Introduction to Plant Breeding The field of applied science that involves changing of the genetic content (genotype) for plant improvement. Methods :- 1. Select from existing population 2. Introduce from outside (different species or varieties) 3. Make crosses and selection for desirable characteristics. 4. Genetic manipulation (mutation, gene transfer, marker-assisted selection, etc.)

Genotypic variation Example : Sweet corn  Improvement for varieties with large ears, early maturity and sweet taste.

Changes in genotype

Definition Variety  Group of individuals (plants) from a species that are distinct in morphology, function and yield from other groups of individuals. Example : Rice – MR 219, MR 220 Oil palm – PS1, PS2, PS3 & PS4 Papaya – Eksotika, Eksotika 2 Coconut – MAWA, Pandan, Matag

Definition Genotype  Overall genetic content of an individual / plant. Phenotype  Appearance / morphology / traits / characteristics of an individual that can be observed or measured.

GenotypePhenotype Environmental influence Environmental influence:  Climate/weather (rain, temperature, sunlight, etc.)  Soil fertility and fertilization  Pests and diseases

Characteristics (traits)  Qualitative : (fruit colour, flower, etc.). Not influenced by environment.  Quantitative : (height, weight, yield, sugar content, etc.). Influenced by environment. 2 classes : Qualitative & Quantitative

Changes in phenotype Require Changes in genotype – genetic makeup Changes in environment

Example, Changes in genotype : Cross between Dura & Pisifera parents x Dura Sh + Dominant & homozygous Pisifera Sh – Recessive & homozygous D x P (Tenera) Sh + Sh – Heterozygous (dominant) Mesocarp Shell Kernel Fiber ring

History of Plant Breeding Early age Plant breeding started when man began to select, plant and domesticate plants. Breeding by selection is made unintentionally based on: - Natural skills Past experiences (limited judgment) Without basic knowledge

History of Plant Breeding New era Breeding was done systematically based on knowledge A field of science Faster progress and development

1798: Thomas Robert Malthus predicted that, in the 19th century, the world will suffer from shortage of food, based of the rate of population increase at much higher rate than increase in rate of food production at that time. This phenomenon did not occur because human being are able to increase crop productivity by using selected varieties and suitable farming practices. History of Plant Breeding

Through human civilization, beginning from 9,000 BC, selected plants were carried by man as they moved. Identification and selection of the kinds and types of favoured and most promising plants are a process of breeding, at that time as an art, rather than science, without a systematic process (slow success).

Major findings that contributed to the development of plant breeding: 1.The discovery of sex in plants 700 BC : Egyptian & Assyrian discovered male and female plants in palms : Nehemiah Grew – anther is the sex organ of plants : Camerarius carried out experiments to isolate castor, maize and mulberry plants  no seeds formed. History of Plant Breeding

2. The discovery of hybrid plants ◦ 1719 : Fairchild – produced new plant with pink flowers from a cross between two plants. ◦ 1761 : Koelreuter – hybrid of Nicotiana rustica X Nicotiana paniculata. Example

3. Rediscovery of Mendel's Law Mendel started the study of hybridization in peas (Pisum sativum) Mendel presented the results to Brunn Society of Natural Sciences  not accepted Corren, DeVries & Tchermark found similar results to Mendel. Thus, Mendel's Law was accepted. History of Plant Breeding

Breeding Goals / Objectives  Reason (for who) a variety is to be developed?  What features/traits in a variety should be developed?

General objectives: Breeding goals varied with:-  Consumer preferences  Place to be planted  Management practices  Change of time (farming and processing technology)  Economic value Breeding Goals / Objectives

Specific objectives: Breeding Goals / Objectives 1) Yield production Higher yields giving higher profits to growers.

Breeding Goals / Objectives Specific objectives: 2) High quality : Nutritional composition (protein, vitamin, carotene, etc.) Attractive external appearances – mango with smooth/clean skin, thornless durian Special traits – seedless grapes, rambutan, honey starfruit

Breeding Goals / Objectives Specific objectives: 3) Plant with suitable adaptation to environment Rain, temperature, wind, etc. Duration of seasonal change  drought, rain. Soil variability.

Breeding Breeding Goals / Objectives Specific objectives: 4) Adaptability to Suitable Technology Processing  groundnut seed size should be suitable to the factory miller and filter. Farm technology  Height of corn plants suitable to the harvesting machinery.  Seed size suitable for mechanical seeder.

Breeding Breeding Goals / Objectives Specific objectives: 5) Resistant to pests and diseases Low maintenance costs. Low chemical (insecticide/pesticide) costs. Safe to eat.

Pest tolerance Virus tolerance