Effects of field conditions, low nitrogen and drought on genetic parameters of protein and tryptophan concentrations in grain of quality protein maize
Date
2008Author
Ngaboyisonga, Claver
Njoroge, Kiarie
Kirubi, Duncan
Githiri, Sam. M
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Quality Protein Maize (QPM) has about twice the amount of lysine and tryptophan of normal
maize and hence represents an important tool of correcting its deficiency in protein quality. However,
the effects of low nitrogen and drought on genetic parameters such as gene action and combining
abilities of protein quantity and quality of QPM are not known. To study how these genetic
parameters are affected by field conditions, low nitrogen and drought, eight inbred lines were
acquired from Centro Internacional Del Mejoramiento de Maiz y Trigo (CIMMYT) and used to
generate single cross hybrids with North Carolina Design II procedures. The single crosses were
evaluated at Kiboko in Kenya in 2006 under optimum, low nitrogen and drought environments.
Observations were performed on protein and tryptophan concentrations in grain. Results showed that,
the gene action of protein concentration was predominantly of additive and maternal natures whereas
that of tryptophan concentration was predominantly of non-additive nature. Field conditions, low
nitrogen, and drought changed the proportions of genetic effects. Field conditions suppressed
maternal effects for protein concentration, but induced non-additive effects for both traits. Low
nitrogen reduced additive and maternal effects on protein concentration while it reduced non-additive
effects on tryptophan concentration. Drought reduced non-additive effects on both protein and
tryptophan concentrations in grain. By changing the proportion of genetic effects, environments
changed magnitudes and directions of general (GCAs) and specific (SCAs) combining abilities.
URI
http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/35676Effects of field conditions, low nitrogen and drought on genetic parameters of protein and tryptophan concentrations in grain of quality protein maize
Citation
Claver Ngaboyisonga, Kiarie Njoroge, Duncan Kirubi, Sam. M. Githiri (2008). Effects of field conditions, low nitrogen and drought on genetic parameters of protein and tryptophan concentrations in grain of quality protein maize. International Journal of Plant Production 2 (2), April 2008Publisher
Department of Plant Science and Crop Protection, University of Nairobi, Kenya