This study analyzed the genetic diversity of 281 Napier grass genotypes from East Africa and ILRI using amplified fragment length polymorphism (AFLP) markers. 216 polymorphic AFLP markers were identified and genetic distance and population structure were analyzed. The results show high genetic variation within populations but low variation among populations. Cluster analysis grouped genotypes according to origin. This data on genetic diversity can help breeding efforts by informing pedigree and introducing new variability to develop resistant and higher quality varieties.

1. GENETIC DIVERSITY OF NAPIER GRASS (Pennisetum purpureum Schumacher)
GERMPLASM BASED ON AMPLIFIED FRAGMENT LENGTH POLYMORPHISM
Bramwel W Wanjala1, 3, 5, A Muchugi2, M Mulaa1, M Obonyo3, J Harvey5, R Skilton5, J Proud4 and J Hanson4*
Kenya Agricultural Research Institute1, International Centre for Agroforestry Research2, Egerton University3, International
Livestock Research Institute (ILRI)- Ethiopia4, Biosciences eastern and central Africa (BecA) Hub, PO Box 30709, Nairobi, Kenya5
Napier grass- an important tropical fodder Outputs
An important forage crop for dairy production systems, Napier grass is among the Develop molecular markers to efficiently
highest yielding tropical grasses. Therefore, it is a promising crop for fodder in the identify traits in the available gene pools of
region. However, production faces major challenges Napier grass. Improve the efficiency,
from biotic and abiotic stresses. Available effectiveness, speed and precision of plant
germplasm is currently wanting for resistance to breeding for abiotic stress tolerance, pest and
major pests and other biotic stresses currently disease resistance, better agronomic traits, and
afflicting N i grass. Th f
ffli i Napier Therefore, germplasm
l improved fodder quality.
i d f dd lit
characterization is an urgent need for improvement
efforts. Results
Polymorphic AFLP markers identified
Genetic distance and Fst
Introduction The variance within populations accounted for 91% while among population
Napier grass (Pennisetum purpureum Schum.) is an important forage crop for dairy variance contributed only 9%
production system in the tropics, including East Africa. Cluster analysis (see below)
The grass produces more dry matter per unit time when compared with other
grasses or legumes.
However, Napier production faces major challenges from biotic & abiotic stresses
and limited access to external inputs like pesticides, fertilizers, and irrigation.
Available germplasm may lack genes for major disease and pest resistance and abiotic
stress tolerance.
Conclusions
The 216 polymorphic AFLP markers assessed genetic variation among the 281
Th l hi k d i i i h
Few attempts have been made to understand genetic variability of Napier grass based
genotypes from the region.
on analyses of genomic DNA.
Evaluation based on AFLP markers would be suitable for providing such The diversity data can be used to compliment other data (Phenotypic,
information due to the high level of polymorphism of this technique. AFLP has Nutritional and Biochemical) and thus offer more reliable pedigree information
advantages over traditional fingerprinting protocols such as RFLP (lower resolution)
and RAPD (lower reproducibility). Recommendations
The objectives of this study were to: identify of polymorphic AFLP markers; conduct Existing genetic variation in Napier grass germplasm from the region should
AFLP-based genotyping of Napier grass accessions in East Africa and ILRI-Forage be utilized and additional variability identified.
germplasm to better inform ongoing breeding efforts.
Introduction of new genetic variability from related or unrelated species
through biotechnology should be used to make better hybrids for disease
resistance, improved nutritional quality and increased biomass.
Project workflow Kenya DNA extraction and
normalization Acknowledgments
We thank, partners from Kenya, Uganda and Tanzania for providing materials
Tanzania AFLP analysis
for genotyping.
BecA Hub KARI Director and other staff.
Uganda ABI3730 xl Genetic
Analyzer Staff and graduate students at the BecA Hub.
Funding for this project was for provided by Association of Strengthening
Data Analysis
ILRI Forage Germplasm Agricultural Research in East and Central Africa (ASARECA).