Principle of Plant Genetics and Breeding Kim Youngmo

Principle of Plant Genetics and Breeding Kim, Youngmo Ph. D. Advisor of KOICA

GENERAL CONCEPTS OF TREE IMPROVEMENT ◆ Forest Genetic ◆ Forest tree breeding ◆ Tree Improvement ◆ Why we need tree improvement? ◆ Important consideration ◆ Step involving in TI

Needed mass propagation methods

Tree Improvement (TI) ￭ Forest Genetic – genetic studies of forest trees ￭ Forest tree breeding – studies on some specific problem to produce a specially desired product ￭ Tree Improvement – combination of all silviculture and tree breeding skill to grow the most valuable forest product as quickly as possible and as inexpensive as possible

Tree Improvement Tree Breeding Forest Genetics

◆ Why we need tree improvement? ￭ Increasing the quality of commercially grown species ￭ Ensuring that stock of the most appropriate genetic origin is used in forest establishment.

◆ Important consideration 1. Breeding for growth and yield 2. Breeding for stem quality 3. Breeding improve wood quality 4. A decade of progress in breeding disease-resistant forest trees 5. Breeding for other high-yielding characters 6. Multiple-trait breeding 7. Research programmer 8. Development and action programmes forest tree improvement 9. Impact of silviculture on forest gene resources 10. Mass production of improved material 11. Interaction between breeding and intensive culture 12. Evaluation of costs and benefits of tree improvement programmes 13. Tree breeding forestry practice

Selection Breeding Production Test

Step involving in TI ◆ Species determination – geographic source ◆ Variability studies - amount, kind and causes of variability ◆ Packaging of desired quality into improved individual ◆ Mass production of improved individuals ◆ Developing and maintaining a genetic base population broad enough for needs in advanced generation

◆ Why do we need TI? ◆ Intensive tree farming ◆ Production of the desired quality timber in maximum amounts in the shortest period of time at reasonable cost TI: - ◆ Improved yields and quality on the more productive forested area ◆ Can grow tree on land that are sub-marginal and no economic for timber production ◆ Develop strains that are more suitable for specialized products or uses

Important consideration: Time>Cost>Quality

VARIATION AND ITS USE ◆ Genetic variability ◆ Environmental variation ◆ Variation caused by man ◆ Racial variation ◆ Mating system ◆ Factors shaping variation ◆ Selection

Genetic variability refers to the potential for a given characteristic or genotype to vary within a population when faced with a particular influence. As the genetic variability of a population increases, so does its resistance to environmental and genetic influences and ultimately extinction. Consequently, genetic variability is directly tied to biodiversity and evolution.

◆ Basis for selection ◆ Especially on the economic traits ◆ Must determine the amount, cause and the nature of variation ◆ The variations in tree species are generally high ￭ Strategy for survival ￭ Long life ￭ Expose to various environmental condition ￭ Giving more opportunity for selection ◆ Basis of variation ￭ At cell level >>>>>> Chromosomes and gene

Causes and kinds of variability Basically the differences among tree resulted from ￭ The differing environments in which the trees are growing ￭ The genetic differences among trees ￭ The interaction between the tree gene types and environment in which they grow P = G + E + Gx. E G = genetic E= environment Gx. E = interaction between G&E

Environmental variation Soil >> Light >> H 2 O >> Space Effect on tree – competition among trees. Factors can be controlled in Silvicultural practices

Genetic Variability Genetic variation = additive gene action + non-additive gene action � � � 2 P = � 2 G + � 2 E 2 G = � 2 GA + � 2 GNA 2 P = � 2 GA + � 2 GNA + � 2 E Additive gene action = cumulative effects of all gene loci influencing trait

Non-additive divided by two ￭ Dominance – interaction of specific affects at a gene locus ￭ Epitasis – interactions among gene loci Most characteristics of economic importance controlled by additive gene action ￭ Additive variance can be used in simple selection. e. g. wood density, bole straightness ￭ non- additive – e. g. growth rate Pest resistance – both additive & non- additive

SOURCE OF PLANTING MATERIAL ◆ Seed source ◆ Strategies of acquiring planting material ◆ Short-term strategy ◆ Long-term strategy ◆ Source of Seed ◆ The importance of source of seed ◆ Success of plantation depends on seed source

◆ Largest, fastest and cheapest gain can be realized through proper species and seed sources Terminology: ￭ Adapted – how well trees are physiologically suited for high survival, good growth, resistance to P & D and adverse condition ￭ Exotic - tree grown and of its natural range ￭ Provenance, geographic source or geographic race • denote the original geographic areas from which seed or other propagules were obtained ￭ Seed source – or origin ◆ Racial variation ◆ natural population ◆ between individual within population variation – racial variation

Clines and ecotypes Cline – a gradient in a measurable characteristic which follows environmental gradients. Variation may/may not base on genetics. Ecotype – a group of plants of similar genotype that occupy a specific ecological niche ￭ Land race ￭ A population of individuals that has become adapted to a specific environment in which it has been planted ￭ Can be the easiest and best way of making quick and large genetic gains

Where races are developed best? ￭ Species with very wide range over environments ￭ Species growing a wide altitudinal range ￭ Species that grown in regions of greatly diverse soils Where to select? ￭ Safest method is to select local source ￭ Outside source that have been proven better ￭ From center of origin

Steps to select seed source ￭ Make decision about the objective of the plantings and the products desired ￭ Obtain all information possible ￭ Survey the area for any plantation of desired species- develop S. P. A ￭ Determine the variation within the seed source or provenance ￭ Operationally used seed from initial land race or best potential provenance while better source being developed (through breeding activity)

Selection ◆ Mass selection ◆ Family selection ◆ Sib selection ◆ Progeny testing ◆ Within-family selection ◆ Family plus Within-family selection

◆ Selection of Plus tree ◆ Candidate Plus tree ￭ A tree that has been selected for grading because of its desirable phenotypic qualities but has not yet been graded or tested. ◆ Selected, superior or plus tree ￭ A tree has been recommended for production or breeding orchard use following grading. It has superior phenotype for growth, form, wood quality or other desired characteristics and appears to be adaptable.

◆ Elite tree ￭ Plus tree that has been proven to be genetically superior by mean of progeny testing. ◆ Comparison trees ￭ Trees that are located in the same stand against which the candidate plus tree is graded. ◆ Advance ￭ Generation selection – A tree selected from genetic test of crosses among parents from previous generations.

Plant Breeders use different methods depending on the mode Of reproduction of crops, which include: Self-fertilization, where pollen from a plant will fertilize reproductive cells or ovules of the same plant Cross-pollination, where pollen from one plant can only fertilize a different plant Asexual propagation (e. g. runners from strawberry plants) where the new plant is genetically identical to its parent Apomixis (self-cloning), where seeds are produced asexually and the new plant is genetically identical to its parent

■ Selection ◆ 1. Individual tree selection / mass selection ◆ Even – aged stands ￭ Concentrated on stands and plantation that average or better performance ￭ Same site quality to the plantation ￭ Known seed source ￭ Medium – aged stands ￭ Pure species composition ￭ Avoid logged over stand ￭ Large enough for selection and comparison trees ￭ Emphasis on high seed production ￭ Thorough and systematic search ￭ Used comparison tree method

◆ Regression line ◆ Volume growth ◆ Age of trees ◆ Uneven aged stand ￭ Regression selection system

◆ Selection of plus tree Eucalyptus spp. Coniferous spp.

2. Family selection the choice of entire families on the basis of their average phenotypic values 3. Sib Selection individuals are chosen on the basis of the performance of their siblings and not on their own performance 4. Progeny testing Selection of parent trees based upon the performance of their progeny

5. Within-family selection Individual are chosen on the basis of their deviation from the family mean, and family values per se are given no weight when selections are made 6, Family plus Within-family selection Two-stage method involve selection on families followed by selection of individuals within families

￭ Strategies in satisfying the need of planting material ￭ Short term strategies ￭ Proven provenances (provenance trial/ Gx. E interaction) ￭ 2. Land Races • A. mangium • Rubber • Oil palm

What is a landrace? A landrace is a local variety of a domesticated plant species which has developed largely adaptation to the natural and cultural environment in which it lives. It differs from a cultivar which has been selectively bred to conform to a particular standard of characteristics. Landrace populations are often variable in appearance, but they can be identified by their appearance and have a certain genetic similarity. Landraces have a continuity with improved varieties. The relatively high level of genetic variation of landraces is one of the advantages that these can have over improved varieties. Although yields may not be as high, the stability of landraces in face of adverse conditions is typically high. As a result new pests or diseases may affect some, but not all, the individuals in the population. What is a cultivar? A cultivar is a plant or grouping of plants selected for desirable characteristics that can be maintained by propagation.

3. Plus trees Seed, vegetative materials 4. Seed Production Areas/Seed Stands poor phenotypes are rogued from the stand good trees are left to intermate.

◆ Long Term Strategies 1) Clone establishment From Plus/Elite trees ◆ Vegetative propagation Macro - grafting - layering - cutting ◆ Clone banks/ Research orchards Clone test

◆ Clonal Forestry ◆ Uniformity ◆ Adaptation ◆ Cost ◆ Wood production ◆ Deployment of GMO’s ◆ Deployment of hybrids and expensive rare seed ◆ The opportunity to gain a better understanding of individual genotype overtimes and oversight

Tissue cultures multiplied in test tubes

Biotechnology

Seed Orchard Seed orchards are stands planted especially for the production of abundant superior seeds. A seed orchard is defined as an area where seeds are mass-produced to increase the genetic quality as quickly and inexpensively as possible (Zobel et al. , 1958)

2) Seed orchard a) Seedling seed orchard Plus trees/elite trees Seed Set up seed orchard Progeny trial Improved seed orchards b) Clonal seed orchard Plus trees/elite trees Vegetative material Set up seed orchard Progeny trial Improved seed orchards

Hybrids ▶ To combine complimentary traits of two parents ▶ To exploit hybrid vigour (heterosis) ▶ Increase the adaptability for afforestation into marginal areas for that species

QUANTITATIVE ASPECTS OF TREE IMPROVEMENT ◆ Experimental design ◆ Genetic values ◆ Heritability ◆ Selection differential and selection intensity ◆ Genetic gain ◆ Method to obtain gain ◆ Mating design

Experimental Design ◆ CRD ◆ RCBD ◆ Incomplete Block Design ◆ Latticed Design ◆ Row and Column Design

◆ RCBD Randomized complete block design The randomized complete block design (RCBD) is one of the most widely used experimental designs in forestry research. The design is especially suited for field experiments where the number of treatments is not large and there exists a conspicuous factor based on which homogenous sets of experimental units can be identified. The primary distinguishing feature of the RCBD is the presence of blocks of equal size, each of which contains all the treatments.

Statistical aspect of FTI ￭ Genetic value - To get the best set of parent trees for breeding. P = G + E + Gx. E ￭ Progeny trial - Evaluate the parents through the performance of the progenies. - eliminate the E effect by giving the same environment ￭ Genetic value is express in term of Combining ability ￭ General Combining Ability (GCA) – the average performance of the progeny of individual when it is mated to a number of other individual in the population.

￭ Specific Combining Ability –the average performance of the progeny of a cross between two specific parents that are different from what would be expected on the basis of their general combining ablity alone. e. g: For parent 2 (male) ￭ GCA = mean of parent 2 – test mean = 17 – 13 = +4 � parent 2 has general ability (GCA 2) for volume of +4 Breeding value of an individual is defined as twice its general combining ability. Breeding value = 2 (GCA) BV parent 2 = 2 (GCA 2) =2 x 4=8

￭ SCA – it always refer to specific cross and never to a particular parent by itself. 3 steps in calculating the SCA : e. g Cross between parents 3 and 6 ( a cross value of 12) Calculate the GCA for both parents GCA 3= -3; GCA 6 = -1 Calculate the anticipated value of the cross (Summation of test mean and the GCA for both parents) Anticipated value = test mean + GCA 3 + GCA 6 = 13 + (-3) + (-1) = 9

Subtract the value calculated in (2) from observed value of the cross. SCA 3 x 6 = observed value – anticipated value = 12 – 9 = +3 This means that cross 3 x 6 is performing 3 volume unit better than would be expected based on the GCA’s of parents 3 and 6.

Genotype X Environment interaction The relative performance of clones, families, provenance or species differ when they are planted in different environment. Situation 1 Situation 2

Heritability is a concept in biology that describes how much of the variation of a trait in a population is due to genetic differences in that population. Other causes of variation in a trait are environment factors and genetic drift. 1) Broad-sense (H 2) The ratio of all genetic variance to the phenotypic variance 2) Narrow-sense (h 2) The ratio of additive genetic variance to phenotypic variance

Selection differential The difference between the mean of selected individual and the population mean __ S= Xs- X

Genetic gain G= h 2 x S or G= i h 2 x P ￭ i = intensity of selection ￭ h 2 = heritability ￭ P = phenotypic standard deviation

Method to obtain gain ￭ Mass selection followed by testing ￭ Phenotypic selection followed by vegetative propagation and testing ￭ Making special crosses

Mating design ￭ Open pollinated mating ￭ Polycross (pollen mix) design ￭ Nested design ￭ Factorial design ￭ Single-pair mating ￭ Diallel

Some items in the future agenda 1. Nursery management for seedling production. 2. Tree seed treatment and seed policy in Cambodia 3. Establishment seed orchard and management 4. Economical tree propagation methods 5. Development Foragri (Agroforestry) model in Cambodia 6. Recommendations for rural development in Cambodia 7. Research of Exotic species in Cambodia

http: //www. slideserve. com/albert/experimental-design-crd-rcbd-incomplete-block-design-latticed-design-row-and-column-design

Agroforestry or agro-sylviculture is a land use management system in which trees or shrubs are grown around or among crops or pastureland. It combines agricultural and forestry technologies to create more diverse, productive, profitable, healthy, and sustainable land-use systems. (Wikipedia) Foragry Foragri means the combination of forestry and agriculture for managing forest land using system. That is to create more diverse, productive, profitable, healthy, sustainable or maximizing land-use systems in forest area. We can say the applying of farm species, shrubs and pasture activities for the purpose of effectively land use through intercrop or using the space among forest land. (Kim, Youngmo)

Foragry area For. Agry area Some crops can be harvested before the tree crown get overlapped Any crop species difficult be grown under the crown covered site