Temperature Response Pattern during Afterripening of Achenes of the Winter Annual Krigia oppositifolia (Asteraceae)


Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Abstract Freshly‐matured achenes of Krigia oppositifolia Raf. were buried in soil at near‐natural temperatures for 0–35 months and then exhumed and tested in light and darkness at (12/12 hr) daily thermoperiods of 15/6, 20/10, 25/15, 30/15 and 35/20°C. Achenes required light for germination and exhibited an annual dormancy/nondormancy cycle, being dormant in spring and nondormant in autumn. High summer temperatures (30/15, 35/20°C) fully promoted afterripening, whereas low temperatures (5, 15/6°C) prevented it. As buried seeds came out of dormancy in summer, they first germinated at medium temperatures (20/10, 25/15°C), but with additional afterripening the maximum and minimum temperatures for germination increased and decreased, respectively. Thus, during afterripening, achenes exhibit type 3 temperature responses, which otherwise are known only in two perennial Asteraceae and one perennial Liliaceae. The physiological responses of achenes of K. oppositifolia are unlike those of most winter annuals, which have type 1 responses—i.e., the maximum temperature for germination increases during afterripening. Also, they are unlike the majority of Asteraceae, which have type 2 responses—i.e., the minimum temperature for germination decreases during afterripening. Type 1 responses, typical of most winter annuals, have yet to be reported in the Asteraceae.

Original languageEnglish
Pages (from-to)111-115
Number of pages5
JournalPlant Species Biology
Issue number2
StatePublished - Dec 1991


  • Asteraceae
  • Krigia
  • seed afterripening
  • temperature response
  • winter annual

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology
  • Plant Science


Dive into the research topics of 'Temperature Response Pattern during Afterripening of Achenes of the Winter Annual Krigia oppositifolia (Asteraceae)'. Together they form a unique fingerprint.

Cite this