樱桃番茄对根际外源碘的吸收及生理反应特性

在深液流水培的营养液中添加浓度为1.0—6.0mg.L-1的碘离子栽培樱桃番茄.根系、叶片和果实的碘含量均表现随着I-浓度提高而增加的趋势.根系的碘含量在I-处理后1周迅速增加；第2周降低,此后呈现逐渐增加的趋势,而且中高浓度处理(3.0～6.0 mg·L-1)的变化趋势比低浓度处理（1.0～2.0mg·L-1）明显....

Absorption of exogenous iodine in rhizosphere and its effects on physiological parameters of cherry tomato plants

Cherry tomatoes(Lycopersicon esculentum var.cerasiforme)were cultured in deep flow hydroponic solution supplemented with graded levels(1.0-6.0 mg·L-1)of iodide(I-).The results showed that the iodine content in roots,leaves and fruits increased with increasing of I-concentration.After I-treatment,initially,the iodine content in roots increased rapidly for the first week;a decrease in the second week followed;and afterwards,a tendency of gradual increase was observed,with more significant changes at higher concentrations of I-(3.0-6.0 mg·L-1) as compared to lower ones(1.0-2.0 mg·L-1).During the first three weeks after the I-treatment,the iodine content in leaves increased significantly with the passage of time;after the third week,the increase tended to slow down for the plants treated with high concentrations of I-(4.0-6.0 mg·L-1),while no significant changes were found at medium or low ones(1.0-3.0 mg·L-1).For plants with I-treatment of 1.0 mg·L-1,the iodine content in roots was higher than that in leaves;for I-treatment of 2.0-6.0 mg·L-1,the iodine content in roots was higher than that in leaves at the early growth stage,but lower than leaves at the later growth stage,which suggested that iodine did not transfer to leaves until it had accumulated in the roots to a certain amount.Making mono-factor and two-factor regression analyses respectively of the correlation between the iodine content in ripen fruits and that in the leaves and the roots after I-treatments of 1-6 weeks,we found that it was the first week after I-treatment that the iodine content in fruits was affected most,and the iodine content in ripen fruits could be predicted with the iodine content in leaves and roots using the dualistic linear regression equation.The I-concentration of 2.0-6.0 mg·L-1 significantly affected the deoxidize amount of triphenyl tetrazolium chloride(TTC) in roots,and the influence mainly appeared within the first three weeks after adding I-to the solutions.The low concentrations of I-(1.0-2.0 mg·L-1) did not affect chlorophyll content significantly,but the medium or high concentration of I-(3.0-6.0 mg·L-1) significantly reduced it.Two weeks after treatment with I-concentration of 2.0-6.0 mg·L-1,the photosynthetic rates(Pn),stomatal conductance(Gs),intercellular CO2 concentration(Ci),transpiration rates(Tr)significantly reduced,while the stomatal limitation values(Ls) increased significantly.