Abstract:

Efficient somatic embryogenesis and plant regeneration in embryonic leaflet culture of peanut (Arachis hypogaea L.) were studied, for providing the methods of somatic hybridization, In vitro mutagenesis and genetic transformation. The embryonic leaflets of 17 peanut cultivars in 5 types were cultured on MSB5 medium (Murashige and Skoog salts plus B5 vitamins) supplemented with 10.0 mg/L 2,4-D to induce somatic embryos. After 4 weeks culture, the explants with somatic embryos were transferred to the medium supplemented with 4 mg/L BAP for somatic embryo germination and plant regeneration. The result showed that the frequencies of somatic embryo induction and plant regeneration were different significantly in 5 peanut types. Intermediate type gave a higher frequency (84.1%-91.2%) of somatic embryo induction and a higher frequency (81.1%-97.0%) of plant regeneration. The frequencies of somatic embryo induction were significantly different among the cultivars in Arachis hypogaea var. vulgaris with a range from 43.9% to 85.0% and Arachis hypogaea var. hypogaea with a range from 42.2%-82.2%, respectively, but the higher frequencies of plant regeneration were obtained in them, sharing a range from 94.3%-96.5% and 88.1%-98.7%, respectively. Arachis hypogaea var. fastigiata showed the lowest frequencies of somatic embryo induction (32.2%-50.0%) and plant regeneration (41.2%-55.1%). The frequencies of somatic embryo induction (61.1%-87.8%) and plant regeneration (63.7%-87.6%) were obtained in Arachis hypogaea var. hirsute. When the plantlets were grafted onto germinated seedlings and transplanted to the field, they grew to maturity and produced viable seeds. The result showed that the regeneration capacity was different among various types of peanut, and the regeneration capacity of Arachis hypogaea var. fastigiata was the lowest.