2026-09-24T18:06:00.717271564Zhttps://repository.nwu.ac.za/server/oai/requestoai:repository.nwu.ac.za:10394/393322022-07-11T12:28:18Zcom_10394_26463col_10394_26478
Botha, P.J.
Henning, Jan Sarel Marthinus
2022-07-11T09:55:08Z
2022-07-11T09:55:08Z
1977
http://hdl.handle.net/10394/39332
MSc, North-West University, Potchefstroom Campus
The effect of N-6-benzylaminopurine (BAP), 8-hydroxyquinoline
sulphate (HQS) and a BAP/HQS mixture on the display life and
external appearance of cut carnation flowers (Dianthus caryophyl
lus L. cultivar White Sim) was investigated. The effect of
these substances on changes in water content, rate of respiration,
total free amino acid content and concentration of the individual free amino acids in senescing petal tissue was examined as
well. The rate of 14co2 production from a-alanine-u- 14c solution applied in presence of the preservatives, during incubation
of petal and receptacle tissue, was determined. This was done
to elucidate the effect of these preservatives on amino acid
breakdown.
Both BAP and HQS prolong the display life and have a beneficial
effect on the appearance of the flowers. A higher water content
is maintained in the petals, especially during the climacteric
and post climacteric stages. The most efficient preservative
is the BAP/HQS mixture.
There are no noticeable changes in the pattern of respiration
and the duration of the preclimacteric period in presence of
the preservatives. The average rate of respiration in petals of
BAP treated flowers is lower than that of untreated flowers.
In the post climacteric stage, however, the rate of respiration
in petals of BAP treated flowers exceeds that of untreated flowers. HQS as well as the BAP/HQS mixture increases the rate
of respiration in the climacteric and post climacteric stages.
All treatments result in the increase of the total amino acid
level although to a lesser extent than in the petals of untreated
flowers. The effect of the preservatives becomes more prominent
in the post climacteric stage. BAP and the BAP/HQS mixture are
more effective than HQS in decreasing the total free amino acid
content.
The concentration of free threonine, serine, asparagine, glutamine, a-alanine, praline, glycine, methionine, phenylalanine,
y-amino butyric acid and histidine are lower in petals of treated
flowers than in the petals of control flowers. The differences
in the concentration of these free amino acids are more pronounced in the post climacteric stage. The preservatives have little
effect on the concentration of free aspartic acid, glutamic acid
and lycine. They also inhibit the characteristic increase in
the concentration of free praline and methionine as senescence
progresses. HQS retards the decrease in water content and prevents the accumulation of praline, glutamine and asparagine under water stress conditions. The reduction of amino acid levels
by the application of BAP is probably caused by the stimulation
of protein synthesis and inhibition of proteolysis.
The rate at which 14 co2 is produced from a-alanine-u- 14c in petal
tissue is higher than in receptacle tissue. However, the preservatives decrease the rate of 14co2 production determined over a
period of 24 hours. BAP seems to have a greater effect than
HQS.
The BAP/HQS mixture is the most effective of these preservatives
in prolonging display life of cut carnation flowers by maintaining
the moisture content of the petals and retarding protein and amino
acid breakdown.
Masters
other
North-West University (South Africa)
'n Ondersoek na die invloed van 8-hidroksikinoliensulfaat en n-6-bensielaminopurien op enkele aspekte van veroudering by angelierblomme
Thesis
open.access