稀土元素镧、铈对铁皮石斛组培苗生长影响的研究

Effects of rare-earth elements La,Ce on test-tube seedling growth of Dendrobium officinale Kimura et Migo

目的探讨添加稀土元素镧、铈对铁皮石斛组培苗以及移栽后铁皮石斛苗的生长的影响,寻找能显著促进铁皮石斛生长发育的稀土元素,以获得品质优良的铁皮石斛苗。方法以铁皮石斛小苗为外植体,通过添加不同浓度硝酸镧、硝酸铈的培养基上进行培养,并对其性状特征、生理活性、移栽后生长状况等进行统计比较研究。结果通过90 d的培养后,添加稀土元素组别的铁皮石斛的鲜质量、根数、株高、叶绿素含量均高于空白组,分蘖数低于空白组,而且随着硝酸镧和硝酸铈浓度的增高,铁皮石斛组培苗的鲜质量、株高、根数、叶绿素含量基本呈递增的趋势,分蘖数呈递减的趋势,硝酸铈浓度为40 mg/L时,其鲜质量、根数、株高最大,分蘖数最少;铁皮石斛移栽培养30 d后,稀土元素组比空白组中的存活率和抽芽率高,硝酸铈为40 mg/L时其生长情况最佳;一定浓度的稀土元素La、Ce能增强铁皮石斛组培苗的T-SOD酶、CAT酶活性和根系活力,添加10.0~40.0 mg/L La^(3+),SOD酶活性和CAT酶活性均呈现先增后降的趋势;添加10.0~40.0 mg/L Ce^(3+),SOD酶活性逐渐增强,但CAT酶活性在Ce^(3+)10~30.0 mg/L时逐渐增强,40.0 mg/L时又稍下降;添加10.0~40.0 mg/L La^(3+),根系活力呈先增后降的趋势,10~30.0mg/L时根系活力逐渐上升,40.0 mg/L时略有下降;添加10.0~40.0 mg/L Ce^(3+),根系活力逐渐上升,40.0mg/L时最高。结论稀土元素镧、铈对铁皮石斛组培苗的生长及T-SOD酶、CAT酶活性和根系活力均有较显著的影响,本文结果为铁皮石斛组培苗的壮苗以及品质的提高提供了依据。

Objective To investigate the effect of rare-earth elements of La and Ce on test-tube seedling and transplants growth of Dendrobium officinale Kimura et Migo（ Dendrobii officinalis caulis）. Methods The seedlings were tested as the explants and cultured with different concentrations of rare-earth elements Laand Ce. The characteristics,physiological activity,and growth status after transplantation were compared statistically. Results After 90 days of culturing,the fresh weight,root number,plant height content of the group adding rare-earth elements were higher than the blank group,and the tiller number was lower than the blank group. The fresh weight,root number,plant height,chlorophyll content increased with the concentration of lanthanum nitrate and cerium nitrate,but the tiller number decreased. When the concentration of cerium nitrate was 40 mg/L,the fresh weight,root number and plant height were the highest,and the tiller number was the least. After transplanting for 30 days,the survival and budding rate of the group adding rare-earth elements were superior to the blank group. Certain concentrations of La and Ce enhanced the activities of T-SOD enzyme,CAT enzyme and root activity of the plantlets. When the concentration of La^3＋ was among 10 - 40 mg/L,the activity of SOD and CAT showed a trend of first increasing and then falling. When the concentration of Ce^3＋ was among 10 - 40 mg/L,SOD enzyme activity increased gradually. The activity of CAT increased when the concentration of Ce^3＋ was among10 - 30.0 mg/L,and decreased slightly at 40 mg/L. When the concentration of La-（3＋）was 10 - 40 mg/L,the root activity first increased and then decreased,and the root activity increased gradually at La^3＋ 10 - 30. 0mg/L,but decreased slightly at 40 mg/L. When the concentration of Ce^3＋ was among 10 - 40 mg/L,the root activity increased gradually,and the highest activity was at 40 mg/L. Conclusion Remarkable changes could be observed on the growth and the T-SOD enzyme,CAT enzyme activity and root activity by adding rare-earth elements La and Ce. It provides a way and basis to improve the seedling growth and the quality of Dendrobii officinalis.