Abstract:

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.

Key words: Phyllostachys violascens 'Prevernalis', mulching cultivation, sheath leaf, carbon and nitrogen metabolism, taste quality of bamboo shoots