Abstract: The peroxide（H₂O₂ ）content and ascorbate（AsA）-glutathione（GSH）cycle in pistil of
two kernel apricot（Prunus armeniaca Linn.）cultivars under different low temperature（18，–1，–2，
–3，–4，–5，–6，–7 ℃）were studied using the artificial climate chamber. The results show that H₂O₂ contents in kernel apricot pistilincreased under the low temperature stress，at–7 ℃，the amount of
‘Weixuan 1’resistant to cold stress was 5.49 times more than control（18 ℃），the amount of
‘Longwangmao’ susceptible to cold stress was 7.22 times more than the control. The content of enzyme like AsA and so on and activity of enzyme like APX and so on in‘Weixuan 1’pistil were higher than those
in ‘Longwangmao’under low temperature，at–7 ℃，the contents of AsA，MDHA，DHA，GSH and
GSSG were decreased by 66%，69%，48%，52%，53% compared to the control（18 ℃）in‘Weixuan 1’
pistil，were decreased by 78%，79%，59%，66%，65% compared to control（18 ℃）in‘Longwangmao’
pistil. At–7 ℃，the activity of APX，MDHAR，DHAR，GPX，GR，GSH/GSSG were 2.87，1.07，
1.42，1.60，1.20，1.03 times more than control（18 ℃）respectively. AsA/DHA was 65% of the control
in‘Weixuan 1’pistil. The activity of APX，DHAR，GPX were 2.41，1.13，1.08 times more than control
（18 ℃）. MDHAR，GR，AsA/DHA，GSH/GSSG were 96%，98%，54%，97% of the control respectively
in‘Longwangmao’pistil. The results indicate that‘Weixuan 1’pistil could maintain efficient metabolism
of AsA-GSH cycle，inhibit the accumulation of H₂O₂  effectivity，this might be one of important reasons for
higher cold tolerance of‘Weixuan 1’.

Key words: kernel apricot, pistil, low temperature stress, AsA-GSH cycle