Developing in vitro selection methods to high temperature stress in pruacan and cacao

Abstract

Increasing in the earth's surface temperature due to global warming threatens the survival of plants in the sub-tropics and in the tropics areas. Looking for plant varieties that can adapt to the threat of global warming impacts is very important at this time. The availability of effective and efficient selection methods are needed to get it. This study aimed to develop an in vitro selection method for resistance to high temperature stress in two tropical plants: Pruacan (Pimpinella pruatjan Molk.) and Cacao (Theobroma cacao L.). The in vitro selection methods were developed by testing the embryogenic culture of pruacan and cacao somatic embryos development under various temperature incubations. The two plants showed a different level of tolerance to high-temperature stress. Temperatures of 35 °C for two months did not cause the death of cacao somatic embryos, but the temperature of 32 °C for 2 and 3 months had caused the death of pruacan somatic embryos by 80 and 90%, respectively. The 100% death of cacao somatic embryos occurred at 40 °C and 45 °C on days 16 and 5 of incubation, respectively. The in vitro selection for high-temperature stress in pruacan and cacao plants were at 32 °C and between 40-45 °C respectively. Developing in vitro selection methods in plant species is needed to face the challenges of climate change in the future.