Table 4.

Media used for the Polyethylene glycol 4000 (PEG4000) concentration test

Treatment	pH	Sucrose (g/L)	PEG4000 (g/L)	Boric acid (mg/L)	Calcium nitrate (mg/L)	Germination rate (%)
PEG4000 medium 1	6.0	50	0	100	200	46.4 ± 7.8
PEG4000 medium 2	6.0	50	50	100	200	73.5 ± 5.0*
PEG4000 medium 3	6.0	50	100	100	200	62.2 ± 7.8*
PEG4000 medium 4	6.0	50	150	100	200	34.1 ± 12.8
PEG4000 medium 5	6.0	50	200	100	200	12.7 ± 2.1
PEG4000 medium 6	6.0	50	250	100	200	11.8 ± 3.0
PEG4000 medium 7	6.0	50	300	100	200	11.2 ± 2.8

Germination rate is the mean ± SD of five replicates. * Indicates the first echelon of multiple comparison results. The ANOVA results showed that pollen germination rates differed significantly (P < 0.001) between treatments with different PEG concentrations