About Lesson
Degrees of inbreeding depression
- 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.
- 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.
- 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.
- 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.