摘要
【目的】土壤pH影响土壤锰(Mn)有效性,酸性土壤易出现Mn过量问题,我国柑橘主要分布在南方红黄壤区,柑橘园酸性或强酸性土壤比例高,柑橘园土壤Mn过量较普遍。为此,我们研究了4种柑橘砧木对Mn过量胁迫的耐受性和生理响应,以期为Mn过量土壤上适宜砧木的选择提供依据。【方法】选用枳、资阳香橙、红橘和沙田柚4种常用柑橘砧木苗为材料,采用蛭石与珍珠岩1∶1的基质进行了营养液栽培试验,营养液中Mn处理包括0.01(对照)、0.05、0.25、1.25和6.25 mmol/L 5个浓度。观察砧木苗的生长反应和中毒症状,处理60天时,测定叶绿素含量和光合参数;处理67天终止处理,测定砧木苗生长量、生物量、过氧化物酶活性、营养元素含量等生理生化指标,并用隶属函数对砧木过量锰的耐受性进行综合评价。【结果】柑橘砧木苗出现锰中毒的症状为叶片失绿,出现褐色坏死斑点;根量变少,呈现褐色斑点。4种砧木苗均在Mn 0.25 mmol/L处理时出现Mn中毒症状,其中枳最先出现症状且最严重,资阳香橙最迟出现症状且最轻;4种砧木在Mn 0.05 mmol/L处理时即出现Mn过量胁迫,表现为地上部和地下部鲜重和干重显著下降,根冠比升高(红橘除外)、叶绿素含量下降、净光合速率降低、气孔开度下降、胞间CO2浓度上升。Mn过量(>0.05 mmol/L)胁迫使4种砧木叶片细胞膜受损,相对电导率和MDA含量上升;清除活性氧的SOD和POD活性上升,CAT活性下降。Mn过量胁迫影响柑橘砧木的营养元素吸收和转运,叶片和根系Mn含量上升,但随Mn胁迫浓度升高,Mn从根系到叶片的迁移率先降低后升高;Mn过量胁迫使砧木叶片K、P、Ca、Mg、Fe、Zn元素含量下降,根系K、P、Fe、Zn含量上升而Ca、Mg含量下降。【结论】不同砧木对Mn过量胁迫耐受性存在明显的差异,综合评价耐性强弱顺序为:资阳香橙>沙田柚>红橘>枳,高锰土壤的柑橘园可选用资阳香�
【Objectives】Soil pH affects the availability of soil manganese(Mn),and excess Mn is prone to occur in acidic soils.Citrus are mainly distributed in the red or yellow soil areas in south China,where the proportion of acid or strongly acid soil area in citrus orchards is high,and excess Mn stress is common in citrus production.For this reason,we studied the tolerance and physiological response of four different citrus rootstocks in Mn excessive stress,in order to provide a basis for the selection of suitable rootstock cultivars in Mn excessive soil.【Methods】In a pot experiment,vermiculite and pearlite in ratio of 1∶1 were used as substrates and Hoagland nutrition solution as nutrient source,and the selected four popular citrus rootstock cultivars included trifoliate orange[Poncirus trifoliate(L.)Raf],Ziyang Xiangcheng(Citrus junos‘Ziyang Xiangcheng’,ZyXc),red tangerine(Citrus reticulata Hort.ex Tanaka,Tanaka)and Shatian pomelo[Citrus grandis(L.)Osb.‘Shatianyou’,StY].Seedlings were subjected to 0.01(CK),0.05,0.25,1.25 and 6.25 mmol/L of Mn in the nutrition solution treatments in this study.The chlorophyll and photosynthetic parameters were determined after treatment for 60 days.The treatment was terminated after 67 days,the physiological and biochemical indexes of citrus rootstock seedling such as growth amount,biomass,peroxidase and element content were measured,and the tolerance of the four rootstocks to excessive Mn was comprehensively evaluated by membership function.【Results】The citrus rootstock seedlings suffered from Mn toxicity had common symptoms such as chlorosis and brown necrotic spots in leaves,less mass and brown spots in roots,etc.Under Mn 0.25 mmol/L treatment,all the four citrus rootstock seedlings showed symptoms of Mn toxicity.Trifoliate orange showed the earliest and most serious toxic symptoms,while Ziyang Xiangcheng showed the latest and lightest ones.The excessive Mn stress was observed in all the four rootstock seedling under Mn 0.05 mmol/L treatment,including the signif
作者
邱洁雅
袁梦
朱攀攀
凌丽俐
曹立
付行政
彭良志
QIU Jie-ya;YUAN Meng;ZHU Pan-pan;LING Li-li;CAO Li;FU Xing-zheng;PENG Liang-zhi(Citrus Research Institute of Southwest University/National Citrus Engineering Research Center,Chongqing 400712,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2021年第1期109-121,共13页
Journal of Plant Nutrition and Fertilizers
基金
国家重点研发计划课题(2017YFD0202006,2017YFD0202002)
国家现代农业(柑橘)产业技术体系建设专项(CARS-26-01A)。
关键词
柑橘砧木
锰过量胁迫
生理响应
耐受性
citrus rootstock
Mn toxicity
tolerance
physiological response
