摘要
紫花地丁(Viola philippica)具有独特的繁育系统,早春可形成开花受精的开放花(chasmogamous flower,简称CH花),夏秋季可形成闭花受精的闭锁花(cleistogamous flower,简称CL花)。在对紫花地丁花形态变化观测的基础上,比较CH种子和CL种子的形态和萌发特性。结果表明:1)CH种子的长度、宽度和千粒重显著大于CL种子(P<0.05);2)两种类型种子在室温下均吸水48 h之后开始萌发;随着温度的降低,初始萌发时间延长。在温周期10℃/20℃时,CL种子发芽率达到50%所需要的时间比CH种子短。3)两种类型种子的最适萌发温度均在20℃/30℃,发芽率在95%以上;在温周期10℃/20℃时,CL种子的发芽率及活力指数显著大于CH种子(P<0.05)。4)在低浓度(0.05~0.10 mol·L^–1)NaCl溶液中,CH种子的发芽率低于对照组(蒸馏水),而CL种子的发芽率高于对照组。复水后两种类型种子的恢复发芽率较低。5)在低浓度(0.05 mol·L^–1)NaCl溶液中,CL种子的活力指数显著高于CH种子(P<0.05)。紫花地丁繁育系统通过季节性转换,产生具有差异的CH种子和CL种子,在维持种群繁衍更新上具有重要意义。
Viola philippica has a unique breeding system.In early spring,it can form chasmogamous(CH)flowers with flowering and fertilization,while in summer and autumn it can form cleistogamous(CL)flowers.The morphological and germination characteristics of CH and CL seeds were compared between these two morphologically different types of flower.The results showed that:1)The length,width,and weight of CL seeds were significantly lower(P<0.05).2)Seeds from the two types of flowers began to germinate after 48 h of water absorption in greenhouse;however,initial germination was delayed by decreasing temperatures.When the thermoperiod was 10℃/20℃,but the time required for the germination rate of CL seeds to reach 50%was shorter than that of CH seeds.3)The optimal germination temperature for the two types of seeds was 20℃/30℃day/night,which triggered a germination rate above 95%.On the other hand,at 10℃/20℃day/night,the germination rate and vitality index of CL seeds were significantly higher than those of CH seeds(P<0.05).4)The germination rate of CH seeds in a low-concentration NaCl solution(0.05~0.1 mol·L^–1)was lower than in a control solution(distilled water),while the germination rate of CL seeds was higher.However,the germination rate of the two types of seeds was lower after recovery by rehydration.5)In a low-concentration NaCl solution(0.05 mol·L^–1),the vitality index of CL seeds was significantly higher than that of CH seeds.In conclusion,the breeding of V.philippica produces different CH and CL seeds through seasonal transformation,a phenomenon of great significance in mediating the reproduction and renewal of the population.
作者
孙慧芳
魏岩
闫紫烟
严成
SUN Huifang;WEI Yan;YAN Ziyan;YAN Cheng(Xinjiang Key Laboratory of Grassland Resources and Ecology,College of Grassland and Environmental Science/Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China;Xinjiang Ecology and Geography Research Institute,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China)
出处
《草业科学》
CAS
CSCD
2020年第9期1729-1737,共9页
Pratacultural Science
基金
乌鲁木齐市科学技术计划项目(Y141320004)
国家自然科学基金项目(31560113)。
关键词
紫花地丁
种子形态
种子萌发
温度
盐胁迫
Viola philippica
seed morphology
seed germination
temperature
salt stree
