CAJ | 학술논문

Biomass allocation,photosynthesis and root morphology of Padus maackii one-year-old bare-root seedlings under constant fertilization ( CF ) , exponential fertilization ( EF ) , doubled exponential fertilization ( DEF ) and no fertilization (CK) regimes were investigated. 1) By the end of the growing season,the root/shoot ratio of seedlings under EF treatment was maximum,and was 6. 7%,14. 3%,23. 1% greater than that with CK,CF and DEF treatment ( P <0. 05),respectively. 2) The order of seedling height and collar diameter with different fertilization was EF>DEF>CF>CK. Seedling height and collar diameter of EF treatment was 16. 6% and 28. 1% higher than those of CK,respectively ( P<0 . 05 ) . 3 ) Tap root length of seedlings under different fertilization treatments was in an order of CK >EF >CF >DEF. The number of first-order lateral root of EF was 19,and more than that with CK,CF,DEF treatment (P<0. 05). 4) Photosynthetic rate of EF treatment was 11 . 66 μmol · m -2 s -1 ,and was 17 . 7% ( P <0 . 05 ) ,7 . 2% ( P <0 . 05 ) and 4. 2% (P>0. 05) greater than that with CK,CF and DEF treatment,respectively. 5) Compared with OF treatment, average length of first-order roots ( absorptive roots ) under EF and DEF treatment was 15 . 8%,16 . 7% higher ( P <0. 05 ) ,respectively; Average diameter of first-order roots under EF and DEF treatment was 5 . 3%,2 . 1% greater than that with CF treatment ( P>0 . 05 ) ,respectively; Specific root length of first-order root under EF and DEF treatment was 13. 9%,14. 7% longer than that with CF treatment (P >0. 05),respectively. The fifth-order root of EF treatment had greater average length,average diameter and specific root length compared with CF treatment. Exponential fertilization regimes effectively promoted photosynthetic rate and improved root morphology, meanwhile, increased biomass accumulation and nutrient absorption in P. maackii seedlings.