Effects of different levels of phosphorus availability on growth and phosphorus absorption of "Chinese Long" sequenced cucumber genotype

Objective To explore the responses of "Chinese long" sequenced cucumber genotype to different phosphorus (P) availability, and to screen an optimal low-P-treatment concentration for cucumber germplasms screening for P efficiency under a hydropoic condition.

Method Hydroponic culture was used to test effects of different P availability on the growth and P absorption of "Chinese Long".

Result and conclusion The results showed that with the decrease in P availability, cucumber plants became shorter and smaller, and new leaves became smaller and old leaves became yellow. Severe P deficiency (10 and 1 μmol·L^-1) significantly inhibited the cucumber plant growth, even resulting in abnormal fruits. Low P availability decreased the biomass and P uptake efficiency of "Chinese Long", but increased its ratio of root to shoot, which preferably allocated carbonhydrate to root. Furthermore, under P deficiency, "Chinese Long" also formed finer roots with a small root diameter, thus increasing the contact area with nutrients in the growth medium. The P concentration of 10-100 μmol·L^-1, for example 50 μmol·L^-1, can be used to screen the cucumber germplasms for P efficiency.