硅对遮荫处理草坪草可溶性糖和氨基酸含量的影响

Influences of Silicon on Content of Soluble Sugars,Amino Acids in Turf-grasses under Shading Stress

采用基质培养法,设自然光照条件下不遮荫和遮荫2个处理,每处理设不施硅和施硅2个硅水平,测定草坪草矮脚虎和海滨雀稗可溶性糖、游离氨基酸和脯氨酸含量,研究施硅对草坪草耐荫性的影响。结果显示:遮荫处理后,矮脚虎和海滨雀稗可溶性总糖、蔗糖和还原糖含量显著下降,游离氨基酸总量显著升高。施硅后,遮荫处理与不遮荫处理的矮脚虎和海滨雀稗可溶性总糖、蔗糖及游离氨基酸总量差异减少。施硅显著提高脯氨酸含量,遮荫处理对脯氨酸影响较小。海滨雀稗可溶性总糖、蔗糖、游离氨基酸和脯氨酸含量低于矮脚虎,施硅和遮荫处理对海滨雀稗影响大于矮脚虎。结果表明:遮荫处理后草坪草非结构性碳水化合物含量下降,而施硅后硅的沉积,促进了草坪草对有限光能的利用,缓解了草坪草非结构性碳水化合物含量的下降,而提高了草坪草的耐荫性。矮脚虎耐荫性高于海滨雀稗。

Soluble sugars,free amino acids and proline were determined in tifdwarf（Cynodon dacytlon × C.transvaanesis）and seashore paspulum（Paspulum vaginatum Swarfz）under Si addition and shading treatments in media culture to study the influences of Si on the shading tolerances of turfgrasses.The results showed that content of total soluble sugars,sucrose and reductive sugars were significantly（P〈0.05） decreased,while free amino acids were significantly（P〈0.05） increased after shading treatment in tifdwarf and seashore paspulum.The differences between CK and shading decreased after Si application.Content of proline was significantly（P〈0.05） increased by Si application but decreased less by shading.The content of total soluble sugars,sucrose,free amino acids and proline were significantly（P〈0.05） higher in tifdwarf than that in seashore paspulum.Less effect was observed in tifdwarf than that in seashore paspulum after Si addition and shading treatments.These results indicated that the non-structural carbohydrates dropped under shading stress which was restored by the higher energy utility induced by Si deposition,thus Si enhanced the shading tolerance of turfgrass.The results also showed that the shading tolerance of tifdwarf was higher than that of seashore paspulum.