狗牙根生长及叶绿素荧光对水分和种植密度的响应

Response of growth and chlorophyll fluorecence characteristics of Cynodon dactylonseedlings to water treatment and plant densities

以盆栽当年生狗牙根(Cynodon dactylon)扦插苗为试验材料,通过模拟水库库区河岸带不同土壤水分及不同种植密度对狗牙根生长、光合色素及荧光特性的影响进行探究。试验设置4个土壤水分处理组:水分对照组(CK)、水淹与干旱交替组(FD)、土壤水分饱和组(LF)和全淹组(FL),4种种植密度:对照(1株·盆-1)、低密度(2株·盆-1)、中密度(4株·盆-1)及高密度(12株·盆-1)。结果表明,1)水分、种植密度及二者的交互作用均显著影响狗牙根叶面积指数、单株总生物量及主茎长(P<0.05)。2)水分、种植密度及二者的交互作用均显著影响狗牙根总叶绿素含量、胡萝卜素含量、叶绿素a/叶绿素b及总叶绿素含量/类胡萝卜素含量(P<0.05);3)水分处理显著影响PSⅡ最大光能转换效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)及光化学猝灭系数(qP)(P<0.05);密度处理对狗牙根叶绿素荧光特性各项指标均无显著影响(P>0.05);二者交互作用显著影响狗牙根光化学猝灭系数(qP)(P<0.05)。本研究表明,可考虑将狗牙根用于水库库区河岸带的植被重建,种植密度以中密度为优。

In order to explore the effects of different water treatments and plant densities on growth,photosynthetic pigments and chlorophyll fluorescence of Cynodon dactylon,4water treatments and 4planting densities including 16 treatments were applied.The water treatments included normal water supply（CK）,light flooding-light drought alternating（FD）,light flooding（LF）and flooding（FL）and planting densities included 1plant per pot（CK）,2plants per pot（low density）,4plants per pot（medium density）,and 12 plants per pot（high density）.The results showed that water treatments,plant densities and their interaction significantly affected（P〈0.05）the total leaf area,total biomass per plant,main stem length,the total chlorophyll,carotenoid content,the ratios of chlorophyll a/chlorophyll b and total chlorophyll/carotenoid in C.Dactylon although the ratios of the chlorophyll a/chlorophyll b and total chlorophyll/carotenoid of each treatment can stay a normal level.Water treatment significantly affected（P〈0.05）the values of Fv/Fm,Fv/Foand qPand the interaction of water treatments and plant densities significantly affected（P〈0.05）the values of qP although plant densities had little effect on fluorescence properties.These results suggested C.dactylon may be suitable for ecological restoration in the riparian zone with medium density.