筛选和培育镉低积累水稻品种的进展和问题探讨  

A perspective on the selection and breeding of low-Cd rice

作　　者：陈彩艳[1] 唐文帮[2] CHEN Cai-yan1, TANG Wen-bang2(1. Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China; 2. College of Agronomy, Hunan Agricultural University, Changsha, Hunan 410128, China)

机构地区：[1]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,湖南长沙410125 [2]湖南农业大学农学院,湖南长沙410128

出　　处：《农业现代化研究》2018年第6期1044-1051,共8页Research of Agricultural Modernization

基　　金：国家重点研发计划(2017YFD0800901);国家科技支撑计划(2015BAD05B02);中科院重点部署项目(KFZD-SW-111)~~

摘　　要：推广镉低积累品种是重金属污染农田安全利用的前提,筛选和培育镉低积累水稻品种已经成为水稻育种家的一个重要任务。近年来人们对镉低积累品种的筛选和培育工作投入较大的精力,但是由于稻米镉积累是一个复杂性状,受环境和基因型共同调控,人们对重金属低积累品种的定义、特征、筛选认定方法等并没有形成一致意见。本文主要介绍了最近几年国内外在镉低积累水稻品种筛选和定向培育方面的最新成果。在此基础上,从遗传学和农学角度提出了我们对镉低积累品种的定义及其特征的理解:镉低积累品种是指在相同环境条件下稻米镉积累量相对较低的品种,其在高镉(有效态)背景下稻米镉含量相对较低,中低镉背景下能达标,而低镉土壤背景下不超标。虽然稻米镉积累受环境和遗传因素共同调控,但镉积累特性遗传率高,降低稻米镉积累量不影响水稻的生育期、产量及其他必需微量元素的含量。镉低积累品种和镉高积累品种稻米镉积累量的差异随环境变化而变化,在高镉背景下相差较大,而在低镉土壤背景下差异变小。因此筛选认定镉低积累品种时,我们建议先在高镉背景下比较不同品种的相对镉含量,筛选镉积累相对较低的品种,然后在低镉条件下评价其产品的达标频率,确定其安全生产所需的环境条件。Rice has been a leading source of dietary Cd, a highly toxic trace element that presents in soil naturally and enters into food chain via soil-to-crop pathway. Natural variation occurs in the uptake, transportation, and compartmentation of Cd in rice. Selection and breeding of low-Cd rice has been a useful tool to prevent rice-derived products from exceeding the maximum limit of Cd. Selection programs for a low-Cd content of rice have been established and a stack of low-Cd rice cultivars have been identified from mega rice germplasms. In addition, low-Cd rice inbred lines and hybrid combinations have been successfully developed with maker-assisted selection in our rational design rice breeding program. In this paper, we updated the latest achievement of low-Cd rice selection and breeding in Southern China and summarized the characteristics of low-Cd rice and defined the low-Cd rice agronomically. Though the Cd level in rice grain is controlled by both environmental and genetic factors, the trait is highly heritable, and low- Cd gene can reduce the average grain Cd levels without destroying rice yield and essential micronutrient element level. Because the difference of grain-Cd level between high-Cd rice and low-Cd ones varied with soil and water conditions, being smaller in environments which generally produced a low grain Cd concentration, and greater in environments that produced a high-Cd concentration, the low-Cd rice should be first identified in a soil context with high Cd bio- availability and then be evaluated for the ability to reduce grains- Cd level below proposed international limits in a low- Cd soil.

关 键 词：水稻 低镉 遗传 筛选 育种 

分 类 号：S503.3[农业科学—作物学]