Bryophytes: Liverworts, Hornworts and Mosses. Bryophytes Plant scien+sts recognize two kinds of land plants §Bryophytes, or nonvascular plants §Tracheophytes , or vascular plants. Distribu+on tropical rainforests, arc+c tundra, and desert boulders Chlorophyta and Bryophyta Charophyta §Chloroplasts with grana §Disintegraon of nuclear membrane during mitosis §Phragmoplast during cytokinesis §Oogamus sexual reproduc+on §Zygotes remain aached to the parental thalli §The parental cells develop transfer cells involved in bringing sugars to the zygote §Plasmodesmata Bryophytes and other land plants. Kingdom Plantae § Mul+cellular diploid sporophyte § Producon of sporogeneous ssue § Tissues produced by an apical meristem. Bryophytes. Non vascular plants Specialized cell for conduc+on Not lignified cells Large free living gametophyte Sporophyte §Achlorophyllous §“Parasi+c” on the gametophyte §Unbranched §One sporangium Plasmodemata Bryophytes. Non vascular plants Cucle Pores Rhizoids Disk-shaped plas+ds in the thalli hexagonal leaf cells with central pore ReproducAon of Bryophytes archegoniophore Asexual: (female sex organ) •Fragmentaon •Gemmae Sexual: •Antheridia •Archegonia •Gametpohytes are haploid •Gametes produced by mitosis Bryophytes need water for fer+lizaon to occur. Sporophyte of bryophytes. Sporophyte of mosses and hornworts contain stomata and two guard cells. •brings up nutrients from the gametophyte through the placenta. Spores covered with sporopollenin. §Cellulose §xylan §lignin §Lipids Extremely resistant to decay and chemicals Bryophyta:Phylums/Divisions § HEPATOPHYTA - the Liverworts § ANTHOCEROPHYTA - the Hornworts § BRYOPHYTA - the Mosses HEPATOPHYTA (hepaAcs) - the Liverworts The Liverworts (wyrt= herb) 6,000 Gametophytes develop directly from spores but some produce protonemata Gametophyte §leafy §thalloid Thalloid liverworts Differen+aon of the thallus into 1. an upper photosynthe+c region with air chambers 2. a ventrally storage zone with abundant lipid reserve and rhizoids. Thalloid liverworts Marchan'a produces the sex organs in Sporophyte • Antheridiophores è antheridia. • Archegoniophores è archegonia. Elaters to help in scaering the spores. Fragmentaon Gemma cups Leafy liverworts 4000 species Leaves generally are monostromac Antheridia produced on the androecial branches. The archegonium is surrounded by the perianth. ANTHOCEROPHYTA - the Hornworts 100 species Gametophy+c thallus lobed or dichotomous The thallus has internal chambers with Nostoc Rhizoids are unicellular Stomata Most species are bisexual. Gametangia develop from superficial cells but never project above the surface Sporophyte: Foot embedded in the gametophyte Long capsule or sporangium. intercalary meristem between the foot and the capsule meristem remains ac+ve indeterminate growth photosynthe+c BRYOPHYTA - the Mosses 12,000 species Protonema Mul+cellular rhizoids Gametophyte •Leafy with more than three ranks of blades •Chlorophyllous •May or may not branch. BRYOPHYTA - the Mosses Protosphagnales appear about 290 million years ago in the Permian. Sphagnum has apical gametangia Sporophyte capsules develop on the pseudopodia BRYOPHYTA - the Mosses “explosive” operculum §closes the opening of the sporangial capsule Sphagnum can absorb water up to 20 +mes its dry weight Sphagnum releases large amount of H+ Class Andreaeidae 101 species granite or calcareous rocks in northern latudes Rhizoids consist of two rows of cells Sporophyte •Foot •Capsule üfour valves that open when is dry and close when is moist. Class Bryidae Protonema §uniseriate branched system that precedes the gametophores. §major photosynthe+c role. Mul+cellular rhizoids present The sporangium opening with peristome. Aendance What evidence is there in support of a charophyte ancestry for plants? .