Studies of the Interrelationships Among Inbreeding, Resistance to Herbivores, and the Transmission of Pathogens in Wild Gourds

许多植物都患有由食草昆虫传播的疾病。植物所遭受的损害既取决于它们对昆虫的吸引力，也取决于它们对疾病的抵抗力。这些反过来又受到植物基因的影响。这些研究调查了甲虫和蚜虫的食草性相互作用、细菌和病毒疾病的感染以及野生葫芦的遗传近交水平。野生葫芦是栽培南瓜的自由生活形式。将进行田间和温室试验，以控制近亲繁殖、草食和疾病暴露。血清学分析和传播生物测定将确定植物的感染水平。拟议的研究将阐明基本的生态和进化问题，如自然种群近亲繁殖的后果、自然种群中疾病的建立和传播以及食物链的动态，并将与小种群物种的管理和保护有关。此外，由于将对攻击南瓜、甜瓜和黄瓜的相同食草动物和病原体进行研究，因此研究结果将有助于制定葫芦作物物种的综合虫害管理计划。此外，了解近亲繁殖、食草动物和病原体之间的相互作用，在培育抗虫传病毒的转基因南瓜品种时尤为重要。如果这些基因逃逸到野生葫芦种群中，关于病毒病原体影响的信息将有助于预测这些转基因在自然界中的影响。

Many plants suffer from diseases spread by insect herbivores. The damage experienced by plants depends both on their attractiveness to insects and on their resistance to disease. These, in turn, are influenced by the plants'genes. These studies investigate interactions among herbivory by beetles and aphids, infection by bacterial and viral diseases, and the level of genetic inbreeding in wild gourds, which are free-living forms of cultivated squashes. Field and greenhouse experiments will be conducted in which inbreeding, herbivory, and exposure to disease will be controlled. Serological analyses and transmission bioassays will determine infection levels in the plants.The proposed studies both will shed light on basic ecological and evolutionary issues such the consequences of inbreeding in natural populations, the establishment and spread of diseases in natural populations, and the dynamics of food chains, and will be relevant for the management and conservation of species with small populations. Moreover, because the same herbivores and pathogens that attack squashes, melons, and cucumbers will be studied, the findings will be useful in the development of integrated pest management programs for cucurbit crop species. Furthermore, knowledge of the interactions among inbreeding, herbivores and pathogens is especially relevant now that transgenic squash cultivars with resistance to insect transmitted viruses are being cultivated. If these genes escape into wild gourd populations, information on the effects of viral pathogens will assist in predicting the impact of these transgenes in nature.