fertilizer (NK)]. In comparison with MH63, MH63 (Cry1C*) experienced declining
grain yields of 15.3–31.0% under different fertilizer applications because of the decreased setting rates
associated with the poorer matter transport-related traits. The grain yield of MH63 (Cry2A*) was averagely
18.4% lower than MH63 in only the N0 treatment due to the accelerated leaf senescence, which was
correlated with the higher ratios of the Bt protein content to the soluble protein content (BTC/SPC) in the
MH63 (Cry2A*) leaves at the filling stage (FS). The yield performance of MH63 (Cry1Ab/Ac) was identical
to MH63. In addition, no significant differences were recorded between Bt-MH63 and MH63 regarding
N and K assimilation. Hence, our results suggest that the Cry1C* and Cry2A* transgenes affect the yield
performance and related traits of MH63 in response to nitrogen and/or potassium applications. |
