Shifting goal posts for pre-breeding: tapping the wild to adapt agricultural systems to climate change

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1 Shifting goal posts for pre-breeding: tapping the wild to adapt agricultural systems to climate change Jaime Prohens Universitat Politècnica de València, Spain

2 Climate change is here... to stay with us!

3 And agriculture will be one of the most affected sectors

4 Climate change will increase abiotic and biotic stresses in many areas

5 A new paradigm: tapping the wild for adapting the crops to climate change Tanksley and McCouch (1997)

6 A new paradigm: tapping the wild for adapting the crops to climate change Tanksley and McCouch (1997) Multitude of stressing environments Adaptation to modifed environments Environments highly modified to avoid stress Not only bottleneck during domestication: -Many species never participated in domestication (geographical reasons or lack of domestication-prone characteristics)

7 A new paradigm: tapping the wild for adapting the crops to climate change Many wild species are tolerant to stress Solanum incanum (eggplant CWR) Solanum chilense (tomato CWR) Oryza rufipogon (rice CWR)

8 Up to now wild relatives have been used in breeding of several crops, but this has been mostly restricted to specific traits (e.g., introgression of disease resistance), especially when looking at commercial varieties One extreme example is tomato

9 Up to now wild relatives have been used in breeding of several crops, but this has been mostly restricted to specific traits (e.g., introgression of disease resistance), especially when looking at commercial varieties We need to shift the goal posts! DISEASE RESISTANCE

10 Up to now wild relatives have been used in breeding of several crops, but this has been mostly restricted to specific traits (e.g., introgression of disease resistance), especially when looking at commercial varieties We need to shift the goal posts! CLIMATE CHANGE ADAPTATION DISEASE RESISTANCE

11 A new paradigm: tapping the wild for adapting the crops to climate change How should we proceed for tapping the wild for adaptation to climate change? -Conventional approach: Use one wild relative for a specific trait -New approach: Introgressiomics for climate change adaptation Mass scale development of multiple plant materials carrying introgressions of genomes from (mostly wild) related species into the genetic background of crops that may allow developing new cultivars adapted to climate change (and other breeding goals) Two possible strategies: -Focused: Strategies aimed at one specific target (drought, high temperatures, climate change adaptation) -Non-focused: Strategies aimed at the massive generation of introgression materials for present and future (unforeseen) needs (climate change adaptation, quality, new challenges)

12 A new paradigm: tapping the wild for adapting the crops to climate change This is not an easy task: -Many undesirable traits in wild relatives (chemical and physical defence traits, low yield, small fruit size) -Many wild plants are difficult to manage under domesticated conditions (germination, adequate development, flowering, fruiting, etc.) -Crossing barriers between crops and wild relatives are frequently present (secondary and tertiary genepools) -Long time needed for developing pre-bred materials readily and easily usable by breeders -Protocols are needed for screening for climate change traits -Crop wild relatives accessions are much less represented than crops in collections -Access to germplasm (CWR, but also crops) collections is perceived as increasingly difficult by breeders -Information on already existing pre-bred materials is often missing or unavailable -Often few available evaluation data on crop wild relatives -The taxonomy of crop wild relatives is sometimes (not to say frequently ) confusing

13 Steps for introgressiomics: 1) Identifying the target wild species: -Primary, secondary and tertiary genepools Based on diversity: -Genetic -Phenotypic -Evaluation -Environments -Origins -Genepools Genepool concept (Harlan and de Wet, 1971)

14 Steps for introgressiomics: 1) Identifying the target wild species: -Primary, secondary and tertiary genepools Based on diversity: -Genetic -Phenotypic -Evaluation -Environments -Origins -Genepools Eggplant prebreeding project

15 Steps for introgressiomics: GP-1 GP-3 GP-2

16 Fruit set (%) Fruit set (%) Steps for introgressiomics: 2) Interspecific hybridization: -Barriers to hybridization (pre-zygotic, post-zygotic) -Techniques to overcome the interspecific hybridization: -Direction of the cross -Pollen mixture -Pollen irradiation -Differences among genotypes -Embryo rescue S. melongena ( ) Primary genepool Secondary genepool Tertiary genepool MEL1 MEL2 MEL3 MEL4 MEL5 MEL S. melongena ( ) Primary genepool Secondary genepool Tertiary genepool MEL1 MEL2 MEL3 MEL4 MEL5 MEL6

17 Steps for introgressiomics: 2) Interspecific hybridization: -Barriers to hybridization (pre-zygotic, post-zygotic) -Techniques to overcome the interspecific hybridization: -Direction of the cross -Pollen mixture -Pollen irradiation -Differences among genotypes -Embryo rescue

Steps for introgressiomics: 3) Hybrids fertility: -Different number of chromosomes -Irregular pairing during meiosis -Use hybrid as maternal parent -Genome duplication to restore fertility Sterile

18 Steps for introgressiomics: 3) Hybrids fertility: -Different number of chromosomes -Irregular pairing during meiosis -Use hybrid as maternal parent -Genome duplication to restore fertility Sterile hybrid (2x) Genome duplication (Partially) fertile hybrid (4x) BC1(4x) BC1(2x) Crossing with tetraploid crop (4x) Anther or microspore culture Successive backcrosses with diploid crop (2x) Interspecific hybrid S. melongena x S. anguivi Crop materials with introgressions

present recombination -Phenotypic selection (Focused strategy)

19 Steps for introgressiomics: 4) Backcrossing -Usually fertility is restored during the backcross process -Some parts may not present recombination -Phenotypic selection (Focused strategy) -Marker assisted selection (Focused and non-focused strategies)

20 Steps for introgressiomics: 5) Development of introgression materials -Introgression lines collections:

21 Steps for introgressiomics: 5) Development of introgression materials -Introgression lines collections:

22 Steps for introgressiomics: 5) Development of introgression materials -Chromosome substitution lines:

23 Steps for introgressiomics: 6) Combination of genes from different wild species -Intercrossing of introgression lines from different wild species -MAGIC populations

24 Steps for introgressiomics: 6) Combination of genes from different wild species -Intercrossing of introgression lines from different wild species -MAGIC populations Successive backcrosses to cultivated (SSD)

change challenges and unforeseen future needs.

25 Massive introgression for tapping the wild : Establishing programmes for the simultaneous introgression from many wild species This will facilitate having materials readily usable by breeders against climatic change challenges and unforeseen future needs. This will allow combining genes from different wild species to get crops adapted not only to disease resistance but to the broader objective of adapting to climate change.

26 Shifting global goal posts From the Drill, baby, drill goal post Coined by Michael Steele in 2008 for supporting increased drilling for petroleum and gas

27 Shifting global goal posts To the Introgress, baby, introgress goal post Coined on Dec at a climate change-cwr workshop in BCN for supporting increased introgression from wild relatives for adaptation of crops to climate change

The Nirvana for breeders working on adaptation to climate change breeders Repository of pre-bred materials with introgressions from multiple wild species Introgression lines species A (GP1)

28 The Nirvana for breeders working on adaptation to climate change breeders Repository of pre-bred materials with introgressions from multiple wild species Introgression lines species A (GP1) Introgression lines species a (GP2) Introgression materials species a (GP3) Multi-wild spp. introgression materials Introgression lines species N (GP1) Introgression lines species n (GP2) Introgression materials species n (GP3) Multi-wild spp. introgression materials Integrated Database : -Phenotypic -Evaluation -Pedigree -Genotypic

Development of Early Blight and Late Blight Resistant Tomatoes. Report of a research supported by:

Development of Early Blight and Late Blight Resistant Tomatoes Report of a research supported by: The Pennsylvania Vegetable Marketing and Research Program December 2009 Majid R. Foolad Professor of Plant