| Cunninghamia lanceolata is a rare quality wood in China.The current research on Cunninghamia lanceolata mainly concentrated in the wood,and the research on plant tissue culture about it is relatively less.There are still some problems in rooting on its tissue culture,such as low rooting rate,slow growth,poor quality of root,has hindered the nurserying and commercial operation.As a new light,the light emitting diode(LED),has been successfully applied to the fields such artificial light,plant breeding,plant and space agriculture,which has a good application prospect in plant tissue culture.At present,the study on the rooting of tissue culture seedling of Cunninghamia lanceolata is mainly focused on the adjustment of basic culture medium and growth regulator,the application of a new type of composite LED can provide a new way to solve this problem.The twelfth generation tissue culture bottle of the same clone of Cunninghamia lanceolata was used,in order to screen the best rooting LED photoperiod and light quality and discusses the relationship between the rooting and physiological and biochemical indexes,the two factor randomized block design was used for exploring the effect of Cunninghamia lanceolata seedling rooting under different LED photoperiod and light quality.In this experiment,three LED photoperiods were set up,there were 8 h/d,16 h/d and 24 h/d;In each LED photoperiod,there were three light qualitys and white as the control,the three light qualitys were red/blue 8:1,red/blue/purple 8:1:1 and red/blue/purple/green 8:1:1:1.The data were analyzed by Excel and SPSS software.The results show that:1.The LED photoperiod 16 h/d was good for plant height,dry matter weight,rooting rate,root length,root surface area,root volume and rooting index increased.The average number of roots was maximum at photoperiod 24 h/d.The results showed that red/blue 8:1,red/blue/purple 8:1:1,red/blue/purple/green 8:1:1:1 LEDs could promote growth and rooting of tissue culture seedlings,however,the best treatment was red/blue/purple/green 8:1:1:1 LEDs.2.The order of root activity of the seedlings was photoperiod 16 h/d,photoperiod 24 h/d and photoperiod 8 h/d.Under photoperiod 16 h/d,the root activity was maximum at red/blue 8:1 LEDs,it was 140.53 ng/(g·h).3.Under the photoperiod 8 h/d and photoperiod 16 h/d,the red/blue/purple/green 8:1:1:1 LEDs was beneficial to the improvement of chlorophyll a,chlorophyll b,chlorophyll a/b,chlorophyll,carotenoid,Fv/Fo,Y(II),qP and ETR.Under the photoperiod 24 h/d,the synthesis of chlorophyll and carotenoid were better at red/blue 8:1 LEDs,and the Y(II)and ETR were the highest in red/blue/purple/green 8:1:1:1 LEDs,there were 0.07 and 7.31,respectively.There was no significant difference in NPQ/4 between different photoperiod at the same light quality.4.Under photoperiod 8 h/d,the accumulation of soluble sugar and soluble protein were inhibited,and the photoperiod 16 h/d and 24 h/d had a positive effect on the accumulation of soluble sugar and soluble protein.The concent of free proline increased in red/blue/purple 8:1:1 LEDs and red/blue/purple/green 8:1:1:1 LEDs under the photoperiod 16 h/d.5.The light photoperiod of 8 h/d was beneficial to the increase of ZR content,but not conducive to the increase of GA3 content.The content of IAA and the ratio of IAA/GA3,IAA/ZR and IAA/ABA were highest at photoperiod 16 h/d.Under the red/blue/purple/green 8:1:1:1 LEDs,the endogenous hormones increased,and the content of IAA is highest at photoperiod 16 h/d.6.The content of MDA and the activity of PPO and GR increased under photoperiod 8 h/d,the activity of SOD,POD and CAT increased under photoperiod 16 h/d,and the activity of APX was maximum at photoperiod 24 h/d.Under the red/blue/purple/green 8:1:1:1 LEDs,the activity of SOD,POD and CAT were highest.7.The photoperiod 8 h/d was beneficial to the increase of phosphorus,potassium and magnesium,and the photoperiod 16 h/d was beneficial to the increase of nitrogen,calcium and iron.The iron content was significantly lower than the control under the red/blue/purple/green 8:1:1:1 LEDs.8.The different photoperiod,light quality and their interaction had significantly influence on the morphological and physiological and biochemical indexes except for the root activity and NPQ/4.There were significant correlation between rooting and chlorophyll a/b,ETR,free proline content,soluble protein content and IAA/ABA;and there was a significant negative correlation between MDA content and rooting.According to the principal component analysis,the photoperiod 16 h/d and red/blue/purple/green 8:1:1:1 LEDs was suitable for Cunminghamia lanceolata seedlings rooting,under this treatment,the rooting rate(95.85%),root length(5.95 cm),root surface area(1.92 cm2),rooting index(24.46),qP(0.14),the content of IAA(74.64 ng/g),IAA/GA3(12.77),IAA/ZR(11.41),IAA/ABA(1.82),SOD activity(352.67 U/g),POD activity(771.20 U/(min·g)),CAT activity(102.20 U/(min·g))and calcium content(2.33 mg/g)were the highest,at the same time,other indicators also have good performance. |
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