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Plant growth regulators

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Plant growth regulators

  1. 1. Plant Growth Regulators<br />MR. NARENDER VERMA (PGT BIO)<br />KV- TAWANG<br /> A. P.<br />Presented By:<br />www.cbse123.co.nr And http://sites.google.com/site/CbseAtHome<br />
  2. 2. What are the two groups of plant growth regulating compounds?<br />Natural vs. Synthetic<br />Natural- found naturally in plants<br />Synthetic- human made<br />Both groups regulate or influence:<br />Cell division<br />Cell differentiation<br />Root and shoot growth<br />Senescence (plant aging)<br />
  3. 3. Promoters vs. Inhibitors<br />Promoters- cause faster growth<br />Inhibitors- reduce growth<br />
  4. 4. What is the difference between synthetic growth regulators and plant hormones?<br />Hormones<br />plant produced natural compounds that inhibit or promote plant growth<br />Major classes of plant growth regulators (hormones) are:<br />Auxins<br />Gibberellins<br />Cytokinins<br />Abscisic acid<br />Ethylene<br />
  5. 5. Auxins<br />Growth promoting chemicals<br />Promote cell division and cell elongation<br />Primary plant auxin is indoleacetic acid (IAA)<br />Common synthetic forms of auxins are indolebutyric acid (IBA) and naphthaleneacetic acid (NAA)<br />Useful in phototropism, geotropism, apical dominance, and root formation<br />Phototropism- plant growth toward a light source<br />Geotropism- plant growth in response to gravitational forces<br />Apical dominance- terminal buds prevent the development of lateral buds on plant stem<br />
  6. 6. Gibberellins<br />Also known as Gibberellic acid or GA<br />Growth promoting chemicals<br />Stimulate stem growth through cell elongation and cell division<br />Commercial supplies obtained from the fungus Gibberella fujikuroi<br />
  7. 7. Cytokinins<br />Promote cell division and delay leaf aging<br />Used as a growth promoter in tissue culture<br />Slows the process of senescence (biological aging) by preventing the breakdown of chlorophyll in leaves<br />
  8. 8. Abscisic acid (ABA)<br />Only natural plant growth inhibitor<br />Growth inhibitor that closes the stomates of plants under water stress<br />Counteracts the effects of auxins and gibberellins<br />Cycocel and B-Nine are two synthetic ABA type growth inhibitors commonly used<br />
  9. 9. Ethylene<br />Gas that forms in tissue undergoing stress<br />Important in the fruit-ripening process and early petal drop of flowers<br />
  10. 10. How do plant hormones control apical dominance?<br />Apical dominance<br />Controlled by auxins where the terminal bud inhibits the development of lower lateral buds<br />In greenhouses, we pinch the terminal bud out of a plant so that the plant branches out and becomes bushy<br />Phototropism<br />Controlled by auxins, which is a plant’s response to grow toward light<br />Geotropism<br />Plant growth response to gravity<br />
  11. 11. What are the benefits of using plant growth regulators?<br />Benefits<br />Promote and accelerate root formation on cuttings<br />Keep fruit on trees longer to allow further ripening achieved by the application of auxin<br />Thin blossom clusters and increase berry size in grapes- achieved by the application of gibberellic acid<br />Increase size and crispness of stalks of celery- achieved by the application of GA<br />Control the size of plants<br />
  12. 12. What are the different types of rooting compounds?<br />Rooting compounds<br />Indoleacetic acid (IAA)- naturally occurring auxin that produces bushy, stunted root systems<br />Indolebutyric acid (IBA)- synthetic form of auxin that produces strong, fibrous root systems<br />Napthaleneacetic acid (NAA)- synthetic form of auxin similar to IBA<br />
  13. 13. Increase the number of flower buds formed<br />Improve the number of flower buds formed<br />Improve the longevity and quality of cut flowers<br />Control vegetative growth and reduce mowing frequency in turfgrass<br />Reduce or eliminate unwanted sprouts and suckers<br />Reduce pollen, for people with allergies, by eliminating flowers on some trees, which also can control unsightliness and odor caused by falling fruit<br />Control the growth of shrubs and hedges<br />
  14. 14. Regulators reduce amount of mowing needed<br />Reduces number of mowings per year<br />Reduces labor and machinery costs<br />Growth regulators beneficial to:<br />1. Lawn care operators<br />2. Cemetery managers<br />3. Golf course superintendents<br />
  15. 15. When should growth regulators be applied?<br />Timing of application can affect how various regulators do their job & their affect on non-targeted plants<br />Ex. Embark should be applied after spring “green-up but before seedhead emergence<br />Some chemical may be washed away if applied before a rain or watering<br />Be sure to read the label to find out when to apply!!!<br />If a crop is edible, how would application affect harvest date?<br />
  16. 16. What are gibberellins and anti-gibberellins?<br />Gibberellins- promote plant growth<br />Anti-gibberellins- counteract the effect of naturally occurring gibberellins<br />Can reduce the rate of growth in shade trees<br />Used be utility companies to control trees that may grow into utility lines<br />How else could anti-gibberellins be used?<br />
  17. 17. Thanks for watching….<br />Share it with your friends<br />Share this on Facebook<br />Tweet this presentation<br />STUDENTS-LEARN<br />

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