Supplemental Table 1: Real-time PCR primers, accession number and expected amplicon sizes of genes

Target gene / Accession number / Forward primer (5'to 3') / Reverse primer (5'to 3') / Product size (bp) / Tm
(℃)
AIV1 / AB334115.1 / ATCATTCGATCGTGGAAAGC / TGGGAAAGGATGAATGAAGG / 181 / 58.00
AIV2 / AB334116.1 / CCCAACCAAGGCAATTTATG / GGTTTAAGCTTGCGTTGCTC / 152 / 58.00
SPS1 / AB334114.1 / GAAGGATGCTCCCAAAATGA / GCGGTTCACACTGTAGCAGA / 248 / 60.00
SUS1 / AB045710.1 / GAGACCCGACGTTATCTGGA / GTTTGGGGGTCACCCTTAGT / 244 / 62.00
SUT1 / KC801340 / GTAACAGAACTACACCCTTTGCTG / GACCCATCCAATCAGTATCAAAG / 188 / 53.00
S6PDH / KC506733 / CAACAAACCTGGGAGGGCATG / GAGGGGTGTGAGCTGTGGGAA / 217 / 49.60
SDH1 / KC506730 / AGTTTAACCTTTTGGCCGGTCCCTTT / CGCCTCTACTAGAAATGTGATACCAAATGC / 151 / 58.00
SDH2 / KC506731 / CCTCACCCCTGCTGCTGCTA / CCCGCCCTCTACATTCTACG / 266 / 65.00
SDH3 / KC506732 / ATTTCGGATTCATCGAGAGGACAGGT / TGTGGTGCATGCCGAGATCTAATACA / 155 / 55.70
SOT2 / AB719045 / AAGGGCCAAGACGTCTGGAA / AGGCCTGCTGAAAGAAATGG / 100 / 61.00
SOT3 / AB719046 / TCGCCACGGTTTTCCTTGAT / CGTGCTGTTGATCGACGATT / 120 / 60.00
ACTIN / JN684184.1 / CCATCCAGGCTGTTCTCTC / GCAAGGTCCAGACGAAGG / 139 / 60.00

Supplemental Table 2:Effect of K application rates on leaves and fruit K concentration of Asian pear in 2014-15

Stages / 2014 / 2015
Control / K150 / K300 / K450 / Control / K150 / K300 / K450
Leaf K concentration
（% DW） / Young fruit stage / 1.69±0.06bA / 1.74±0.05bA / 1.83±0.05aA / 1.87±0.04aA / 1.64±0.14bB / 1.66±0.13bB / 1.65±0.10bBC / 1.88±0.18aB
Enlargement phase I / 1.58±0.02cB / 1.76±0.07aA / 1.70±0.07abAB / 1.67±0.05bB / 1.64±0.05cB / 1.79±0.05abB / 1.73±0.05bcB / 1.82±0.09aB
Enlargement phase II / 1.46±0.05cC / 1.63±0.08bB / 1.67±0.06abB / 1.73±0.04aB / 1.63±0.04cB / 1.69±0.05cB / 1.94±0.04bA / 2.20±0.15aA
Maturity / 1.34±0.02cD / 1.35±0.04bcD / 1.40±0.01abC / 1.44±0.04aC / 1.45±0.02bC / 1.45±0.10bC / 1.53±0.07bC / 1.64±0.10aC
One month after harvest / 1.40±0.10bC / 1.45±0.07bC / 1.68±0.08aB / 1.73±0.11aB / 1.82±0.07cA / 2.00±0.01abA / 1.93±0.02bA / 2.04±0.02aAB
Fruit K concentration （% DW） / Young fruit stage / 1.52±0.06bA / 1.68±0.05aA / 1.58±0.06bA / 1.56±0.05bA / 1.63±0.06bA / 1.64±0.03bA / 1.70±0.77abA / 1.75±0.08aA
Enlargement phase I / 1.28±0.02abB / 1.35±0.05aB / 1.23±0.06bB / 1.28±0.06abB / 1.42±0.05aB / 1.41±0.09aB / 1.41±0.07aB / 1.47±0.10aB
Enlargement phase II / 1.14±0.06cB / 1.21±0.06bC / 1.28±0.05aB / 1.19±0.05bcC / 1.32±0.08aB / 1.27±0.06aC / 1.35±0.09aB / 1.31±0.06aBC
Maturity / 0.94±0.03cC / 1.01±0.05bD / 1.05±0.06abC / 1.07±0.04aD / 1.23±0.05bC / 1.33±0.08aBC / 1.33±0.04aB / 1.32±0.04aC

Note：The experiment was set up with four K2O levels: 0 (control), 150 (K150), 300 (K300) and 450 (K450) kg ha-1. The data was separated within the same line.The leaves and fruits samples were collected atyoung fruit stage (10/5), enlargement phase I (22/6), enlargement phase II (20/7), maturity (11/8), one month after harvest (11/9) in 2014 and repeatedat young fruit stage(11/5), enlargement phase I (16/6),enlargement phase II (16/7),maturity(16/8) in 2015.Different lowercaseletters indicate significant differences between means at same row and differentuppercase letters significant differences between means at same column at different fruit development stages (Tukey’s test, P <0.05). DW: dry weight

Supplemental Table 3 Effect of K application rates on leaves and fruit K accumulation of Asian pear in 2014-15

Stages / 2014 / 2015
Control / K150 / K300 / K450 / Control / K150 / K300 / K450
Leaf K accumulation
（g plant-1DW） / Young fruit stage / 77.36±2.44abC / 74.93±2.74bC / 80.80±1.33abB / 84.37±6.56aB / 68.97±3.57dC / 74.95±3.10cC / 88.54±4.08bC / 90.79±1.85aE
Enlargement phase I / 92.82±1.78cA / 95.57±3.37bA / 97.81±4.09abA / 99.20±1.42aA / 68.98±0.28cC / 85.39±2.15bB / 92.33±1.12bC / 96.03±0.14aD
Enlargement phase II / 91.87±1.26bA / 93.43±1.09bA / 96.94±1.68abA / 97.92±1.23aA / 87.77±2.78cA / 104.68±1.27bA / 121.72±3.67aA / 114.11±0.48aA
Maturity / 83.51±3.26bB / 89.05±8.95abAB / 93.38±6.87abA / 97.03±0.25aA / 71.93±1.01dB / 81.92±0.34cB / 105.98±2.70bB / 108.26±3.28aB
One month after harvest / 83.21±6.65aB / 83.88±1.66aB / 84.25±10.39aAB / 84.68±1.61aB / 71.46±1.05dB / 78.06±1.95cC / 105.50±1.11bB / 101.61±2.25aC
Fruit K accumulation
（g plant-1 DW） / Young fruit stage / 4.74±0.52aD / 5.00±0.28aD / 4.99±0.11aD / 3.90±0.40aD / 3.65±0.20cD / 4.32±0.27bD / 4.97±0.22bD / 5.19±0.30aD
Enlargement phase I / 39.43±2.58aC / 39.53±2.92aC / 40.45±2.96aC / 41.69±1.55aC / 8.69±0.19cC / 11.15±0.67bC / 11.97±0.43bC / 12.84±0.35aC
Enlargement phase II / 70.59±4.11cB / 81.05±3.31bB / 88.77±6.17abB / 91.29±2.64aB / 45.07±0.44bB / 43.37±1.08bB / 52.16±0.58aB / 54.66±3.14aB
Maturity / 82.88±2.10cA / 100.89±4.23bA / 105.52±3.37abA / 107.70±2.17aA / 75.54±0.81dA / 85.69±2.73cA / 103.80±2.40bA / 108.83±2.96aA

Note：The experiment was set up with four K2O levels: 0 (control), 150 (K150), 300 (K300) and 450 (K450) kg ha-1. The data was separated within the same line.Based on leaf to fruit ratio as 37:1 in Asian pear, the total K accumulation in leaves and fruit were calculated according to the following equation: Leaf K accumulation (kg plant-1) = leaf biomass (kg plant-1)×leaf K concentration (%)×10-2. Fruit K accumulation (kg plant-1) = fruit biomass (kg plant-1)×fruit K concentration (%)×10-2. DW: dry weight.Different lowercase letters indicate significant differences between means at same row and different uppercase letters significant differences between means at same column at different fruit development stages (Tukey’s test, P <0.05).

Supplemental Fig. 1:The effect of K application rates on leaf net photosynthetic rate (a) and SPAD (b) in 2014-15. The experiment was set up with four K2O levels: 0 (control), 150 (K150), 300 (K300) and 450 (K450) kgha-1. Different letters indicate significant differences between means (Tukey’stest, P <0.05).

Supplemental Fig. 2: The effect of different K application rates on the dynamic changes of average single fruit weight in the consecutive 2 years (2014 and 2015).The histogram represents the average single fruit weight and the scatter diagram represents the fruit yield. The experiment was set up with four K2O levels: 0 (control), 150 (K150), 300 (K300) and 450 (K450) kg ha-1. Different letters indicate significant differences between means (Tukey’s test, P <0.05).

Supplemental Fig. 1

Supplemental Fig. 2