Conidia sentence example
The simple sporophore does not necessarily terminate in conidia, however.
Bees carry the spores of Scierotinia as they do the pollen of the bilberries, and flies convey the conidia of ergot from grain to grain.
The fungus mycelium grows between the cuticle and the epidermis, the former being ultimately ruptured by numerous short branches bearing spores (conidia) by means of which the disease is spread.
Pear trees may 2, Section of leaf surface showing the also be attacked by a great spores or conidia, c, borne on long variety of insect pests.
This disease has been successfully treated with a spray of copper sulphate and lime, or sulphate of iron; solutions of these salts prevent the conidia from germinating.Advertisement
The mycelium of Sphaceloma grows just beneath the cuticle of the vine, through which it soon bursts, giving rise to a number of minute hyphae, which bear conidia.
Bornet describes free conidia in Arnoldia minitula, and Placodium decipiens and Conidia-formation has been described by Neubner in the Caliciae.
In one view they are mere asexual conidia, and the term pycnoconidia is accordingly applied since they are borne in structures like the non-sexual pycnidia of other fungi.
More generally the hypha below the septum grows forwards again, and repeats this process several times before the terminal conidium falls, and so a chain of conidia results, the oldest of which terminates the series (Erysiphe); when the primary branch has thus formed a basipetal series, branches may arise from below and again repeat this process, thus forming a tuft (Penicillium).
Or the primary hypha y first swell at its apex, and put forth a series of short peg-like branches (sterigmata) from the increased surface thus provided, each of which develops a similar basipetal chain of conidia (Aspergillus), and various combinations of these processes result in the development of numerous varieties of exquisitely branched sporophores of this type (Botrytis, Botryosporium, Verticillium, &c.).Advertisement
The same laws apply to the individual hyphae and their branches as to simple sporophores, and as long as the conidia, sporangia, gametes, &c., are borne on their external surfaces, it is quite consistent to speak of these as compound sporophores, &c., in the sense described, however complex they may become.
The mucilage surrounding endospores of Mucor, conidia of Empusa, &c., serves to gum the spore to animals.
In many cases the slimy masses of spermatia (Uredineae), conidia (Claviceps), basidiospores (Phallus, Coprinus), &c., emit more or less powerful odours, which attract flies or other insects, and it has been shown that bees carry the flagrant oidia of Sclerotinia to the stigma of Vaccinium and infect it, and that flies carry away the foetid spores of Phallus, just as pollen is dispersed by such insects.
Mycelium well developed; sexual reproduction by zygospores; asexual reproduction by sporangia and conidia.
Conidia (basidiospores) borne in fours on a special conidiophore, the basidium.Advertisement
When the free ends of the hyphae emerge again into the air they swell up into spherical bodies which may either fall off and behave as conidia, each putting out a germ-tube and infecting the host; or the germ-tube itself swells up into a zoosporangium which develops a number of zoospores.
Pythium is of interest as illustrating the dependence of zoospore-formation on conditions and the indeterminate nature of conidia.
The development of the "conidia" as true conidial spores or as zoosporangia may occur in one and the same species (Cystopus candidus, Phytophthora infestans) as in Pythium described above; in other cases the direct conidial germination is characteristic of genera - e.g.
Plasmopara, &c. In Cystopus (Albugo) the "conidia" are abstricted in basipetal chain-like series from the ends of hyphae which come to the surface in tufts and break through the epidermis as white pustules.
The classification of the Mucorini depends on the prevalence and characters of the conidia, and of the sporangia and zygospores - e.g.Advertisement
Empusa Muscae causes the wellknown epidemic in house-flies during the autumn; the dead, affected flies are often found attached to the window surrounded by a white halo of conidia.
In these three genera the conidia are cast off with a jerk somewhat in the same way as the sporangium of Pilobolus.
The yeast-conidia, which bud off from the conidia or their resulting mycelium when sown in nutrient solutions, are developed in successive crops by budding exactly as in the yeast plant, but they cannot ferment sugar solutions.
It is the rapid spread of these yeast-conidia in manure and soil waters which makes it so difficult to get rid of smuts, &c., in the fields, and they, like the ordinary conidia, readily infect the seedling wheat, oats, barley or other cereals.
Brefeld regards the budding process as the formation of conidia.Advertisement
Four ripe asci, a i, a2, with eight spores, a 3, a4, with yeast-like conidia abstricted from the spores.
They have characteristic conidiophores bearing numerous conidia, and also cleistothecia which are spherical in form and yellowish in colour.
The conidia are fragrant and are carried by bees to the stigma of the bilberry; here they germinate with the pollen and the hyphae pass with the pollen tubes down the style; the former infect the ovules and produce sclerotia, therein reducing the fruits to a mummified condition.
Besides the special ascocarps, accessory reproductive organs are known in the majority of cases in the form of conidia.
They have never been found to cause in fection, and they have not the characters of conidia; the large size of their nuclei, the reduction of their cytoplasm and the absence of reserve material and their thin cell wall all point to their being male gametes.
Grows to form a fungus-like, branching mycelium with aerial hyphae bearing conidia.
A conidial suspension of the fungus (1x 10 6 conidia per ml) was sprayed on young hazelnut and walnut twigs.
In some of the true Ascomycetes, such as Penicillium glaucum, the conidia if grown in saccharine solutions, which they have the power of fermenting, develop single cell yeast-like forms, and do not - at any rate for a time - produce again the characteristic branching mycelium.
Salmon also found that injury of a leaf by mechanical means, by heat, by anaesthetics, &c., would affect the immunity of the plant and allow infection by conidia which was not able to enter a normal leaf.
Cell budding takes place in yeast and in the formation of the conidia of Fungi.