which wheat for smallholder ethiopian farmers? the...

Matteo Dell’[email protected]

IWGS – Tulln, April 2017

Which wheat for smallholder Ethiopian farmers? The quantitative genetics of traditional knowledgeMatteo Dell’Acqua, Yosef G Kidane, Dejene K Mengistu, Chiara Mancini, Melfa and WorkayeFarmer Communities, Elisabetta Frascaroli, Carlo Fadda, Mario Enrico Pè



Small farms (1 to 3 Ha) comprise the vast majority of worlds’ agriculture - especially in Developing Countries

Varied agroecologies – Low inputs – Poor access to seeds

Source: FAO data; Graeub et al., 2015

most of the worlds’ farms are small farms

most of the food comes from small farms

98% 70

% Some provoking thoughts:

Are we sure we are addressing the smallholder farming system in the proper way? Are smallholder farmers marginal in a breeding perspective? Is the smallholder farming system a burden or a resource?Can we join modern technology and tradition to meet the needs of smallholder agriculture?



The case of Ethiopia

• 96.5 Million people (2° in Africa)

• 70 million small farmers (70% of the population)

• Per capita GDP is 550 $

• Center of diversity for several crops

• Plenty of unique durum wheat landraces cultivated on a local, cultural basis. Some poorly introduced modern varieties from abroad



A core collection of 373 Ethiopian durum wheat landraces and 27Ethiopian improved lines genotyped with the illumina 90K array

12 traits measured in 2 locations 2 replicas 2 years

Genome-wide association study (GWAS) conducted to identify marker-trait associations (MTA) of breeding value (agronomic traits, phenology traits, disease resistance)

Background to this study

GWAS for Septoria reistanceMengistu et al. 2016. Plant Biotechnology Journal



Tracing the genetic basis of farmers’ traditional knowledge

Is farmers’ knowledge a quantitative phenotype?

• Consistent

• Repeatible

• Heritable

How is it related with

metric phenotypes?

• What do small farmers want?

Can we identify the genetic bases of

farmers’ traditional knowledge?

• Are there QTL for farmers’ appreciation?

Which is the right wheat for Ethiopian farmers? Is it Tall? Short? Early? Late?

Can we extract farmers’ traditional knowledge and use it to identify breeding targets for farmers’ appreciation?



12 metric traits collected

In each, 400 Ethiopian genotyped wheat accessions laid down in a replicated lattice design

6x groups

Scores 1 to 5 given for each farmer trait

Evaluation given to each unlabeled plot, groups entering from randomentry points, scoring system devised to avoid bias, individual scores recorded

192,000 datapoints36,000 datapoints

15x Men 15x women

Focus group discussions to Identify traits most relevant to farmers:

1. Earliness2. Tillering capacity3. Spike morphology

+4. Overall assesment

Study design

Two agroecologies: Hagreselam, Geregera



Scoring system (excercise)



Farmer scores are highly repeatable, both between replicas within location and among locations.

Simple traits (earliness) are more consistent that composite traits (overall)

Farmer scores are repeatible and heritable



Farmers’ evaluation is composite.Spike measures (except spike lenght) are very important in overall appreciation. Plant height and number of effective tillers are also important.

We can produced a ranking of varieties to be readily distributedbased on i) trait bearing on overall and ii) score variance

38% of the top 50 accessions are

identified in both locations

Farmer scores are related to metric traits

Canonical Correspondence Analysis

earliness

days to

flowering

overall

yield

spike

height



Can we trace the molecular bases of farmers’ knowledge?

Some MTA are identified by metric traits and farmer scoresNot all farmer groups are equal: we see differences among genders and locationsSome MTA are identified by farmers but not by metric traits



Unlike metric values, farmer evaluations build on the time dimension, considering altogether the field conditions over time under which genotypes were grown

Farmers are able to identify signals for thousand grain weight, although they do not directly measure it

Spik

e tr

aits

Ove

rall

trai

ts

With a 5% Bonferroni threshold, several significant signals are identified

Farmers’ knowledge may be integrated in breeding evaluations to identify marker trait associations relevant for smallholder agriculture



Way forwardFarmers’ traditional knowledge to identify wheat adressing local needs through Genomic Selection (GS) and high definition QTL mapping

Nested Association Mapping (NAM) population of 50 founders

and ~ 6,500 RILs F7 (1,200 genotyped)

poster n° 219



Take home messages

• Small farmer evaluations are reliable, synthetic phenoytpes. Gender differences must be accounted for

• Small farmers’ appreciation is composite and hardly amenable to a few metric phenotypes

• Small farmers’ traditional knowleldge provides genomic targets not completely overlapping to metric phenotypes

• Small farmers’ unconscious knowledge may represent a untapped resource in a breeding perspective

Yosef Kidane, PhDBogale Nigir, MDCherinel Aleml, MD

Dejene Mengistu, PhDChiara Mancini, MD

Carlo Fadda, PhD Prof. Mario Enrico PèMatteo Dell’Acqua, PhD



Thank you!



Broad molecular and phenotypic diversity

Landraces have broad variation in

agronomic traits. Some landraces

have interesting stress resistance

traits (drought – pests)

Ethiopian landraces are

unique and very diverse

among them



The importance given to farmer traits is varied among genders and location



We can compute a PCA out of the 10 metric traits

When we project the top ranking varieties on the PCA space, we see farmers prefer the same trait combination

No clear structure, low correlations

with original variables

Farmer scores provide an holistic evaluation of wheat traits



There are more people feeding out of small farms than out of big farms; and there will be more

• Extremely varied agroecologies

• Low-input agriculture (rainfed)

• Poor access to improved seeds

• Political instability

Some provoking thoughts: Are we sure that smallholder farming is marginal? Is small farming a burden or a resource? Can we join modern technology and tradition?



MTA identified by overall evaluation only partially overlap those identified by a PCA of phenotypic traits

These MTA are good candidates to be simultaneously considered in breeding wheat lines meeting small farmers’ needs



Evaluations are mostly consistent

between genders

In Hagreselam, men and women

are less consistent

In all cases, quality traits (overall

and spike) are less consistent

than agronomic traits (tiller and

earliness)



The two fields are somewhat different both in evaluation criteria and in

agronomic performances (cultural + environmental reasons)



Farmer scores were used to produce a ranking of the 400 varieties

giving a weight to each trait measured (overall having one at all times)

Two methods:

1. Variance: the higher the standard deviation of the scoring, the

lower the importance of the trait

2. Correlation to overall



Ranking obtained with the two

methods was averaged in a super-

ranking

• In both cases, top ranking was

achieved by varieties already

possessed by farmers

• The top quartile of the 400 varieties

was scoring better than most of

farmers’ material

• Varieties duplicated in both set and

blindly evaluated achieve similar

scores



Farmer scores

distributions are all normal

except earliness in

Hagreselam

Phenotype

distributions show

different performances

in the two locations

which wheat for smallholder ethiopian farmers? the...

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