In this article we will discuss about the chromosome number and economic importance of bryophytes.
Chromosome Number in Bryophytes:
Until recently the range of chromosome numbers in the Hepaticae was thought to be n = 5 in the Anthocerotales, n = 8 or 9 in the Marchantiales, n = 9 or 10 in the thalloid Jungermanniales, and n = 8 or 9 the leafy Jungermanniales, with occasional polyploid species in many genera.
With the discovery of Takakia with a basic chromosome number of n = 4, it has been suggested that this is the basic number in the Hepaticae and that most of the genera are polyploids with n = 8, or polyploids with an additional chromosome, n = 9. It could be, as has been suggested by Fulford (1965) that possibly the number n = 4 has been derived from a basic number of n = 8 or 9.
In Polytrichum all species examined, with a few exceptions, have a chromosome number of 7. In Sphagnum most species have n = 19 (with 2-6 ‘m’ chromosomes in addition).
Economic Importance of Bryophytes:
The economic importance of the bryophytes is not obviously apparent, but they may be beneficial indirectly. The bryophytes are, practically speaking, the first colonizers on bare and exposed grounds. By their actions, which are partly mechanical and partly chemical, they can convert the top surface of rocks, lava or similar other substrata into soil.
Then, when some of them die this soil becomes enriched with the organic matter. Subsequently, the pteridophytes and the seed-bearing plants appear in succession and finally a bare rocky surface is converted into a green forest. Further, on account of their extremely high capacity for absorbing and retaining water, they help in preventing soil erosion, and even may control flood to some extent.
The Bryophytes are very important economically as they form the peat, which can be used as a fuel in place of coal. The peat is produced as a result of accumulation of mosses, particularly Sphagnum, in huge numbers in swamps and bogs; these mosses undergo slow decomposition and become compacted and carbonized.
The ‘peat moss’ prepared from Sphagnum is used by the poultry people as bedding for the livestock as well as by the gardeners to increase the water-retaining capacity of the soil and for keeping it porous.
Sphagnum and other mosses, growing on the banks of ponds, jheels and lakes, form the quaking bogs, whose water appears to possess antiseptic and preserving properties. The larger mosses are sometimes used for packing delicate and fragile materials.
Previously they were employed for stuffing cushions. The horticulturists and florists utilize Sphagnum for packing seedlings, cut flowers and other nursery stocks. It is also used as a substratum for germinating seeds. On account of the extremely efficient absorptive and antiseptic properties Sphagnum was used extensively for dressing wounds during the Russo-Japanese War as well as in World War I.
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