Geographic and Ecological Distribution of Genomic DNA Content Variation in Microseris douglasii (Asteraceae)

TLDR: A correlation between the amount of precipitation and DNA content was temporally observed within a single population near Jolon, California, over a 15-yr interim, and natural selection may be responsible for the observed distributional pattern of DNA content.

Abstract: We measured nuclear 2C DNA content (Feulgen absorbancy) of 222 plants of Microseris douglasii representing 24 geographically, ecologically, and morphologically diverse populations in California. The DNA content among plants varied more than 20% and was not correlated with morphological traits. Mean DNA contents of populations varied about 14%. For most populations, the DNA content was relatively uniform, even when the biotypes were morphologically diverse. Populations with higher DNA contents were restricted to the more mesic sites, generally with well-developed soil. A correlation between the amount of precipitation and DNA content was temporally observed within a single population near Jolon, California, over a 15-yr interim. Natural selection may be responsible, at least in part, for the observed distributional pattern of DNA content.