Plant Diversity ›› 2013, Vol. 35 ›› Issue (3): 273-279.doi: 10.7677/ynzwyj201313047

• Articles • Previous Articles     Next Articles

Morphology and Germination Features of Achenes of 12 Species of the Genus Saussurea (Asteraceae) in Western Sichuan Plateau

 ZHANG  Da-Cai, LI  Shuang-Zhi, HOU  Xiong-Hui, ZHANG  Ming-Qi   

  1. The Faculty of Forestry, Southwest Forestry University, Kunming 650224, China
  • Received:2013-03-21 Online:2013-05-25 Published:2013-04-22
  • Supported by:

    科技部科技基础性工作专项重点项目 (2007FY110100)和国家自然科学基金 (31160044)

Abstract:

This paper analyzed the shapes of achenes of 12 species in the genus Saussurea DC., and their micromorphological features and germination, and discussed the relationship between achene shapes and germination characteristics with geographical distribution. The mainly achene shapes included three types, namely oblanceolate, cylindrical and cylindricalobtriangular. The amplitude of achene length, width and thickness was large, and the mean value was over 10%. The surface of achenes can be divided into 3 types based on micromorphological characters, namely striate ornamentation, reticulate ornamentation and pitted ornamentation, and the stripe type was the most common. The micromorphological features of achenes are stable, and it was an ideal taxonomic character. The percentage of germination differed greatly among species, and the highest was 98%, but the lowest was just 40%. The geographical distribution of species of Saussurea was significantly correlated with their length of achene pappus and 100grain weight. It also positively correlated with achene plumpness, and the proportion of pappus weight to achene, but the correlation was insignificant. These species of Saussurea in this paper had a high proportion of pappus weight to achene, which was good for longdistance dispersal, and their high germination rate and 100grain weight provided security for the growth of seedling, therefore, these species potentially had a wide distribution in the QinghaiTibet Plateau.

Key words:  Micromorphology, Geographical distribution, Pappus, Saussurea, Achene

CLC Number: 

  • Q 944