福建柏低温胁迫下一些生理指标的变化

Variations of some physiological indices of Fukiencypress under the low-temperature stressed treatment

对不同种源 (福建仙游、南靖、德化 )的福建柏〔Fokieniahodginsii (Dunn)HenryetThomas〕 1～ 2年生苗进行- 8℃及 - 15℃低温胁迫处理 ,结果表明 ,处理 2 4h ,叶片内叶绿素和脯氨酸的含量比对照 (自然低温 - 4℃ )都有所升高 ,而根活力指标均有所降低。且种源间差异明显 ,仙游和南靖种源叶绿素和脯氨酸含量的增加率均大于德化种源 ;根活力指标的降低率为仙游 <南靖 <德化。仙游种源 2年生苗低温处理 2 4h ,叶绿素和脯氨酸含量均升高 ,但处理 48和 72h时叶绿素含量明显下降 ;脯氨酸含量在处理 72h时明显升高。田间同步观测表明 ,在 - 4℃ 2 4h自然低温条件下 ,2年生苗仅出现少量侧枝顶端鳞叶轻微受冻 ;经 - 8℃持续 48h自然低温 ,则出现中度 (Ⅱ级 )冻害(多数苗木未见顶梢受冻 ) ;而经 - 8℃处理 72h以及 - 15℃处理 48h和 72h的苗木绝大多数冻死。上述生理指标的变化 ,可为评估耐寒种源及北移引种提供依据。

The result on the low\|temperature stressed treatment (-8℃, -15℃) to the 1\|2 a seedlings of Fukiencypress 〔\%Fokienia hodginsii \%(Dunn) Henry et Thomas〕from different provenance (Xianyou, Nanjing, Dehua in Fujian Province) demonstrates that, when treating for 24 hours, the contents of chlorophyll and proline in leaves increased in comparison with the control of natural low temperature at -4℃ with the root vitality decreasing. Moreover, the differences among provenances were quite marked. The increase rates in chlorophyll and proline were that the provenances of Xianyou and Nanjing were higher than that of Dehua while the decrease rates in root vitality were Xianyou<Nanjing<Dehua. The contents of chlorophyll and proline in leaves of 2\|year\|old seedlings from Xianyou all increased during 24 hours; with markedly dropping in chlorophyll during 48 and 72 hours and markedly increasing in proline during 72 hours. The synchronous observations in fields showed that, under the conditions of natural low temperature of -4℃ for 24 hours, only slight freeze injury was observed in phyllades at the top of some branches in 2\|year\|old seedings, under -8℃ for 48 hours the medium degree of freeze injury (Grade Ⅱ) was occurred (freeze injury of the tips of branch was not observed for majority of the seedlings); while the great majority of seedlings were freezed to death under -8℃ for 72 hours and -15℃ for 48 and 72 hours. With use of the above\|mentioned variations of physiological indices, it is possible to seek the means for evaluating the origin of freeze\|resist provenances and provide the scientific basis for introducing the species northwords.