The Ecological Consequences of Hybridization of Asexual Microbial Symbionts

物种间的杂交是一个众所周知的生物过程，它能迅速创造出新的物种和生物体的变种。例如，大约95%的蕨类植物物种和70%的开花植物物种是由杂交（结合两个物种的基因）产生的。杂交植物包括重要的农作物，如现代小麦。许多动物物种也是两个亲本物种杂交的结果。我们对微生物物种之间的杂交知之甚少，尽管其生态后果可能是巨大的。例如，导致荷兰榆树病和破坏美国森林的侵袭性致病性真菌是由两种良性真菌菌株杂交而成的。本研究研究了一种生活在农艺禾草和原生禾草内部的内生真菌杂交的生态效应。内生菌是生活在植物内部的共生真菌，通常不会引起疾病。相反，这些内生菌促进了植物的生长、竞争能力和对食草动物的抵抗力。本研究将研究内生菌的杂交如何改变它所生活的草的生长、繁殖和生存。该研究对牧草、草皮和原生草的福利具有重要意义，所有这些都经常感染内生菌。此外，由于微生物通过人类活动在全球范围内传播，杂交机会大大增加。这些微生物杂交事件可能对其宿主（包括作物、人类和牲畜）产生积极或消极（例如致病）影响。因此，了解杂交微生物伙伴如何影响其原生宿主草和农艺作物是至关重要的。

Hybridization between species is a well-known biological process that rapidly creates new species and varieties of living organisms. For example, approximately 95% of fern species and 70% of flowering plant species and have arisen from hybridization (combining genes from two species). Hybrid plants include important crop plants such as modern wheat. Many species of animals are also the result of hybridization between two parental species. Much less is known about hybridization between microbial species, although the ecological consequences can be dramatic. For example, the aggressive and pathogenic fungus that causes Dutch elm disease and devastated American forests resulted from hybridization of two benign fungal strains. This research studies the ecological effects of hybridization of a fungal endophyte that lives internally in both agronomic and native grasses. Endophytes are symbiotic fungi that live inside plants and do not usually cause disease. Instead, these endophytes improve growth, competitive abilities and resistance to herbivores that consume the plant. This research will examine how hybridization of the endophyte alters the growth, reproduction and survival of the grass in which it lives. This research has important implications for the welfare of pasture, turf and native grasses, all of which are often infected with endophytes. Furthermore, hybridization opportunities have dramatically increased as microbes are transported globally by human activities. These microbial hybridization events may result in either positive or negative (e.g., pathogenic) effects on their hosts, including crops, humans and livestock. Understanding how hybrid microbial partners influence their native host grasses and agronomic crops is therefore essential.