- P is the significance level of the factor (n.s.: not significant; *<0·05; **<0·01; ***<0·001). % is the percentage of variability explained by the factor. Factors that have not been considered in the model are represented with a dash (–).
- a roentgen: resistant; S: prone.
- b Amount of inoculated seedlings.
- c Imply wilting commission ± SE.
- d Letters label homogeneous communities of the Fisher’s LSD take to (P = 0·05).
Hydraulic conductivity and susceptability to help you cavitation
Vulnerability to cavitation (Pfifty and P80), Kxmaximum and absolute conductivity (Kx) did not differ significantly among the types of crosses (Fig. 1; Table 3). Loss of conductivity began at ?0·3 MPa and progressed at a similar rate in all crosses, i.e. there were no differences in the slope of VCs (P = 0·87; Table 3).
- a WP 20 d.a.i., wilting percentage 20 days after inoculation; VC slope, ‘a’ parameter of the exponential sigmoid: PLC = 100/(1 + exp[a(??b)]); P50, applied pressure at which the sample loses 50% hydraulic conductance; P80, applied pressure at which the sample loses 80% hydraulic conductance; Kxmax, maximum xylem specific conductivity; VLmax, maximum vessel length; bVL, vessel length distribution parameter; WD, wood density; VD, vessel diameter; VTA, vessel transectional area; THC, relative theoretical hydraulic conductance; VF, vessel frequency; (t/b) 2 , resistance to implosion; PGV, percentage of grouped vessels; VPG, vessels per group; VGA, vessel groups per area; CLVF, contribution of large vessels (VD >70 ?m) to flow; CMVF, contribution of medium vessels (40 < VD < 70 ?m) to flow; CSVF, contribution of small vessels (VD <40 ?m) to flow.
- b Roentgen: unwilling, S: susceptible. Suggest value ± SE. Letters title homogeneous organizations in this a varying (P = 0·05, Fisher’s LSD strategy).
- cP-value in the anova.
- *log-transformed to meet up with anova standards; **inverse-turned in order to satisfy anova requirements.
Despite P80 and Kxmax not differing between crossing types, these variables were positively correlated with WP 20 d.a.i. for the 24 selected trees (P < 0·05; Table S1). Nevertheless, the coefficient of correlation was low in both cases (R 2 < 0·20).
Anatomical keeps
Maximum vessel length (VLmax) ranged from 69 to 118 mm. S ? S trees had 30–40% significantly longer conduits and a higher percentage of longer vessels (Fig. 2a; Table 3). There was a negative correlation between Kxmax (log-transformed) and bVL (R 2 = 34·5, P = 0·0026; Table S1): plants with shorter vessels had lower conductivity.
S ? S progeny showed the widest vessels (VD; Table 3), and were unique in having vessel diameters greater than 90 ?m (Fig. 2b). The progeny of the S ? S cross also had larger VTA, and a THC twice as high as the other two groups (Table 3). CLVF, CMVF and CSVF did not differ among crossing types (P > 0·05, Table 3). As expected, Kxmax (log-transformed) was positively correlated with THC (R 2 = 32·6, P = 0·0035; Table S1) and VD (R 2 = 28·8, P = 0·0068; Table S1). In addition, R ? R individuals showed a significantly higher VF (c. 20%) and a greater (t/b) 2 (P < 0·05; Table 3). Meanwhile, S ? S saplings had significantly higher PGV (Table 3). There were no differences in WD, VPG or VGA between the groups (P > 0·05; Table 3).
Both ?pd and ?md progressively decreased after DED inoculation (Fig. 3a). Seventeen d.a.i., ?pd had dropped more than 0·25 MPa and 47 d.a.i. c. 1 MPa, independent of the type of crossing (Fig. 3a). ?md dropped from ?1 MPa to almost ?3 MPa in S ? S progeny at the end of the experiment. From the thirteenth d.a.i., ?md of R ? R cross progeny was significantly different from S ? S cross progeny.