水分亏缺对小麦碳同化物的动员与分配

MOBILZATION AND DISTRIBUTION OF CARBON ASSIMILATES OF WHEAT UNDER WATER DEFICITS

利用14 CO2 对小麦花前光合标记 ,在开花灌浆全期通过对对照 (CK)、中度胁迫(MS)、严重胁迫 (SS) 3个水分处理试验表明 :在灌浆过程中 ,中度胁迫处理叶中花前14 C 同化物输出比例为 1 6 56% ,略高于对照和严重胁迫 ,收获时同化物滞留最少( 8 68% )。严重胁迫处理颖壳中14 C 同化物外运比例最高 ,为 8 70 % ,约为对照和中度胁迫处理的 2倍。 3种水分处理茎中同化物输出比例不明显。胁迫程度增加 ,旗叶中同化物输出比例和撤退量增加 ,籽粒对同化物调运速度与比例增加。表明水分亏缺促进了籽粒对花前叶、鞘、颖壳等“临时库”

Three water treatments,control(CK),moderate stress(MS) and severe strss(SS) during anthesis and filling stage were designed and,photosynthes was labelled by using 14 CO 2 at fore\|anthesis.The results showed that output rate of 14 C assimilate at fore\|anthesis of moderate stress treatments in leaves was 16\^56%,slightly higher than that of control and severe stress dring grain filling,and amounts of assimilate store was 8\^68%,and reach the lowest when harvested.Under severe stress exports rate of 14 C assimilate in shells was highest(8\^70%),and was about two times taht of control and moderate stress.The rate of assimilate exports in stems was not obviously different in three water treatments.With the stress increasing the rate of assimilate output in flag leaf increased,and transport rate to seeds raised,too. It was concluded that water deficit enhanced remobilization of fore\|anthesis assimilate from leaves,sheathes,shells to seeds,and compensated economic yields in late stage.