Table 1.

The influence of salt (NaCl) and freezing on chlorophyll fluorescence of excised leaves of six Crataegus genotypes.

Genotype	Fo	Fm	Fo/Fm	Fv/Fo	Fv/Fm	PIp
C. × grignonensis (n = 4)
Control	46.8	235.4	0.244	3.27	0.756	12.85
2%	45.8^{^ns}	224.2^{^ns}	0.255^{^ns}	3.13^{^ns}	0.745^{^ns}	11.61^{^ns}
6%	52.5^*	207.3^*	0.316^*	2.63^*	0.684^*	8.86^*
9%	52.3^*	202.4^*	0.320^*	2.47^*	0.680^*	7.57^*
6% + −7°C	40.37^*	149.0^*	0.323^*	2.37^*	0.678^*	9.14^*
−1°C	44.8^{^ns}	230.5^{^ns}	0.227^{^ns}	3.50^{^ns}	0.773^{^ns}	21.13^*
−3°C	45.1^{^ns}	280.5^*	0.194^*	4.18^*	0.806^*	23.71^*
−7°C	43.6^{^ns}	67.9^*	0.661^*	0.54^*	0.339^*	0.68^*
−7°C + 6%	37.03^*	139.1^*	0.324^*	2.34^*	0.676^*	7.96^*
C. laevigata ‘Pauls Scarlet’ (n = 4)
Control	44.9	215.5	0.249	3.13	0.751	14.32
2%	47.9^{^ns}	206.1^{^ns}	0.271^{^ns}	2.88^{^ns}	0.729^{^ns}	12.68^{^ns}
6%	42.3^{^ns}	204.8^{^ns}	0.250^{^ns}	3.11^{^ns}	0.750^{^ns}	13.65^{^ns}
9%	47.2^{^ns}	202.5^{^ns}	0.273^{^ns}	2.91^{^ns}	0.727^{^ns}	13.98^{^ns}
6% + −7°C	32.9^*	102.5^*	0.394^*	1.81^*	0.606^*	4.54^*
−1°C	45.0^{^ns}	263.9^*	0.203^*	3.94^*	0.797^*	25.45^*
−3°C	41.8^*	264.8^*	0.190^*	4.30^*	0.810^*	29.78^*
−7°C	32.8^*	91.9^*	0.434^*	1.50^*	0.566^*	3.14^*
−7°C + 6%	40.7^*	112.2^*	0.425^*	1.59^*	0.575^*	4.27^*
C. maximowiczii (n = 3)
Control	47.0	314.8	0.191	4.31	0.809	23.86
2%	42.7^*	217.9^*	0.312^*	3.09^*	0.688^*	14.91^*
6%	39.9^*	195.9^*	0.329^*	2.75^*	0.671^*	9.58^*
9%	31.3^*	125.8^*	0.460^*	1.84^*	0.540^*	5.35^*
6% + −7°C	30.7^*	97.9^*	0.469^*	1.72^*	0.531^*	7.50^*
−1°C	44.2^{^ns}	315.8^{^ns}	0.183^{^ns}	4.50^{^ns}	0.817^{^ns}	27.46^{^ns}
−3°C	43.7^*	359.9^*	0.190^{^ns}	4.04^*	0.798^{^ns}	27.89^{^ns}
−7°C	40.7^*	253.3^*	0.209^{^ns}	3.97^*	0.791^{^ns}	18.44^*
−7°C + 6%	36.8^*	182.9^*	0.264^*	3.26^*	0.736^*	19.70^*
C. monogyna (n = 12)
Control	49.2	229.2	0.234	3.31	0.766	14.59
2%	51.1^{^ns}	215.5^*	0.291^{^ns}	2.87^*	0.709^{^ns}	12.60^{^ns}
6%	50.7^*	210.4^*	0.292^{^ns}	2.67^*	0.708^{^ns}	9.99^*
9%	60.4^*	144.9^*	0.460^*	1.52^*	0.540^*	4.75^*
6% + −7°C	39.9^*	137.4^*	0.342^*	2.19^*	0.658^*	7.45^*
−1°C	41.9^*	218.8^*	0.229^{^ns}	3.43^{^ns}	0.772^{^ns}	17.44^{^ns}
−3°C	41.3^*	233.6^{^ns}	0.212^*	3.80^*	0.787^*	21.12^*
−7°C	29.0^*	93.0^*	0.363^*	1.84^*	0.637^*	3.76^*
−7°C + 6%	53.1^*	117.6^*	0.512^*	1.23^*	0.488^*	2.63^*
C. oxyacantha (n = 5)
Control	47.9	300.2	0.194	4.17	0.806	25.45
2%	42.6^*	215.6^*	0.242^*	3.41^*	0.758^*	20.15^*
6%	44.1^{^ns}	231.8^*	0.231^*	3.57^*	0.769^*	21.94^*
9%	46.5^{^ns}	195.5^*	0.293^*	2.83^*	0.707^*	12.65^*
6% +−7°C	38.1^*	110.5^*	0.397^*	1.65^*	0.603^*	2.45^*
−1°C	40.1^*	239.3^*	0.208^{^ns}	3.91^{^ns}	0.792^{^ns}	19.54^*
−3°C	39.7^*	264.4^*	0.187^*	4.39^*	0.813^{^ns}	25.75^{^ns}
−7°C	35.6^*	110.9^*	0.382^*	1.74^*	0.618^*	3.18^*
−7°C + 6%	46.5^{^ns}	136.2^*	0.406^*	1.76^*	0.594^*	5.54^*
C. prunifolia (n = 6)
Control	49.9	239.2	0.268	2.89	0.722	7.80
2%	48.6^{^ns}	210.5^*	0.288^{^ns}	2.64^{^ns}	0.712^{^ns}	7.05^{^ns}
6%	51.2^{^ns}	203.8^*	0.312^{^ns}	2.42^*	0.688^*	5.61^*
9%	59.3^*	197.9^*	0.367^*	1.99^*	0.633^*	3.62^*
6% + −7°C	50.4^{^ns}	78.0^*	0.671^*	0.55^*	0.330^*	3.26^*
−1°C	53.6^{^ns}	247.6^{^ns}	0.283^{^ns}	2.74^{^ns}	0.723^{^ns}	9.08^{^ns}
−3°C	53.0^{^ns}	263.2^*	0.274^{^ns}	3.19^{^ns}	0.746^{^ns}	10.11^*
−7°C	54.9^{^ns}	88.3^*	0.654^*	0.54^*	0.346^*	0.27^*
−7°C + 6%	49.2^{^ns}	78.1^*	0.668^*	0.54^*	0.332^*	0.65^*

All values mean of n trees, 30 leaves per tree.
Species = *, Freezing = *, Salt = *, Species × Freezing × Salt = *
↵ns = not significant,
↵* = P = 0.05.