用^(45)Ca示踪法研究小麦对钙的吸收及其在土壤中的移动

STUDIES ON THE ABSORPTION AND TRANSPORTATION OF CALCIUM IN WHEAT BY USING ^(45)Ca TRACER METHOD

本试验利用~45Ca示踪法,研究了小麦对钙的吸收和运转。结果表明,用0.1％~45CaCl_2浸种,~45Ca能被吸入籽粒内,并且48小时的吸收量比24小时的吸收量高1倍以上。涂抹试验表明,无论苗期还是后期,叶片涂抹~45Ca均能被叶片吸收,吸收的钙能转移到邻近的叶片。土壤引入的钙可以被根系吸收并能转移到地上部。钙在石灰性土壤中移动性很差,在淋溶条件下,1周时间仅有0.4％的钙下移1cm。PEG胁迫试验表明,干旱条件影响小麦幼苗对钙的吸收,在一定范围内,随胁迫程度增大,吸收钙量下降,但当溶液水势低于—0.18MPa时,小麦对钙的吸收量又逐渐增高。

The role of the absorption and transportation of calcium was studied in wheat by using 45Ca tracer in this experiments.The results showed that calcium could be absorbed by seed soaked in -the solution of 0.1% 45CaCl2 and the amount of Ca absorbed in 48 hours was about twice as much as that in 24 hours.The smearing test indicated that cal'cium could be absorbed by the leaves treated with 45Ca both in seedling and maturing stage. Calcium absorbed by the leaves could be transported to the leaves nearby.Calcium could be absorbed by roots and transported to the above-ground parts when it was applied to the soils.The test showed the movement capacity of calcium was very bad in calcareous soil.Only 0.4% of calcium applied moved down 1cm under the learning condition in one week.The stress test with PEG treatment suggested that the absorption of calcium was affected by the drought condition in wheat seedlings Calcium absorbed by seedlings was reduced with the increase of stress intensity to a certain extent, but when the water potential was less than-0.l8MPa, Ca absorption by wheat increased gradually.