Fig. 2. Principal component analysis (PCA) of genotypic mean trait
values showing multivariate dependency between the measured traits:
Relative growth in leaf area (meanRGRA), Total number of leaves (mean
TL), Total leaf area (meanTNL), Total leaf dry weight (meanTLDW),
Specific leaf area (meanSLA), Root volume to leaf area ratio (meanRL).
The two first axis, PC1 and PC2, account for 46 % and 20 % of the
total variation respectively.
What is the relationship between performance in ample and
restricted-water conditions?
The type II regression where the genotypic means of growth-related
traits were regressed to each other in ample-water versus restricted
water revealed that across the four traits, the genotypes that performed
well in ample water performed relatively less well in restricted water.
In all cases of the aforementioned regressions, the slope was less than
one. For RGRA there was no significant relationship
between the values in ample water and those in restricted water
suggesting that comparatively well-performing genotypes are strongly
compromised in restricted water. See Fig. 3 and Appendix Table A.7. for
a table with statistics.