施肥对黄栀子幼苗生长与光合特性的影响

Effects of Fertilization on Growth and Photosynthetic Characteristics of Gardenia jasminoides Seedlings

以1年生黄栀子(Gardenia jasminoides)实生苗进行土壤盆栽试验;试验肥料分别为氮肥(尿素,N质量分数为46%)、磷肥(过磷酸钙,P_(2)O_(5)质量分数为14%)、钾肥(硫酸钾,K质量分数为60%),以不施肥处理作为对照(CK);施肥设计3种组合,T_(1)(施N肥0.25 g/株、施P肥0.20 g/株、施K肥0.10 g/株)、T_(2)(施N肥0.50 g/株、施P肥0.20 g/株、施K肥0.20 g/株)、T_(3)(施N肥0.75 g/株、施P肥0.20 g/株、施K肥0.30 g/株),共4个处理,每个处理3次重复,每个重复10株,共120株;处理30d后,进行各评价指标的测定。以黄栀子幼苗株高、地径、叶面积、叶片叶绿素质量分数、光合日变化以及光饱和点、光补偿点、暗呼吸速率为评价指标,分析氮磷钾平衡施肥对黄栀子光合特性的影响,优化黄栀子幼苗氮磷钾的施肥设计。结果表明:不同施肥配比的黄栀子幼苗株高、地径、叶面积、生物量与对照相比,均有显著性提高。黄栀子幼苗净光合速率日变化、气孔导度日变化,均呈“双峰”趋势,且两者呈正相关关系;胞间CO_(2)摩尔分数呈先下降后上升趋势,与净光合速率呈负相关关系。T_(3)处理,氮肥、钾肥的增施,提高了黄栀子幼苗叶片叶绿素质量分数、净光合速率,叶绿素质量分数高出对照99.30%。各处理间,表观量子效率无差异,光饱和点随着氮肥、钾肥增施均有增加,光补偿点、暗呼吸速率随着氮肥、钾肥增施则不断减少。T_(3)处理的苗木,具有高饱和点、低补偿点、低暗呼吸速率,说明T_(3)处理的黄栀子苗木具有较强的光合能力。综合考虑认为,在供试的3个施肥处理中,T_(3)处理最有利于黄栀子幼苗生长,同时增强其光合能力。

Annual Gardenia jasminoides seedlings were used for soil pot experiment.The test fertilizers were nitrogen fertilizer(urea,N mass fraction of 46%),phosphate fertilizer(superphosphate,P_(2)O_(5) mass fraction of 14%),potassium fertilizer(potassium sulfate,K mass fraction of 60%),and no fertilization treatment was used as a control(CK);three combinations of fertilization designs,T_(1)(N fertilizer 0.25 g/ind.,P fertilizer 0.20 g/ind.,K fertilizer 0.10 g/ind.),T_(2)(N fertilizer 0.50 g/ind.,P fertilizer 0.20 g/ind.,K fertilizer 0.20 g/ind.),T_(3)(N fertilizer 0.75 g/ind.,P fertilizer 0.20 g/ind.,K fertilizer 0.30 g/ind.),a total of four treatments,each treatment for three times’repeat,ten strains each,for a total of 120 strains.After 30-d treatment,the measurement of each evaluation index was performed.Taking the plant height,ground diameter,leaf area,leaf chlorophyll mass fraction,photosynthetic diurnal variation,light saturation point,light compensation point,and dark respiration rate of G.jasminoides seedlings as evaluation indicators,the effects of nitrogen,phosphorus and potassium balanced fertilization on the photosynthetic characteristics of Gardenia jasminoides were analyzed.Optimizing the fertilization design of N,P and K for G.jasminoides seedlings.The plant height,ground diameter,leaf area and biomass of G.jasminoides seedlings with different fertilization ratios were significantly increased compared with the control.The diurnal variation of net photosynthetic rate and stomatal conductance of G.jasminoides seedlings showed a“double peak”trend,and the two were positively correlated;the intercellular CO_(2)mole fraction first decreased and then increased,which was negatively correlated with the net photosynthetic rate.In T_(3)treatment,with the increase of nitrogen and potassium fertilizers,the chlorophyll mass fraction and net photosynthetic rate of leaves of G.jasminoides seedlings were increased,and the chlorophyll mass fraction was 99.30%higher than that of the control.There was no difference in apparent quantum efficiency among treatments,the light saturation point increased with the increase of nitrogen and potassium fertilizers,and the light compensation point and dark respiration rate decreased continuously with the increase of nitrogen and potassium fertilizers.The seedlings treated with T_(3) had high saturation point,low compensation point,and low dark respiration rate,indicating that the seedlings of G.jasminoides treated with T_(3) had strong photosynthetic capacity.In conclusion,among the three fertilization treatments tested,treatment T_(3)was the most beneficial to the growth of G.jasminoides seedlings,and at the same time enhanced its photosynthetic capacity.