dc.description.abstract | Outcropping and yield prediction study.. were conducted in four
populations of grain amaranth, populations 1008 and 1024 ( hypochondriacs)
nd 1034 and 434 (cruentus). The studies were conducted at Kabete Campus
ot the University of Nairobi and National Horticultural Research Station, Thika
during the lone rains and the short rains of 1988. A two-replicate alternate row
.method where dominant red pia.ention parent was planted in the center with
the recessive green placentation parent on either side was used. Both
intraspecific and inter specific outcrossing rate estimates were determined and
utilized to describe the breeding system of erain amaranth species (~
hypochondriacs and cruentus). Quantitative traits, plant height, head
length of the mature plant, seed yield per plant, sun dried head weight of the
mature plants, days to flowering and days to .maturity were used to determine
yield predictors in the four grain amaranths.
High intraspecific and interspecific outcrossing rate variations were
noted in both the two species with a high ability to outbreeding exhibited by
~ cruentus. Intraspecific outcrossing rate for the two species oscillated
around 10 per cent with interspecific outcrossing rate of about 3.87 per cent.
There was sufficiently very high locational and seasonal variations for the
outcrossing rate estimates. The probable factors contributing to the
variations were believed to be locational, seasonal and pollinator density
variations, and genetic structural differences alongside genotype x
environment interaction.
Hultiple regression and multiple correlation analyses showed that plant
height and head length were constantly strongly correlated to seed yield per
plant. Head weight offered good prediction levels for seed yield for the
-Viitour
populations. Day. to flowering and days to maturity did insignificantly
correlate to leed yield per plant tor .ost ot the analyses hence were not
regarded important yield predictor variable in the present study.LSD •of the .eans for the six quantitative traits investigated .howed variation
between the .eans of the two seasons tor so.e of the traits and variation
between the .earns ot the two locations for the four populations uled in the
present study. Outcropping and correlation analyses indicated that breeding
system of grain amaranths requires further research tor the establishment of
marketing system that would exploit natural pollination for the crop improvement
and development. | en |