CARDINAL TEMPERATURES FOR GERMINATION OF THE MEDICINAL ANDDESERT PLANT, Calotropis procera

Abstract

-Calotropis procera, Apocynaceae, is a wild perennial shrub that originated in the Persian deserts. It is known to provide key resources in degraded ecosystems to about 80 animal species. C. procera is regenerated by seed and produces lots of small seeds that are dispersed by wind; nonetheless, its density is very low. The purpose of this study is to estimate the cardinal temperatures including the base, optimum, and maximum temperatures of Calotropis procera looking at two different ecotypes in the Iranian desert. The germination behavior of C. procera seeds was tested at temperature regimens of 0, 5, 10, 15, 20, 25, 30, 35 and 40 o C and was analyzed using linear regression models. The rate of germination increased between base and optimum thermal conditions, and decreased between optimum and maximum thermal conditions. The base, optimum and maximum temperatures for germination of C. procera seeds were estimated at 19.10, 30.75 and 47.80 o C for the Fars and 20.00, 31.82 and 49.69 o C for the Zahedan desert, respectively. Temperature and germination were rated to determine the seeding dates of the C. procera. Overall, cardinal temperatures for germination were dependent on local climate characteristics for the range of adaptations in plant growth of the given species.

Germination of the exotic Calotropis procera (Aiton) W.T. (Apocynaceae) in Mexico

“…Initial germination experiment. According to the high germination percentage obtained in the first experiment, fifteen days after collection, seeds of C. procera showed no primary dormancy, which is in accordance with research from species in other countries where it is either a native or an exotic species (Sen et al 1968, Leal et al 2013, Bebawi et al 2015, Taghvaei et al 2015, probably meaning that the different environmental conditions experienced by the seeds during their development have not affected their dormancy behavior. Calotropis procera seeds are nondormant in agreement with other exotic species (Gioria et al 2018, Xu et al 2019 like Asphodelus fistulosus L. (Guerrero-Eloísa 2017) but differs from others that have shown dormancy (El-Keblawy & Al-Rawai 2006, Wijayabandara et al 2013, Ozaslan et al 2017.…”

Finding out Relationships Among Some Morpho-Biochemical Parameters of Christ's Thorn (Ziziphus spina-christi) under Drought and Salinity Stresses

“…Under water and salinity stresses, leaf length and width are decreased, which it leads to a decrease in photosynthesis (Cochard et al, 2002;Zhou et al, 2013). Knowledge of genetic association between economical production of plants and their components under water deficit and salinity conditions would improve the efficiency of breeding programs by identifying appropriate indices for selecting plant varieties (Ahmed et al, 2014;Khattak et al, 2014;Taghvaei et al, 2015).…”

Predicting the seedling emergence time of sugar beet (Beta vulgaris) using beta models

“…These models can efficiently predict emergence percentages under different environmental stresses such as salinity, drought, and freezing (Bradford 2002). Logistic models (Kamkar et al 2008) and segmented models (Taghvaei et al 2015) have been used to predict the time of emergence at different temperatures and soil water content levels by researchers. Soil texture is another main environmental factor for the time of emergence, especially for spring crops like the sugar beet, because close crusting of the soil surface is controlled by soil texture.…”