黄土高原不同地区杜松的种子萌发特性及其与生态因子的相关性

选取黄土高原5个地区杜松(Juniperus rigida)种子,采用种子萌发实验及相关分析的方法,研究其大小特征、萌发特性及其与生态因子的相关性,以了解不同地区杜松的种子萌发特性。结果表明,不同地区杜松的种子大小差异显著,府谷地区的种子最大、最重,平均长6.83 mm,宽3.56 mm,千粒重为25.89 g;种子长及种子长宽比随纬度的升高、土壤全磷含量的增加而变小;种子千粒重随1月和7月均温的增加而增加,随土壤有机质、速效磷、全氮含量的增加而减少。种子大小对萌发特征影响显著,种子萌发率、萌发势及发芽指数均随种子长、种子长宽比的增加呈减小的趋势。不同地区杜松的萌发差异显著,武川的种子萌发最快最高,府谷与贺兰山最慢、最低;萌发率、萌发势及发芽指数均随纬度的升高而增加,萌发势和发芽指数随土壤全磷含量的增加而增加。研究认为武川及浑源地区是杜松优良的选种地。

Seed germination performance of Juniperus rigida in different regions of the Loess Plateau and its relation with ecological factors

In the present study, the biological characteristics of seed germination were investigated for five typical populations of Juniperus rigida growing in different regions of the Loess Plateau, and their relation with climatic and soil factors were studied. The results showed significant difference in seed size among the five regions, with Wuchuan being the smallest with respect to seed length (6.83 mm), width (3.56 mm), and seed weight (25.89 g). Seed length and ratio of length/width decreased as latitude and soil total phosphorus content increased. Seed weight increased with increased mean temperature in January and July, but decreased with increased organic matter, available phosphorus and total nitrogen of soil. There was a significantly negative correlation between germination and seed size. Seed germination differed among regions, with Wuchuan region being the fastest and highest whereas Fugu the slowest and lowest. Germination rate, germination energy and germination index increased with latitude. Additionally, Wuchuan and Hunyuan are suitable for growing Juniperus rigida.