礦物養份及光合作用生成物之輸運與柑桔穗砧組合關係之研究（一）桶柑與溫州蜜柑

Transport Effect of Some Mineral Nutrients and Photosynthates with Reference to Srock-scion Relationship in Citrus 1. Citrus tankan and Citrus unshiu

柑桔穗砧組合關係，對樹壽，果實品質以及產量等之影響至為深遠，究基導致因素，除生理問題外則以影響養料上下輸運之問題為多，本試驗由礦物份及光合作用產物之有效輸運觀點，試圖探覓較利於養份輸送之柑桔穗組合。試驗以桶柑（Citrus tankan Hay.）及溫州蜜柑（Citrus unshiu Hort. Ex Tan.）為接種，接合於酸桔（Citrus sunki Hort. Ex Tan）,廣東檸檬（Citrus limonia Osb.）以及枳殼（Poncirus trifoliate [L] Raf.）等砧木，分別處理32P，35S，45Ca及86Rb等放射性核種，以追索其上運狀況，另以14CO2處理地上部組織經追索交合作用生成物下運狀況，由各種穗砧組合之比較性輸送效果，作為柑桔穗砧組合選擇之參考。所獲結果，從礦物養份之上運情形觀。則不論接穗為桶柑或溫州密柑，其不同根砧組合所測得放射活性均呈枳殼＞酸桔＞礦物檸檬之明顯趨勢，但光合作用生成物之下運，以桶柑為接種時呈廣東檸檬＞酸桔＞枳殼，而以溫州密柑為接穗時，則呈枳殼＞廣東檸檬＞酸枳。然適宜之穗砧組合選擇當兼顧上下順暢輸運，以收良好之營養效應。本試驗以放射追蹤方法達成，對液態閃光光譜測算時，顏色抑制之校正方法曾加討論。

In is understood that the stock-scion relationship in citrus plants greatly influences the age of citrus and the quality of its product as well as its yield. Aside from the inherent physiological problems, the upward and downward transport of nutrients through the graft union may be the most crucial problems in the factors involved. By the movement consequence of some mineral nutrient or photosynthates, this experiment was tentatively to search for the proper stock-scion unions in citrus plants which are favorable for nutrients and foods movement. Citrus tankanand C. unshiu were grafted on the rootstocks including C. sunki, C. limonia and Poncirus trifoliate respectively. 32P, 35S, 45Ca and 86Rb radionuclides were administered individually from the nutrient solution in tracing for the status of upward movement, and 14CO2 was treated in the above-ground parts in tracing for the downward movement status of labeled photosynthates. The comparisom effect from different stock-scion relations were introduced as a reference for citrus top root selection. In the trial for upward movement of mineral nutrients, the results revealed that either C. tankan or C. unshiu, when grafted on three various stocks, the radioactivity obviously showed that P. tridoliata＞C. sunki＞C. limonia. While in the trial for photosynthates downward movement, it revealed that C. limonia＞C. sunki＞P. trifoliate in case of C. tankan as the scion, but in case of C. unshiu as the scion, the results showed that P. trifoliate＞C. limonia＞C. sunki. Logically, in securing a perfect nutritional effect, the compatible top root conjugation in citrus propagation for realizing a two-way free movement for each case is highly expected. The radiotracer techniques were carried out in this experiment and the correction method for colour quenching problems in liquid scintillation spectrometry was also discussed.