Complementary Genes

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Phytogeography Practical

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Phytogeography is the study of distribution of plant species and elucidation of origin of flora. The word " phytogeography" was derived from two Greek words 'Phyto = Plant' and ' Geografia= Geography '. It is controlled by evolution, climate,  and geographical barriers. Chorology, the mapping of plant boundary, is one of the important core principles of the study of plant distribution to decode the factors like evolution and environmental barriers which shape green footprint of our planet. D.Chatterjee in 1962 divided India into nine phytogeographical regions,viz.:- (1) Western Himalayas,(2) Eastern Himalayas, (3) Indus Plain ,(4) Gangetic Plain ,(5) Assam, (6) Central India, (7) Deccan ,(8) Malabar ,and (9) Andaman and Nicobar Islands. Geographical location,Type of vegetation, average rainfall, altitude, and two major plants of each regions are listed below:- Western Himalayas: Kashmir, Northern Punjab,Kumaon ranges of Uttranchal Subtr...
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Mushroom Cultivation

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A few important questions and answers for the students (1) What is spawn ?        Spawn is a fungal growth medium that already has mycelial fragments of mushroom which is used by the mushroom growers as inoculum. Fig. A packet of paddy straw mushroom spawn (2) What are the different types of spawn ? Mushroom spawns are of different types:- (i)  Natural spawn (ii) Milltrack spawn (iii) Brick spawn (iv) Flake spawn (vi) Tobacco spawn (vii) Grain spawn (3) Describe the method of spawning . Terrier (1945) first used wheat grain in spawning. Chang and Li, 1982 describe the following steps of grain spawning:- (i) Wheat grains are boiled first till it is half cooked, then water is drained off. (ii)To this 2% Calcium carbonate is mixed thoroughly. (iii) Then the mixture is transferred into glass tubes/ flasks. (iv)After plugging with non-absorbent cotton the mixture is autoclaved at 121°C for 30 minutes. (v) After cooling down to 30°C - 40°C , gr...
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Plant Physiology

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        Transpiration Transpiration is defined as water loss in the form of vapour from the internal tissues of aerial parts of the plant body through stomata,lenticels,etc. under the influence of sunlight and other factors .        Antitranspirants A plant utilised 1% of absorbed water in metabolism, the rest transpired. Moreover, during drought plants show wilting which reduces 50% of plant yield. In horticulture practices some chemicals  in the form of antitranspirants  are used to reduce the rate of transpiration without hampering other  metabolic process like photosynthesis and growth. Types of Antitranspirants  : (i) Stomatal closing type : These chemicals like phenylmercuric acetate( PMA ) and absecic acid ( ABA )  induce closer of  stomata  to cut down the rate of  transpiration. On application of PMA at very low concentrations, stomata closed partially for 2 weeks.  Drawbacks : Due to closure ...
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