Studies on the pre-harvest sprouting resistance of Kenyan commmercial varieties of wheat (Triticum aes tivum L.)
Abstract
In searching for pre-harvest sprouting
resistant wheats (Triticum aestivum L.) for
breeding purposes in many countries, one of the
major hindrance has been the identification of
varietal factors governing the resistance and how
each factor correlates to sprouting. This study
was undertaken to determine those factors that
contribute to sprouting resistance in 25 Kenyan
wheat cultivars. The major factors which were
found to confer resistance to sprouting in this
study are high seed dormancy, high germination
inhibition by the chaff, slow rate of water uptake
by germinating seeds and low alpha-amylase content
in seeds exposed to high humidity and rain prior
to harvest wide varietal differences were observed
in every factor studied and these were significantly
correlated with sprouting in the field or in
la~oratory, however dormancy and aloha-amylase
content had stronger correlations with s~routing
than the o~her two factors. Cultivars that showed
sprouting resistance had two or more of these
factors suggesting that adequate resistance would
only be achieved when several factors are
incorporated in a variety. Varieties having
desirable attributes were identified and could
form the basis of breeding against sprouting in
Kenyan wheats. Cultivars ranking for a particular
factor varied with seasons. 7here was ranking
consistency in some cultivars for a particular
factor studied in various seasons but some deviated.
Two or more seasons data would provide a better
varietal ·picture in the factors governing
sprouting resistance than one season's data.
This study was also undertaken to determine
the number of genes controlling red seed coat
colour in four wheat cultivars. The study also
included inheritance of dormancy in Kenya Kongoni/
PAA cross and its relation to seed coat colour.
Red seed coat colour was observed to be controlled
by one gene in Kenya Fahari (K2H), Kenya Tembo
(KTS) and Bounty (STY) and by two genes in Kenya
Kongoni (KKN). Seed dormancy was observed to be
low in STY and KFH, intermediate in KT6 and high
in KKN. This suggested that increase in genes
controlling red seed coat colour would increase
dormancy. It was further observed that dormancy
in KKN was controlled by two recessive genes with
a heritability of 0.79. This implied that it is
possible to select for dormancy in early generations
When Large populations are created.
Citation
Kireu, P.M.K(1983). Studies on the pre-harvest sprouting resistance of Kenyan commmercial varieties of wheat (Triticum aes tivum L.)Sponsorhip
University of NairobiPublisher
Departmeni of Animal Production, University of Nairobi
Description
Msc Thesis