Biotic and Abiotic Mechanisms for the Maintenance of Variation in Flower Form of an Alpine Wildflower

9508741 Gerhardt解释遗传变异是如何产生的，如何在生物体中分布，并随着时间的推移而保持，是进化生物学的一个主要目标。决定有机体繁殖成功的特征的遗传变异尤其重要，因为它是物种在新的环境挑战下成功延续自己的能力的基础。对于动物传粉的植物，其中一个属性就是花的形状。花的形态是一个复杂的特征，同时影响植物资源利用、敌人的行为和授粉的可能性。本文研究了落基山脉最丰富和生态优势的花之一——粘蓼的花形态变化的环境因素。具体来说，实验将测试动物传粉者喜欢的大而艳丽的花朵是否会为未来的生长和生存付出高昂的资源成本，以及/或使植物更容易受到花朵捕食者的影响。这样的生态权衡可以解释为什么在粘草和几乎所有其他已研究的自然和农业植物物种中，花形式的遗传变异会随着时间的推移而持续存在。目前农业在作物施肥、灌溉和化学病虫害防治方面的支出相当可观。本文所述的研究可以通过提出如何对花的形态进行遗传优化来减少从植物生长中转移的资源数量和因虫害而损失的胚珠数量，同时继续确保充分的授粉，从而降低这种成本。通过这种方式，拟议的研究有可能使向日葵、蓝莓、草莓、苜蓿和油菜籽以及无数其他动物授粉作物的种植更加经济和环保。

9508741 Gerhardt Explaining how genetic variation arises, is distributed among organisms, and is maintained over time is a major goal of evolutionary biology. Genetic variation in the characteristics that determine an organism's reproductive success is especially important, because it underlies the capacity of species to perpetuate themselves successfully under new environmental challenges. For animal-pollinated plants, one such attribute is flower form. Flower morphology is a complex trait that simultaneously influences plant resource use, the behavior of enemies, and the likelihood of pollination. This proposal addresses the environmental factors maintaining morphological variation in the flowers of one of the most abundant and ecologically dominant flowers of the Rocky Mountains, Polemonium viscosum. Specifically, experiments will test whether the large showy flowers preferred by animal pollinators exact a high cost in resources for future growth and survival and/or make plants more apparent and susceptible to flower predators. Such ecological tradeoffs could explain why genetic variation in flower form persists over time in P. viscosum and nearly every other natural and agricultural plant species that has been studied. Current farming expenditures on crop fertilization, irrigation and chemical pest management are considerable. The research described here could reduce such costs by suggesting how flower form can be genetically optimized to alleviate the amount of resource diverted from plant growth and the number of ovules lost to pest damage, while continuing to ensure adequate pollination. In this way, the proposed studies have the potential to make the cultivation of sunflowers, blueberries, strawberries, alfalfa and rapeseed, among myriad other animal-pollinated crops, more economical and environmentally sound.