不同光源对柚木组培苗生长发育的影响

Effects of various LED lights on growth and development of Tectona grandis plantlets in vitro

关键词:  柚木组培苗,光照,生长,叶表面结构

Key words:  Tectona grandis plantlets, illumination, growth, leaf surface structure

摘要:

该研究采用不同光源处理柚木组培继代苗,通过测定株高、叶宽、叶鲜重、全株干重、叶绿素含量和观察叶片上下表皮结构,研究不同光源对柚木组培苗生长发育的影响,并筛选适宜其快速生长发育的光环境。结果表明:不同光照下顶芽培养的植株高生长顺序为H_FL﹥H_1RB﹥H_S﹥H_2RB﹥H_3RB﹥H_D,茎段培养的腋芽高生长顺序为h_FL﹥h_S﹥h_D﹥h_1RB﹥h_2RB﹥h_3RB。LED红蓝组合灯(2RB、3RB)处理下植株最大叶宽显著大于荧光灯(FL)、全光谱灯(S)和无补光设备(D)处理,并随RB光强增加,最大叶宽及叶鲜重显著增加。全株干重以D和S光照处理显著低于其它光照处理。RB系列和S光照处理下的叶绿素总含量高于对照FL和D处理组。2RB和3RB光照处理下叶片的上表皮细胞不规则多角形,相互镶嵌排列,其它光照处理下上表皮细胞呈圆形。下表皮气孔数量在有补光设备处理(S、RB、FL)时是无补光设备处理(D)的1.5倍以上,2RB和3RB光照处理下气孔张开度大于对照FL和D处理组,且保卫细胞呈井型突起。参试光源中,柚木组培苗增殖阶段选择荧光灯或全光谱灯为好,高生长显著,腋芽分化和生长快,有利于提高增殖率; 而RB红蓝组合灯(3RB、2RB)适合壮苗培养,叶大苗壮,全株生物量大,且叶表面结构发育成熟,有利于提高光合作用。

Abstract:

The development and application of light-emitting-diodes(LEDs)provide more light sources for plant tissue culture. In this study, the subculture plantlets of Tectona grandis were treated by different LEDs, then the growth index(plant height, leaf width, fresh leaf mass and whole-plant dry weight)and chlorophyll content were measured and the leaf surface structures were observed underelectron microscopy, in order to discover the effects of LED lights on the growth and development of plantlets and to find the optimal light environment for their rapid growth. The results showed that the plantlet height was H_FL﹥H_1RB﹥H_S﹥H_2RB﹥H_3RB﹥H_D and the axillary bud height was h_FL﹥h_s﹥h_d﹥h_1RB﹥h_2RB﹥h_3RB, under the following six different lights: fluorescent lamp(FL), three mixtures of R plus B LED(1RB, 2RB, 3RB), full spectrum light LED(S)and scattered light(D). The maximum leaf width was significantly larger in plantlets that were cultured under 2RB and 3RB than those under FL, S and D. Moreover, the maximum leaf width and fresh leaf mass increased significantly aslight intensity of RB increased. Undercondition D and S lights, the plant dry weights were significantly lighter than those under the other LEDs. Chlorophyll contents were greater in plantlets under RB and S than those under condition FL and condition D. The adaxial epidermal cells of plantlets under 2RB and 3RB were in the shape of irregular polygonand inlaid each other, while those under other conditions appeared in the shape of circles. The stomata amounts on the abaxial of plantlets under lights(FL, RB, S)were 1.5 times more than that under no lighting equipment(D). The stomatal pores of plantlets under 2RB and 3RB opened more widely than those under condition FL and D, the guard cells appeared as well-type protuberance. Overall, the fluorescent light and the full spectrum light LED were suitable for Tectona grandis multiplication culture according to significant height growth of plantlets and fast differentiation of axillary bud, and further contributed to increase the proliferation rate. On the other hand, mixtures of R plus B LED(3RB, 2RB)were beneficial in strong seedling culture with big leaf sizes, strong seedling, high biomass, fully-developed leaf epidermal structure, contributing to increase photosynthesis.