SELECTION AND EVALUATION OF ECOTYPES OF POTENTIAL GRASS SPECIES FOR RESEEDING THE ASALS OF KENYA PhD Proposal By Kirwa Everlyne Cheptarus B.Sc, M.Sc Supervisors:

SELECTION AND EVALUATION OF ECOTYPES OF POTENTIAL GRASS SPECIES

FOR RESEEDING THE ASALS OF KENYA

PhD Proposal By Kirwa Everlyne Cheptarus B.Sc, M.Sc

Supervisors:Dr. Kiarie Njoroge, UoNDr. George N. Chemining’wa, UoNDr. William Ngoyawu Mnene, KARI

Introduction• ASALs have great potential but overlooked

• The fastest-growing agricultural subsector

• 30% agric. GDP in developing nations (IFAD, 2010).

• In Kenya: – 70% livestock pop. – Valued Kshs 70b – 67% of red meat (Juma et al., 2010)

…Introduction 92% of Nat. Parks &Reserves’ land 90% wildlife. 80% of country’s eco-tourism for over Kshs

50b p.a (ALMP, 2005).fragile lands & currently degraded o land subdivisions & changes in land uses, o Increasing human & livestock pop. o overgrazing & bush encroachment o increasing incidence of droughts

Livestock production constraint esp. feed availability

…IntroductionRehabilitation technologies e.g. reseeding, (Kiptarus

2005; Mnene, 2006; Nyariki et al., 2008; Manyeki, et al., 2011)

Various grass species tested for reseeding, e.g.

However, seeds not available commercially

Horsetail grass (Chloris roxburghiana)

Maasai lovegrass (Eragrostis superba)

African foxtail (Cenchrus ciliaris)

Bush rye(Enteropogon macrostachyus)

Farmer capacity building

Justification• To commercialize, must standardize quality & a

sustainable seed system

• Poor establishment still a constraint to reseeding

• Several ecotypes exist

• Knowledge on the level & structure of variation within & among these grass populations for sustainable seed collection, utilisation & conservation

• And for ecotype seed yield potential by nutrient level & water interaction

Grass seeds processing

Hand sorting

Packaging

Objectives

Broad objective• To screen for higher productivity in various

ecotypes of four preferred & adapted range grasses under different production regimes

Grass hay on transit

Grass seeds packaged for sale in informal market

Objectives cont…Specific Objectives

• To identify the most productive ecotypes of four range grasses in seed & herbage yield

• To genetically characterize ecotypes of four range grasses

• To evaluate the effects of N-fertilizer use & irrigation on quantity & quality of seeds of selected ecotypes of four range grasses

Research Hypotheses• The seed & herbage traits of the ecotypes are

related to one another & to some traits of agronomic importance

• There is differentiation in ecotypes due to eco-geographical variation?

• Fertilizer or irrigation positively affects seed yield traits of the ecotypes

Materials & MethodsThree (3) experiments to be conducted:• Identification of the most productive ecotype in seed &

herbage production

• Genetic characterization of ecotypes

• Effect of fertilizer use & irrigation on seed production in grass ecotypes

Study site• 4 sites based on climatic variation:

- Kiboko A & B - Buchuma - Mariakani

Exp. 1: Identification of the most productive ecotype in seed & herbage production

Grass seed collectiono 4 counties by Agro-ecological zones (AEZ) & altitude

- Kilifi (AEZ III) - Taita Taveta (AEZ IV) - Makindu (AEZ V) - Kajiado (AEZ VI)

o 5 purposively selected sites in each countyo 20 plants harvested using randomly stratified technique

(Guarino et al., 1995)o Viability tests - KARI Kiboko labs

…Experiment 1o Seeds to be sown in trays o Seedlings transplanted to field at 1x1 m spacing

Experimental designo Split plot design, 3 replications, each 16 plotso Spp & ecotypes as main & subplot, respectivelyo Plot size of 4 x 4 m with inter-row spacing of 1 m

Data collection• Agro-morphological traits according to IBPGR (1985) & van de

Wouw et al. (1999)

…Experiment 1Character units

1. Plant number No

2. Plant height cm

3. Leaf length cm

4. Leaf breadth mm

5. Growth habit Code

6. Stem thickness mm

7. Ligule length mm

8. Biomass yield ton/ha

9. Nutritive value %10. Days to start, 50%

& 100% flowering No

Character units

11. Panicles per plant No

12. Total tillers at maturity No

13. Fertile tillers at maturity No

14. Fascicle colour code

15. Inflorescence length cm

16. Inflorescence width cm

17. Inflorescence ratio -

18. Spikelets number No

19. 1000-seed weight g

20. Seed viability %

21. Seedling vigour g

…Experiment 1

• Weather data for source of seed collectionso Annual mean rainfall (mm), annual mean temperature

(°C), Mean diurnal temperature range (°C), Elevation (m) & Latitude (Degrees)

Data analysis• Analysis of variance (ANOVA) & mean separation using

GenStat• Correlation analysis between the plant traits & the

environmental factors

Exp 2: Genetic characterization of ecotypes

Plant sampling• Fresh leaves from 10 plants per ecotype will be randomly

sampled following procedure by Odat et al., (2004)

Laboratory analysis• Genomic DNA extraction by a modification of a CTAB method

(Doyle & Doyle (1987)• Amplified Fragment Length Polymorphism (AFLP) analysis

according to the standard procedure described by Vos et al. (1995).

…Experiment 2AFLP-based data analysis• Genetic diversity, ordination analysis & Analysis of Molecular

Variance (AMOVA) with GenAlEx software (Peakall & Smouse, 2009)

• Cluster analysis using PopGen32 population genetic analysis software (Yeh et al., 1997)o Genetic distance, matrix dendrogram, F statistics, gene

diversity over loci, proportion of polymorphic loci, Shannon index & gene frequency (Nei 1987; McDermott & McDonald 1993)

Exp 3: Effect of N-fertilizer use & irrigation on seed production of grass ecotypes

Experimental design• Soil sampling along plot diagonals & analysis for OC, EC, pH, total

N, available P, K, Ca & Mg

• Sowing of the ecotypes in split-split plot design, 3 reps

• Irrigation, fertilizer & ecotype as main plot, sub-plot & sub-sub plot, respectively

• Treatments: with/without irrigation, with/without N-fertilizer

…Experiment 3

Character/Trait units1. Days to start, 50% & 100%

flowering No

2. Panicles per plant No3. Total tillers at maturity No4. Fertile tillers at maturity No5. Inflorescence length cm

Character/Trait units6. Inflorescence width cm7. Inflorescence ratio -8. Spikelets number No9. 1000-seed weight g10. Seed viability %11. Seedling vigour g

Data collection

• Weather records will be kept during the experimentation period

Data analysis• ANOVA & mean separation using GenStat

Expected outputs• The most productive ecotypes of four range

grasses in seed & herbage production identified

• Ecotypes with wide adaptation to different ecological settings identified through genetic characterization

• Effect of fertilizer use on quality & quantity of seeds of ecotypes of four range grasses under irrigation evaluated & documented

Budget summaryActivity Amount (Ksh)

1. To identify the most productive ecotype of four

range grasses in seed & herbage production

418,000

2. Genetic characterization of ecotypes of

potential range grasses

966,225

3. To evaluate effect of fertilizer use on quality &

quantity of seeds of ecotypes of four range

grasses under irrigation

302,000

Grand Total 1,686,225

Workplan

Activity

Period: Q2 2012-Q4 2014; Start April 2012- Dec 2014Apr –Dec 2012 Jan – Dec 2013 Jan – Dec 2014 Q2Y1 Q3Y1 Q4Y1 Q1Y2 Q2Y2 Q3Y2 Q4Y2 Q1Y3 Q2Y3 Q3Y3 Q4Y3

Experiment 1

Site identification

Seed collection

planting

Data collection

Data analysis

Thesis writing

Experiment 2

Planting of seeds

Laboratory analysis for genetic characterization

Thesis writing

…Workplan

Activity

Period: Q2 2012-Q4 2014; Start April 2012- Dec 2014Apr –Dec 2012 Jan – Dec 2013 Jan – Dec 2014 Q2Y1 Q3Y1 Q4Y1 Q1Y2 Q2Y2 Q3Y2 Q4Y2 Q1Y3 Q2Y3 Q3Y3 Q4Y3

Experiment 3

Soil sampling

Seedbed preparation

Planting

Data collection

Data entry & analysis

Thesis writing

Thank you all