102
4.3.3 Phenological Characters
Bud burst and bud set phenologies were evaluated during the second growing season in the last mentioned trial representing 40 open-pollinated families from
four environmentally contrasting natural populations of Argentina (Barbero 2014).
The phenophase of the terminal bud of each sapling was registered every other day,
according to a scale of five categories (similar to that presented in Chap. 3 for
N. alpina), from September 4 to October 28 (bud burst) and from March 14 to April
1 (bud set).
On average for the entire trial, buds were open (phenophase 3) in the 258 DOY
(September 15) and closed in the 446 DOY (March 21). Both factors, population
and family, were significant for bud burst, but only population had a significant
effect on bud set. Similarly to growth initiation and finalization, Epulauquen was the
most different population for these traits (it was, on average the last in bud bursting
and the first in bud closing), and differentiation among populations was estimated as
low for bud burst (Q ST = 9%) but high for bud set (Q ST = 67%). Intrapopulation
variation presented the opposite pattern, that is, higher variation for bud burst
(h
2
= 0.33) than for bud set (h
2
= 0.07). Mean bud and growth phenologies measured
in Epulauquen population were consistent with its mean growth, since it was the
population with the shortest vegetative period and the lowest height reached at the
end of the first growing season, as observed in other studies (Azpilicueta et al.
2014). The results of this trial regarding the main traits analysed (those already
described and some others) are presented in Table 4.2.
Table 4.2 Genetic variation of four environmentally contrasting Argentinean Nothofagus obliqua
populations in quantitative traits measured in a progeny trial installed in Bariloche (see
description above)
Trait
Mean
Mean h
2
CV A
Q ST
Shoot height 1st year [cm]
61.0
0.22
8.96
Shoot height 2nd year [cm]
97.1
0.25
14.03
–
Collar diameter 1st y. [mm]
8.1
0.07
5.16
–
Collar diameter 2nd y. [mm]
14.1
0.03
2.68
–
Height growth initiation 2nd y. [DOY]
332
0.02
3.47
0.11
Height growth cessation 2nd y. [DOY]
388
0.06
4.13
0.47
Branching index
4.5
0.09
19.62
–
Specific area of preformed leaves [cm
2 /g]
128.3
0.12
11.17
0.05
Marcescent leaves 2nd year [%]
37.2
0.52
6.49
0.18
Bud burst [DOY]
257.6
0.33
1.13
0.09
Bud set [DOY]
446.4
0.07
6.84
0.67
Vegetative period [days]
188.9
0.27
1.84
0.38
Mean value, mean narrow sense heritability, additive genetic variation coefficient and quantitative
differentiation (from Barbero 2014)
M. M. Azpilicueta et al.
4.3.3 Phenological Characters
Bud burst and bud set phenologies were evaluated during the second growing season in the last mentioned trial representing 40 open-pollinated families from
four environmentally contrasting natural populations of Argentina (Barbero 2014).
The phenophase of the terminal bud of each sapling was registered every other day,
according to a scale of five categories (similar to that presented in Chap. 3 for
N. alpina), from September 4 to October 28 (bud burst) and from March 14 to April
1 (bud set).
On average for the entire trial, buds were open (phenophase 3) in the 258 DOY
(September 15) and closed in the 446 DOY (March 21). Both factors, population
and family, were significant for bud burst, but only population had a significant
effect on bud set. Similarly to growth initiation and finalization, Epulauquen was the
most different population for these traits (it was, on average the last in bud bursting
and the first in bud closing), and differentiation among populations was estimated as
low for bud burst (Q ST = 9%) but high for bud set (Q ST = 67%). Intrapopulation
variation presented the opposite pattern, that is, higher variation for bud burst
(h
2
= 0.33) than for bud set (h
2
= 0.07). Mean bud and growth phenologies measured
in Epulauquen population were consistent with its mean growth, since it was the
population with the shortest vegetative period and the lowest height reached at the
end of the first growing season, as observed in other studies (Azpilicueta et al.
2014). The results of this trial regarding the main traits analysed (those already
described and some others) are presented in Table 4.2.
Table 4.2 Genetic variation of four environmentally contrasting Argentinean Nothofagus obliqua
populations in quantitative traits measured in a progeny trial installed in Bariloche (see
description above)
Trait
Mean
Mean h
2
CV A
Q ST
Shoot height 1st year [cm]
61.0
0.22
8.96
Shoot height 2nd year [cm]
97.1
0.25
14.03
–
Collar diameter 1st y. [mm]
8.1
0.07
5.16
–
Collar diameter 2nd y. [mm]
14.1
0.03
2.68
–
Height growth initiation 2nd y. [DOY]
332
0.02
3.47
0.11
Height growth cessation 2nd y. [DOY]
388
0.06
4.13
0.47
Branching index
4.5
0.09
19.62
–
Specific area of preformed leaves [cm
2 /g]
128.3
0.12
11.17
0.05
Marcescent leaves 2nd year [%]
37.2
0.52
6.49
0.18
Bud burst [DOY]
257.6
0.33
1.13
0.09
Bud set [DOY]
446.4
0.07
6.84
0.67
Vegetative period [days]
188.9
0.27
1.84
0.38
Mean value, mean narrow sense heritability, additive genetic variation coefficient and quantitative
differentiation (from Barbero 2014)
M. M. Azpilicueta et al.