生态学报2017，Vol.37Issue(16)：5382-5390,9.DOI:10.5846/stxb201605271024
人工模拟降雨格局变化对红砂种子萌发的影响
Effects of simulated precipitation change on seed germination of Reaumuria soongorica
摘要
Abstract
Seed germination is considered to be the most important and sensitive factor in response to changes in the moisture and heat phases during the natural process of plant regeneration.The northwest arid areas of China are drought areas that are most sensitive to precipitation changes.Reaumuria soongorica,a super-xerophytic shrub,exhibits a strong tolerance to drought,cold,saline-alkali soil,and barren landscapes,and is a long-lived species.Our objective was to investigate how precipitation changes affect the physiological and ecological processes of seeds of R.soongorica to determine the regeneration mechanisms and changes in the patterns of this key species.Seeds of R.soongorica were collected in the fall of 2013 at the Linze Inland River Basin Research Station of the Chinese Academy of Sciences.We set up a growth-chamber experiment with two factors:precipitation quantity (natural precipitation as a control,reduction of 30％,and increase of 30％) and interval (time elapsed between two precipitation events,5 and 10 days).Germinated seeds were counted daily until the end of germination.The results showed that increasing precipitation (+30％) resulted in a significantly enhanced germination rate and germination potential by an average of 45.69％ and 39.86％,respectively,especially when the precipitation interval was extended from 5 to 10 days (a single rainfall reached up to 6 mm).In addition,the germination rate and potential reached their maxima by an average of 68.33％ and 63.33％,respectively.Therefore,the rainfall threshold for the germination of R.soongorica was determined to be 6 mm.The germination index and vigor index were significantly increased by an average of 57.67％ and 121％ (P＜0.05),respectively,with increasing precipitation quantity (+30％).Extension of the precipitation interval under increasing precipitation (+30％) resulted in a reduced germination index and vigor index,but the effect was not statistically significant.Increasing precipitation (+30％) under the extended precipitation interval treatments accelerated the course of germination,and the germination periods were shorter.Reducing the precipitation by 30％ had no significant effects on the course of germination.Therefore,seed germination was mainly affected by precipitation quantity,but the effect was dependent on the precipitation interval.Overall,the seed germination percentage increased under a precipitation pattern of increasing precipitation (+ 30％) with an extended precipitation interval,the breeding success rate and seedling establishment ability were enhanced,and seedling regeneration was promoted.R.soongorica showed characteristics of delayed germination under the condition of natural rainfall and reduced precipitation(-30％),which could increase the seedling emergence and growth of the seedlings under further favorable environmental conditions and improve the long-term adaptability of plants to the environment.关键词
降雨间隔时间/降雨量/种子萌发/幼苗更新Key words
precipitation interval/precipitation quantity/seed germination/seedling regeneration引用本文复制引用
单立山,李毅,张正中,白蕾,段桂芳,种培芳..人工模拟降雨格局变化对红砂种子萌发的影响[J].生态学报,2017,37(16):5382-5390,9.基金项目
国家自然科学基金(41361100,31560135,31360205,41461044) （41361100,31560135,31360205,41461044）
甘肃省科技支撑项目(1604FKCA088) （1604FKCA088）
甘肃省高等学校科研项目(2015A-067) （2015A-067）
甘肃农业大学青年研究生指导教师扶持基金(GAU-QNDS-201605) （GAU-QNDS-201605）
