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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=753362
• 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和草本茎在授粉、传粉者吸引、发育、生长、成熟和有性生殖的内部小气候中的功能。拟议的跨学科研究，包括功能植物形态学在器官，组织和细胞水平。再加上微气象学，从紫外到红外的光学生物物理学，以及通过标准仪器进行的温度测量，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。 花的特征体现了植物与传粉者的相互适应。宏观和微观特征通过传粉者的感官（视觉，化学和触觉）感知起作用。颜色通常与气味和表皮微结构特征相结合。它们一起提供镜面（镜面）到哑光（漫射）反射，可能还有彩虹色和荧光。表皮或叶肉组织、细胞器（质体）或原生质溶液中的色素对着色效果有不同的影响（Kubelk-Munk模型）。此外，许多花通过太阳照射来温暖，这有助于生长和成熟，并且被花晒传粉者使用。最著名的是diaheliotropic（太阳跟踪）碗状花反射太阳能炉。较少了解的是封闭和短柔毛花的低温制度。据推测，太阳辐射穿透半透明的结构，加热内部结构，重新辐射红外线，成为被困，一个微型温室。热/光生物物理中空草本茎作为微型温室构成类似的新的研究。初步数据（2017年）表明，空心是常见的（约2/3。取样的120种草本植物），这些茎（测试的5种）被加热到高于环境温度5-6 ℃。拟议的花和茎的热/光生物物理学研究将通过观察和实验，研究植物结构内微热环境（通过小型温度传感器和红外热成像测量）的发生率和程度及其对自然和受控条件下生长、成熟和生殖产量的影响。将通过显微镜和组织学结合紫外-可见-近红外反射/吸收分光光度法（包括透明度、透明度、荧光等），发射率、导热率。 对不同植物和植物结构中的这些特征进行量化，将允许对植物组织的色度、结构、解剖学和热特性进行比较评估，这些特性与植物在不同生境中以及在一天和一年的不同时间对自然辐射能的不同使用的适应意义有关。