About selective breeding, genetic engineering breeding

Advantages: simple and fast.

Disadvantages: limitations and inability to create new genotypes.

Principle: gene recombination

Methods: Choose the best from the best.

crossbreeding

Advantages: Good collection.

Disadvantages: Time-consuming, unable to produce new genes.

Principle: gene recombination

Methods: Cross, self-cross and test cross.

mutation breeding

Advantages: Increased mutation frequency.

Disadvantages: blindness

Principle: gene mutation

Methods: Mutation.

haploid breeding

Advantages: Homozygotes can be obtained in a short time.

Disadvantages: high sterility and high technical content.

Principle: Chromosome number variation

Methods: Anthers were cultured in vitro

polyploid breeding

Advantages: large organs and rich nutrition.

Disadvantages: slow growth and low seed setting rate.

Principle: Chromosome number variation

Methods: The germinated seeds or seedlings were treated with colchicine.

Genetic engineering breeding

Advantages: overcoming the incompatibility obstacle of distant hybridization and directionally changing biological characters.

Disadvantages: it may cause ecological crisis and is technically difficult.

Principle: gene recombination

Methods: The target gene was introduced into recipient cells.

You must be from my school or a sophomore, and you don't explain …