Basidiocarp - Wikipedia
The secondary mycelium is dikaryotic, in that it has two haploid nuclei, one from each the other nucleus divides inside the clamp connection and the two daughter as the mushrooms, a mass of basidia form a structure called a basidiocarp. Eventually, the secondary mycelium generates a basidiocarp, which is a fruiting a type of symbiotic relationship between a fungus and plant roots; the plants. Whats the relationship between a basidiocarp and a mycelium? mycelium develops basidiocarps. What do basidia produce? basidiospores (sexual spores) .
The dolipore septum has a bagel-shaped pore in its center. The club fungi reproduce asexually by producing asexual spores or by fragmentation of mycelium. The sexual reproduction phase of the club fungi involves three developmental stages of the mycelium.
In the primary stage, a haploid spore germinates and grows a germ tube, which develops into mycelium.
Mushroom Life Cycle
The mycelium initially contains a single haploid nucleus. Then, its haploid nucleus divides and septa form between the nuclei. A secondary mycelium forms upon conjugation of two sexually compatible hyphae.
The secondary mycelium is dikaryotic, in that it has two haploid nuclei, one from each parent. As the dikaryotic mycelium grows, the cells divide and more septa are formed between the new cells.
BASIDIOCARP - Definition and synonyms of basidiocarp in the English dictionary
Each of the new cells in the secondary mycelium has one haploid nucleus from each parent. This is assured by clamp connections, specialized structures unique to the club fungi. These are loop-like hyphae which connect the cytoplasm of adjacent cells and through which nuclei move during cell division. In particular, during cell division, one nucleus divides directly into the newly formed cell; the other nucleus divides inside the clamp connection and the two daughter nuclei migrate through the clamp connection in opposite directions to the two daughter cells.
The tertiary mycelium is simply an organized mass of secondary mycelium. It is a morphologically complex tissue and forms structures such as the typically mushroom-shaped basidiocarps commonly seen in nature.
Sexual reproduction of the club fungi begins upon fusion of two primary hyphae to form a club-shaped structure, known as a basidium. Second, the two haploid nuclei inside the basidium fuse together to form a diploid zygote. Third, the zygote undergoes meiosis to form two haploid nuclei. Fourth, these two haploid nuclei undergo mitosis to form a total of four haploid nuclei. These four nuclei then migrate into projections, which form on the tip of the basidium.
These projections then develop into four separate haploid spores, each with a single nucleus. In the species of club fungi which are large and fleshy, such as the mushrooms, a mass of basidia form a structure called a basidiocarp.
The spores on the basidia are released from the underside of the fleshy gills of the mushroom. The color and shape of the basidiocarp, as well as the color of the spores are often diagnostic for species identification. This large phylum includes species which are known as mushrooms, toadstools, earthstars, stinkhorns, puffballs, jelly fungi, coral fungi, and many other interesting common names. It is the third and last step in sexual reproduction. It takes place in basidium prior to basidiospores formation.
Karyogamy is immediately followed by meiosis. Thus, the basidiospores, formed after meiosis, are haploid. Development of the Basidiocarp or Sporophore: The development of the basidiocarp takes place from the subterranean mycelial strand known as rhizomorph. After absorbing sufficient food material mycelium produces fruiting bodies, which are very small in size and remain underground.
These tiny, pin head structures come above the soil under favourable conditions i. These are the primodia of basidiocarp. A longitudinal section of button stage shows that it can be differentiated into a bulbous basal portion representing the stalk region and an upper, hemispherical part which at maturity forms the cap or pileus region.
A ring like cavity gill chamber develops at the junction of stalk and pileus region Fig. At this stage the basidiocarp is not fully open but the young pileus is connected with stalk by a membrane known as partial or inner veil or velum. Due to rapid absorption of water and food material, the stalk further elongates. The button projects above the soil and elongates considerably.
The growth is very slow at the lower portion of the button while it is very rapid at the upper portion. As a result of such growth the button develops into umbrella like cup Fig. Velum gets broken due to enlargement of the cap and elongation of the stalk.
It exposes the hymenium or the gills. Atkins described the development of basidiocarp as hemiangiocarpic i. Simultaneously, the development also takes place in the gill region. The tissue of the upper region of the gill chamber differentiates into slow and fast growing alternate bands called primordiutn of gills. Gills or lamellae are of three types i. Structure and Anatomy of Basidiocarp: The mature fruiting body can be differentiated into three parts i.
It is the basal part of the basidiocarp. In this region the hyphae run longitudinally parallel to each other. A transverse section of stipe shows that it is made up of two kinds of tissue, i. The stipe at its top supports a broad umbrella shaped cap called pileus.
The mature pileus is 5 to From the underside of the pileus hang approximately to strips or plates of tissues known as gills or lamellae. The gills are white or pinkish in young condition and turns brown or purplish black at maturity.
A transverse section of the gill T. It is the middle part of the gill. This region is made up of loosely arranged interwoven mass of plectenchymatous tissue of long, slender hyphae. These hyphae run, more or less, longitudinally.
The hyphae of the trama region curve outwards towards each surface of the gill. They end in small diametric cells forming a compact layer known as sub-hymenium. It is the outermost layer and lies on the surface of sub-hymenium covering both sides of the gill.
Some branches emerge out almost at right angle to the sub-hymenium and develop a palisade like layer consisting of basidia fertile and the paraphyses sterile Fig. Some of the sterile cells become enlarged and project beyond the basidial layer. They are called as cystidia. The basidia are spore producing bodies. The young basidia arise from the terminal, bi-nucleate cells of the sub-hymenium layer Fig.
- Meaning of "basidiocarp" in the English dictionary
- Fungi - Basidiomycota, Club Fungi
As the basidium grows, the two nuclei of the dikaryon fuse to form the synkaryon karyogamy, Fig. The diploid nucleus soon undergoes meiosis to form four haploid nuclei Fig. Simultaneously, four narrow tube-like structures develop at the top of the basidium.
These are called sterigmata sing, sterigma. The sterigmata swell at their tips and each forms a small, single basidiospore by budding. A large vacuole develops in the basdium due to which the cytoplasm and nucleus one in each migrate into the budding basidiospore Fig.
Agaricus: Habitat, Structure and Reproduction
Thus, four haploid basidiospores are formed in a basidium. The young basidiospore is un-pigmented but it develops brown or black pigments at maturity.
The mature basidiospore is attached obliquely at the top of the sterigmata. It has minute projection at one side of its attachment called hilum or hilar appendix Fig.
Discharge and Dispersal of Basidiospores: A drop of liquid develops at the hilum. It increases in size gradually and attains a size of about one-fifth of the spore Buller, At this stage the basidiospores are generally shot away from the sterigmata. According to the latest view, the liquid drop is contained in a limiting membrane.
The membrane ruptures and releases a pressure at the base of the basidiospore. Basidiospores are shot horizontally from where they fall vertically downwards.