Plant Breeding and Selection

Crop Improvement

• Crop improvement is necessary to meet the demand of the growing global population, projected to increase food production by 70%.
• Factors contributing to food insecurity include competing claims for land, water, labor, energy, and capital, as well as biotic and abiotic stresses.

History of Crop Improvement

• Ancient selections of crops are still cultivated today, such as dates.
• The transfer of plant resources between Europe and the New World was triggered by Columbus's arrival in America in 1492, increasing genetic variation.

Methods of Crop Improvement

• Selection involves three distinct steps: selecting plants from a genetically variable population, growing progeny rows for observation, and comparing selected lines to commercial varieties.
• Hybridization brings together desired traits from different plant lines via cross-pollination, combining homozygous inbred lines to generate new traits.

Mutation Breeding

• In the 73 years of mutation breeding (1939-2013), 3,218 varieties were obtained, including 824 rice, 312 barley, 274 wheat, 96 maize, and others.

Limitations of Conventional Methods

• Conventional breeding can only be done between plants that can sexually mate, limiting the new traits that can be added.

Molecular Breeding and Marker-Assisted Selection

• Plant breeders use molecular markers to identify specific genes and predict whether a plant will have the desired trait.
• Genetic linkage helps predict the presence of a desired gene.

Genetic Engineering

• Genetic engineering involves taking a gene from one organism and putting it into the DNA of another, creating Genetically Modified Organisms (GMOs).
• Examples include Bt corn and Roundup Ready crops.

Transgenic Plants

• Transgenic plants are created by putting DNA into tissue culture cells, allowing for the transfer of genes between species.

Specific Crop Varieties

• Pusa Nayanjyoti: a hybrid with orange roots, high carotene content, and tolerance to powdery mildew and nematode.
• Arka Suraj: a hybrid with deep orange roots, tolerance to powdery mildew and nematode, and a yield potential of 15 t/ha.
• NS 854 F1: a hybrid with long, cylindrical roots, high disease tolerance, and a yield potential of 150-175 g.
• Super Kuroda: a hybrid with cylindrical roots, high disease tolerance, and excellent color and shape.