摘要
【目的】玉米品种根系构型及解剖结构决定着其氮素利用的效率。研究不同年代推广的玉米品种根系构型与解剖结构的演进规律,可为选育高产氮素高效利用型玉米新品种提供理论依据。【方法】以20世纪80年代至今推广的8个玉米品种掖单13号(YD13)、农大108(ND108)、郑单958(ZD958)、先玉335(XY335)、京科968(JK968)、中单909(ZD909)、登海605(DH605)、登海618(DH618)为试验材料,进行大田和土柱栽培两种试验。大田试验施氮量为N 236.25 kg/hm^2和不施氮,土柱试验为N 4.5和1.5 g/plant,定期取样测定根系相关指标、干物质及氮素积累与分配。【结果】近代玉米品种籽粒产量和氮素积累量均显著高于早期品种,高氮处理2000’s以后品种(JK968、ZD909、DH605、DH618)较之前的4个品种分别增加14.7%和11.7%,低氮条件下分别增加16.1%和20.6%;高氮处理,1990’s玉米品种ND108、ZD958根系干重较1980’s品种YD13平均减少54.2%,2000’s以后的品种JK968、ZD909、DH605、DH618较1990’s玉米品种平均增加23.2%,但仍少于YD13;次生胚根数目随品种更替呈现逐渐增加趋势;根系皮层通气组织(RCA)占根系横截面积的比例随品种更替呈现增加趋势,而根系皮层细胞层数(CCFN)和细胞大小(CCS)虽有差异,但并无明显变化趋势;2000’s以后品种D95(95%的根系干重所达到的土层深度)较之前品种增加23.7%,表明近代品种根系下扎能力增强,在深层土壤中的根系分布比例增加。在同一氮素水平下,根干重、D95、RCA%与氮素积累量呈显著线性正相关,根系呼吸速率和氮素积累量呈显著线性负相关。【结论】现代玉米品种的氮素吸收量与氮素利用效率显著高于早期品种,在低氮条件下优势更明显。随品种更替,次生胚根数目增多,利于玉米苗期的生长;根系总量呈现先减少后增加的趋势,根系下扎能力明显增强,深层土壤中根系显著增加。现代玉米品种根系RCA占根系横截面积比例显著增加,减少了根系呼吸消耗,有利于产量的提高。
【Objectives】Root architecture and anatomical structure of maize decide its nitrogen use efficiency.The study on the renovation of root characters of maize cultivars released since early 1990 s will provide a theoretical basis for selecting new variety of maize with high yield and high nitrogen use efficiency.【Methods】Field and pot experiments were conducted, and 8 maize cultivars promoted since 1980 s were used as materials.They were Yedan 13（YD13）, Nongda 108（ND108）, Zhengdan 958（ZD958）, Xianyu 335（XY335）,Jingke 968（JK968）, Zhongdan 909（ZD909）, Denghai 605（DH605） and Denghai 618（DH618）. No nitrogen application and N 236.25 kg/hm^2 were designed in the field experiment, N 4.5 g/plant（HN） and 1.5 g/plant（LN）were for the pot experiment. Roots and plants samples were regularly collected, some root system indices, dry matter, nitrogen accumulation and distribution were determined. 【Results】The yields and N accumulation amount of recent promoted maize varieties were higher than those of the previous ones. The average yield and N accumulation amount of the cultivars after 2000＇s（JK968, ZD909, DH605 and DH618） were increased by14.7% and 11.7% under high N treatment, and 16.1% and 20.6% under low N treatment. The root dry weight,nodal root number, root length, root surface area and root volume showed trends of decreases in the first and then increases over time. The root dry weights of the1990＇s varieties（ND108 and ZD958） were decreased by54.2% compared to the1980＇s variety（YD13） under the high nitrogen level, while the root dry weights of the varieties after 2000＇s were increased by 23.2% compared to the 1990＇s varieties and still lower than that of YD13. The number of seminal roots increased gradually with change of the varieties. The root cortical aerenchyma（RCA） for root cross-sectional area ratio increased with change of the varieties, but the number of cell files（CCFN） and cortical cell size（CCS） had no obvious tendency. The D95（Root depth above which 90%of root length is locatted） of the cultivars after 2000＇s increased by 23.7% compared to those before 2000＇s,indicating that the depth of root penetration increased. There was a significant positive linear correlation between the N accumulation and D95 and RCA% under same nitrogen level, while the correlation between the N accumulation amount and the root respiration rate was exactly opposite. 【Conclusions】The nitrogen uptake and use efficiency of modern maize cultivars are significantly higher than those of previous one. The increased number of seminal root is beneficial to maize seedling growth. The root volume in the deep soil is obvious increased. The increase in RCA% of current maize cultivars leads to reduced root respiration which is beneficial to the increase of yield.
作者
刘梅
吴广俊
路笃旭
徐振和
董树亭
张吉旺
赵斌
李耕
刘鹏
LIU Mei WU Guang-jun LU Du-xu XU Zhen-he DONG Shu-ting ZHANG Ji-wang ZHAO Bin LI Geng LILt Peng(State Key Laboratory of Crop Biology/College of Agronomy, Shandong Agricultural University, Tai＇an, Shandong 271018, China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2017年第1期71-82,共12页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金项目(31371576
31401339)
国家重点研发计划(2016YFD0300106)
国家"十二五"科技支撑计划(2013BAD07B06-2)
国家公益性行业(农业)科研专项经费项目(201203100
201203096)
山东省现代农业产业技术体系(SDAIT-02-08)
国家现代农业产业技术体系建设项目(CARS-02-20)
山东省农业重大应用技术创新课题
山东省玉米育种与栽培技术企业重点实验室资助
关键词
玉米
品种更替
氮素利用率
根系
maize
replacement of varieties
nitrogen use efficiency
root
