Micropropagation of Physalis angulata L. and P. chenopodifolia Lam. (Solanaceae) via indirect organogenesis

The husk tomato ( Physalis spp.) is an exceptional commercial crop for its nutritional and medicinal properties where the whole plant is used. This has led to the search for new micropropagation methods to accelerate plant production in the field. P. angulata and P. chenopodifolia were micropropagated via shoot proliferation of axillary buds and indirect organogenesis. Shoot multiplication was performed on Murashige and Skoog (MS) basal medium supplemented with 2.22, 4.43, or 6.65 μM 6-Benzylaminopurine (BAP) combined with 2.32, 4.64, or 6.96 μM Kinetin (Kin). For P. chenopodifolia , the largest number of new shoots was obtained by adding 4.64 μM Kin (10.47 ± 2.25 shoots per explant); for P. angulata , the best treatment was obtained with a combination of 4.43 μM BAP and 2.32 μM Kin (8.47 ± 2.91 shoots per explant). Indirect organogenesis was performed by placing leaf sections of both Physalis species on MS medium supplemented with 2.22, 4.43, 6.65, or 8.87 BAP combined with 1.13, 2.26, or 3.39 μM 2,4-dichlorophenoxyacetic acid (2,4-D). P. chenopodifolia showed the highest number of new indirect shoots (37.14 ± 3.54) with the addition of 1.13 μM 2,4-D and 6.65 μM BAP; P. angulata had the highest result (22.71 ± 2.5 shoots per explant) with 1.13 μM 2,4-D and 4.43 μM BAP. Stimulation of root induction was obtained in different mediums with auxins 1.07, 2.68, 5.37, or 8.05 μM 1-Naphthaleneacetic acid (NAA) and 1.41, 2.85, 5.70, or 8.55 μM Indoleacetic acid (IAA). The regenerated plantlets resulting from the rooting process were acclimatized and transferred to the greenhouse. The average of shoots per explant in the indirect organogenesis method was higher than the axillary bud culture method. These results could provide an efficient alternative for the micropropagation and conservation of these species with high commercial potential.