Adecisiontree to identify smartmethodsParticipatory Plant Breeding (PPB) is based ondecentralized on-farm breeding, which requiresappropriateexperimentalmethods.A decision tree (cf. page 2) has been developedwithinDIVERSIFOOD, to match experimental design andstatistical methods to a particular PPB project,accordingtoitsobjectivesandexperimentalconstraints.Most of the methods have been implemented in an R Package: PPBStats (developed in DIVERSIFOODdeliverableD3.2anddescribedinD3.1),whosecodeishostedon:https://github.com/priviere/PPBstatsThedecisiontreeisorganisedaccordingtotheobjectivesoftheexperiments.Foreach,thereareseveralmethodsbasedondifferentexperimentaldesignsthatrequirespecificconditions(e.g.numberofplotsperlocation;ofreplicatedgermplasmswithinandbetweenlocations).

IdentifyingtheobjectivesoftheexperimentDataanalysesfromPPBprogrammesmayhaveoneormultipleobjectives.Thefirststepistoidentifytheobjective(s)oftheexperiment(ingreenonthedecisiontree),amongthefollowing:Fourtypesofinformationcanbeconsidered:agronomic/nutritionaldata,sensorydata,networktopology

oftheseedcirculationandmoleculardata.

ExperimentaldesignsandstatisticalmethodsavailableFourexperimentaldesignscanbeused:D1:fully-replicatedblockdesign;D2:incompleteblockdesign;D3:row-columndesign;D4:satellite-farms&regional-farms.Ninestatisticalmethodscanbeused,dependingonthedesign,thetypeofdataandtheobjectives:M1:Nonparametricmethods;M2:Multivariateanalyses (PCA);M3:Geneticdistances& trees;M4a:Anova;M4b: Spatial analysis; M5: Mixed models for incomplete block designs; M6: AMMI and GGE; M7a:Bayesianhierarchicalmodelintra-location;M7b:BayesianhierarchicalmodelGxE;M8:Networkanalysis;M9a:Nappingtests;M9b:Hedonictests;M9c:Rankingtests.

SuggestedreadingsRivière, P., J.C.Dawson, I. Goldringer, andO.David. 2015. “HierarchicalBayesianModeling for Flexible Experiments inDecentralizedParticipatoryPlantBreeding.”CropScience55(3).Gauch,H.G.2006.“StatisticalAnalysisofYieldTrialsbyAMMIandGGE.”CropSci46(4):1488–1500.M.Singh,R.S.Malhotra,S.Ceccarelli,A.Sarker,S.GrandoAndW.Erskine (2003)Spatialvariabilitymodels to improvedryland fieldtrials.ExperimentalAgriculture39(2):151-160.

ATFIRSTGLANCE

Decentralizedon-farmbreedingrequiresappropriatemethodsdueto:

-onfarmsspecificconditions;-collaborativeapproachwithfarmers.Adecisiontreehasbeendevelopedto

selectthemostappropriateexperimentaldesignsandmethods,accordingtotheobjectivesandthe

experimentalconstraints.

SMARTMETHODSFORDECENTRALIZEDON-FARMBREEDING

DIVERSIFOOD INNOVATION FACTSHEET #11, Sept. 2018

• Toimprovethepredictionofatargetvariableforselectionbyanalysingagronomic/nutritionaltraits.• Tocomparedifferentvarietiesorpopulations(hereaftercalledgermplasms)evaluated forselection indifferent

locationsbyanalysingagronomic/nutritionaltraitsandbysensoryanalysis.• Tostudytheresponseofgermplasmsunderselectionoverseveralenvironmentsbyanalysingagronomictraits.• Tostudydiversitystructureandidentifyparentsforcrossingbasedoneithergoodcomplementarityorsimilarity

forsometraitsbyanalysingagronomictraitsandmoleculardata.• Tostudynetworksofseedcirculationbyanalysingnetworktopology.

This Innovation Factsheet is the result of the collectivework ofDIVERSIFOODpartners, coordinated by Isabelle Goldringer(INRA)withthesupportofPierreRivière(RSP),FrédéricRey(ITAB)andAmbrogioCostanzo(ORC).