【摘要】 以祁连圆柏Sabina przewalskii和圆柏Sabina chinensis为材料,研究了圆柏属植物的抗冷冻性与针叶δ13C值季节变化的关系。结果表明,两种圆柏属植物的δ13C值均随温度的降低而减小并在整个冬季维持较低水平。表明圆柏属植物为了抵抗低温的伤害,加强了自身能量物质的消耗,即呼吸作用增强,导致植物体内的δ值偏向更负。在整个测定期中,祁连圆柏的δ13C值都显著高于圆柏的δ13C值,表明在低温胁迫过程中,圆柏为适应低温、提高其抗冷冻能力所消耗自身能量物质的量远高于祁连圆柏。这与祁连圆柏具有较强的抗冷冻适应性策略一致。此外,两种圆柏属植物碳同位素组成与月均温度表现出极显著的线性相关性,并且与脯氨酸(Pro)质量分数、针叶相对含水量(RWC)也都表现出极显著的线性相关性。因此,碳同位素组成可以作为鉴定圆柏属植物抗冷冻性的又一重要指标。更多还原

【Abstract】 Seasonal changes of δ13C values were examined in the needles of Sabina przewalskii and Sabina chinensis,aimed to probe into their relationships with freezing tolerance.The results showed that the δ13C values in needles of the two species declined with monthly average temperature decreasing and maintained a relatively lower value during the whole winter.It indicated that the two species consumed more self substances in order to adapt to low temperature.As a result,the δ13C values decreased.The δ13C values of S.przewalskii were significantly higher than those of S.chinensis,it suggested that S.chinensis must consume more self substances than S.przewalskii under low-temperature stress.S.przewalskii showed a more prevailing strategy than S.chinensis in order to develop the tolerance to freezing.Furthermore,strong significant linear relationships were observed between δ13C value and monthly average temperature,between δ13C value and Pro content,and between δ13C value and RWC in needles of S.przewalskii and S.chinensis.These results suggested that the δ13C values in the needles can be used as another index to evaluate freezing tolerance of Sabina.更多还原