Chin J Plant Ecol ›› 2007, Vol. 31 ›› Issue (6): 1037-1045.DOI: 10.17521/cjpe.2007.0131

• Research Articles • Previous Articles     Next Articles


WANG Ju-Hong(), CUI Xian-Liang, CHEN Xue-Lin, DU Guo-Zhen()   

  1. Key Laboratory for Arid Agroecology of the Ministry of Education, Lanzhou University, Lanzhou 730000, China
  • Received:2006-01-31 Accepted:2007-04-24 Online:2007-01-31 Published:2007-11-30
  • Contact: DU Guo-Zhen


Aims Seed germination and seed size are crucial plant life history traits related to seedling establishment, survival, competition and fitness. Study of germination ecology of native species not only increases understanding of seed traits, reproductive strategy and physiological adaptation, but also can be applied in ecological restoration. Mesad and siccocolous species with different water requirements may have different life-history strategies to respond to different selective pressures. Our main purposes were to determine: 1) differences in germination characteristics between mesad and siccocolous species in the arid and semiarid zone and 2) relationship of germination to seed size.

Methods Seeds of 42 mesad and 22 siccocolous species from the Hexi Corridor of Northwest China were air-dried, cleaned and stored at room temperature about 3-4 months and then stored at 2-4 ℃ for 40 d. Germination was determined under an alternating temperature regime (25 ℃/5 ℃; 12 h light/dark). Four main germination indices were recorded: germination percentage, germination rate, days to first germination and germination period. PCA was used to survey the germination patterns of the 64 species, and Pearson Correlation Analysis was used to determine the relationship of seed size and germination.

Important findings There are four main germination patterns: rapid, intermediate, slow and low germination. Low germination percentages (≤20%) were found in 14.28% mesad and 50% siccocolous. There are significant differences in seed size between mesad and siccocolous (p=0.003). There also is a significant negative correlation between germination and seed size in mesad, with smaller-seeded species having higher germination percentages (r=-0.467**, p=0.002) than larger-seeded ones, but not in siccocolous (p>0.05). Findings indicate that mesad and siccocolous species under different water conditions are subjected to different selective pressures and have evolved different life-history strategies.

Key words: seed germination, seed size, life-history strategy, mesad, siccocolous