The pciniaresentation describe the life cycle of Pythium, Albugo, Erysiphae, Claviceps, Ustilago, Puccinia. both sexual spores (called oospores) and asexual spores (called sporangia) in a many-stage (polycyclic) disease cycle. infection stag heads oospore productt0n zoo spores. \. SEXUAL c germ1not1~. Oospores -overwintering spores. 8. Figure 8. Life cycle of Albugo candlda.
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The walls between them fuse to form a gelatinous disc-like structure called disjunctor or separation disc or intercalary disc. Reaching a certain size it is delimited from the sporangiophore by a basal septum.
Albugo Albugo candidaon Capsella bursa-pastoris Scientific classification Phylum: The separation discs are dissolved by water, and the sporangia are set free. Towards the end of sporangial maturation, the dictyosomes become quiescent, mitochondria decreased in number and also the amount of endoplasmic reticulum. Articles with ‘species’ microformats. White rust is an economically important foliar disease, lie substantial yield losses and eventual death of various crops.
The sex organs arise on separate hyphae called the male and the female hyphae A. The thick oospore wall then cracks. Stevens suggested that Albugo possesses diploid somatic nuclei which undergo meiosis in the gametangia antheridia and oogonia.
The oldest sporangia have none. National Center for Biotechnology Information. It bears remnants of the connectives or disjunctor pads at both the ends. The number of haustoria per cell varies from one to several.
The antheridium develops on the terminal end of another hypha lying very close to the oogonium. Oospore is the only diploid structure in the life cycle. The latter then continues to grow leaving the haustorium as a side branch. They are thick walled on lateral sides and thin walled at tip.
The oogonium develops a papilla like out growth at the point of contact with the antheridium.
This is a question and answer forum for students, teachers and general visitors for exchanging cyxle, answers and notes. The method of control is tailored to specific crops and production systems. In between each two sporangia a gelatinous pad develops acting as a qlbugo of two sporangia from each other. When the sporangia are formed in abundance on innumerable sporangiophores, the pressure is caused; the host epidermis ruptures and hundreds of sporangia are seen on the surface of the host in the form of white creamy powder forming pustules.
The exospore is ruptured and the endospore comes out as a thin vesicle Off. It is separated by a cross wall from the rest of the male hyphae. The sporangia are produced at the tip by abstraction method. The sporangial wall increased 3-fold the thickness.
On germination, they put out a short germ tube which enters the host through stomata Fig.
Ultimately the male nucleus fuses with the female nucleus karyogamy. The number of functional egg nucleus in ooplasm is one. Tewari and Skoropad investigated the fine structure and development of A. It is surrounded by periplasm rich in vacuolate cytoplasm containing membranous organelles. It absorbs water and swells. In Albugo each successive sporangium is capable of seceding from the sporangiophore or from the young sporangium.
It is multinucleate nuclei but only one nucleus remains functional at the time of fertilization in C. Sometime after all the nuclei of ooplasm migrate into the periplasm D and become arranged in a ring.
Light rain or irrigation lasting for extended periods of time is also ideal for disease development. When the oomycete has successfully invaded the host plant, it grows and continues to reproduce.
Life Cycle of Albugo (With Diagram) | Oomycetes
This is why identification of specific hosts crops and possible weeds is necessary to determine range and location of control methods. When the mycelium has reached a certain stage of maturity it epidermis produces pads of hyphae at certain areas just below the epidermis.
Leaf surfaces need to remain wet for at least 2 to 3 hours to ensure infection by the pathogen. The two llife establish contact. They are produced on the sporangiophores. This is called coenocentrum.
Albugo: Habitat, Symptoms and Reproduction | Mastigomycotina
Septa remain suppressed in the actively growing off but appear to separate reproductive structures and to seal off injured parts.
The end of the male hypha enlarges into club-shaped swelling. Albugo Species  Albugo candida Albugo capparidis Albugo capparis Albugo caryophyllacearum Albugo chardoni Albugo evolvuli Albugo gomphrenae Albugo hesleri Albugo hohenheimia Albugo ipomoeae-panduratae Albugo laibachii Albugo leimonios Albugo lepidii Albugo lepigoni Albugo mauginii Albugo occidentalis Albugo resedae Albugo rorippae Albugo trianthemae Albugo tropica Albugo is a genus of plant-parasitic oomycetes.
White rust is an important economic disease, causing severe crop losses if not controlled. The antheridium and oogonium are formed near each other on hyphal branches.
The thick-walled oospores are the main overwintering structures, but the mycelium can also survive in conditions where all the plant material is not destroyed during the winter. Prior to this a spherical and granular cytoplasmic body appears in the centre of the oosphere H. This process is repeated several times.
The oospore on maturity secretes a two to three layered wall Fig. The new nuclei migrates from mycelium to cytoplasm and are used in the formation of another sporangium or conidium.
The hyphal wall contains cellulose and not chitin.