mohsen zafaranieh; arman Azari
Abstract
The present study tries to quantify germination response of Guar (Cyamopsis tetragonoloba) to temperature and water potential. Performed in Vali-e-Asr University laboratory in 2020, it is a completely randomized design in a factorial arrangement with four replications. It aims at quantifying the rate ...
Read More
The present study tries to quantify germination response of Guar (Cyamopsis tetragonoloba) to temperature and water potential. Performed in Vali-e-Asr University laboratory in 2020, it is a completely randomized design in a factorial arrangement with four replications. It aims at quantifying the rate of Guar germination in response to temperature, and water potential. The seeds have been germinated at seven temperatures (5, 10, 15, 20, 25, 30, and 35°C) and six water potentials (0, -0.2, -0.4, -0.6, -0.8, and -1 MPa). The results reveal that the Beta function is suitable for describing the response of seed germination temperature, and water potential. Under different water potentials, base, optimum, and maximum temperatures have been 7.3-12°C, 22.1-25.8°C, and 32.2-36°C, respectively. The hydrothermal time parameters are 268.3 bar °C h, -1.103 MPa and, 8.36°C for ɵHT (hydrothermal time constant). The data obtained from these models can be used to establish and manage guar for cultivation in different areas.
Elham Nozarpour; Reza Tavakkol afshari; Elias Soltani; Naser Majnon hoseini
Abstract
This study was conducted to evaluate the effects of water potential and temperature on seed germination rate of lemon balm (Mellissa officinalis L.). The seeds were incubated in various temperatures of 20, 23, 25, 27, 30 and 32ºC and water potentials of 0, -0.2, -0.4, -0.6 and -0.8 MPa in three ...
Read More
This study was conducted to evaluate the effects of water potential and temperature on seed germination rate of lemon balm (Mellissa officinalis L.). The seeds were incubated in various temperatures of 20, 23, 25, 27, 30 and 32ºC and water potentials of 0, -0.2, -0.4, -0.6 and -0.8 MPa in three replications. This study was conducted in Seed Laboratory, College of Agriculture and Natural Resources, University of Tehran in Karaj in 2015. Data were analyzed using combined statistical design in a completely randomized design in several places. Segmented function was evaluated to describe cardinal temperatures. The base, optimum and ceiling temperatures of lemon balm were 17.30, 30.9 and 35ºC under optimum conditions of water potential, respectively. The base temperature increased gradually with decreasing water potential and increased to 21.25°C in -0.8 MPa water potential. The optimum temperature decreased to about 28°C by decreasing water potential to -0.6 MPa. Lemon balm seeds did not germinated in 5, 10, 15 and 35°C in any moisture levels. The R2 value of hydrothermal time model was 0.55. The hydrothermal value was 71.41 MPa oday and According to this model seed germination of lemon balm needs to 71.41 MPa oday. The results can be used for future studies on the seed biology and ecology of lemon balm.