液培条件下磷水平对两种磷效率小麦根际特征的影响

Effect of phosphorus levels on rhizospheric characteristic between the different phosphorus efficiency wheats under liquid culture condition

为探讨磷高效型小麦(小偃54)和磷低效型小麦(京411)在不同磷水平下根际特征的差异,测定了液培条件下苗期小麦的植株生物量和吸磷量、根际pH值与根系分泌的酸性磷酸酶活性等。结果表明,不同磷水平(P0:0、P1:0.5 mmol/L和P2:1 mmol/L)下,磷高效型小偃54的植株吸磷量和根部生物量从移苗第6 d起明显高于磷低效型京411,在P0水平下尤为明显,且随培养时间的延长两者差距逐渐增大;小偃54的根际pH值在移苗初期与京411并无明显差异,随着培养时间的延长,小偃54的根际pH值显著低于京411,但两者单位根系分泌质子量差异逐渐减小。从移苗第6 d到第18 d,小偃54在不同磷水平下酸性磷酸酶的分泌量均显著高于京411;小偃54在P0水平下根系分泌的酸性磷酸酶量显著高于P1和P2水平,而京411从第12 d起才有相同规律,小偃54比京411对磷胁迫反应快且强度大。由此可见,在不同磷水平下,磷高效型小偃54在苗期的各项测定指标均优于磷低效型京411,在P0水平下两者根际特征差异尤为显著,且两种小麦根际特征差异与苗期生长天数有很大的关系。

To investigate rhizosphere characteristic differences between the phosphorus-high efficiency wheat （Xiaoyan 54） and phosphorus-low efficiency wheat （Jing 411） under the different P treatments,plant biomass,P uptake,rhizospheric pH and root secretion of acid phosphatase activity were measured with liquid culture condition at the wheat seedling stage.The results showed,under the different P treatments （P0：0,P1：0.5 mmol/L and P2：1.0 mmol/L）,Xiaoyan 54 for root biomass and plant P uptake indexes was significantly higher than Jing 411 from the 6th day of transplant seedlings,especially,for P0 treatment,their differences were greater with gradually increasing culture time; there was no significant difference on the rhizospheric pH between Xiaoyan 54 and Jing 411 when transplant seedings,and rhizospheric pH of Xiaoyan 54 was significantly lower than Jing 411 with the growth of culture time,but differences of unit root secretion proton between them were gradually decreased.From 6th day to 18th day of the transplant seedlings,acid phosphatase activity of Xiaoyan 54 was significantly higher than Jing 411 under three phosphorus levels; and acid phosphatase activity of Xiaoyan 54 with P0 treatment were significantly higher than with P1 and P2,however,Jing 411 had the same as the above results from the 12th day; compared to Jing 411,Xiaoyan 54 was response of fast and strength under conditions of low phosphorus.In a word,Xiaoyan 54 for the indexes measured were better than Jing 411,and their differences between them were particularly evident under P0 treatment in the seedling stage and related to the growth stages.