Abstract
This study was carried out to identify the optimum condition for priming, as a series of experiments for the enhancement of germination percentage and germination synchronization in cool-season turfgrass seeds. The optimum priming conditions to maximize the germinability in both Kentucky bluegrass and Tall fescue was a 1 day treatment of 100 mM $K_3PO_4$ at $25^{\circ}C$. The seeds treated with the optimum priming condition enhanced the germinability compared to control, and shortened the time for germination with reduced $T_{50}$ and mean daily germination (MDG). However, as the concentration and treatment period of NaOH or KOH increased, significantly decrease in germination percentage was observed. Germination percentage in Creeping bentgrass and Bentgrass was below 10%, regardless of priming treatment. However, the priming treatment with 200 mM $KNO_3$ for three days improved the germination up to 6%, which was not a statistically significant level. The most effective priming period for Kentucky bluegrass and Tall fescue was one day treatment, but the germinability was suppressed as the treatment period was extended until six days. For priming chemical treatment, germinability was improved with the concentration of 100 mM, while it was reduced at higher concentrations of 200 mM and 300 mM.
Kentucky bluegrass와 Tall fescue에서는 발아력을 극대화시킬 수 있는 priming 최적 처리 조건은 100mM의 $K_3PO_4$ 용액으로 $25^{\circ}C$에서 1일간 처리였다. Priming 처리된 종자는 무처리에 비해 높은 발아율을 보였고, $T_{50}$과 MDG가 단축되어 신속한 발아를 유도하였다. 반면 NaOH나 KOH는 처리농도가 높아지고 처리기간이 길어질수록 발아력이 급격하게 저하되어 priming 화학제로는 적당하지 않았다. Creeping bentgrass 및 Bentgrass에서는 priming 처리에 관계없이 발아율이 10% 미만으로 낮았다. 그러나 200mM의 $KNO_3$ 로 3일간 priming 처리하면 발아율을 6%까지 향상시킬 수 있었으나, 현저한 수준은 아니었다. Kentucky bluegrass와 Tall fescue에서 priming 처리 기간은 1일 처리가 발아율 향상에 가장 좋았고, 처리 기간이 6일로 길어질수록 발아율이 저하되었고 발아 속도는 지연되었다. 또한 priming 화학제의 처리 농도는 100 mM 처리가 발아력 증진에 좋았으나, 200 mM과 300 mM로 처리농도가 높아지면 발아율이 감소하였다.
