Principles of Plant Breeding (2+1)

Limitation of asexual reproduction

1. It leads to extreme genetic uniformity within clones which become genetically vulnerable to disease and pest or abrupt changes in environmental factors.
2. Long time storage of propagules like tubers, stem, cutting, etc. loosing vigour and viability. The long time preservation of germplasm in such crops is a practical problem. Tubers, rhizomes, stem cuttings etc. are bulky and require considerable space for conservation.
3. A large part of the produce is required for propagation.
4. The reduced fertility and seed set creates problem in making crosses on large scale. a highly photo- and thermo-sensitive nature of these crops puts restrictions on hybridisation.
5. Small mutations keep on accumulating and may ultimately alter the genetic composition of the clones.
6. The genetical analysis is difficult due difficulty to induce flowering, high sterility and perennial life cycle.