关键词: 豆科, 新疆沙冬青, 迁地保护种群, 自然种群, 开花物候

Abstract:

Ammopiptanthus nanus is both half endemic and relict species listed in China Plant Red Data Book and a typical evergreen broad-leaved shrub in dry deserts of Asia. In this article, comparative flowering phenology of A. nanus was observed in both ex-situ conservation and natural population in 2005. The main results are as follows: A. nanus flowered once a year under different environments and possessed same flowering frequency. The date of first flowering and the date of flowering peak in natural population were later than those in ex-situ conservation population and the duration of flowering was longer than that in ex-situ conservation condition at individual and population levels. There were very significant and significant differences in the date of first flowering (F=764.23, P<0.01) and the duration of flowering (F=46.50, P<0.001) between two observation sites respectively. Flowers per inflorescence were more and the inflorescence duration was longer in natural population. There were very significant differences in number of flowers per inflorescences (F=80.10, P<0.001) and inflorescence duration (F=84.06, P<0.001). The frequency distribution of inflorescence duration at two observation sites was distinctly different, more concentrated in ex-situ conservation than in natural population. The Inflorescences had similar flowering order in both sites, starting from the near base to two ends of inflorescences. The mean longevity of individual flower had no differences between two habitats. Inflorescences of A. nanus possessed markedly different flowering amplitude at two observation sites and the flowering pattern could be characterized as irregular, un-continuous bimodal amplitude in ex-situ conservation population and single amplitude with mass blooming in natural population. There were some correlations among flowering time, flowering numbers each day and its fruiting number at inflorescence level, and the correlation between these parameters were different at two observation sites. In the above flowering parameters, the flowering frequency of both individual and population, the flowering order of inflorescences and the mean longevity of individual flower under different environment were almost the same, while the date of first flowering and duration at individual and population levels, the flowers, the duration and flowering amplitude of inflorescences in A. nanus have close relation with changes of environments.

Key words: Fabaceae, Ammopiptanthus nanus, ex-situ conservation population, natural population, flowering phenology