鉀離子對於氨基酸與醣類運送進入玉米胚乳的影響

Effects of Potassium on the Movement of Amino Acids and Sugars into Maize Endosperms

本研究的主要目的在於探討鉀離子對於氨基酸和醣類運送進入玉米種子的影響以及種子產量和植株倒伏的相關性。以發育中的玉米雜交品種B73×Mol7種子在體外測試不同濃度的鉀離子對於50mM 3H-glutamine和200mM 14C-sucrose運送的影響。結果發現鉀離子對於氨基酸和醣類運送有相似的調控現像，當鉀離子濃度增加到100mM時最能促進有機養份的運送，但是鉀離子濃度增加到200mM時反而有抑制的現象。以四個雜交品種B73×LH51，FS854；LHE136×LH82及A632×LH39進行田間實驗，發現在低氮肥狀態下，鉀肥對於種子的產量和植株倒伏有正相關的影響。本文對於此一正相關性有進一步的討論。

Efforts were made to study effects of potassium (K) on the movement of amino acids and sugars into maize (Zea mays L.) kernels and the relationship between grain yield and lodging severity. Developing kernels of maize hybrid B73 × Mol7 were incubated in vitro in a reaction mixture containing 50 mM 3H-glutamine, 200 mM 14C-sucrose, and varying amounts of K salts to determine K effects on the transport of these organic nutrients into endosperms. Results indicate that the kinetics of K effect on glutamine and sucrose transports were similar, and the movement of these two organic nutrients into endosperms reached a maximum level when K concentrations increased to 100 mM. The degree of stimulation declined at higher levels of K. There was a positive correlation between grain yield and lodging severity for the four maize hybrids 873 x LH51, FS854, LHE136×LH82, and A632 x LH39 evaluated. The relationship between dry matter accumulation in kernels and lodging severity of stalk was discussed.