Breeding of Vegetable, Spice and Tuber crops (2+1)

Synthetic Variety

• The use of synthetic varieties for commercial cultivation was first suggested in maize(Hayes and Garber(1919).
  
• A synthetic variety is produced by crossing in all combinations a number of inbreds(4-6) that combine well with each others.
• The inbreds are tested for GCA. Synthetic is maintained by open pollination.
• The lines that make up a synthetic may be usually inbred lines but open pollinated varieties, or other populations tested for GCA also used. Synthetic varieties are common in grasses, clover, maize and sugar beet.
  
• The normal procedure is equal amounts of seeds from parental lines is mixed and planted in isolation.
• Open pollination is allowed.

Features of Synthetic Variety

• Heterogeneous
• Synthetic variety can be developed by using clones, inbreds or OPV i.e. open pollinated variety
• Cross pollination is must
• Maintained by open pollination
• Unlike composite variety, exact reconstitution of synthetic variety is possible
• More adaptive to varying growing conditions as compared to hybrids
• Less uniform as compared to hybrids
• Less attractive as compared to hybrids
• Show some amount of heterosis as compared to OPV
• Have better disease resistance

Steps involved in synthetic variety

• Development of synthetic varieties consists of 4 major steps.
• Isolation of inbred lines
• Evaluation of inbred lines for GCA
• Intermating of good general combining inbreds in all possible combinations.
• Mixing the seed of all F1 crosses in equal quantity