Zou Xuexiao

Seed micromorphology and germination characteristics of wild and cultivated pepper strains

To illustrate the effects of domestication on wild pepper, we compared the seed micromorphology and germination characteristics of two wild pepper strains and their corresponding cultivars. The results showed that compared to their corresponding cultivars, wild pepper seeds are significantly smaller, have more groove and ridges on the surface, higher water imbibition rate, higher germination rate and higher α-amylase activity, and digest starch granules faster. The results indicate that the smaller wild seeds are easier to spread; more grooves and ridges on the surface and higher hilum ratio benefit their water imbibition, and rapid decomposition of starch granules and higher α-amylase activity are in favor to germination. By contrast, increased seed size will lead to a reduced germination rate and decreased adaptive ability to water environmental change. Thus, seed size is the result of natural and artificial selection, and whether larger seeds of various pepper cultivars are meaningful in evolution is debatable.