耐低钾籼稻幼苗根部的K~ (~(86)Rb~ )运输和通量分析

用通量分析的方法比较研究籼稻73—07和税稻80—66根部K~ (~(86)Rb~ )的吸收和运输的差异。耐低钾的籼稻73—07根部吸收和运输K~ (~(86)Rb~ )的速率显著高于不耐低钾的釉稻80—66。前者的J_(oc)和J_(cx)分别为后者的5.9和5.6倍。籼稻73—07根部的Q_c和Q_v均高于籼稻80—66。由于上运速度快,籼稻73—07的t_c/2显著小于籼稻80—66,表明籼稻73—07根部的K~ (~(86)Rb~ )周转快,有利于根部从低钾介质中吸收K~ 。

The Study of K~ (~86Rb~ ) Transport and Compartmentation in Roots of Potassium Deficiency Tolerant Rice Cultivar

In ordtr to compare the mechanisms ofK~ (~(86)Rb~ ) transport in and absorption bycultivars of indica rice tolerant and sensitive topotassium deficiency, the fluxes and the com-partmentation of potassium in rice roots werestudied. The results showed that potassiumdeficiency tolerant cultivar indica rice 73-07,with much higher J_(oc) and J_(cx) as well as K_(oc)and K_(cx) than those of potassium deficiencysensitive cultivar indica rice 80-66 (Table 1and Table 3) was more efficient in K~ (~(86)Rb~ )absorption and transport, although the twoparameters related with tonoplast (K_(cv) andK_(vc) had only little differcnce. The valuesof Q_c and Q_v in roots of indica rice 73-07were also higher than those of indica rice80-66. Taking K~ (~(86)Rb~ ) transport toshoot into account, t_(c/2) of indica rice 73-07was only half of that of indica rice 80-66(Table 2), which indicated that K~ (~(86)Rb~ )in the cytoplasm of roots of the former varietyturned over more quickly than that of thelatter. All the studied characteristics of in-dica rice 73-07 are favorable to the absorp-tion of potassium by its roots from low potas-sium medium, which may account for its toler-ance to potassium deficiency.