不同品种茶树生长对氮素浓度的响应差异

Growth Characteristic of Different Cultivars of Tea Plant in Response to Nitrogen Contents

利用盆栽沙培法,研究了铁观音、福鼎大白茶、黄旦等6个基因型茶树对氮素浓度的响应差异。试验表明:(1)在低氮胁迫下茶树株高、根干重、地上部重、叶片SPAD值等显著降低;茶树根重、根冠比与茶树总生物量之间呈显著正相关(P<0.05)。(2)不同基因型茶树对氮素吸收利用能力差异较大,其中福鼎大白茶、春闺属低氮高效基因型。(3)低氮胁迫下,茶树根冠比显著增加,铁观音根冠比的变异幅度最大,为20.97%;基因型对茶树根冠比具有决定作用,不同基因型茶树根冠比的差异很大,如铁观音仅为0.71,春闺为1.81。(4)在低氮条件下,根冠比与叶片SPAD值可作为筛选耐低氮茶树品种的参考指标。

Vegetative propagatedplantsof6tea cultivarsweresand cultured in pots andfertilizedwithnutrient solution containing 0, 0.06, 0.60and 6.00mmol/L nitrogen.The growth characteristicsof tea plantswere analyzed underthefournitrogenlevels.The results showed:(1)Plant height, root FW, shoot FWandSPADvalue of leaves decreased significantly undernitrogen deficiency stress.Total biomassshowedpositivecorrelationswithroot FW androot shoot radio(P<0.05).(2)The nitrogen utilization abilities were variedwidely with the genotypes oftea plant. Among 6 tea cultivars, ‘Fudingdabaicha’and ‘Chungui’ were identified to the genotypeswithhigh use efficiencyunderthe low nitrogen content.(3)The root shoot ratios were higherundernitrogen deficiency stressand the maximalvariation range was 20.97% as in ‘Tieguanyin’.Root shoot ratiodiffered significantly bygenotypes. The root shoot ratios for ‘Tieguanyin’ and ‘Chungui’ were 0.71 and 1.81,respectively.(4)It was demonstrated that root shoot ratioand SPAD valuesunder nitrogen deficiency stress could beused asscreening indexesfor low-N toleranttea cultivar.