水稻耐碱生理和遗传机制研究现状与展望

碱(化)土是指土壤胶体中含交换性钠较多(碱化度>15%)、呈强碱性反应(pH>8.5)、土壤结构性差、含盐量不高的一类土壤,常与盐土相伴存在,两者统称为盐碱土。与盐土中中性盐(NaCl)对作物造成的胁迫不同的是,碱土中碱性盐(NaHCO₃和Na₂CO₃)对作物造成的胁迫不仅包括离子毒害和渗透胁迫,更严重的是根外高pH值对作物的伤害。利用"以稻治碱"的传统方法可以大规模改良碱(化)土壤,增加农业耕地面积。因此,了解和掌握水稻对碱胁迫的适应性,创建碱地水稻高效栽培技术,培育水稻耐碱新品种,对提高碱(化)土地利用率,保障区域粮食安全具有重要的现实意义。本文基于近年来国内外研究报道,从水稻耐碱形态和生理特性、耐碱基因定位与克隆、耐碱种质鉴定筛选以及水稻耐碱性遗传改良等4个方面进行综述,并对未来水稻耐碱性研究进行展望,以期为"以稻治碱"、改土增粮提供一定的理论依据。

Current Status and Prospect of Research on Physiology and Genetic Mechanism of Alkali Tolerance in Rice

Alkaline(alkalized)soil refers to a type of soil in which the soil colloid contains a high level of exchangeable sodium(alkalinity>15%),showing a strong alkaline reaction(pH>8.5),with poor soil structure,and without a high salt content.Alkaline soils and saline soils often coexist,which are collectively called salinealkaline soils.Different from the stress caused by neutral salt(NaCl)in the saline soil to the crops,the stress caused by the alkaline salt(NaHCO₃and Na₂CO₃)in the alkaline soil not only includes ion toxicity and osmotic stress,but also more serious damage to crops due to the high pH outside the roots.The traditional method of"reducing alkaline content with planting rice"can improve alkalized soil on a large scale and increase agricultural land area.Therefore,it is important to understand and master the adaptability of rice to alkali stress,create efficient cultivation technique of rice for alkaline land,and then develop new rice varieties with alkali resistance,which are of great practical significance for improving the utilization rate of alkaline(alkalized)land and ensuring regional food security.Based on recent domestic and foreign progresses reported,this paper reviews the rice alkali-tolerance in aspects of morphology and physiological characteristics,gene location and cloning,germplasm identification and screening,and genetic improvement,and present prospects for future research on alkali tolerance of rice.The purpose of this article is to provide a theoretical basis for the improvement of soil and grain by"reducing alkaline content with planting rice".