Role of trichomes and pericarp in the seed biology of the desert annual Lachnoloma lehmannii (Brassicaceae)

摘要

In the long course of angiosperm evolution from the early Cretaceous to the late Tertiary, a diversity of fruit morphologies has developed, including those that facilitate dispersal and inhibit seed germination (Eriksson 2008). It is well known that dispersal of fruits is promoted by presence of a succulent mesocarp or by various attachments such as bracteoles, pappus, hooks, spines and trichomes (Werker 1997 ). In some species, the pericarp can influence seed germination and seedling establishment by inhibiting water absorption, inhibiting radical protrusion and/or producing germination inhibitors (Hu et al 2009, Cousens ef al 2010). However, little is known about the effects of these attachments on other aspects of seed biology. Thus, the broad purpose of our research was to determine the role of pericarp and its trichomes on dispersal, settlement onto the soil surface and germination of the desert annual Lachnoloma lehmannii.