Optimizing plant interactions with mycorrhizal fungi to improve forage productivity and stress tolerance

丛枝菌根真菌（AMF）和重要的植物共生体，为植物提供许多益处，包括增加对土壤养分的获取，耐旱性和耐盐性。优化植物与AMF的相互作用有可能提高农业的可持续性，尽管农业实践减少了AMF对植物的好处。培育快速生长和养分吸收的植物选择对AMF的依赖，而耕作，肥料和农药减少土壤中AMF的丰度。对于饲料作物，AMF可能特别重要，因为饲料通常生长在养分含量低、养分保持力差和盐分增加的边缘土地上。然而，在优化AMF在牧草中的效益方面，几乎没有做过什么工作。我们将采取双管齐下的方法来解决这个问题：1）选择对AMF反应积极的饲料植物，2）鉴定和培养对饲料作物有益的AMF，特别是在盐碱条件下。为了选择AMF反应基因型，我们将使用两种常见的豆科牧草（苜蓿和红豆草）的现有育种苗圃。我们将首先确定与AMF相关的植物性状（如定植、AMF组成），这些性状与增强的生长和对低营养和干旱的耐受性相关。然后，我们将测试这些植物的后代是否表现出相似的性状和AMF的好处。重要的是，这些试验包括将评估AMF效益并可立即推荐的商业品种。为了培养有益的AMF，我们将从含盐和非含盐的天然草原上取样土壤。这是从我们的假设，天然草原将有更多的AMF多样性和AMF采样从盐碱草原将更耐盐。然后，培养的AMF将用于测试它们是否增加三种耐盐牧草类型的生长和耐盐性：豆科植物（苜蓿），多年生草（高冰草）和一年生草（大麦）。结合起来，这个项目将确定我们是否可以为AMF的利益培育饲料作物，以及我们是否可以开发AMF接种物，有利于饲料作物。

Arbuscular mycorrhizal fungi (AMF) and important plant symbionts that provide many benefits to plants, including increased access to soil nutrients, drought tolerance, and salinity tolerance. Optimizing plant interactions with AMF has the potential to enhance agricultural sustainability, although agricultural practices reduce plant benefits from AMF. Breeding plants for rapid growth and nutrient uptake selects against dependency on AMF, whereas tillage, fertilizers, and pesticides reduce the abundance of AMF in the soil. For forage crops, AMF may be especially important as forages are often grown on marginal lands that lave low nutrients, poor nutrient retention, and increased salinity. Little work has been done, however, to optimize the benefits of AMF in forages. We will take a two-pronged approach to this issue: 1) selecting forage plants that respond positively to AMF and 2) identifying and culturing AMF that are beneficial to forage crops, especially in saline conditions. To select for AMF responsive genotypes, we will use existing breeding nurseries of two common forage legumes (alfalfa and sainfoin). We will first identify AMF-associated plant traits (e.g. colonization, AMF composition) that are associated with enhanced growth and tolerance of low nutrients and drought. We will then test whether the progeny of these plants exhibit similar traits and AMF benefits. Importantly, these trials include commercial varieties that will be assessed for AMF benefits and can be immediately recommended. To culture beneficial AMF, we will sample soils from both saline and non-saline native grasslands. This follows from our hypothesis that native grasslands will have more diverse AMF and that AMF sampled from saline grasslands will be more salt tolerant. The cultured AMF will then be used to test whether they increase growth and salinity tolerance of three salt-tolerant forage types: a legume (alfalfa), a perennial grass (tall wheatgrass grass), and an annual grass (barley). Combined, this project will determine if we can breed forage crops for AMF benefits and if we can develop AMF inoculums that benefit forage crops.