O male phase first stigma not receptive anther lever

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o Male Phase First Stigma: not receptive
Anther: lever-mechanism o Female Phase Afterwards Style grows longer Temporal + spatial separation & selfing o Within-flower: Cross o Between-flowers: Check Within-ind. asynchrony of & phases… Self incompatibility BIOA02H3 - Lecture 09 How to avoid doing it yourself Temp./spat. separation and selfing o Selfing ‘accidents’ still happen… Self incompatibility o No fertilization with own pollen!! o Biochemical self recognition Self pollen, outcross pollen, stigma, growing pollen tube, style, ovule o Multiple flowering adaptations at once!! Sage: separated in time & space & self incompatibility Why all 3? T & S Separation:ease of pollen pickup and delivery (better mechanics) Self Incompatibility: ultimate selfing avoidance!! o Pears, cherries, plums Sex slaves of the plant kingdom Flowers o Ingenious solution of angiosperms non-directed and directed mobility of pollen to seek egg o Today: extreme diversity in the types of flowers o invention of flowers: triggered largest diversity of plants ever Forces behind the evolution of flowers o Main forces Assurance of seeds set Sheer mechanics, bring female and male gametes together and at least eplace the two parents Inbreeding Avoidance Create high-quality offspring [do it yourself inbreeding depression] o Pollination Syndromes Specialization on a narrow set of pollinators vs. Use of many different pollinator groups o Generalist Pollinators Opportunistic flowers Multiple flowers making up landing platforms for insects oof different sizes to roam
Non specialized food: pollen and nectar o Pollination syndromes Specialization Of floral architecture to optimize pollen uptake and deposition On senses of pollinators for precise attraction [sight, smell, touvh] On food requirements of pollinators [fitting reward] o Shape, colour, odor, reward Abiotic pollination [wind, water] o Undirected Biotic Pollination [animals] o Directied Wind Pollination o 10% of all plants are wind-pollinated o Wind pollination more common in/at: Habitats with fewer insects or generally more wind: Higher latitude and altitude Dry environments Open vegetation Island floras o Wind pollination Small, inonspicous flowers No special colours No nectar Long filaments Long [feathery branched] styles/stigma Plain & overlooked Why waste energy on wind? o Very small fraction of pollen reaches stigma Cheap but not very efficient Large quantity of pollen necessary Biotic Pollination o More precise & directed Pollinator needs reward [pollen, nectar[ Specialized organ construction o Often only a restricted set of pollinators can take reward adaptation to specialized pollinators Biotic Pollination [Animals] o Wide range of pollinators Specialists rely on a more narrow group of pollinators Sometimes: exclusive relationship one pollinator serves one plant = co- evolution Generalists flowering plants attract wide range of pollinators
Biotic Specialized Pollination Syndromes o Bees

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