摘要
研究了生长于不同生境下的沙芥(Pugionium cornutum(L.)Gaertn.)和斧翅沙芥(Pugionium dolabratum Maxim.)种子萌发对光照和温度的响应。结果表明:沙芥和斧翅沙芥种子在光下萌发受到显著(P<0.05)的抑制作用,其中沙芥种子萌发受光的抑制作用强于斧翅沙芥种子。在黑暗10—40℃恒温条件下,沙芥和斧翅沙芥种子在15—35℃范围内均可萌发,在15℃和35℃下沙芥种子的萌发要优于斧翅沙芥种子;其种子分别在25℃和30℃下达到最佳的萌发响应,在此条件下斧翅沙芥种子的萌发特性优于沙芥种子。在黑暗变温条件下,沙芥和斧翅沙芥种子在20/30℃(12h/12h)下达到最佳的萌发响应,此处理下的萌发率高于其各自最佳恒温处理下的萌发率,其萌发后幼苗下胚轴和胚根的长度较最佳恒温处理有明显的下降,但它们的干重却差异较小,说明变温处理有利于两种种子的萌发和形成强壮的幼苗。综上所述,沙芥和斧翅沙芥种子在黑暗和20/30℃变温条件下有利于种子萌发和幼苗建成。
Controlled experiments were conducted to investigate the effect of light and temperature on seed germination of Pugionium cornutum （L.） Gaertn. and its congeners P. dolabratum Maxim.,to better understanding how they adapt to desert habitats at seed germination stage. Results showed that light significantly （P0.05） inhibited seed germination,and the inhibition effects was stronger on P. cornutum than P. dolabratum. At constant incubating temperature and darkness,the seed of both species can germinate at gradients from 15℃ to 35℃,and the germination percentages of P. cornutum were significantly higher than those of P. dolabratum at 15℃ and 35℃ respectively. The optimal germination temperature for P. cornutum and P. dolabratum were at 25℃ and 30℃ respectively. Under alternating temperature and darkness conditions,the optimal temperature for seed germination of two congeners was both occurring at 20/30℃（12h/12h）. Percentages of seed germination were higher at 20/30℃ than their respective optimal constant temperatures of both species; In addition,seedling hypocotyl and radicel length of both species developed at 20/30℃ were shorter than that at 25℃ and 30℃ respectively,but their dry weight were not obviously declined. Indicating alternating temperature has advantages for seed germination and seedling development of two congeners. In summary,darkness and at 20/30℃ daily alternating temperatures are the favorable conditions for seed germination and seedling establishment of these two desert species.
出处
《生态学报》
CAS
CSCD
北大核心
2010年第10期2562-2568,共7页
Acta Ecologica Sinica
基金
国家基金资助项目(30860174,30260067,30460080)
内蒙古自治区科技攻关资助项目(20050305,20060202)
内蒙古自治区自然科学基金资助项目(200108020501,200308025013)
关键词
沙芥
斧翅沙芥
种子萌发
沙生植物
恒温
变温
Pugionium cornutum （L.） Gaertn.
Pugionium dolabratum Maxim.
seed germination
psammophyte
constant temperature
alternating temperature
作者简介
通讯作者Corresponding author．E—mail：haolizhe@public．hh．nm．cn
