覆盖雷竹笋箨叶碳氮代谢特征及其与竹笋食味品质的关系

Characteristics of Carbon and Nitrogen Metabolism in Sheath Leaves and Its Relationship with Taste Quality of Phyllostachys violascens‘Prevernalis’Shoots under Mulching

【目的】探究雷竹林地覆盖对竹笋箨叶碳氮代谢的影响,以及箨叶的变化是否会影响竹笋食味品质,以此揭示竹笋食味品质形成机制,为高品质竹笋培育提供参考。【方法】以立地条件一致的自然经营雷竹林和覆盖雷竹林为研究对象,对自然笋和覆盖笋箨叶养分含量、碳氮代谢酶活性和竹笋食味品质指标进行测定分析。【结果】1)雷竹覆盖笋箨叶可溶性糖、淀粉、非结构性碳水化合物(NSC)含量和蔗糖合成酶、谷氨酸合酶、硝酸还原酶、谷氨酰胺合成酶活性较自然笋均显著升高,而箨叶N含量则相反。2)覆盖雷竹笋可溶性糖含量、糖酸比和甜味氨基酸含量及其比例较自然笋均显著升高,而酸味、苦味、粗糙类及鲜味物质含量及比例降低。3)冗余分析结果显示,雷竹笋箨叶可溶性糖、淀粉、NSC含量以及蔗糖合成酶、硝酸还原酶、谷氨酸合酶、谷氨酰胺合成酶活性与竹笋甜味物质含量呈显著的正相关关系,与竹笋苦涩味、酸味和纤维类物质含量呈负相关关系,而箨叶N含量则相反。【结论】覆盖对雷竹笋箨叶碳氮代谢有重要影响,雷竹笋箨叶可以通过适应性调节来应对覆盖条件下的环境剧烈变化,从而改善竹笋食味品质。

【Objective】Phyllostachys violascens‘Prevernalis’is an elite bamboo shoot species.Woodland mulching cultivation can obviously change the environmental conditions,such as temperature,water and light in the growth area of whip system,promote bamboo shoot germination earlier,and significantly improve the economic benefits of bamboo forest.However,the changes of carbon and nitrogen metabolism characteristics of sheath leaves under mulching and their relationship with the taste quality of bamboo shoots are not clear.This study aims to explored whether the mulching cultivation cover of P.violascens‘Prevernalis’forest can significantly affect the carbon and nitrogen metabolism of sheath leaves and whether the changes can affect the taste quality of bamboo shoots,which is of great significance for revealing the formation mechanism of bamboo shoot quality,and provides a reference for the cultivation of high-quality bamboo shoots.【Method】This experiment was conducted in natural management and mulched bamboo forests with the same site conditions,and the nutrient content,carbon and nitrogen metabolic enzyme activity and taste quality index of natural and mulched bamboo shoots were measured and analyzed.【Result】1)Compared with the natural shoots,the contents of soluble sugar,starch,NSC and the activities of sucrose synthase,glutamate synthase,nitrate reductase and glutamine synthetase in sheath leaves of mulched bamboo shoots were significantly higher than those of natural shoots,however the N content was on the contrary.2)Compared with the natural shoots,the soluble sugar content,sugar-acid ratio,sweet amino acid content and proportion of mulched shoots significantly increased,while total acid,oxalic acid,cellulose,bitter amino acids,aromatic amino acids and fresh amino acids contents decreased significantly.3)Redundancy analysis showed that the contents of soluble sugar,starch,NSC and the activities of sucrose synthase,nitrate reductase,glutamate synthase,glutamine synthetase were significantly positively correlated with the sweet matter content of bamboo shoots,but negatively correlated with the bitter taste,sour taste and fiber content of bamboo shoots,while the N content of bamboo shoots was on the contrary.【Conclusion】Mulching has an important effect on the carbon and nitrogen metabolism of P.violascens‘Prevernalis’sheath leaves,which can cope with drastic changes in the environment under mulching conditions through obvious adaptive regulation,so as to improve the taste quality of bamboo shoots.