Induction of Haploid Embryos in Datura metel by Anther Culture.

Microspores, with a haploid number of chromosomes, are destined to produce the male gametophyte, which hosts the male gametes that fertilize the female egg cell. During microsporogenesis, a particular stage of development is amenable to be switched to undergo embryogenesis and developed into a haploid plant. By doubling the chromosomes, a doubled haploid plant, homozygous for all the gene loci, is produced. These plants are useful to study the expression of recessive genes and in plant breeding as a rapid pathway to achieve homozygosity.

[Plant regeneration and clonal propagation system of Datura metel].

OBJECTIVE: To study the condition of plant regeneration and clonal propagation system of Datura metel. METHODS: Stems and leaves of Datura metel were used as explants, effects of different hormones for callus induction and plant regeneration of leaves and clonal propagation system of stems were studied and optimized. RESULTS: The optimal way to obtain sterile explant for leaves were sterilized in 75% ethyl alcohol for 6 s then 0.1% HgCl2 for 6 min; Stems were sterilized in 75% ethyl alcohol for 8 s then 0.1% HgCl2 for 7 min. The optimal medium for callus of leaves was MS + 1.0 mg/L 6-BA + 0.1 mg/L NAA; The optimal medium for callus induction of clustered buds was MS + 2.0 mg/L 6-BA + 0.2 mg/L NAA; The optimal medium for clonal propagation system of stems was MS + 3.0 mg/L 6-BA + 0.05 mg/L NAA. The best medium for rooting induction was MS + 0.5 mg/L IBA. Transplant survival rate of plantlet was greater than 90% in humus soil-pearlite (5:1). CONCLUSION: The condition of plant regeneration and clonal propagation system of Datura metel is established.

[Scopolamine and hyoscyamine synthesis in hair roots culture of Datura metel].

OBJECTIVE: To establish the hair roots culture system of Datura metel and study the hair roots growth and biosynthesis of scopolamine and hyoscyamine in hair roots culturing system. METHOD: Direct degermed cotyledon of wild D. metel was infected by Agrobacterium tumefaciens strain C58C1 to obtain hair roots. Growth curves and scopolamine and hyoscyamine biosynthesis curves were determined. The scopolamine and hyoscyamine from different hair roots lines were examined by HPLC. RESULT: Hair roots induction rate reached 70%. After 25 days cultured in 1/2 MS liquid nutrient medium, the hair roots weight, content of scopolamine and hyoscyamine reached maximum, tow high efficient accumulation hyoscyamine and scopolamine hair roots lines M1 and M2 were obtained. The medial accumulation coefficient of hyoscyamine and scopolamine were 2.53 times and 5.37 times compared with the leaves of wild D. metel respectively. CONCLUSION: The established hair roots induction and culture system of D. metel provided a foundation for further obtaining scopolamine and hyoscyamine.