籼粳杂交后代幼苗NH_4^+吸收、同化的效率

Efficiency of NH_4^+ Uptake and Assimilation in the Indica × Japonica Hybrid Rice Seedlings

以籼稻广陆矮4号为母本与粳稻黄金光、笹锦为父本的杂交后代作试验材料,试验结果表明,籼粳杂交后代幼苗的生长大于它的亲本。杂交后代和它的亲本在NH_4^+吸收速率上的差异为:母本(籼)>杂交后代>父本(粳)。杂交后代和母本在NH_4^+吸收速率上的差异小于和父本的差异,可能母本对杂交后代在NH_4^+吸收速率上的影响大于父本。NH_4^+吸收的K_m,杂交后代<父本<母本。I_m是母本>杂交后代>父本,但母本与杂交后代之间的差异较小。杂交后代NH_4^+的吸收具有偏低的K_m,偏高的I_m,有较高的NH_4^+吸收效率。NH_4^+同化效率,杂交后代有杂种优势,比亲本高10%上下。

The hybrid of indica rice (Guanglu'ai 4) and japonica rice (Koganehikari orSasanishiki) were used as experimental materials. The results indicated as follows: The growth of indica× japonica hybrid was greater than that of its parental lines. The difference of NH_4^+ uptake rate betweenhybrid and parental lines is in following order: maternal line (indica rice) >hybrid>paternal line(japonica rice). The difference of NH_4^+ uptake rate between maternal line and hybrid is less than that between hybrid and paternal line. It seems that the maternal line has larger influence on the NH_4^+ uptake rateof hybrid as compared with paternal line. The K_m of NH_4^+ uptake rate was in the order: hybrid<paternalline<maternal line, while the order of I_m was maternal line>hybrid>paternal line, but the difference be-tween maternal line and hybrid was less. So hybrid had lower K_m and higher I_m and absorbedNH_4^+ efficiently. The heterosis of NH_4^+ assimilation efficiency was observed in hybrid rice, about 10% overthat of its paternal lines.