摘要
选择青藏高原东部高寒草甸的32科524种植物种子,探讨了温度、海拔与种子大小对种子萌发特性的影响.研究结果表明变温极显著地影响种子萌发,能够解释萌发率变异的3.4%.在5/15℃,5/20℃,10/25℃3个变温处理下,物种萌发比例分别为78.7%,83.4%,91.3%,平均萌发率分别为36.4%,40.6%,47.2%.其中5/15℃变温处理下物种萌发比例与萌发率均最低,表明高寒低温不利于种子萌发.同时,温度对种子萌发的影响依赖于系统发育,科分类能够解释样区物种种子萌发总变异的34.9%.10个主要科植物种子在变温5/15℃,5/20℃,10/25℃处理下表现出不同的萌发特性,各个科的最高与最低萌发率差异显著.总体而言,禾本科平均萌发率最高(73.6%),豆科的最低(8.2%),各个科对温度变化表现出不同的适应机制.种子采集地海拔与平均萌发率显著相关,能够解释萌发率总变异的2.3%.种子萌发率随海拔升高而降低.与前人研究结果不同的是本次研究结果表明种子大小与萌发率间呈显著的负相关.一方面,样区内随海拔升高,种子有变小的趋势,有利于萌发率的增加;另一方面,高海拔比低海拔地区温度低,不利于种子萌发.样区内各物种的萌发特性受到以上正负影响的双重作用,呈现出各异的萌发特性.
The effects of temperature,altitude and seed mass on germination were studied.Seed germination characteristics of 524 species（32 families） existing on the eastern edge of Qinghai-Tibet Plateau were investigated. It was found that alternating temperature had a significant effect on germination,and contributed 3.4%of total variation in percentage germination.The mean proportion germination of all species was 78.7%,83.4%and 91.3%,the mean percentage germination of all species was 36.4%,40.6%and 47.2%at 5/15℃,5/20℃and 10/25℃respectively.Both the lowest percentage germination and the lowest proportion germination occurred in 5/15℃,which indicated that alpine low temperatures had a negative impact on seed germination.It was aslo found that seed germination was strongly related to phylogeny,with the family accounting for 34.9%of total variations in percentage germination.The germination response to temperature among seeds from 10 main families varied significantly.The highest germination occurred in Poaceae（73.6%）,and the lowest in Fabaceae（8.2%）.The altitude of the origin had a marked effect on the total percentage germination,and contributed 2.3%of total variation in percentage germination.Seeds from a high altitude displayed lower percentage germination.Different from the results of previous studies,we found a significant negative relationship between seed mass and percentage germination.The seeds from a high altitude were heavier than those from a low altitude,which had a beneficial effect on seed germination.The temperature of a high altitude region was lower than that of a low altitude,which had an adverse effect on seed germination.Both would affect seed germination characteristics.
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
2013年第3期377-383,共7页
Journal of Lanzhou University(Natural Sciences)
基金
国家自然科学基金重点项目(40930533)
国家自然科学基金项目(41171214,31170430,30960060,31160118)
新世纪优秀人才支持计划项(NCET-10-0465)
中央高校基本科研业务费专项资金项目(223000-860629)
关键词
温度
海拔
种子大小
系统发育
萌发特性
高寒草甸
temperature
altitude
seed size
phylogeny
germination characteristics
alpine meadow
