Thesis (MPhil)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: A thesis undertaken to quantify genotype-by-environment interaction within Eucalyptus
grandis clones growing in the eastern portion of South Africa. Thirty one sites were selected
to represent the "traditional" E. grandis growing areas of South Africa. Eleven common
macro- site variables and twelve common micro- site soil variables were recorded at each site.
Twenty seven E. grandis clones and four E. grandis hybrid clones were then evaluated over
these 31 sites. An incomplete latin square design was used to evaluate the 31 test clones, and
five E. grandis controls were incorporated into the trial design to link the 31 sites.
Volume production, stem form, stem defects and survival were assessed at two and five years,
as well as the disease infestation of three stem cankers at five years. The analytical methods
which were used to evaluate and quantify the GEl portion of the study are the analysis of
variance (ANOV A), correlation analysis, and joint regression analysis (IRA) together with
the analysis of co-variance (ACOV AR). The growth-site association for volume production,
stem form and Endothia disease infestation were investigated using factor analysis (FA), and
equations derived for the species and for the individual clones using a stepwise multiple
regression approach.
GEl, as evaluated through JRA, revealed that an increase in site productivity lead to a positive
linear response in productivity on a clonal level, and that there was a diverging or fanning
pattern among the regression lines of the clones. This tendency was also observed for both
the stem form and the Endothia infestation. Hence, no significant changes in the rankings of
the clones were found, and only relevant differences between the clones were found to change
significantly. Juvenile-mature genetic correlations for volume production and the stem form
showed moderate (rg = 0,66 and rg = 0,70) correlations between the two and the five year
assessments.
On a species level, rainfall was the main environmental factor responsible for volume
production, while latitude was the main influence on stem form and Endothia infestation. On
an individual clone basis, some micro-site soil factor interaction within the clones was found
for the growth-site response models.
Keywords: Eucalyptus grandis, genotype environment interaction, clones, site factors,
growth-site response, ANOV A, ACOV AR, GEl, FA, JRA, / AFRIKAANSE OPSOMMING: 'n Studie is ondemeem om die genotipe-omgewingsinteraksie van Eucalyptus
grandis klone, wat in die oostelike deel van Suid-Afrika groei, te kwantifiseer. Eenen-
dertig groeiplekke is geselekteer om die "tradisionele" E. grandis groeiplekke in
Suid-Afrika te verteenwoordig. Elf gemeenskaplike makro-groeiplek veranderlikes
en twaalf gemeenskaplike mikro-groeiplek veranderlikes is by elk van die groei areas
opgeteken. Sewe-en-twintig E. grandis klone en vier E. grandis basterklone is daama
oor hierdie 31 groeiplekke geevalueer. 'n Onvolledige Latynse roosterontwerp is
gebruik om die 31 toetsklone te evalueer en vyf kontroles is gebruik om die
groeiplekke gemeenskaplik te verbind.
Volume produksie, stamvorm, stamdefekte en oorlewing is op twee- en vyfjarige
ouderdomme geevalueer terwyl besmetting met drie stamkankers op vyf jaar
beoordeel is. Die analitiese metodes wat gebruik was om genotipeomgewingsinteraksie
te evalueer en te kwantifiseer is die variansie analise (ANOYA),
korrelasie analise, en gesamentlike regressie analise (JRA) tesame met ko-variansie
analise (ACOY AR). Die groeiplek assosiasie vir volume produksie, stamvorm en
Endothia besmetting is ondersoek deur gebruik te maak van faktor analise (FA), en
vergelykings is verkry vir die spesies en individuele klone deur gebruik van 'n
stapsgewyse meervoudige regressie benadering.
Genotipe-omgewingsinteraksie, soos geevalueer deur JRA, wys dat 'n toename in
groeiplek produktiwiteit lei tot 'n positiewe lineere reaksie in produktiwiteit op
klonale vlak en dat daar 'n divergerende patroon tussen die regressielyne van die
klone is. Hierdie tendens is ook vir beide die stamvorm en Endothia besmetting
waargeneem. Gevolglik is nie-beduidende veranderings in die rangorde van die klone
gevind en slegs reletiewe verskille tussen klone is gevind. Onvolwasse-volwasse
genetiese korrelasies vir volume produksie en stamvorm toon matige korrelasies
(rg =0.66 en rg =0.70) tussen die twee- en vyfjaar metings.
Op 'n spesiesvlak was reenval die oorheersende omgewingsfaktor verantwoordelik vir
volume produksie terwyl die breedtegraad ligging stamvorm en Endothia besmetting
bemvloed het. Op individuele kloonvlak het sommige mikro-groeiplek interaksie
binne klone bygedra tot die groei en groeiplek reaksie modelle.
Sleutelwoorde: Eucalyptus grandis, Genotipe-omgewingsinteraksie, klone, groeiplek
faktore, groeiplek reaksie, ANOY A, ACOY AR, FA, JRA
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/51988 |
| Date | 04 1900 |
| Creators | Pierce, Brian Thomas |
| Contributors | Van Wyk, G., Verryn, S. D., Stellenbosch University. Faculty of AgriSciences. Dept. of Forest and Wood Science . |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 170 p. |
| Rights | Stellenbosch University |
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