Collaborative Proposal: Integrating Morphological and Molecular Systematics of Alternaria and Related Fungal Genera

合作提案：整合链格孢属和相关真菌属的形态学和分子系统学

• 批准号: 0416314
• 负责人: Tobin Peever
• 金额: --
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0416314&HistoricalAwards=false
• 关键词: Collaborative; Proposal; Integrating; Morphological; Molecular

0416314Peever Species of the fungus genus Alternaria are economically important in plant disease, food toxicology, medical mycology, and ecology, yet this large genus has not been comprehensively studied using modern tools of DNA analysis. A workable taxonomic system is critically needed that will ensure consistent and reliable identification of species and promote advanced studies in comparative biology. Toward this end, the principal objectives of collaborative work by Barry Pryor at University of Arizona and Tobin Peever at Washington State University are to: 1) establish evolutionary relationships among Alternaria species based upon comparison of DNA sequences from several genes, 2) re-examine and establish new criteria for delimiting Alternaria species based upon comparison of DNA among populations within species, and 3) evaluate morphological characters that critically define species validated by DNA analysis. Embedded within these objectives are additional goals of creating taxonomic identification keys based upon morphological characters that can be used by research, industry, and regulatory professionals, and developing an on-line database for the dissemination of data generated from these and other related studies. This database will serve as a world-wide resource for the advancement of contemporary research on Alternaria and related fungi. The scope of the proposed research is both timely and comprehensive in regard to the evolution of asexually-reproducing fungi, of which Alternaria is a key representative. In general, taxonomy for most organisms is based primarily on the development and characteristics of sexual structures, which normally have proven to be consistent with evolutionary relationships based upon DNA analyses. Thus, one of the primary limitations in the study of asexual fungi is the lack of sexual structures; only recently have studies begun to examine and contrast the characteristics of asexual fungi with data derived from DNA analysis. However, these studies seldom address intra-specific variation among populations, which is critical for delimiting the boundaries between species. Within Alternaria, a considerable range of inter- and intra specific diversity exists in asexual characters. Moreover, the occurrence of many Alternaria species over large geographic areas provides an ideal opportunity for comprehensive studies on intra-specific variation. Thus, the diversity in morphological traits encompassed within Alternaria provides a fertile ground for testing hypotheses relating to the evolutionary significance of asexual characters, and for comparing morphology-based taxonomy with DNA-based taxonomy of asexual fungi. The effective integration of the asexual fungi into a common evolutionary framework with the sexual fungi is a widely recognized goal of mycological research worldwide. A comprehensive study of Alternaria will contribute significantly to this objective. More importantly, the diversity and evolution of species within the asexual lineage of Alternaria positions this study as a foundation for future research into evolutionary processes that shape asexual fungal lineages and asexual organisms in general.

链格孢属（Alternaria）真菌在植物病害、食品毒理学、医学真菌学和生态学方面具有重要的经济意义，但尚未使用现代DNA分析工具对该大属进行全面研究。迫切需要一个可行的分类系统，以确保一致和可靠地鉴定物种，并促进比较生物学的高级研究。为此，亚利桑那大学的巴里·普赖尔和华盛顿州立大学的托宾·皮弗合作的主要目标是：1）基于来自几个基因的DNA序列的比较，建立链格孢属物种之间的进化关系，2）基于种内种群之间的DNA比较，重新检查并建立新的划分链格孢属物种的标准，和3）评估通过DNA分析验证的严格定义物种的形态特征。嵌入在这些目标是额外的目标，创建分类识别键的基础上，可以使用的研究，工业和监管专业人员的形态特征，并开发一个在线数据库，从这些和其他相关研究产生的数据的传播。该数据库将作为一个全球性的资源，促进对链格孢属和相关真菌的当代研究。建议的研究范围是及时和全面的无性繁殖真菌的进化，其中链格孢属是一个关键的代表。一般来说，大多数生物的分类学主要基于性结构的发育和特征，这通常已被证明与基于DNA分析的进化关系一致。因此，无性真菌研究的主要限制之一是缺乏有性结构;直到最近才开始研究无性真菌的特征，并将其与DNA分析数据进行对比。然而，这些研究很少涉及种群之间的种内变异，这对于划定物种之间的界限至关重要。在链格孢属内，无性性状存在着相当大范围的种间和种内多样性。此外，许多链格孢属物种在大的地理区域的发生提供了一个理想的机会，对种内变异的综合研究。因此，内链格孢属的形态特征的多样性提供了一个肥沃的土壤，用于测试有关的假设无性特征的进化意义，并比较基于形态学的分类与基于DNA的分类无性真菌。将无性真菌与有性真菌有效地整合到一个共同的进化框架中是世界范围内真菌学研究的一个广泛认可的目标。对链格孢菌的全面研究将有助于实现这一目标。更重要的是，链格孢属无性谱系内物种的多样性和进化将本研究定位为未来研究塑造无性真菌谱系和无性生物的进化过程的基础。