Improving drought tolerance in maize (zea mays)

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Improving drought tolerance in maize (zea mays)

  1. 1. Improving Drought Tolerance in Maize -J.Delince
  2. 2. Drought stress  It is a period of shortage of rainfall or non-availability of the rainfall to the crop plants.  More than 20% yield loss is through drought  Drought at seedling stage stops cell division and cause cessation of growth  Drought reduces the length and weight of shoot  Drought reduces the photosynthesis( Affects PS-1 and create reactive electron species and degrade chloroplast)  Drought at critical stages(Tasselling and Silking) cause severe yield loss
  3. 3. Maize: Irrigation profile  Maize needs well distributed rainfall  The rainfall should be 500- 750mm  Tasseling and silking stages(70th and 85th ) are critical  Critical stage needs copious irrigation
  4. 4. Types of Drought resistance  Drought escape  Drought avoidance  Drought tolerance
  5. 5. Drought tolerance:  The plant will face the drought but it shows less effect on it’s yield though it is affected by the drought
  6. 6. Varieties of maize for Drought tolerance  PAC-745, BH-19, SAMPARN, PAC748, KMH-408710,  YSC 354, CML470/ CML472,  PAC-740, C900MG, VIVEK HYBRID-9
  7. 7. Ways to improve yield  Growing very high yielding varieties under stress conditions may give moderate yields  Followed by eliminating negative traits  Improving drought tolerant varieties- recurrent selection
  8. 8. Improvement of drought tolerance  Finding drought- tolerant traits and its mechanisms  These genes are multigenic and low frequency genes  The frequency is increased by recurrent selection
  9. 9. Mechanism of drought tolerance  May not flower and recover on watering  May close the stomata and reduce transpiration  Increased depth of roots  Short anthesis and silking interval  Degree of leaf rolling  Abscisic acid production  Amino acids like aspargine, proline production, glycine betaine production
  10. 10. Breeding programs  Conventional selection  Marker aided Recurrent selection- Asr-1 gene  Quantitative trait loci- checking gene presence in stress and non-stress conditions  Transgenic programs  Using secondary traits in breeding programmes
  11. 11. Thank you

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