Pollination Biology for Sexual Reproduction in Plants - Unlike for Animals • Rely on Movement of (1) Pollen,(2) Young Embryo Encased
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Sexual Reproduction in Plants • Movement onto land is an issue Pollination Biology for sexual reproduction in plants - unlike for animals • rely on movement of (1) pollen,(2) young embryo encased . real story of the birds & bees . in a seed (or fruit), or (3) spores and beetles, bugs, butterflies, bats pollination biology seed dispersal Sexual Reproduction in Plants Coevolution Pollination and seed/spore dispersal important Coevolution – interactions between two different clades as aspects of biosystematics in plants: selective forces on each other, resulting in adaptations that • Gene flow increase their interdependency • Outcrossing vs. inbreeding • Reproductive isolation Animal-flowering plant interaction is a classic example of coevolution: • Speciation spore dispersal • Co-speciation (coevolution) pollination biology seed dispersal • Plants evolve elaborate methods to attract animal pollinators • Animals evolve specialized body parts and behaviors that aid plant pollination 1 Coevolution Divergence vs. Convergence • classic example of both divergence and convergence in • insect lineages diversified prior to angiosperms, but co- pollination is the family Polemoniaceae opted by and responded to by angiosperms • frequent shifts to different “pollination syndromes” from ancestral bee pollination V. Grant hummingbird bat Polemoniaceae Ipomopsis aggregata subsp. attenuata tip color = Phlox subulata subsp. subulata Linanthus californicus Ipomopsis arizonica Linanthus dichotomus Ipomopsis congesta Linanthus dianthiflorus Ipomopsis pumila spiritus − DNA tree with Linanthus parryae Phlox oklahomensis Phlox stansburyi Phlox drummondii subsp.Phlox glaberrimadrummondii subsp. interior Phlox maculata subsp. maculata pollinator Phlox condensata Divergence vs. Convergence Phlox multiflora pollinators Phlox diffusa Ipomopsis aggregata subsp. formosissima Ipomopsis aggregata subsp. Ipomopsis tenuituba subsp. latiloba Phlox bryoides Ipomopsis aggregata subsp. candida Ipomopsis polyantha Ipomopsis sancti Ipomopsis multiflora subsp. multiflora Phlox andicola Ipomopsis aggregata subsp. bridgesii Ipomopsis longiflora subsp. australis Ipomopsis longiflora subsp. neomexicana Ipomopsis rubra Ipomopsis tenuituba Ipomopsis aggregata subsp. aggregata Phlox pilosa subsp. pilosa Phlox roemeriana Ipomopsis spicata subsp. spicata Ipomopsis macombii Ipomopsis thurberi mapped onto it Phlox cuspidata Ipomopsis congesta subsp. montana Ipomopsis polycladon Phlox pilosa subsp. fulgida Ipomopsis effusa Phlox divaricata Ipomopsis guttata Phlox paniculata Ipomopsis tenuifolia • another example is evolution of orchid floral form in Platanthera Microgilia minutiflora Loeseliastrum depressum Phlox stolonifera Langloisia matthewsii Microsteris gracilis Langloisia punctata Phlox dolichantha Eriastrum eremicum subsp. eremicum Leptosiphon liniflorus Hummingbird ? Leptosiphon grandiflorus Eriastrum wilcoxii of Northern Hemisphere Eriastrum luteum Leptosiphon parviflorus Eriastrum sapphirinum subsp. dasyanthum Eriastrum sapphirinum subsp. sapphirinum Leptosiphon jepsonii Eriastrum densifolium subsp. austromontanum ancestral! LeptosiphonLeptosiphon androsaceus bicolor Eriastrum densifolium subsp. sanctorum Eriastrum densifolium Leptosiphon breviculus Loeselia mexicana Leptosiphon pygmaeus Loeselia glandulosa subsp. conglomerata Aliciella latifolia Leptosiphon nuttallii Aliciella hutchinsifolia Gymnosteris parvula Aliciella triodon Polemonium pauciflorum Aliciella micromeria Aliciella leptomeria Polemonium elegans Polemonium micranthum Aliciella heterostyla Aliciella formosa Polemonium viscosum Aliciella mcvickerae Polemonium molle Aliciella stenothyrsa Polemonium flavum Aliciella pinnatifida Polemonium confertum Aliciella pentstemonoides Aliciella tenuis Polemonium brandegeei Polemoniaceae Aliciella caespitosa Polemonium caeruleum Aliciella subnuda Polemonium acutiflorum Aliciella haydenii Polemonium occidentale Acanthogilia gloriosa Polemonium pulcherrimum Fouquieria columnaris Fouquieria splendens Polemonium californicum Fouquieria macdougalii Polemonium delicatum Fouquieria diguetii Polemonium boreale Fouquieria ochoterenae Polemonium vanbruntiae Fouquieria formosa Polemonium reptans Fouquieria fasciculata Cantua pyrifolia Fouquieraceae Allophyllum gilioides Cantua candelilla Allophyllum violaceum Cantua bicolor Allophyllum integrifolium Cantua quercifolia Allophyllum glutinosum Cobaea trianae sister to phlox Allophyllum divaricatum Cobaea scandens Collomia cavanillesii Cobaea penduliflora Collomia biflora Cobaea aschersoniana Saltugilia caruifolia family Collomia macrocalyx Saltugilia splendens subsp. splendens Collomia renacta Saltugilia australis Collomia linearis Saltugilia splendens subsp. grantii Collomia mazama Gilia capitata Gilia capitata subsp. abrotanifolia Collomia rawsoniana Gilia capitata subsp. pedemontana Collomia tinctoria Gilia capitata subsp. mediomontana Gilia achilleifolia subsp. achilleifolia autogamy Collomia heterophylla Gilia angelensis Navarretia pubescens Gilia nevinii Navarretia fossalis Gilia achilleifolia subsp. multicaulis Gilia millefoliata bat Gilia valdiviensis Gilia clivorum NavarretiaNavarretia atractyloides hamata Gilia tricolor subsp. tricolor Gilia laciniata bee Gilia scopulorum NavarretiaNavarretia peninsularis viscidula Gilia leptantha subsp. leptantha Navarretia leucocephala subsp. minima Navarretia mellita Gilia crassifolia Gilia clokeyi Gilia stellata Gilia ophthalmoides Navarretia squarrosa Gilia ochroleuca subsp. ochroleuca beetle Navarretia capillaris Gilia ochroleuca subsp. bizonata Gilia mexicana Gilia latiflora subsp. latiflora Navarretia leptalea Gilia cana subsp. bernardina Gilia jacens Gilia cana Gilia leptantha subsp. purpusii Gilia cana subsp. triceps Gilia tenuiflora subsp. tenuiflora Gilia interior Platanthera leucophaea bird Gilia diegensis Gilia modocensis Gilia inconspicua Gilia malior Gilia ochroleuca subsp. exilis Gilia minor Gilia tetrabreccia Gilia sinuata fly Gilia tweedyi Gilia flavocincta subsp. australis Gilia austrooccidentalis Prairie-fringed orchid moth/hawkmoth Gilia transmontana Gilia leptantha subsp. pinetorum Gilia latiflora subsp. excellens Gilia cana subsp. speciosa butterfly Gilia brecciarum subsp. neglecta long−tounged fly Gilia brecciarum subsp. brecciarum Ph.D. Work by Jeff Rose 2 Divergence vs. Convergence What is Pollination? • DNA relationships indicate remarkable divergent and convergent • Pollination: The transfer of pollen from the male anther to the shifts - 3 separate shifts to nocturnal hawkmoth pollination female stigma, in same plant or between two plants Platanthera Evolution of the Flower Evolution of the Flower Evolution of the flower is linked with evolution of • closed carpel for protection of pollination syndromes and why divergence/convergence is ovules and seeds pervasive in floral features • bisexual flowers to bring male and female parts closer • primitive flowers had separate pollen- and carpel-bearing structures such as in Archaefructus (and in all gymnosperms) Archaefructus Drimys - basal angiosperm 3 Evolution of the Flower Evolution of the Flower • fusion of carpels into one pistil - • epigyny - protection of • fusion of floral parts - efficient deposition of pollen and ovules from probing animals tubular structures for movement of pollen tubes down restricting nectar access one or few style lobes Evolution of the Flower Evolution of the Flower • exotic landing platforms, spurs, nectaries, etc - Placement of both stamens and carpels in the same flower specialization for specific pollinators causes inbreeding - subsequent selection for outcrossing • protogyny or protandry - temporal sequence of anthesis or stigma receptivity 1. female phase 2. male phase Protogyny in Asimina - pawpaw (Annonaceae) 4 Evolution of the Flower Evolution of the Flower Placement of both stamens and carpels in the same flower Placement of both stamens and carpels in the same flower causes inbreeding - subsequent selection for outcrossing causes inbreeding - subsequent selection for outcrossing • self incompatibility - chemical on surface of pollen and • heterostyly - reciprocal stigma/style that prevent pollen tube germination separation of anthers & on the same flower (S allele incompatibility system) stigmas • unisexuality - reversal back to separate sexes in flowers Primula - primrose Cucurbita - zucchini Pollination Syndromes Insect Pollination - Entomophily • morphologically convergent adaptive trends exhibited by Modern insect pollinators the floral features of pollinated plants and, in animal pollination, the mouthpart structure and other flower- • Beetles -- Coleoptera interactive features of the pollinators • Flies -- Diptera Passive Active • Ants -- Hymenoptera • Butterflies -- Lepidoptera 1. Wind - anemophily 3. Animal - zoophily • Moths -- Lepidoptera 2. Water - hydrophily (ornithophily, entomophily) • Bees -- Hymenoptera Primitive type of insect pollination appears to be beetle or fly pollination 5 ANA Pollination Beetle Pollination • likely that beetles first visited the female cones of conifers and fed on the pollination droplet exudates • function of pollination droplet originally for capture of wind-blown pollen — shift as food attractant for beetles as in Welwitschia Welwitschia American Journal of Botany January 2009 ANA grade has surprising number of . including thermophily (heat to pollination types . volatize scents for fly pollination) in Illicium floridanum Beetle Pollination Beetle Pollination • beetle flowers usually • beetle flowers are pale or dull in color,