不同生境条件下光照强度对蓝花楹光合色素含量及开花的影响

Effects of light intensity on photosynthetic pigment content and flowering of Jacaranda mimosifolia D. Don in different habitats D. Don in different habitats

探明同种植物在不同生境条件下的生长发育特性是实现高品质植物配置与造景的有效途径.以四川省成都市温江区温江公园(W)、光华大道(G)、四川农业大学成都校区四教B区(B)及C区(C)4个试验点成年蓝花楹(Jacaranda mimosifolia D.Don)为研究试材,采用数字式照度计测量同一时段不同生境下以及不同时段不同生境下的光照强度,同时测定叶绿素a(Chl a)、叶绿素b(Chl b)和类胡萝卜素(Car)含量.结果显示:在观测期内蓝花楹的叶绿素含量及组分因生境条件不同而各异,在各生境下Chl a约占总量的79%,与Chl总量的相关性达到极显著水平(R^2=0.88,P<0.001);Chl b约占总量的21%,与Chl总量的相关性也达到极显著水平(R^2=0.81,P<0.001),但不及Chl a.在开花物候期内,各生境下光照强度对光合色素含量的影响也不一致,表现出光照强度显著高于B、C而树龄低于W的G,其Chl、Chl a、Chl b、Car含量皆显著低于C、B、W(P<0.05).在开花的物候表现上,经历萌芽、抽梢、展叶后约40d,太阳辐射强度日均总量2 100 W/m^2或在当日12:00-14:00辐射强度达到或大于470 W/m^2并持续4 d以上的蓝花楹即可进入开花状态.本研究表明,在蓝花楹开花物候期前后光照强度对其开花有显著影响,开花物候表现与光合色素含量及变化无关系.

This paper attempts to explore the effects of light intensity on the growth and development and f lowering of Jacaranda mimosifolia D. Don, so as to provide some technical and theory support for landscape management in specific habitats. The test materials were 20–60 year old adult J. m imosifolia D. Don from 4 different habitats in Wenjiang of Chengdu, Sichuan Province, including Wenjiang Park（W）, Guanghua Avenue（G）, Sichuan Agricultural University region B（B） and region C（C）. The solar radiation intensity was measured for different habitats i n the same period, or for different habitats in different periods by using digital luxmeter（250 lx/（W m^-2））. The experiment also determined the content of chlorophyll（Chl）, chlorophyll a（Chl a）, chlorophyll b（Chl b） and carotenoids（Car） during the flowering phenophase. The results showed that the content and composition of Chl was different depending on the habitats, among which Chl a accounted for 79%（R^2 = 0.88, P 0.001） and Chl b accounted for 21%（R^2 = 0.81, P 〈0.001）. During the flowering phenophase, the J. mimosifolia in habitat G, though of similar age with those of the other three ones, had significantly lower content of Chl, Chl a, Chl b and Car（P〈 0.05）. Plants under 2 100 W/m^2 daily or 470 W/m^2 during 12：00-14：00 began spiking（an elongated flowering branch protruding through the base） in 4 days after sprouting and leafing. The results indicated that light intensity influences the flowering of J. mimosifolia D. Don in different habitats.