不同物料富锰基质育秧对分蘖期水稻的降镉潜能与机制  

The potential and mechanism of cadmium reduction in tillering rice by raising seedlings with different manganese rich substrates

作　　者：丁欣雅 黄芸培 丁明军[1] 王鹏[1] 张华[1] 聂明华 黄高翔 DING Xin-ya;HUANG Yun-pei;DING Ming-jun;WANG Peng;ZHANG Hua;NIE Ming-hua;HUANG Gao-xiang(College of Geography and Environment,Jiangxi Normal University,Key Laboratory of Poyang Lake Wetland and Watershed Research,Ministry of Education,Jiangxi Normal University,Nanchang Jiangxi 330022)

机构地区：[1]江西师范大学地理与环境学院,江西师范大学鄱阳湖湿地与流域研究教育部重点实验室,江西南昌330022

出　　处：《中国土壤与肥料》2024年第5期120-128,共9页Soil and Fertilizer Sciences in China

基　　金：国家自然科学基金(42107034);江西省主要学科学术和技术带头人青年项目(20225BCJ23016);井冈山农高区省级科技专项“揭榜挂帅”项目(20222-051245-03);江西师范大学研究生创新基金项目(YC2022-S246)。

摘　　要：我国稻米镉(Cd)超标问题较为严峻,培育富锰(Mn)秧苗具有降低水稻吸收Cd的潜力,但目前缺乏成熟的富Mn育秧基质。以泥炭(N)、蛭石(Z)、椰糠(Y)、黄泥(H)、有机肥(F)和稻壳炭(D)为基质原料,按照不同原料配比制备8种富Mn基质,以常规基质(60%泥炭+20%椰糠+20%蛭石,60N20Y20Z)为对照,比较研究各基质理化特征、秧苗生长及Mn浓度、移栽后水稻镉吸收转运规律,探讨富Mn基质对水稻的降镉潜能及相关影响因素。结果表明:各基质富Mn后全Mn含量比对照(369 mg·kg^(-1))提升了1.07~2.38倍,为764~1247 mg·kg^(-1),且基质全Mn含量与容重呈显著负相关,与其他理化参数关系不明显;不含黄泥的富Mn基质明显抑制秧苗生长,植株根系和茎叶干重较对照分别下降23.8%~50.1%和15.8%~39.2%,而含黄泥的富Mn基质则不影响水稻生长,甚至有促生作用;含黄泥富Mn基质的秧苗Mn吸收效率比对照高0.15~3.74倍,且黄泥占比越高,秧苗对Mn的吸收效率越高;反之,不含黄泥的富Mn基质则不利于秧苗对Mn的吸收;因此,40%泥炭+20%椰糠+20%蛭石+20%黄泥(40N20Y20Z20H)富Mn基质处理中秧苗根系和茎叶Mn浓度最高;秧苗移栽后,富Mn基质40N20Y20Z20H育秧处理使分蘖期水稻根部和地上部Cd浓度分别下降16.0%和39.6%,且根部Cd向地上部的转运系数降低27.5%。富Mn基质40N20Y20Z20H育秧配合基施石灰可使水稻地上部Cd浓度进一步下降65.8%;结构方程模型(SEM)结果显示,水稻根部Mn浓度对根系Cd吸收和转运均有抑制作用,从而影响了水稻地上部Cd浓度。40%泥炭+20%椰糠+20%蛭石+20%黄泥富Mn基质对促进水稻生长和降低Cd吸收的效果较好,具有较好的田间应用前景。The problem of cadmium(Cd)in rice exceeding the standard in China is relatively serious,and the cultivation of manganese(Mn)rich seedlings has the potential to reduce the absorption of Cd by rice,but at present there is a lack of mature Mn-rich seedling breeding substrate.This study used peat(N),vermiculite(Z),coconut bran(Y),yellow-mud(H),organic fertilizer(F),and rice husk biochar(D)as substrate materials to prepare 8 kinds of Mn-rich substrates with different raw material ratios.Conventional substrate(60%peat+20%coconut bran+20%vermiculite,60N20Y20Z)were used as the control to compare the physical and chemical properties of the substrates,seedling growth and Mn content,as well as the absorption and transportation of Cd in rice after transplantation were studied,and the Cd reduction potential in rice and related factors of Mn-rich substrates were explored.The results showed that the Mn concentration in Mn-rich substrates increased by 1.07-2.38 times compared to the control(369 mg·kg^(-1)),ranging from 764-1247 mg·kg^(-1).The Mn concentration in the substrates was significantly negatively correlated with the bulk density,and was not significantly related to other physicochemical parameters.The Mn-rich substrates without yellow-mud significantly inhibited the growth of seedlings,and the dry weight of plant roots and shoots decreased by 23.8%-50.1%and 15.8%-39.2%,respectively,compared to the control.However,the Mn-rich substrates containing yellow-mud did not affect rice growth,and even benefited to rice growth.The Mn absorption efficiency of seedlings in Mn-rich substrates containing yellow-mud was 0.15-3.74 times higher than that of the control,and the higher the proportion of yellow-mud,the greater the Mn absorption efficiency.On the contrary,a Mn-rich substrate without yellow-mud was not conducive to the absorption of Mn by seedlings.Therefore,the Mn-rich substrate containing 40%peat,20%coconut bran,20%vermiculite,and 20%yellow-mud(40N20Y20Z20H)resulted in the highest Mn concentration in the roots and shoots

关 键 词：土壤镉污染 育秧基质 富锰 转运 水稻 

分 类 号：S511[农业科学—作物学] X173[环境科学与工程—环境科学]