BREEDING TECHNIQUE FOR FOREST TREES

AKSHAY KUMARId no. 39695M Sc Ag Genetics and Plant BreedingGBPUA&T Pantnagar

WHAT IS TREE ?

Plant having a permanently woody main stem or trunk, ordinarily growing to a considerable height, and usually developing branches at some distance from the ground.

WHAT IS TREE BREEDING?

Tree breeding is the application of genetic, reproductive biology and economics principles to the genetic improvement and management of forest trees.

or The application of genetic principles and practices to the

development of individual trees, varieties or populations more suited for the human needs.

Tree improvement- Tree improvement includes the practices of silviculture and tree breeding meant to enhance the total yield . In simple world ,tree improvement is an additional tool of silviculture that deals with the genetics make up of the tree to be used in forest practices

MAJOR CONTRIBUTION OF TREE BREEDING

Plantation tree growth rates of 25 m³/ha/yr are harvested at an age of 6 year. With genetic improvement and tree breeding, average growth rates of 35 m³/ha/yr are being anticipated (Kellison, 2005)

The average productivity of poplar under agro forestry system is 20-25 m3/ ha/ yr, which is five times higher than traditional forest throughout Punjab, Haryana, UP and some parts of Bihar, West Bengal and Assam state (Singh et al., 2001).

LINKAGES OF TREE BREEDING WITH TREE IMPROVEMENT

1. Tree improvement relies on traditional breeding techniques - Selection of superior (plus candidate) trees for volume and stem

straightness, and grafting these into breeding orchards and producing seed orchards.

2. Success of tree improvement depends upon tree breeding, silviculture and molecular genetics of species and its particular varieties.

IMPORTANCE OF TREE BREEDING

Tree breeding helps in increasing yields and shortened rotations.

The goal of tree improvement for Agroforestry is to increase the effectiveness of land for productivity, suitability and sustainability of land use for rural communities.

There are a number of key problems or needs that can be addressed by appropriate use of multipurpose tree species through tree breeding strategy.

Breeding programs of fast growing multi-purpose tree species for farmland planting.

ESSENTIAL FEATURES FOR TREE BREEDING

Choosing appropriate species and sources is the single most important genetic decision in Tree Breeding.

Components which are of almost universal importance for tree breeding are High rate of net photosynthesis. Efficient light interception. Full utilization of the growing season. Efficient use of water and nutrients. Rapid juvenile growth. Tolerance to competition. Tolerance to Abiotic stress. Freedom from Insect and diseases. Suitable biomass properties and Ease of reproduction and plantation establishment .(Koski and Vihera-aarnio)

TREE BREEDING VERSUS CROP BREEDING

CROP BREEDING

• Reproductive maturity in a few months.

• Short crop rotations.• Crop breeding is done with

domesticated varieties.• Flowering is known.• Early flowering.• Easy hybridization.• Planted on uniform, well

prepared sites.• Easy come back.

TREE BREEDING

• While most trees require many years.

• Long rotation.• Starts with wild stands of

trees.• Not known.• Late flowering.• Tough.• May be planted over a

much wider range of soils, sites, and climatic zones.

• Tough.

CAUSES OF VARIATION

1. ENVIRONMENTAL - Temperature Humidity, rainfall Wind, soil depth, nature of soil etc.2. GEOGRAPHIC – Longitude Latitude and Altitude3. GENETIC - Mating system Mutation Gene flow

ENVIRONMENTAL VARIATION

• Environmental -The nature does the selection work , if not disturbed by the human factor. The factors governing environment variations are temperature, humidity, rainfall, wind, soil depth, nature of soil etc.

• Geographic – the longitude, latitude and altitude bring about changes in the species, though environment plays an important role in it.

GENETIC VARIATION

GENETIC – The change in gene frequency or genetic makeup from one generation to another brings greater variation. these variation are caused by (a) mating system (b) Mutation(c) gene flowMating system the type of mating system or pollination mechanism existing in a species has its effect on the variation. The cross pollinated increases heterozygous population.Mutation helps in maintain variability in a species. The mutated gene is the source of hereditary variability.when the out crossing takes place with original population of the area, resulting in gene migration and thereby causing variation.

COMPONENT OF GENERAL BREEDING STRATEGY

SURVEYING AND IDENTIFICATION OF SUPERIOR PHENOTYPE

ESTABLISHMENT OF CLONAL BANK

CARRYING OUT CLONAL MATING

CARRYING OT GENETIC TEST

MANIPULATION OF TIME IN BREEDING CYCLE

ESTABLISHMENT OF SEED ORCHARD

PRODUCTION OF QUALITY PLANTING STOCK

MAINTENANCE OF BROAD GENETIC BASEMANAGEMENT OF INBREEDING IN BREEDING AND PRODUCTION POPULATIONCONTINUITY IN IMPROVEMENT PROGRAMME

A TREE BREEDER CONSIDERATION

Most tree species are out-crossing; inbred lines do not exist; and pedigree tracking is critical

Traits of interest are typically controlled by many genes and have low heritability

Most tree species possess a lot of genetic variability for most traits of interest. Improved varieties must be widely adapted and retain a lot of diversity

Trees require a lot of land and time to breed and test, and desirable traits are not always easily measured

Trees must be bred to survive over decades in highly heterogeneous environments.

SELECTION CRITERIA

Selection criteria comprises of the character. Growth parameter Volume Stem straightness Branching pattern Wood density Drought resistance Resistance to specific pest etc.

The basic information required for the selection of plus tree is The biology of the variability present in the species The economic score and The heritability of the particular trait for selection is taken up

BREEDING OBJECTIVE

To improve the quantity and quality of the produce- - improvement of timber wood. -pulp –wood. -fuel –wood. Economic return per time on a unit land . Quality aspect such as fibre length , specific gravity . Disease resistance. Input use efficiency. Conserve the available biodiversity in that species for future.

BREEDING CYCLE IN TREE BREEDING

STAGES OF SELECTION AND GENETIC GAIN

TREE BREEDING TECHNIQUES

CONVENTIONAL TREE BREEDING TECHNIQUES1. Plus tree selection2. Provenance test3. Hybridization and production 4. Accelerated breeding

MODERN TREE BREEDING TECHNIQUES-1.SEED ORCHARDS2.MICROPROPAGATION - 1- Somatic embryogenesis

2-Organogensis3.GENETIC ENGINEERING- 1 -Agrobacterium mediated gene transefer

2 -Biolistic method of gene transfer

CONVENTIONAL TECHNIQUES

1-PLUS TREE SELECTION

The selection process involves two considerations Preliminary reporting of the outstanding tree called candidate

tree Final appraisal and approval as plus tree

There are basically three method applied for the selection of a plus tree

Comparison tree selection Baseline selection Regression method

1. COMPARISON TREE METHOD OF SELECTION

Suitable for even aged natural stands First selection of candidate tree – screened for traits in relation

to few surrounding trees Comparison tree should be selected from dominant or co-

dominant crown with similar age and site conditions, approximately within 100m range from the candidate tree

Superiority of the candidate tree over the average of the comparison tree is worked out for each trait

Candidate tree is designated as plus tree if it proves superior to the comparison trees; otherwise rejected

A candidate tree is compared with its nearest neighbours in a stand

GENERAL PRECAUTIONS FOR CANDIDATE TREE SELECTION

Selection should be done from uniform age Comparison tree should be selected from the near vicinity of

the candidate tree The candidate tree should be 5% superior in height and 20% in

dbh The candidate tree must be free from apparent pest and

disease damage Trees should have good seed production capacity

2-BASE LINE METHOD

It is the selection made simultaneously for all the characters but rejecting all individuals that fail to meet the minimum selection standard for any one trait

Method based the fixation of minimum acceptable standard level for each trait. Individual are located and their values for traits of interest are compared with the MSS, below which individual are eliminated regardless of their acceptability in other characteristic

This method is useful in uneven aged stands when the comparison tree adjacent to the candidate trees is not available

The candidate tree in this case is not compared with the surrounding tree

TREE HEIGHT USING A CLINOMETER DIAMETER AT BREAST HEIGHT (DBH)

3-THE REGRESSION SELECTION SYSTEM

The most useful method of tree grading for the uneven –aged or mixed species type stands

A regression selection system is built by sampling a number of tree for a desired characteristics, such as volume growth on a given site, and then plotting them against age

No need for comparison tree in this method suitable for all aged or mixed species

Regression is used as follow-• A candidate tree is chosen, based on

the judgement of the breeder and measured for the characteristics desired, such as height or volume.

• The trait is plotted on the regression graph using the proper age and site. If the candidate tree falls at some defined distance above the regression line, it is acceptable and the higher above, the more desirable it become. When the value of the characteristic falls below the acceptable level, the tree is rejected

PLUS TREES SELECTED IN VARIOUS STATES   States of India

Species U.P. Punjab & Harayana

T.N. Kerala & A&N Land

M.P. Maharashtra Orrisa & Goa

Rajasthan Gujrat &

D&N

Karnataka A.P. A&N

Azadirachta indica 47 40 - - -

Dalbergia sissoo 130 - 43 - -

Casuarina equisetifolia   91 - - -

Tectona grandis - 53 330 - 50

Eucalyptus tereticornis - 42 - - -

Dalbergia latifolia - - 15 - -

Tecomella undulata - - - 15 -

Acacia nilotica - - - 4 -

Prosopis cineraria - - - 6 -

Acacia tortilis - - - 8 -

Pinus roxburghii 97 - - - -

2-PROVENANCE TESTING

• Provenances are the original geographical area from which seeds or other propagules was obtained.

• Seed are collected from a number of widely scattered stand and the seedling are grown under similar condition to select a seed source for better growth and adaptability.

ROLE OF PROVENANCE TESTS IN TREE BREEDING AND IMPROVEMENT

• Provenance testing is essential to obtain yield per unit area.• Plus tree selected without provenance testing may not be

superior• Assure breeder that he has the best genotype• To screen the naturally available genetic variation and choose

the best available type for further breeding work

THE IDEAL SEQUENCE OF PROVENANCE TESTING IS • Range wide provenance phase• Restricted provenance phase• Provenance providing phase

1-RANGE WIDE PROVENANCE PHASE-• This phase is the testing phase for all the geographical variation available

within the species. 10-30 provenance are selected and tried during this phase

• The trial is laid out on small plot size 2-RESTRICTED PROVENANCE PHASE• On the basis of the RWPP 3-5 provenance are selected that are found

suitable for the site under test

3-PROVENANCE –PROVIDING PHASE• To confirm the result of restricted provenance phase, this trial is laid out

under normal plantation condition

3-HYBRIDIZATION Hybridization as a broad term refers to

natural or man-made crosses of individuals of unlike genetic constitution.

OBJECTIVES OF HYBRIDIZATION-• A tree species valuable for its timber

characteristics, but lacking in resistance to a potent disease or insect pest, may be combined with a closely related resistant species to produce a hybrid including all the desirable characteristics.

• A species desirable for a certain region from a forestry standpoint but lacking in winter or summer hardiness may be combined with a hardy species to produce a hybrid adaptable to the region.

TWO METHODS FOR PRODUCTION OF HYBRID SEED IN COMMERCIALLY USABLE QUANTITIES

• Direct utilization of F1 or first-generation hybrid seed.

• Alternatively, the F1 generation may be utilized as an intermediate for the production of F2 generation hybrids in seed orchards by open pollination or by controlled pollination

EVALUATION OF HYBRID

Zobel (1951) used 12 characters for evaluating hybridization between Coulter and Jeffrey pines, including cone, seed, foliage and oleoresin characters

Mergen (1959) reported on studies indicating that stomata distribution is a reliable criterion of pine hybridity

Identification on the basis of physical characteristics of seeds, cones, twigs, and

leaves; study may include the internal anatomy of the leaves; also their colour, pubescence and number and position of stomata

Characters as resin chemistry in pines (Mirov, 1942, 1946)

Comparisons may be made with parental physiological responses such as growth phenology, winter hardiness, and drought resistance

P. trichocarpa X P. deltoides = Hybrid Poplars (TD variety)

MAINTENACE AND PRODUCTION (VEGETATIVE PROPAGATION )

Vegetative propagation resulting genetically identical to the original “donor” plant.

One of the most important tool and widely used in tree breeding to manage breeding population more effectively.

Mass production.

METHOD-1-CUTTING 1-STEM CUTTING- Eucalyptus, Casuarinas . 2-ROOT CUTTING- Dalbergia sisoo, Populous alba.2-LAYERING 1- AIR LAYERING 2- SIMPLE LAYERING- 3-SERPENTINE LAYERING3-GRAFTING

4-ACCELERATED BREEDING APPROACHES

Essential requirement for generation interval can be shortened in tree breeding programme

Accelerated breeding, reducing the time required to mate parent tree and collect seed from them once they are selected

Involve understanding about the basic physiological processes involved with maturation and in reproduction in tree and how this process can be manipulated to promote flowering

Accelerated breeding techniques can reduce generation interval and thereby increase genetic gain per unit time .

MODERN TECHNIQUES

1- SEED ORCHARD A seed orchard is a plantation of genetically superior tree,

isolated to reduced pollination from genetically inferior outside source, and intensively managed to produce frequent abundant, easily harvested seed crops. (Zobel et al. 1958)

KIND OF SEED ORCHARD • Clonal seed orchard• Seedling –seed orchards

1-CLONAL SEED ORCHARD

In clonal seed orchard the vegetative material of selected phenotypes or plus tree is planted in area with good isolation, under condition favouring flowering and fertilization, and managed for the production of maximum amount of seeds

CLONAL SEED ORCHARD ARE OF TWO TYPE Clonal seed orchard without progeny testing Progeny tested clonal orchard

WITHOUT PROGENY TESTED• This consist of tree selection in the wild plated stand, grafting

of scion and establishment of seed orchard

• No progeny testing is carried out

• It is appropriate method if natural population is in danger of extinction or produce little seed in natural habit and for gene conservation

PROGENY –TESTED

Orchard of this kind contains large number of clone obtain through plus tree selection and grafting. Progenies are tested after open pollination and orchard is rouged on the basis of progeny- test result in which only the best clone are retained.

2-SEEDLING –SEED ORCHARD

In the seedling orchard, progenies from open or controlled pollination of selected phenotypes are planted at normal plantation spacing

The identity of families is maintained in order to allow to rouging among families and among the individual within families, bases on their phenotypic performance

2-MICRO PROPAGATION

Micro propagation refers to in-vitro clonal propagation Production of true to type plant is large number in short

duration Most versatile method of ensuring uniformity Micro propagation generally involve 4 steps Initiation of aseptic culture shoot multiplication rooting

of in-vitro formed shoots transplantation of plant to a potting mixture

1-SOMATIC EMBRYOGENESIS

• Pioneering studies on somatic embryogenesis in conifers were conducted in Canada in the period of 1968–1980 (Durzan & Steward 1968, Chalupa & Durzan 1973, Durzan & Chalupa 1976).

• In 1985 Hakman et al. (1985) and Chalupa (1995) initiated somatic embryogenesis in European spruce.

SOMATIC EMBRYOGENESIS- Can be defined as non –sexual developmental process ,which produce bipolar embryo from the somatic cell.

TWO TYPES- Direct somatic embryogenesis Indirect embryogenesis

DIRECT EMBRYOGENESIS- refers to the development of embryo directly from the original explant tissue. There are some pre-embryogenic determined cells that give rise to embryo without an intervening callus phase .

INDIRECT SOMATIC EMBRYOGENESIS – it is the formation of embryo from callus indirect somatic embryogenesis takes place through induced embryogenesis determined cells.

SOMATIC EMBRYOGENESIS OF ECONOMICALLY IMPORTANT TREE SPECIES

• Abies (NawrotChorabik 2008; 2009; Salaj & Salaj 2003/4)• Picea (Klimaszewska et al. 2010; Mihaljević &Jelaska

2005) • Pinus (Lelu-Walter et al. 2008; Klimaszewska et al. 2001)• Taxus (Nhut et al.424 Embryogenesis 2007) • Acer (Ďurkovič & Mišalová 2008)• Castanea (Corredoira et al. 2003)• Quercus (Toribo et al. 2005) • Salix (Naujoks 2007) and • Ulmus (Ďurkovič & Mišalová 2008; Mala et al. 2007).

3-ORGANOGENESIS

In plant tissue culture, organogenesis is a process of differentiation by which plant organs are formed.

Organogenesis can achieved by two modes1. Organogenesis through callus formation 2. Emergence of adventitious organ directly from explants Several limitations, low shoot proliferation in forest trees, excessive phenolic exudation(Linington, 1991), and shoot tip necrosis (Bargchi & Alderson, 1996) are pronounced in tree

tissue culture.

ADVANTAGES OF MICROPROPAGATION

• Year around production of plant irrespective of seasonal constraint.

• Small space is required

• Small tissue is required as an explant, hence saves the scion wood to a great extent.

4-GENETIC ENGINEERING-

Agrobacterium mediated genetransfer

Biolistic method of gene transfer

CURRENT STATUS OF TREE GENETIC ENGINEERING

GENE TRANSFER METHODS IN FOREST TREE SPECIES-Procedures for genetic transformation of forest trees differ little from those for other plant species and are mainly confined to the use of Agrobacterium, with a few reports on particle bombardment-mediated transformation.

THE MAJOR OBSTACLES TO EFFICIENT PRODUCTION OF TRANSGENIC TREES ARE-

Difficulties in plant regeneration from Agrobacterium-infected or particle-bombarded explants;

Transgene instability during the long lifespan of forest trees.

AGROBACTERIUM-MEDIATED TRANSFORMATION OF POPULUS SPECIES

PROCEDURE-

BIOLISTIC METHOD

KEY TARGETS FOR TREE GENETIC ENGINEERING

1-ENHANCED TOLERANCE TO ABIOTIC STRESS: DROUGHT, SALINITY AND HIGH AND LOW TEMPERATURE -.

• choline oxidase (codA) gene from Arthrobacter globiformis resulted in increased tolerance to NaCl in several lines of Eucalyptus globules.

• manganese superoxide dismutase (SOD) gene from Tamarix androssowii in a hybrid poplar (Populus davidiana Populus bolleana) resulted in enhanced SOD activity on exposure to NaCl, along with a remarkable increase in growth.

2-ENHANCED RESISTANCE TO BIOTIC STRESS: INSECTS AND DISEASE-

In 2002, insect-resistant black poplar (P. nigra) containing Bt genes was approved for commercialization by the Chinese Gene Security Committee.

Hybrid poplars transformed with a cowpea trypsin inhibitor gene (CpTI) exhibited resistance to three defoliating insects: forest tent caterpillar (Malacosoma disstria), gypsy moth (Lymantria dispar) and willow moth (Stilpnotia candida).

3-Enhanced root development has been achieved by modifying the expression of genes involved in the biosynthesis of plant hormones.

4-Improved wood properties -six genes involved in lignin biosynthesis were down regulated using. suppression of genes encoding enzymes that act early in the biosynthetic pathway is the most effective strategy for reducing lignin content.

5-ENHANCED HERBICIDE RESISTANCE-CP4 was isolated from the Agrobacterium strain CP4 and encodes an enzyme that has a low affinity for the herbicide glyphosate .

6-PHYTOREMEDIATION OF ENVIRONMENTAL POLLUTANTS-

Populus deltoides has been transformed with the merA and merB genes, which encode organomercury lyases. Transgenic plants grown in vitro were highly resistant to phenylmercuric acetate and were able to detoxify organic mercury compounds considerably faster than non-transgenic controls or plants containing either of the two transgenes alone.

PROBLEM PECULIAR TO TREE BREEDING AND IMPROVEMENT

• Time-Require many year to produce the desired traits like volume wood maturity ,resin etc. they take years to bear flower and seed

• Necessity of seed - Needs to be concerned with seed production and effort to experiment on the stimulation of flowering and fruiting

• No come back- Once a plantation has raised by using a certain seed lot, it cannot be replaced in midway by other seed , as it will give high economic loss. However in crop plant another seed can be used in next season. This is a disadvantage in tree breeding.

• Scarcity of basic genetic information about trees

CONCLUSIONS

Tree breeding helps in mass production of seedlings for achieving higher productivity of timber and wood products. Both conventional and modern techniques have been used for tree breeding in global and Indian level. It assists in supplying large quantities of timber and wood for growing enormous demand of wood market across the world including India. Since modern tree breeding techniques are advancing each day, it has a great potentiality to supply large biomass demand of the world including India.

Plant a Tree, plant a new life….Take care of trees. They take care of you

thank you