不同种源顶果木幼苗生长、光合和叶绿素荧光特性比较

Comparison of growth,photosynthetic,and chlorophyll fluorescence characteristics for different provenances of Arcocarpus fraxinifolius

以河池都安、百色田林和西双版纳3个种源顶果木1年生实生苗为试验材料,研究其幼苗生长、光合色素含量、光合响应参数和叶绿素荧光参数在种源间的差异及其受种源地气候因子的影响。结果表明:(1)河池都安种源在最大净光合速率(P_(max))、光饱和点(LSP)、叶绿素a(Chla)、叶绿素b(Chlb)、类胡萝卜素(Car)、PSⅡ原初光能转化效率(F_(v)/F_(m))、电子传递速率(ETR)和实际光化学效率(ΦPSⅡ)均显著高于百色田林和西双版纳种源(P<0.05),而表观量子效率(AQY)、光补偿点(LCP)和发光化学猝灭系数(NPQ)在3个种源间差异不显著(P>0.05)。表明河池都安种源对于光环境的适应范围更广、光能转换效率更高、最大净光合速率更大,这与其生长表现相一致。(2)种源地气候因子对生长特性和光合特性有显著影响;种源地年均降雨量、年日照时长与试验地越接近的都安种源生长最好,P_(max)最大;而与试验地相差较大的西双版纳种源则生长表现最差,P_(max)最小。由此可见,种源地气候差异引起的遗传差异是造成不同种源顶果木在生长和光合特性差异的原因之一。

We examined the growth,photosynthetic pigment content,photosynthetic response parameters,and chlorophyll fluorescence parameters of 1⁃year⁃old seedlings of three provenances of Arcocarpus fraxinifolius(Hechi Duan,Baise Tianlin and Xishuangbanna)and analyzed the influences of climatic factors of the provenance sites.The results showed that:(1)The maximum net photosynthetic rate(P_(max)),light saturation point(LSP),chloro⁃phyll a(Chla),chlorophyll b(Chlb),carotenoid(Car),PSⅡprimary light energy conversion efficiency(F_(v)/F_(m)),electron transfer efficiency(ETR)and actual photochemical efficiency(ΦPSⅡ)of Hechi Duan provenance were significantly higher than those of the other two provenances(P<0.05),while apparent quantum efficiency(AQY),light compensation point(LCP)and luminescence chemical quenching coefficient(NPQ)showed no variation among the three provenances(P>0.05).It indicated that Hechi Duan provenance had a wider range of light adaptation,higher light energy conversion efficiency and higher maximum net photosynthetic rate,which was consistent with its growth performance.(2)The climatic factors of the provenance site had a significant impact on the growth characteristics and photosynthetic characteristics.The Hechi Duan provenance,whose climatic factors(average annual rainfall and annual sunshine duration)were closer to that of the experimental site,showed the best growth and the largest P_(max).The Xishuangbanna provenance with larger difference in climatic factors to the experi⁃mental site had the lowest growth and the smallest P_(max).It is concluded that genetic differences caused by climatic differences of provenance sites are one of the main reasons responsible for the differences in growth and photosynthetic characteristics of A.fraxinifolius among different provenances.