본 연구의 목적은 선형, 쌍곡선, 베타 함수를 이용하여 상추의 주요 온도를 예측하기 위함이다. 상추 종자를 항온 생육상에서 발아시켰다. 온도처리는 $10^{circ}C$, $14^{circ}C$, $16^{circ}C$, $20^{circ}C$, $24^{circ}C$, $28^{circ}C$와 $32^{circ}C$였다. 100개의 종자를 9cm 페트리디쉬에 필터페이퍼 2장을 깔고 4반복 실시하였다. 유근이 1mm 나왔을 때를 발아로 하였다. 시간에 따른 발아율은 로지스틱 함수로 계산하였다. 최저, 최적, 최고 온도는 50% 발아한 시점의 역수를 온도에 따른 함수로 표기하여 나타내었다. 선형 함수의 경우, 최저, 최적, 최고 온도는 각각 $7.9^{circ}C$, $23.3^{circ}C$, $28.0^{circ}C$였으며, 쌍곡선 함수의 경우, 최저, 최적, 최고 온도는 각각 $9.7^{circ}C$, $19.5^{circ}C$, $29.4^{circ}C$였으며, 베타 함수인 경우, 최저, 최적, 최고 온도는 각각 $3.7^{circ}C$, $20.7^{circ}C$, $32.0^{circ}C$였다. 최저, 최적, 최고 온도 범위는 각각 $3.7{sim}7.9^{circ}C$, $19.5{sim}23.3^{circ}C$, $28.0{sim}32.0^{circ}C$이었다.
The objective of this study was to estimate cardinal temperatures for germination of lettuce (Lactuca sativar L.) using bilinear, parabolic, and beta distribution functions. Seeds of lettuce were germinated in a growth chamber at 7 constant temperatures: 10, 14, 16, 20, 24, 28, and $32^{circ}C$. Four replicates of 100 seeds were placed on two layers of filter paper in a 9 cm petri-dish. Radicle emergence of 1 mm was scored as germination. The time course of germination was modeled using a logistic function. These minimum, optimum, and maximum temperatures were estimated by regression of the inverse of time to 50% germination rate against the temperature gradient. In bilinear function, minimum, optimum, and maximum temperatures were $7.9^{circ}C$, $23.3^{circ}C$, and $28.0^{circ}C$, respectively. In parabolic function, minimum, optimum, and maximum temperatures were $9.7^{circ}C$, $19.5^{circ}C$, and $29.4^{circ}C$, respectively. In beta distribution function, minimum, optimum, and maximum temperatures were $3.7^{circ}C$, $20.7^{circ}C$ and $32.0^{circ}C$, respectively. Minimum, optimum, and maximum ranges of temperatures were $3.7{sim}9.7^{circ}C$, $19.5{sim}23.3^{circ}C$, and $28.0{sim}32.0^{circ}C$, respectively.
