Murugaiyan Varunseelan, Ali Jauhar, Frei Michael, Zeibig Frederike, Pandey Ambika, Wairich Andriele, Wu Lin-Bo, Murugaiyan Jayaseelan, Li Zhikang
Rice Breeding Platform, International Rice Research Institute (IRRI), Los Baños, Philippines.
Institute of Crop Sciences and Resource Conservation (INRES), University of Bonn, Bonn, Germany.
Front Plant Sci. 2021 Oct 29;12:753063. doi: 10.3389/fpls.2021.753063. eCollection 2021.
Rice remains a major staple food source for the rapidly growing world population. However, regular occurrences of carcinogenic arsenic (As) minerals in waterlogged paddy topsoil pose a great threat to rice production and consumers across the globe. Although As contamination in rice has been well recognized over the past two decades, no suitable rice germplasm had been identified to exploit in adaptive breeding programs. Therefore, this current study identified suitable rice germplasm for As tolerance and exclusion based on a variety of traits and investigated the interlinkages of favorable traits during different growth stages. Fifty-three different genotypes were systematically evaluated for As tolerance and accumulation. A germination screening assay was carried out to identify the ability of individual germplasm to germinate under varying As stress. Seedling-stage screening was conducted in hydroponics under varying As stress to identify tolerant and excluder genotypes, and a field experiment was carried out to identify genotypes accumulating less As in grain. Irrespective of the rice genotypes, plant health declined significantly with increasing As in the treatment. However, genotype-dependent variation in germination, tolerance, and As accumulation was observed among the genotypes. Some genotypes (WTR1-BRRI dhan69, NPT-IR68552-55-3-2, OM997, and GSR IR1-5-Y4-S1-Y1) showed high tolerance by excluding As in the shoot system. Arsenic content in grain ranged from 0.12 mg kg in Huang-Hua-Zhan () from China to 0.48 mg kg in IRAT 109 () from Brazil. This current study provides novel insights into the performance of rice genotypes under varying As stress during different growth stages for further use in ongoing breeding programs for the development of As-excluding rice varieties for As-polluted environments.
水稻仍然是世界人口快速增长的主要主食来源。然而，淹水的稻田表土中经常出现致癌性砷矿物，这对全球水稻生产和消费者构成了巨大威胁。尽管在过去二十年中，人们已经充分认识到水稻中的砷污染问题，但尚未确定适合在适应性育种计划中利用的水稻种质。因此，本研究基于多种性状确定了耐砷和排砷的适宜水稻种质，并研究了不同生长阶段有利性状之间的相互联系。对53种不同基因型进行了耐砷性和砷积累的系统评价。进行了发芽筛选试验，以确定各个种质在不同砷胁迫下的发芽能力。在不同砷胁迫下的水培条件下进行苗期筛选，以确定耐性和排砷基因型，并进行田间试验，以确定籽粒中砷积累较少的基因型。无论水稻基因型如何，随着处理中砷含量的增加，植株健康状况均显著下降。然而，在基因型之间观察到发芽、耐性和砷积累的基因型依赖性差异。一些基因型（WTR1-BRRI dhan69、NPT-IR68552-55-3-2、OM997和GSR IR1-5-Y4-S1-Y1）通过在地上部系统中排除砷而表现出高耐性。籽粒中的砷含量范围从中国的黄花占（）的0.12毫克/千克到巴西的IRAT 109（）的0.48毫克/千克。本研究为不同生长阶段不同砷胁迫下水稻基因型的表现提供了新的见解，以便在正在进行的育种计划中进一步用于开发适合砷污染环境的排砷水稻品种。
