ABSTRACT
Objective: To establish the chemical mutagenesis in vitro system of Mentha haplocalyx,the effects of different plant hormone combination and Vc on the induction of mint stem adventitious buds and the mutation effects of different concentrations of NaN3 on their calli were studied. Methods: The internodes of mint used as the material,and based on the preliminary experiment, the effects of different concentrations of TDZ,6-BA,NAA and Vc on adventitious buds induction rate were researched. On the basis of screening the best induction formula, the Mentha haplocalyx calli were treated with different concentrations of NaN3ï¼ 0,2,4,6,8,10,12,14,16 mg/Lï¼. Results: The optimum medium for calli induction and adventitious buds formation was MS + 0. 1 mg / L TDZ + 0. 2 mg / L NAA + 1mg / L Vc + 30 g / L sucrose + 5. 5 g / L agar, the treatment concentration of NaN3 for LD50of calli induction was 14 mg / L for 10 d,or 12 mg / L for 20 d,or 10 mg / L for 30 d. Plantlet could differentiate from the calli treated with NaN3. By comparing to the regenerated plants,81 mutants had been selected. Conclusion: A chemical mutagenesis in vitro system for Mentha haplocalyx with NaN3 was preliminarily established.
Subject(s)
Mentha , Plant Growth Regulators , Plant Stems , Regeneration , Sodium Azide , Tissue Culture TechniquesABSTRACT
A pot experiment was conducted to investigate the effects of high temperature and humidity stress [(40 +/- 2) degrees C/(30 +/- 2) degrees C, RH (95 +/- 5)%/(70 +/- 5)%, 10 h/14 h (day/night)] at the physiological maturity stage of two spring soybean cultivars (Xiangdou No. 3 and Ningzhen No. 1) on seed vigor indices, main nutritional components and coat anatomical structure. High temperature and humidity stress were found to cause the decrease of seed viability, germination potential, and germination percentage as well as the dehydrogenase and acid phosphatase activities, but increased the seed cell membrane permeability as well as H+, soluble sugar and leucine levels in the seed soaking liquid of each cultivar. Moreover, the stress led to irregular changes of seed oil and protein contents and alteration of anatomical structure of episperm and hilum in the two cultivars. A shortterm stress (less than 5 h) had no significant impact on seed vigor, but a long-term one (more than 48 h) caused rapid decrease of seed vigor indices. Xiangdou No. 3 showed less decreases in seed germination potential and enzyme activities, and less increase in extravasation content in the seed soaking liquid, had compact seed coat and intact hilum, suggesting it was more resistant to high temperature and humidity stress.
