生态学报2018，Vol.38Issue(8)：2896-2905,10.DOI:10.5846/stxb201706091044
夏玉米对土壤水分持续减少的响应及其转折点阈值分析
Responses and tipping point of summer maize to consecutive soil water decrease
摘要
Abstract
Maize plays an important role in food security and the development of livestock husbandry in China.Drought is the most important meteorological hazard for summer maize production.Drought accounts for 64％ of the total area affected by the four meteorological disasters (drought,flood,storm,and cold) in major summer maize producing areas in China.Accurate and timely access to drought information is critical to the safety of summer maize production.Drought indicators can indicate the occurrence and degree of drought.The plant eco-physiology indicators can reflect the degree of water shortage and drought tolerance of plants directly.There are tipping points for the response of summer maize to drought.That is,when water is below a certain critical point,it will have a significant impact on plant physiology and other indicators.The different sensitivity of indicators to drought results in different tipping points.In this study,two water treatments (adequate water supply and stop water supply from jointing stage) were designed to simulate the responses and tipping point of summer maize "Zhengdan 958" to consecutive decrease in soil water.The study was conducted at the station of ecological environment and agro-meteorology of the China Meteorological Administration (39 ° 08'N,115 ° 40'E) in 2015.Six plots (2m×4m) were used for the two water treatments (three replicates for each).The results indicated that:the physiological indicators were adversely affected after 10 days when water deficit accumulated to 34mm and relative soil water content decreased to 64％.Biomass was restricted after 20 days when water deficit accumulated to 66 mm and relative soil water content decreased to 56％.Morphological characteristics began to be depressed when water deficit accumulated to 86mm and relative soil water content decreased to 52％.Among the physiological indicators,the water content and water potential of the first fully expanded leaf at the top were affected first.The sensitivity of physiological indicators' response to consecutive soil water decrease was ranked as:the water content and water potential of first fully expanded leaf at the top ＞ the water content of third fully expanded leaf at the top ＞ the water content of total leaves ＞ the water content of stem=the chlorophyll content of third fully expanded leaf at the top ＞ the chlorophyll content of first fully expanded leaf at the top,and their tipping points in terms of the relative soil water content were 64％,62％,61％,60％,60％,and 59％,respectively.In terms of the accumulative biomasses,the stem biomass was the first to be impacted,followed by root biomass;and the tipping points in terms of the relative soil water content for both were 56％.For morphological characteristics,the number of leaves decreased first.The sensitivity of morphological indicators to consecutive soil water decrease was ranked as:leaf number ＞ plant height ＞ total leaf area;and the tipping points in terms of the relative soil water content were 52％,47％,and 46％.The response of summer maize to soil drought process was as follows:physiological characteristics changed firstly,followed by biomass accumulation,and finally morphological characteristics.These results can provide a reference for the development and monitoring of drought in summer maize objectively.关键词
夏玉米/土壤水分持续减少/敏感性/阈值Key words
summer maize/consecutive soil water decrease/sensitivity/threshold引用本文复制引用
石耀辉,周广胜,王秋玲,麻雪艳,冯晓钰..夏玉米对土壤水分持续减少的响应及其转折点阈值分析[J].生态学报,2018,38(8):2896-2905,10.基金项目
国家自然科学基金重点项目(41330531,31661143028) （41330531,31661143028）
公益性行业(气象)科研专项(重大专项)(GYHY201506001-3) （气象）
