研究彙報第八十四期 ， Page 11- 28，出版時間：2004- 9，
利用離體葉片累積不同光照量之方法，可以得到不同可溶性固形物含量 (SSC) 之葉片。量測葉片之 SSC 與化學定量分析之可溶性碳水化合物 (TSC) ，二者間具有線性關係。另一方面，以葉片吸取 1~5% 之蔗糖溶液，得到含不同 SSC 與 TSC 之葉片，二者間亦具一次或二次相關。於下午採收，累積較高光照量之植株上葉片，具有較高之 SSC ，同時比早上採收或經 16 小時黑暗後採收之葉片，有較長之瓶插壽命。離體葉片經累積光照量，提高 SSC 後，比對照有較長之瓶插壽命。吸取 2 或 5% 之蔗糖溶液之離體葉片，較未吸取蔗糖之處理具有較高之 SSC 及 TSC ，同時有較長之瓶插壽命。缺水逆境下，菊花葉片之光合作用受到抑制， SSC 及 TSC 變化小，而逆境下葉片之澱粉含量則顯著降低，而且瓶插壽命較短。葉片經 3 ℃貯藏 5 或 10 天， SSC 或 TSC 會增加，而澱粉減少，總非結構性碳水化合物含量減少，瓶插壽命減短。量測 13 個品種菊花葉片之 SPAD( 葉綠素計讀值 ) 、 SSC 、 SLW(specific leaf weight) 及瓶插壽命，四個觀測值在品種間均有顯著差異，唯觀測值彼此之間不具相關性。利用屈光度計量測之 SSC 可以估算 TSC 含量。當 SSC 被人為因素調高時，葉片之瓶插壽命延長。但是當碳水化合物合成受到抑制或葉片儲藏於低溫時，澱粉含量降低，而非 SSC 。 SSC 無法作為菊花葉片之瓶插壽命指標。
Relationship between Soluble Solid Contents Changes and Senescence of Chrysanthemum Leaves
The soluble solid contents (SSC) of detached chrysanthemum leaves could be regulated by removing sink then accumulating carbohydrate reserves under supplemental lighting. There was a linear relationship between SSC and total soluble carbohydrate (TSC), which was analyzed by chemical analysis, in a series of different SSC. A quadric or a linear regression relationship between SSC and TSC were also found in leaves absorbed 1-5% sucrose.
Leaves harvested in the afternoon had higher SSC and longer vase lives in the dark than leaves harvested in the morning or after 16 hrs of continuous darkness. Detached leaves accumulated more SSC by more supplemental lighting and their vase lives were longer. Both SSC and TSC increased and vase lives extended when leaves were preserved in the solution with 2 or 5% sucrose.
SSC of leaves detached in an irrigated or water stress condition were not significantly different. However, starch reduced markedly when photosynthesis was obviously inhibited under water stress. Vase lives of leaves shortened when plants suffered water-stress. On the other hand, SSC and TSC increased but starch reduced when leaves were stored at 3 ℃ for 5 or 10 days. In consequence, total non-structural carbohydrate decreased and vase lives shortened when leaves experienced 5 or 10 days 3 ℃ storage.
The SPAD (chlorophyll meter reading), SSC, SLW (specific leaf weight) and vase lives of detached leaves among 13 chrysanthemum varieties were significantly different. However, there were no correlations among 4 observed indicators.
Soluble solid contents measured by a refractometer could estimate total soluble carbohydrates. The vase lives of leaves extended when SSC of leaves were increasingly regulated. However, starch, not SSC, reduced when carbohydrate assimilation was inhibited or leaves were stored in low temperature. SSC of leaves could not be used as vase life indicator of chrysanthemum leaves.
Key words: chrysanthemum, senescence, refractometer, soluble solid contents, carbohydrate.