Cardinal temperatures for germination of Salvia leriifolia Benth

Abstract

Summary The focus of this study is based on the examination of the germination traits and the development of thermal models of the medicinal plant Salvia leriifolia Benth. A laboratory experiment was carried out at constant temperatures ranging from 0 to 35°C, at 5°C intervals in a completely randomized design with eight replications. To describe the germination rate response to temperature, three regression models, namely Intersected-Lines (ISL), Quadratic Polynomial (QPN) and Five-Parameters Beta (FPB) were used. The highest Germination Percentage (GP) (92.8%) occurred in 15°C, but GP in the range of 10-25°C was not significant (p≤0.05). The germination process stopped at 0°C and at above 30°C. The results indicated that the highest Germination Rate (GR), the lowest Mean Germination Time (MGT) and also times to 50% germination (D50) were obtained at 20°C. Seeds did not reach to their 50% germination level in temperatures higher than 25°C. The FPB model had the best realistic estimation for cardinal temperatures. Based on models estimation, Base (Tb), Optimum (To) and Ceiling (Tc) temperatures were in the ranges of (1-1.9°C), (18.1-20.8°C) and (34.5-38.7°C), respectively.

Estimation of the cardinal temperatures for germination of four Satureja species growing in Iran

“…Similar results have been reported for GP, MGT and GR m of most plant species [20,22,26,42,43]. Most reports showed that increased temperature up to optimum followed by increased GR but declined thereafter [35,44,45].…”

“…Khalili et al [43] and Heidari [28] reported Beta model to be the best one for interpreting germination rate of savory (Satureja hortensis) and milk thistle (Silybum marianum L.). Beta function model have been used by Jame and Cutforth [30], Dashti et al [35] and Parmoon et al [62] as the best-fitting output for cardinal temperatures, by its higher R 2 and lower RMSE. Tabrizi et al [34] also reported that FPB and ISL were the best fitted models for cultivated and natural stand seeds of Thymus transcaspicus.…”

“…There are various mathematical models describing germination responses to temperature, among which three have been used more often: intersected lines (ISL), quadratic polynomial (QPN) and five-parameters beta (FPB) [22,28,34,35].…”

Evaluación de tratamientos pregerminativos en semillas de Prosopis caldenia

“…A partir de los datos de germinación, por medio de métodos analíticos, se elaboraron los siguientes índices de germinación: Tasa de germinación [4] (TG) durante el periodo para cada tratamiento, según la siguiente ecuación (Dashti et al 2015), [4] Donde TG: tasa de germinación, n i : número de semillas recién germinadas en el momento t i , t i : tiempo (días) desde el inicio de la observación de la prueba de germinación y K: último día del experimento. Velocidad de germinación [5] (González-Zertuche y Orozco-Segovia 1996).…”

Quantifying Cardinal Temperatures of Chia (Salvia hispanica L.) Using Non-Linear Regression Models

“…reached the highest final germination at 25 • C, compared with 4 • C and 10 • C [50], while Noroozak (Salvia leriifolia Benth.) has an optimal range between 15 and 25 • C, with a calculated Tb, To, and Tc of 1.00 • C, 19.0 • C, and 36.5 • C, respectively [51]. On the other hand, in an analysis conducted on 11 different medicinal plants [52], including two belonging to the Salvia genus, it was observed that Salvia sclarea L. and Salvia nemorosa L. reached the highest final germination and GR in the treatments at 20 The GR observed in our analysis was 1.4-fold and 2.2-fold higher than the one previously reported by Nadtochii et al [53] for 25 • C, and 30 • C (13.1 ± 0.1 and 9.7 ± 0.1), while at 20 • C, the GR was similar between the works (12.6 ± 0.1 and 12.75 ± 0.72, respectively).…”