唐璐 王晟 但建国

摘  要：為深入了解普通野生稻的根表铁膜形成能力及其与根系特征的关系，本研究对海南省不同地区的8个普通野生稻居群进行了水培铁胁迫试验。结果表明：普通野生稻的根表铁膜随居群而异。HLY、XLB、HQF等3个居群具有较强的根表铁膜形成能力，其根表铁膜相对数量分别为480.58、382.66、364.05 mg Fe/（cm·株）。根表铁膜数量与根生物量、主根表面积、侧根表面积、根系表面积和根系体积均呈正相关;而根表铁膜相对数量与根生物量、根系表面积、侧根表面积及其所占比率呈正相关;但是，根表铁膜含量仅与侧根表面积所占比率呈正相关，根表铁膜厚度与这些根系特征参数均无相关性。根表铁膜的4个指标与根孔隙度之间均无相关性。因此，侧根表面积及其所占比率是影响根表铁膜的重要因子，可作为筛选具有较多根表铁膜的普通野生稻居群的关键依据。

关键词：普通野生稻;铁膜;根系特征中图分类号：S31;S511.9      文献标识码：A

Iron Plaque Formation on Roots from DifferentOryza rufipogon Populations

TANG Lu， WANG Sheng， DAN Jianguo^*

Institute of Tropical Agriculture and Forestry， Hainan University， Haikou， Hainan 570228， China

Abstract： In order to determine the effects of root characteristics on iron plaque formation on the roots ofO. rufipogon， eight populations were collected from different areas in Hainan， and investigated with hydroponic experiments. Iron plaque was induced by exposing the roots to a Kimura B nutrient solution supplemented with 0.532 mmol/L FeSO₄for 24 h. All the four iron plaque indices showed that iron plaque formation on the roots was significantly different among theO. rufipogon populations. The relative amount of iron plaque for HLY， XLB， and HQF populations was 480.58， 382.66， 364.05 mg Fe/（cm·plant）， respectively， which was much higher than those for the others. The amount of iron plaque per plant was positively related to most parameters of the roots， such as root biomass， surface area of adventitious roots， surface area of lateral roots， surface area and volume of root system. The relative amount of iron plaque on the roots had positive correlation with surface area of the lateral roots and its proportion， as well as root biomass and volume of root system. The content of iron plaque on the roots was only positively related to the proportion of surface area of the lateral roots. However， the amount of iron plaque per root surface area was not significantly correlated with the above parameters of the roots. All the four iron plaque indices had no correlation with root porosity. In summary， the major factors influencing iron plaque formation on the roots were surface area of lateral roots and its proportion， which could be used as the pivotal root parameters for confirming the populations ofO. rufipogonwith more iron plaque on roots.

Keywords： Oryza rufipogon; iron plaque; root characteristics

DOI： 10.3969/j.issn.1000-2561.2020.06.027

普通野生稻（Oryza rufipogon Griff.）作为栽培稻的祖先，其资源价值研究越来越被人们重视。普通野生稻由于经受不良环境的选择而拥有丰富的遗传多样性，这也是亚洲栽培稻（Oryza sativaL.）的重要基因源^[1-4]。普通野生稻属于多年生水生植物，其根系发达，根生物量与根孔隙度也远大于亚洲栽培稻^[5]。水生植物的根系表面因适应淹水和环境胁迫会形成铁氧化物胶膜（简称根表铁膜），它的形成需要根系处于局部氧化状态和富含大量的Fe²⁺的环境^[6-7]。

水稻根系发达的通气组织提高了根系的泌氧能力^[8-9]，同时根孔隙度也可以用来反映根系通气组织的发育程度即根系的泌氧能力^[10]。……