Optical & physical properties of flowers & stems: UV to IR & surface texture adaptations for little-known thermal relations in plant growth and reproduction

光学的

• 批准号: RGPIN-2018-04820
• 负责人: Kevan, Peter
• 金额: $ 2.4万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=684903
• 关键词: Optical; physical; properties; flowers; stems

Biophysical and optical properties contribute to functionality of flowers and herbaceous stems in pollination, pollinator attraction, interior microclimate for development, growth, maturation and sexual reproduction. The proposed interdisciplinary research, embraces functional plant morphology at organismic, tissue and cellular levels. That, coupled with micrometeorology, optical biophysics from UV to IR, and thermometry through standard instrumentation, constitutes a new, interdisciplinary approach in botany with ramifications in co-evolutionary ecology. ******Floral features embody plant-pollinator co-adaptations. Macro- and microscopic features work via sensory (visual, chemical and tactile) perception by pollinators. Colours are often coupled to scent and epidermal microtextural features. Together they provide mirror-like (specular) to matte (diffused) reflections and perhaps iridescence and fluorescence. Pigments in epidermal or mesophyllic tissues, in organelles (plastids) or in protoplasmic solution, variously influence effectiveness in coloration (Kubelk-Munk models). Further, many flowers warm by insolation that aids growth and maturation and, as used by flower-basking pollinators. Best known are diaheliotropic (sun-tracking) bowl-shaped flowers as reflective solar furnaces. Less understood are microthermic regimes in enclosed and pubescent blossoms. Presumably insolation penetrates translucent structures, heats interior structures which re-radiate IR that becomes trapped, a microgreenhouse. Thermal/optical biophysics of hollow herbaceous stems acting as microgreenhouses constitutes similarly novel research. Preliminary data (2017) indicate that hollowness is common (2/3 of ca. 120 herb species sampled) and such stems (5 species tested) become heated by 5-6 C above ambient. ******The proposed research on the thermal/optical biophysics of flowers and stems will examine, through observation and experimentation, the incidence and extent of microthermic environments (measured by small temperature sensors and IR thermal imaging) within plant structures and their influences on growth, maturation and reproductive output under natural and controlled conditions. Biophysical mechanisms will be examined in selected plants through microscopy and histology combined with (UV-visible-near IR reflectance/absorbance spectrophotometry (to include transparency, translucence, fluorescence etc.), emissivity, thermal conductivity. Quantification of those characteristics in different plants and plant structures will allow for comparative assessments of colorimetric, structural, anatomical, and thermal properties of plant tissues associated with the adaptive significance of plants' differential, and presumably varying, usages of natural radiant energy in various habitats and at different times of day and year.

生物物理和光学特性有助于花卉和草本茎在授粉、传粉者吸引、发育、生长、成熟和有性繁殖的内部小气候方面的功能。这项拟议的跨学科研究涵盖了生物、组织和细胞层面的功能植物形态。这与微气象学、从紫外线到红外的光学生物物理学以及通过标准仪器进行的测温相结合，构成了植物学中一种新的跨学科方法，并在共同进化生态学中产生了影响。*花卉特征体现了植物-传粉者的共同适应。宏观和微观特征通过传粉者的感官(视觉、化学和触觉)感知发挥作用。颜色往往与气味和表皮的微纹理特征相联系。它们一起提供镜面(镜面反射)到哑光(漫反射)反射，或许还提供虹彩和荧光。表皮或叶肉组织、细胞器(质体)或原生质液中的色素对着色效果有不同程度的影响(Kubelk-Munk模型)。此外，许多花通过日光照射而变暖，这有助于生长和成熟，并被晒花的传粉者所利用。最广为人知的是碗形花，具有日光效应(跟踪太阳)，是太阳炉的反射器。不太清楚的是封闭花和青春花中的低温机制。据推测，阳光穿透了半透明的结构，加热了内部结构，这些结构重新辐射了被捕获的IR，这就是微型温室。作为微型温室的中空草本茎的热/光生物物理构成了类似的新研究。初步数据(2017年)表明，中空是常见的(约120种草本植物样本的2/3)，这样的茎(测试的5种)变得比周围环境高5-6摄氏度。*拟议的花和茎的热/光生物物理研究将通过观察和实验来研究植物结构内低温环境(通过小型温度传感器和红外热成像测量)的发生率和程度，以及它们在自然和可控条件下对生长、成熟和繁殖产量的影响。将通过显微镜和组织学结合(UV-可见光-近红外反射/吸收光谱(包括透明度、半透明、荧光等)、发射率、热导率等)来研究选定植物的生物物理机制。对不同植物和植物结构中这些特征的量化将允许对植物组织的比色、结构、解剖和热学特性进行比较评估，这些特性与植物在不同生境以及一天和一年中的不同时间对天然辐射能量的不同使用情况的适应意义有关。