Beauty Farming Life

  Terminology *Seed coat : A layer by which a seed is covered. *Kernel: Without seed coat, the rest part of seed is combinedly called kernel. *Testa : Outer layer of seed coat. *Tegmen: Inner layer of seed coat. *Endosperm : It is the storage food materials of seed which is situated outside the cotyledons. *Epicotyle : A part of the embryo, which produces seed or the above ground part of the plant. *Coleoptile : The first leaf above the cotyledons which encloses the stem tip and other part of the plant. *Hilum : A depressed mark or scar from where the seed was attached directly with placenta in legumino pods. *Mesocotyle : In some monocotyledonous plant like wheat, rice etc. the part of the seedlings stems below the shoot gets elongated which is called Mesocotyle. *Radicle : Post primordial in the embryo of a seed. *Plumule : The major young bud of the embryo within a seed or seedling from which the aerial portion of the plant will develop. *Cotyledo...

Question Bank of Genetics and Plant Breeding (207).https://cststudy.blogspot.com/ Question Bank of Genetics and Plant Breeding (207) 1. Cytology: (a) Define cell. (15) (b) Draw and label a plant cell. (15) (c) What is meant by meiotic cell division? (14) (c) Describe meiotic cell division. (11)                                                            (d) Briefly describe the events of prophase-I in Meiosis-I cell division. (14) (e) Write down the genetical significance of mitotic and meiotic cell division. (14, 13, only meiotic-10) (c) Describe the principal events of mitosis cell division. (15) (d) Define chromosome. (14, 13, 10) (e) Write the special types of chro...

B.Sc.Ag. (Hons) Part-IV     Features of Drought. https://cststudy.blogspot.com/ Features of Drought In Bangladesh, problems of drought,- salinity and alkalinity are of major concern among environmental stresses. Drought refers to the condition of soil moisture deficiency or water scarcity. Soil drought is more common in the arid and semi-arid tropics and in the areas of steep slope. Thus desert areas are more prone to drought conditions.  The ability of crop plants to grow, develop and reproduce normally under moisture deficit conditions is referred to as drought resistance. In other words, drought resistance refers to survival of plants under water deficit or scarcity conditions without injury. Improvement in the drought tolerance ability of a plant is known as drought hardening. Main features of drought are given below: 1. Drought is characterized with soil moisture deficit or low soil moisture. 2. Arid and semi-arid areas are more prone...

B.Sc.Ag. (Hons) Part-IV Drought Resistance, Plant characters associated with drought resistance. https://cststudy.blogspot.com/ Drought Resistance It is the ability of a plant to maintain favorable water balance and turgidity even exposed to draught conditions there by avoiding stress and its consequences. Stress avoidance due to morphological, anatomical characteristics which themselves are the consequences of the physiological processes induced by drought these zerophytic characteristics are quantitative a d vary according to environmental conditions. A favorable water balance under drought conditions can be achieved by transpiration before a• soon as stress is experienced. These are called "water savers" or Accelerating water uptake sufficiently so as to replenish the lost water called as "water spenders" Plant characters associated with drought resistance Morphological & Anatomical Grain yield; maximum root length, Roo...

B.Sc.Ag. (Hons) Part-IV     Mechanisms of Drought Resistance. https://cststudy.blogspot.com/ Mechanisms of Drought Resistance There are four different mechanisms which help in survival of plants under moisture deficit conditions. There are: 1)       Drought escape. 2)       Drought avoidance. 3)       Drought tolerance. 4)       Drought resistance. The last one refers to true drought resistance. These are briefly described below: 1. Drought Escape The simplest way of survival under drought conditions is to escape drought. Generally, drought occurs either in the mid or late-crop season. Drought escape is most common in case of plants grown in desert regions. They complete their life cycles in 4 to 6 weeks. Drought escape also plays an important role in some crop plants. For Example, yields of early varieties of wheat, sorghum, maize, an...

B.Sc.Ag. (Hons) Part-IV    Morphological Characters associated with drought resistance.  https://cststudy.blogspot.com/ Morphological Characters associated with drought resistance Drought resistance is associated with various morphological and physiological features or actors of crop plants. Morphological characters which are associated with drought resistance included earliness, shape, size and structure of stomata, size, number and orientation of eaves, presence of cuticle, Waxiness on leaf lamina and stem, rooting pattern, growth habit etc. They are discussed below- 1. Earliness Earliness is a desirable character which leads to drought escape in many crops. For example, in wheat, sorghum, maize, and rice yield of early maturing varieties is less affected by severe drought than late maturing varieties. 2. Stomatal Features Sunken, small size and less number of stomata are associated with drought resistance. Control of stomatal aperture i...

B.Sc.Ag. (Hons) Part-IV     Physiological features associated with drought resistance.  https://cststudy.blogspot.com/ Physiological features associated with drought resistance Various physiological characters which are related to drought resistance are photosynthetic rate, transpiration rate, osmotic concentration etc. These factors are briefly discussed below: 1. Osmotic adjustment As a plant, detect a water deficit stress, it may accumulate a variety of osmotically active compounds such as amino acids, sugars and ion inside its cells, resulting in a lower of the cell osmotic potential. Water present in intercellular spaces then flows towards the inside of those cells. This process called "Osmotic adjustment", was proposed as a potential factor that could enable plants to maintain turgor and survive better at low water status. It has however been argued that osmotic adjustment probably does not allow the plant to draw much extra water from the soil...

B.Sc.Ag. (Hons) Part-IV     Measurement of Drought Resistance in Plant Breeding.  https://cststudy.blogspot.com Measurement of Drought Resistance in Plant Breeding Various procedures are used for measuring drought resistance in crop plants. The most commonly used procedures include: 1)       Leaf water retention. 2)       Photosynthesis. 3)       Yield performance. 4)       Root lengths of seedlings. These techniques can be used for large scale screening of segregating populations in breeding programme. 1. Leaf Water Retention In this method leaves are excited from the plant and are allowed to dry. The slower drying genotypes are considered as drought tolerant. In other words, the high water retainer genotypes are considered as drought tolerant. The cut leaf method was used in wheat, barley and oats. In wheat, two varieties Pelissier and Pit...

    B.Sc.Ag. (Hons) Part-IV     Distinguish between Biotic & Abiotic Stress. https://cststudy.blogspot.com    Distinguish between Biotic & Abiotic Stress Biotic stress Abiotic stress 1. Biotic stress include living organism. e.g. insect; pest, bacteria, fungi etc. 1. Abiotic stress include physical factor: of environment. e.g. Temperature, moisture, wind, soil salinity and alkalinity etc. 2. The effect of biotic stress is changeable. 2. The effect of abiotic stress is stable. 3. The effect of biotic stress is density dependent. 3. Density independent. 4. Directly related to stress. 4. Indirectly related to stress.  5. Generally man cannot control it. e.g. High temperature beyond the control of stress. 5. Generally man can control it such as spraying, insecticides in case of insect. If you can'...

B.Sc.Ag. (Hons) Part-IV     Types of drought resistance, Drought Resistance Mechanism. https://cststudy.blogspot.com/ Drought Resistance Mechanism The ability of a crop species or variety to grow and yield satisfactorily in areas subjected to periodic water deficits is termed as drought resistance, Types of drought resistance 1. Drought escape: The ability of a plant to complete the life cycle before serious soil and plant water deficits develop. 2. Drought tolerance with high tissue water potential: The ability of the plant to endure periods of drought whilst maintaining a high plant water stress. This is also referred to as drought avoidance (Levitt, 1972). 3. Drought tolerance with low tissue water potential : The ability of the plant to endure periods without significant rainfall and to endure low tissue water potential. Table - Mechanisms of drought resistance (after Jones et al. 1981) 1. Drought escape (a) Rapid phenolo...