On the basis of literature and my calculations it was established that a chlorophyll (Chl) particle anchored with a phytol chain to the thylakoid membrane takes up about 1 nm2 of the surface area. At an irradiance of 287 W m-2 the leaves of cabbage seedlings become saturated with photosynthetically active radiation (PAR) thus reaching the maximum photosynthetic rate of 100 µg(C) m-2 s-1, that is 5 CO2 molecules per 1 nm2 per second, and the maximum power with which the Chl particle supplies the process of photosynthesis is 15 aJ.
When insect herbivores develop over many generations on the same plant species, their descendants may evolve physiological adaptations that enable them to develop more successfully on that plant species than naïve conspecifics. Here, we compared development of wild and lab-reared caterpillars of the cabbage moth, Mamestra brassicae, on a cultivar of cabbage Brassica oleracea (cv. Cyrus) and on a wild plant species, sorrel, Rumex acetosa, on which the wild strain had been collected and reared for two earlier consecutive generations. The lab strain had been reared on the same cabbage cultivar for more than 20 years representing > 200 generations. Survival to adult did not vary with strain or plant species. Both strains, however, developed significantly faster when reared on R. acetosa than B. oleracea. Pupae from the field strain were larger when reared on B. oleracea than on R. acetosa, whereas the identity of the plant species did not matter for the lab strain. Our results show that long-term rearing history on cabbage had little or no effect on M. brassicae performance, suggesting that some generalist herbivores can readily exploit novel plants that may be chemically very different from those on which they have long been intimately associated., Jeffrey A. Harvey, Eke Hengeveld, Miriama Malcicka., and Obsahuje bibliografii