A new Phytologist study of the North American herb Campanula Americana revealed that western populations have darker purple pollen due to extremely high temperatures than eastern populations where white to light-purple pollen is more common.
The findings revealed that dark pollen outperforms light pollen under higher temperature and UV rays.
Study author Dr Matthew Koski of the University of Virginia said, "In light of global change, temperature stress could be an increasingly important selective agent on pollen pigmentation."
According to researchers, differential heat tolerance among pollen colour variants can contribute to geographic variation in pollen pigmentation.
Western populations also experience more extreme high temperatures and elevated UV-B irradiance.
The research appears in New Phytologist journal. (ANI)