研究了温室条件下紫外线-B（UV-B）辐射（0.029 J·m-2·s-1）和外施α-萘乙酸（α-NAA）（2 mg·L-1）相互作用对栝楼（Trichosanthes kirilowii）幼苗生长及蒸腾速率的影响。本实验设一个对照（T0）和3个处理：外施α-NAA（T1），增加UV-B辐射（T2），增加UV-B辐射并外施α-NAA（T3）。实验结果：增强UV-B辐射明显降低栝楼的株高及叶面积，根、茎、叶重均较对照低，因而总生物量也较对照低，干物质积累量减少。UV-B辐射增强，对栝楼植株含水量几乎无影响，但却明显增加叶气孔阻力，降低蒸腾速率。与对照（T0）相比，外施α-NAA（T1）明显增加株高及叶面积，根、茎、叶重均增加，因而单株总生物量较对照增加，但干物质积累量增幅不大，植株水分含量较对照略高；叶气孔阻力呈降低趋势，蒸腾速率呈增大趋势。在有UV-B辐射下外施α-NAA（T3），与T2相比，植株高度、叶重及叶面积降低趋势明显减轻，但根、茎生物量，单株总生物量及干物质积累量并无明显增加；叶气孔阻力降低，蒸腾速率增大。分析认为，栝楼幼苗根系发达，根冠比接近1，而UV-B辐射下补充α-NAA对根、茎影响小，同时本试验处理时间短（5周），表现为对生物量增加及干物质积累量的影响效果不明显，但株高、叶面积明显增加，且在一定程度上减小了叶的气孔阻力，增大了蒸腾速率。结果表明：UV-B辐射能对栝楼的根、茎、叶生物量及干物质积累量产生影响，同时也能引起栝楼叶气孔阻力增加及蒸腾速率降低，但若同时外施α-NAA，则这种影响有减轻的趋势。该结果暗示，α-NAA能增强栝楼幼苗对UV-B辐射的耐受能力，可能是弥补了UV-B辐射引起的IAA含量的降低，减少了内源ABA的积累，减轻叶片气孔阻力，增大蒸腾速率，促进了植株生长。
The depletion of the stratospheric ozone layer has been well documented. So ultraviolet-B (UV-B) radiation (280-320 nm) reaching the earth surface has increased since the 1970s. Although extensive studies were conducted about negative biological and ecological effects of enhanced UV-B radiation, little was known about the inside mechanism and effects of increased UV-B irradiation and feasible protective measures of plants. In this paper, the effects of naphthyl acetic acid (α-NAA) (2 mg·L-1) and UV-B radiation (0.029 J·m-2·s-1) on the growth and transpiration rate in pots in greenhouse-grown Trichosanthes kirilowii seedlings were investigated. Four treatments were included in the experiment: no addition of α-NAA and UV-B radiation (T0), addition of α-NAA (T1), exposure to enhanced UV-B radiation (T2), addition of α-NAA and exposure to UV-B radiation (T3). The results showed that enhanced UV-B radiation reduced the height and leaf area of plants, and the weight of roots, stems and leaves. As a result, total biomass and accumulation of dry matter were decreased. Exposure to UV-B radiation significantly increased the stomatal diffuse resistance and decreased the transpiration rate; however it hardly affected the water content of seedlings. Compared to the controls (T0), addition of α-あ??脴?膟?膗
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