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Mechanisms and genetics of iron toxicity tolerance in African rice

非洲水稻铁毒性耐受机制和遗传学

基本信息

批准号：
BB/R020388/1
负责人：
Guy Kirk
金额：
$ 114.84万
依托单位：
CRANFIELD UNIVERSITY
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2018
资助国家：
英国
起止时间：
2018 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FR020388%2F1
关键词：
Mechanisms genetics iron toxicity tolerance

项目摘要

Rice is a major staple food across sub-Saharan Africa (SSA) and demand for rice is increasing rapidly with changes in consumer preferences and urbanization. However, domestic production currently accounts for only about 60% of consumption; imports to SSA amount to a third of the global rice trade. Accordingly there are various national and international initiatives with ambitious plans for increasing production across SSA. There are ample agro-climatically suitable wetlands in inland valleys and elsewhere to support a large intensification and expansion of rice area. During the rainy season, rice is the only possible crop on low-lying wetlands, so it does not compete with other crops for land or water. However, besides agricultural production, i.e. mainly rice-based systems including fish, vegetable, fruit and livestock production, inland valleys also provide local communities with forest, forage, hunting and fishing resources and they are important for water buffering and as biodiversity hot spots. Development for agricultural production must be done in such a way as to avoid compromising these locally- and regionally-important ecosystem services. This will require improved rice germplasm and nutrient and water management suited to these systems, so as to minimise the land area required. It will also require technologies for assessing which areas across SSA are best suited to intensification and expansion of rice-based farming, without compromising other ecosystem goods and services. It is estimated that with realistic improvements in germplasm and management, less than 10% of the total inland valley area in SSA would be sufficient to meet the total demand for rice in Africa. But various biophysical constraints need to be overcome; one of the most important is the soil health problem iron (Fe) toxicity.Iron toxicity is a set of severely yield-limiting disorders associated with high concentrations of reduced ferrous iron (Fe(II)) in flooded paddy soils. It is exclusively a problem of paddy rice, linked to the biogeochemistry of flooded, anaerobic soil. It is a particular problem in African rice systems because of the nature of the soils, which are highly weathered, nutrient-depleted and rich in Fe oxides, in contrast to the young alluvial rice soils of the Asian lowlands. It affects a large part of the existing and potential rice area in SSA (estimates vary from 20-60% of the area) and causes large yield losses (up to 90%). There are currently efforts to exploit tolerance of it in the indigenous African rice germplasm in breeding and management programmes at AfricaRice and elsewhere. But this is constrained by the complexity of the disorder and by poor understanding of the underlying mechanisms and genetics of tolerance, which reflects its relative unimportance in Asian rice systems where most rice research has been focused. We propose to provide the bioscience and tools required to (a) elucidate the mechanisms and genetics of tolerance to Fe toxicity in indigenous African germplasm, in support of rice breeding and management programmes, and (b) assess the potential of improved germplasm and management to raise the productivity of existing and new rice-based farming systems across SSA. We will especially focus on Oryza glaberrima ('African' rice) species, indigenous to W Africa, and sub-species of Oryza sativa ('Asian' rice) indigenous to Madagascar. We will use a combination of soil chemistry, plant physiology and molecular genetics approaches with field work in W Africa and Madagascar, supported by controlled-environment and laboratory work in the UK. We will also map the spatial extent of different types of Fe toxicity in existing and potential rice areas across SSA, and we will develop GIS tools for assessing the potential for improved germplasm and nutrient and water management to raise the productivity of rice-based farming systems in these areas.

大米是撒哈拉以南非洲地区的主要主食，随着消费者偏好和城市化的变化，对大米的需求正在迅速增长。然而，国内生产目前仅占消费量的60%左右;撒哈拉以南非洲的进口量占全球大米贸易的三分之一。因此，有各种国家和国际倡议，提出了在整个撒南非洲增加产量的雄心勃勃的计划。在内陆山谷和其他地方有大量适合农业气候的湿地，可以支持水稻种植面积的大规模集约化和扩大。在雨季，水稻是低洼湿地上唯一可能的作物，因此它不会与其他作物争夺土地或水。然而，除了农业生产，即主要以稻米为主的系统，包括鱼、蔬菜、水果和牲畜生产之外，内陆山谷还为当地社区提供森林、饲料、狩猎和渔业资源，它们对于水缓冲和生物多样性热点都很重要。农业生产的发展必须避免损害这些对当地和区域具有重要意义的生态系统服务。这将需要改进水稻种质以及适合这些系统的养分和水管理，以最大限度地减少所需的土地面积。它还需要技术来评估整个撒南非洲哪些地区最适合强化和扩大以水稻为基础的农业，而不损害其他生态系统产品和服务。据估计，随着种质和管理的实际改进，撒哈拉以南非洲内陆河谷总面积的不到10%就足以满足非洲对水稻的总需求。但是，水稻土的铁毒害是一系列严重的产量限制性病害，与水稻土中高浓度的还原性亚铁（Fe（II））有关。这完全是水稻的问题，与淹水厌氧土壤的生物地球化学有关。这是非洲水稻种植系统中的一个特殊问题，因为非洲土壤的性质与亚洲低地的冲积水稻土壤相比，风化程度高，养分耗尽，富含氧化铁。它影响了撒南非洲大部分现有和潜在的水稻种植面积（估计为20-60%），并造成大量产量损失（高达90%）。目前正在努力在非洲水稻和其他地方的育种和管理方案中利用非洲本土水稻种质对它的耐受性。但这受到了疾病复杂性以及对耐受性的潜在机制和遗传学缺乏了解的限制，这反映了它在亚洲水稻系统中的相对不重要性，而大多数水稻研究都集中在亚洲水稻系统中。我们建议提供所需的生物科学和工具，以（a）阐明非洲本土种质对铁毒性的耐受性机制和遗传学，以支持水稻育种和管理计划，以及（b）评估改良的潜力。（B）管理以提高整个撒哈拉以南非洲现有和新的水稻农业系统的生产力。我们将特别关注原产于西非的Oryza glaberrima（“非洲”水稻）物种和原产于马达加斯加的Oryza sativa（“亚洲”水稻）亚种。我们将结合土壤化学，植物生理学和分子遗传学方法，在西非和马达加斯加进行实地工作，并得到英国受控环境和实验室工作的支持。我们还将绘制不同类型的铁毒性在整个SSA现有和潜在的水稻地区的空间范围，我们将开发GIS工具，用于评估改善种质和养分和水管理的潜力，以提高这些地区的水稻种植系统的生产力。

项目成果

期刊论文数量（7）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Mechanisms of genotypic differences in tolerance of iron toxicity in field-grown rice

DOI：
10.1016/j.fcr.2023.108953
发表时间：
2023-07
期刊：
Field Crops Research
影响因子：
5.8
作者：
Toavintsoa Rajonandraina;T. Rakotoson;M. Wissuwa;Y. Ueda;T. Razafimbelo;A. Andriamananjara;G. Kirk
通讯作者：
Toavintsoa Rajonandraina;T. Rakotoson;M. Wissuwa;Y. Ueda;T. Razafimbelo;A. Andriamananjara;G. Kirk

Magnesium supply alleviates iron toxicity-induced leaf bronzing in rice through exclusion and tissue-tolerance mechanisms.