缺硼对黄瓜幼苗生长和光合特性的影响

目的】研究缺硼对黄瓜幼苗光合生理生化的影响。【方法]采用沙培法，以川绿1号为供试品种，研究缺硼对黄瓜幼苗的叶面积、光合速率、Rubisco酶活性、碳水化合物含量的影响。【结果]缺硼处理抑制了黄瓜幼苗的根、茎叶生物量的增加，增加了冠根比，减小了叶面积；在缺硼条件下，黄瓜幼苗叶片中的淀粉、可溶性糖、还原糖和总碳水化合物的含量增加，蔗糖含量降低；净光合速率明显降低，Rubiso酶活性和叶绿素a、b含量明显减少，而叶绿素a／b变化不明显。【结论】缺硼通过增加叶片中的碳水化合物，降低Rubisco酶活性，减少光合色素，进而降低光合速率来抑制黄瓜幼苗生长。

EEffects of Boron Deficiency on Growth and Photosynthetic Characteristics of Cucumber Seedlings

Objective] The aim was to study the effects of boron deficiency on the photosynthesis physiology and photosynthesis biochemical of cucumber seedlings. Method] Chuanlv No.1 was sand cultured to study the effects of boron deficiency on leaf area, photosynthetic rate, Rubisco enzymatic activity and carbohydrate content of cucumber seedlings. Result] Boron deficiency inhibited the biomass increase of root, stem and leaf, increased the shoot to root ratio and reduced leaf area. Under the boron deficiency condition, the contents of starch, soluble sugars, reducing sugars and total carbohydrates increased and the content of sucrose decreased. The net photosynthetic rate, Rubisco enzymatic activity and the contents of chlorophyll a and chlorophyll b decreased significantly, while there was no significant change on chlorophyll a/b. Conclusion] Boron deficiency inhibit the growth of cucumber seedlings by means of increasing the carbohydrates content of leaves, reducing Rubisco enzymatic activity, decreasing photosynthetic pigment and inhibiting photosynthesis.