Genetic diversity of populus ilicifolia populations in Kenya using amplified fragment length polymorphism (AFLP) markers.
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Date
2014-10-03
Authors
Mutegi, Sammy Muraguri
Journal Title
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Publisher
Kenyatta University
Abstract
Many species in the genus Populus and their hybrids are economically valuable, fast
growing, short rotation woody crops for producing wood, fiber, and biofuels, as well as
sequestering atmospheric carbon in large plantations and agroforestry settings. Industrial
facilities to produce liquid transportation fuels from Poplar feedstock are currently being
built in the USA. Populus ilicifolia locally known as Tana River Poplar is the only
species in the Populus genus that falls within the tropics. It occurs in river valleys of
Tana, Athi, Ewaso Nyiro and Tsavo River in Kenya. P. ilicifolia is threatened by
massive felling by humans, floods and destruction by large herbivores. As such the
species populations have become decimated to IUCN vulnerable status. Unlike its
relatives in Americas, Europe and Asia, P. ilicifolia have received very little attention for
utilization and conservation. Incorporating this species into on-going tree improvement
. and genom ics research on temperate Populus species is expected to have tremendous
economic and scientific benefits to Kenya. The genome of P. trichocarpa a member of
this genus has already been fully sequenced. Use of marker assisted breeding which
reduces the tree improvement period by more than half will be the best approach.
Samples will be collected from three locations along the species natural ranges (i.e. Athi,
Ewaso Nyiro and Tana Rivers), and compared with 10 reference samples from the USA.
This study will assess the genetic diversity of P. ilicifolia using amplified fragment length
polymorphism (AFLP) markers and flowering loci (FTI and FT2) specific markers. FTI
and FT2 genes are involved in reproductive and vegetative growth respectively of the
species and have been extensively studied in the temperate species of genus Populus.
Reproductive and vegetative growth is important for adaptation of a species to different
environments. Upon assessment using these markers, molecular data produced will be
analyzed by employing GenALEx 6.5 software. Genetic diversity of P. ilicifolia will be
quantified by calculating the rate of polymorphism and the proportion of polymorphic
loci based on the number of variants and the average expected heterozygosity based on
the frequency of variants. The relationship among the P. ilicifolia populations will be
displayed using a dendogram based on similarity matrices. The information generated
will be important in laying down conservation and utilization strategies for the species.
The assessment of the genetic relatedness of FT loci between P. ilicifolia and the
template Poplar species will also has the potential for application in the species tree
improvement through molecular breeding
Description
School of Pure and Applied Sciences, SD 235 .M8