ABSORPTION, TRANSLOCATION AND ASSIMILATION OF ^<16>N AND ^<45>Ca IN SOME VERGETABLE CROPS

研究了<45>水培番茄叶片表面、茎、节、果实和根系对钙的吸收和转运。我们发现：1）当钙供应到叶片的任一表面时，它被很好地吸收并且仅在所施加的叶片中转移到远端。钙不向根、茎、上部叶和茎尖等器官转移。2)3）在节位施钙时，植株吸收和转运的钙量最大，且吸收的钙向植株上部和叶片正上方转运最多。4)果实中的钙被充分吸收并分配到果实内部。5)从根部供应的钙被转运到植株的各个部位。6)在氮素研究中，首先比较了尿素、硝酸盐和铵态氮在不同氮浓度、溶液pH、溶液温度和镍浓度下对番茄幼苗钙吸收和转运的影响。在此基础上，比较了水培番茄不同生育期对尿素、硝态氮和铵态氮的吸收、转运和同化。以硝态氮为示踪物，比较了叶面喷施尿素与硝态氮、铵态氮的吸收、运转和同化<15>作用。

The absorption and translocation of Ca were measured after ^<45>Ca was supplied to either surface of lamina, the stem, the node, fruits, and the roots of the water-cultured tomato plants. We found that : 1) When Ca was supplied to either surface of the lamina, it was well absorbed and translocated only to the distal end in the applied leaf. Ca was not translocated to other plant organs such as roots, stem, upper leaves or shoot apices. 2) When supplied at the stem, absprption and translocation to the upper part of the plant was detected more for Ca than P.3) When supplied at the node, the amount of Ca absorbed and translocated was the largest in comparison with other plant organs and portions, and absorbed Ca was well translocated to the top portion of the plant and immediately above the supplied leaf. 4) Ca supplied at the fruit was well absorbed and distributed to the inner parts. 5) Ca supplied at the root was translocated to all parts of the plant. 6) The absorption and the translocation of Ca in leaves and fruits were monitored by the autoradiography.In the N study, at first, urea as N source for tomato seedlings was compared with nitrate and ammonium under different N concentration, solution pH, solution temperature, and nickel concentration. Then, the absorption, translocation, and assimilation of urea were compared with those of nitrate and ammonium at different growth stage of water-cultured tomato plants. The absorption, translocation, and assimilation of urea supplied by foliar application were also compared with those of nitrate and ammonium by using ^<15>N as a tracer.