光照处理下氮素对笋期麻竹笋芽萌发的调控

[Objective]Light intensity and nitrogen concentration were the key factors affecting the germination of shoot buds and the growth and development rate of Dendrocalamus latiflorus.In the growth process of Dendrocalamus latiflorus,only by maintaining the balance of light and nitrogen and coordinating the supply,can the best interaction be exerted on the growth of Dendrocalamus latiflorus.Because there are few studies on the effects of light and nitrogen on the development of lateral buds of different plants,it is of great significance to carry out this study to guide rational fertilization and improve fertilizer use efficiency in field production,and to alleviate the effects of low light stress on lateral bud development through nitrogen fertilizer application.In this study,by analyzing the absorption and utilization of nitrogen by Dendrocalamus latiflorus in shade environment,the effects of light and nitrogen coupling on the germination of shoot buds of Dendrocalamus latiflorus at shoot stage were explored.It can further provide a theoretical basis for the coupling of light intensity and nitrogen to regulate the germination of shoot buds of Dendrocalamus latiflorus,and also provide a scientific basis for the adjustment of stand density and efficient management of nutrients during the cultivation of Dendrocalamus latiflorus shoots.[Method]By setting low,medium and high nitrogen supply(1.5,4.5 and 7.5 g·cluster⁻¹)conditions,the germination status and physiological and biochemical characteristics of Dendrocalamus latiflorus shoots under different gradients of light(10％,40％and 100％light intensity)were studied.Two-way analysis of variance was used to analyze the absorption and utilization of nitrogen in Dendrocalamus latiflorus under shading environment,and to explore the effect of nitrogen fertilizer level on the germination ability of Dendrocalamus latiflorus under different light intensities.[Result]The results showed that low nitrogen(1.5 g·clump-1)and medium nitrogen(4.5 g·clump-1)addition had no significant effect on the germination number of shoots at the early stage of shooting,but the highest value was at 40％light intensity.The number of shoots germinated under high nitrogen(7.5 g·clump-1)was higher under 10％light intensity than that under 100％light intensity,but significantly lower than that under 40％light intensity(P＜0.05).In the middle stage of shoot emergence,light nitrogen treatment had a significant effect on shoot germination(P＜0.05).The germination number of shoot buds under low nitrogen addition was higher than that under 100％light intensity after 10％light intensity.Under high nitrogen addition,the germination ability of shoot buds was the strongest under 40％light intensity,and the content of C,N and starch in leaves was positively correlated with the germination number of shoot buds.At the end of shooting,the number of bud germination decreased significantly with the decrease of light intensity(P＜0.05).Low and medium nitrogen addition,after 10％light intensity,stop shooting;under low,medium and high nitrogen addition,the number of shoot bud germination under 40％and 100％light intensity was positively correlated with Pn,stomatal conductance(gs),transpiration rate(Tr),sucrose,soluble sugar,starch,leaf ammonium nitrogen and nitrate nitrogen.[Conclusion]The effect mechanism of nitrogen addition on the germination of bamboo shoots was different under different light intensity.There was a significant interaction between light intensity and leaf,soil carbon and nitrogen and nitrogen concentration.Nitrogen had a compensatory effect on the inhibition of shoot germination by low light at the early and middle stages of shoot emergence.At the end of shoot emergence,nitrogen could not compensate for the inhibitory effect of weak light on shoot germination..