Course Content
Qualitative and quantitative characters (qualitative and quantitative characters in crops and their inheritance)
0/2
Biometrical techniques in plant breeding (assessment of variability, aids to selection, choice of parents, crossing techniques, genotype-by- environment interactions)
0/3
Selection in self-pollinated crops (progeny test, pureline theory, origin of variation, genetic advance, genetic gain)
0/5
Hybridization techniques and its consequences (objectives, types, program, procedures, consequences)
0/4
Genetic composition of cross-pollinated populations (Hardy-Weinberg law, equilibrium, mating systems)
0/4
Breeding methods in self-pollinated crops (Mass, Pure line, Pedigree, Bulk, Backcross, etc)
0/5
Learn Introductory Plant Breeding with Rahul
About Lesson

Degrees of inbreeding depression

  1. High inbreeding depression :
  • Eg : alfalfa and carrot show very high ID.
  • A large proportion of plants produced by selfing show lethal characteristics and do not survive.
  1. Moderate inbreeding depression :
  • Eg : Maize, Jowar and Bajra etc. show moderate ID.
  • Many lethal and sublethal types appear in the selfed progeny, but a substantial proportion of the population can be maintained under self-pollination.
  1. Low inbreeding depression :
  • Eg : Onion, many Cucurbits, Rye and Sunflower etc. show a small degree of ID.
  • A small proportion of the plants show lethal or subvital characteristics.
  • The loss in vigour and fertility is small ; rarely a line cannot be maintained due to poor fertility.
  1. Lack of inbreeding depression :
  • The self-pollinated species do not show ID, although they do show heterosis. It is because these species reproduce by self-fertilization and as a result, have developed homozygous balance.
Scroll to Top