Exercise 9

crop breeding

art, science, and busines sof improving the genetic make-up of crops to increase productivity

Genetics

Branch of biology that studies heredity and variation in organisms

Breeding

Activity of controlling the mating and production of offspring

Selection

Process of selectively propagating plants with desirable characteristics

Phenotype

appearance or measurement of a character

Genotype

Genetic constitution of an individual

Environment

Comprises all external factors that can influence expression of the genes controlling the character

Plant genetic resources

Any plant genetic materials of actual or potential value for food and agriculture

plant genetic resources

• Are the genetic material found in plants that can be used for crop breeding

• Provide the raw materials for developing new varieties with desired traits

Germplasm conservation

essential activitiy of plant breeding

Germplasm

seeds and plants used as building blocks in breeding new cultivars

Self-Pollination (autogamy)

• Pollen from a flower fertilizes the ovule of the same flower or another flower on the same plant

• Ex. rice, wheat, soybean

Cross-Pollination (Allogamy)

• Pollen from one plant fertilizes the ovule of another plant

• Ex. corn, sugar beet, sunflower

Mixed Pollination (Facultative)

• Self-pollinate and cross-pollinate, depending on environmental conditions or availability of pollinators

• Ex. sorghum, cotton

Asexual or Vegetative Propagation

• Reproduce without involving seeds, using structures like tubers, bulbs, or cuttings

• Ex. sweet potato, banana,

mutation breeding

Induction of mutations using physical or chemical mutagens to create new genetic variation

Marker-assisted selection (MAS)

Uses DNA markers linked to desirable traits to select plants, enhancing efficiency and precision in breeding

Double Haploid (DH) Technology

Produces homozygous lines in a single generation by inducing haploids and doubling their chromosomes

somaclonal variation

• exploits genetic variation from tissue culture for traits like disease resistance

Genome editing

• Precise modifications of DNA using tools like CRISPR-Cas9 to enhance or knock out specific genes for desired traits

recombinant DNA technology

genetic engineering

Genetic engineering

involves introducing specific genes into a crop’s genome to enhance traits

Transgenic

incorporating genes from different species

Cisgenics

• using genes from the same or closely related species

Participatory Varietal Selection (PVS)

simple way for breeders and agronomists to learn which varieties perform well on-farm and are preferred by farmers (IRRI)