Lagenidiales perenosporales uniflagelate whiplash and

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Lagenidiales, Perenosporales Uniflagelate, Whiplash and Posteriorly positioned Uniflagelate, Tinsel and Anteriorly positioned Biflagellate, Unequal Whiplash, Anteriorly positioned Biflagellate, Unequal-One Whiplash and the other tinsel, Anteriorly positioned Classification of the Mastigomycotina into various classes and orders
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CLASS - Chytridiomycetes Formerly referred to as Chytrids and characterized by the presence of motile cells or zoospores made up of a single, posteriorly positioned, whiplash flagellum. Mycelium is non-septate, diploid and form resting spore or sporangium. The thallus can be holocarpic or eucarpic while some posses non- nucleate rhizomycelium or rhizoids Their chief wall component is chitin and β -glucan, and exist as parasites of higher plants ( Synchytrium, Olpidium, Physoderma ), algae ( Phlyctochytrium ) and a few aquatic animals ( Coelomomyces, Batrachochytrium ). They reproduce both sexually and asexually by spores while capable of sexual reproduction by any of the following methods (i) planogametic copulation e.g. Olpidium, Synchytrium , (ii) gametangial copulation e.g. Zygorhizidium
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Mycelium Fig. 12: Illustration of varied mycelia formed by members of the Class-Chytridiomycetes
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The Class – Chydridiomycetes comprised 4 Orders separated on the basis of their LIFE CYCLE. The 4 orders are as presented.
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Order - Chytridiales The order Chytridiales comprised more primitive members of the Class-Chytidiomycetes and live as either parasites of algae, other chytrids, aquatic fungi, animals (mosquito lavae, fish eggs, amphibians, rotifers, insects exoskeleton or saprophytes (plant debris). Their unique features include coenocytic unbranched monocentric and polycentric thalli. The monocentric thallus may be: (i) Endobiotic – thallus occur completely within the living host (obligate parasite); (ii) Epibiotic – thallus occur partly within (somatic structure) and partly outside(reproductive structure) the host; (iii) Interbiotic – thallus rhizoidal part occur within the host with the most part outside.
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Fig. 13: Schematic illustration of the different thalli formed by members of the Order - Chytriales
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Continuation Monocentric thalli may be without rhizoids and holocarpic (entire thallus function in reproduction) or eucarpic (thallus differentiated into reproductive and somatic parts) The thallu produced by the Chytridiales may be uninucleate or multinucleate. Some members cause disease of animals and economic crops e.g. Chytridiomycosis ( Batrachochytrium dendrobatidis ); Black wart disease ( Synchytrium endobiotum ), Damaged grass root ( Olpidium brassicae ) During the life cycle, the sporangium formed may be operculate (apical lidded nipple or opening called papilla in a discharge tube) or inoperculate (without any opening) The also form Apophysis apart from rhizoids.
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Continuation The chytridiales members reproduce asexually by means of zoospores formed by the continuous cleavage of the zoosporangium cytoplasm .
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