Excellence in Research: Developing a Model System for Studying the Determinants of Flower Morphology in Tropical Dioecious Trees

在许多植物物种中，人们可以在单独的植物上或在同一植物上发现雄花和雌花的存在，或者单个花携带雄蕊（雄性）和雌蕊（雌性）部分。 遗传和环境之间的相互作用，在决定花的类型和花器官的发展，在这样的植物仍然在很大程度上没有调查。为了研究这一现象，项目小组将使用Coccoloba diversifolia（pigeonplum），这是一种原产于佛罗里达南部、加勒比、墨西哥南部和中美洲新热带沿海地区的植物。它是一种重要的原生热带树木，并显示出上述不同程度的花朵图案。该团队将对这种植物物种的基因组进行测序，并对野生种群中发现的遗传学和开花模式进行分析，以确定在调节花和花器官发育中发挥作用的基因组区域。 拟议的实验，数据收集和分析将提供一个很好的机会和源材料，以培养代表基因组学，生物信息学，生物数据科学和保护方面各种人才的研究生和本科生。在雌雄异株的分类群中，决定哪些生物个体是雌蕊的，哪些是雄蕊的因素和机制仍然没有很好的理解。在少数情况下，异形染色体已被确定为一个主要的决定因素。在其他情况下，环境因素被确定为主要决定因素。然而，即使是这些情况下似乎没有确定严格的决定因素。此外，研究这些现象的生物系统绝大多数是草本和温带的。该项目旨在研究遗传学和环境的相互作用，在确定雌蕊和雄蕊的个人在热带树木与变量花的表达。该项目将（1）使用短读段和长读段DNA测序沿着邻近连接的组合组装和注释研究分类群Coccoloba diversifolia的完整核基因组，（2）通过群体采样，浅层全基因组鸟枪测序和形态特异性读段的鉴定来鉴定有助于确定雌蕊或雄蕊个体的遗传区域，（3）通过记录花形态与环境条件的关系，评估环境在决定花形态中的作用。佛罗里达南部的一个多叶植物属。该项目团队将为来自服务不足社区的学生提供体验式学习、基因组学和生物信息学方面的培训和技能发展机会。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

In many plant species, one can find presence of male and female flowers on separate plants or on same plants or single flowers carrying both the stamens (male) and pistil (female) parts. The interplay between genetics and the environment in determining the flower type and development of floral organs in such plants remains largely uninvestigated. To study this phenomenon, the project team will use Coccoloba diversifolia (pigeonplum), a native of neotropical coastal areas of Southern Florida, Caribbean, Southern Mexico and Central America. It is an important native tropical tree and shows a varying degree of flower patterns mentioned above. The team will sequence the genome of this plant species and profile the genetics and flowering patterns found in a wild population to identify the regions of genome that play a role in regulating the development of flowers and floral organs. The proposed experiments, data collection and analyses will provide an excellent opportunity and source material to train the graduate and undergraduate students representing the full spectrum of diverse talent in genomics, bioinformatics, biological data science and conservation. Among dioecious taxa, the factors and mechanisms determining which biological individuals are pistillate and which are staminate are still not well understood. In a small minority of cases, heteromorphic chromosomes have been identified as one major determinant. In other cases, environmental factors have been identified as major determinants. Yet even these cases appear not to identify strict determinants. Moreover, the biological systems in which these phenomena are studied, have been overwhelmingly herbaceous and temperate. The project looks to examine the interplay of genetics and the environment in the determination of pistillate and staminate individuals in a tropical tree with variable floral expression. The project will (1) assemble and annotate the complete nuclear genome of the study taxon Coccoloba diversifolia using a combination of short- and long-read DNA sequencing along with proximity ligation, (2) identify the genetic regions contributing to the determination of pistillate or staminate individuals through population sampling, shallow whole genome shotgun sequencing and the identification of morphology-specific reads, and (3) assess the contribution of environment in determining flower morphology through the documentation of flower morphology ratios in relation to environmental conditions for populations of C. diversifolia in South Florida. The project team will provide training and skills development opportunities to students from underserved communities on experiential learning, genomics, and bioinformatics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.