Callus induction in papaya (Carica papaya L.) and synseed production for low temperature storage and cryopreservation

Abstract

The mid-to long-term preservation of papaya (Carica papaya L.) would allow for the safeguarding of important germplasm. In this study, soft friable callus (SFC) and hard callus (HC) were induced from the first two true leaves of 10-day-old seedlings containing a midrib derived from the germinated seed of two cultivars ('Rainbow' and 'Sunrise Solo'). Following germination on a Murashige and Skoog (MS) medium that contained 3% sucrose and was free of plant growth regulators (PGRs), sections of the first true leaves from 10-day-old seedlings were exposed to seven published callus or somatic embryogenesis protocols for zygotic embryos, leaves or hypocotyls. Optimal SFC and HC induction was carried out on a half-strength MS medium following the Fitch (1993) or the Ascêncio-Cabral et al. (2008) protocol, respectively. SFC formed shoots that could then convert to plants when transferred to a full-strength MS medium devoid of PGRs. Plantlets 10-cm tall were acclimatised in two steps: first by in vitro acclimatisation in aerated vessels, the Vitron, under CO 2 -enriched (3000 ppm CO 2 ), then by the transfer of individually rooted plantlets in Rockwool ® blocks to a substrate of soil: pine bark : perlite (1:1:1, v/v/v). SFC and HC were then encapsulated in alginate beads, which were exposed to low temperature storage (LTS) at 10°C and 15°C, and also cryopreserved for 30 days. All encapsulated alginate beads that contained SFC, HC or leaf tissue that had been stored under LTS or cryopreserved were able to regenerate callus when placed on an optimal callus induction medium. Plants derived from the control, LTS and cryopreservation protocols, either from SFC or HC, were successfully acclimatised.

Kriopreservasi Tunas in Vitro Pepaya ‘Sukma’ Dengan Perlakuan Prakultur, Loading, Dan Dehidrasi Dengan Pvs2 Dan Modifikasinya

“…Tunas tersebut mampu tumbuh kembali sebesar 70%. Kriopreservasi dengan eksplan tunas pucuk juga telah dilakukan oleh Silva (2014). Silva (2014) menggunakan 2 varietas pepaya yaitu Rainbow dan Sunrise Solo dan menggunakan bahan material berupa eksplan kalus kompak (hard callus), kalus embrio genik, dan jaringan daun.…”

Effects of Drying Temperature on the Physicochemical Characteristics and Functional Properties of Papaya Seeds (Carica papaya L.)

“…Emeruwa [8] demonstrated the pronounced efficacy of papaya fruit and seed extracts against the bacteria Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, and Shigellaflexneri that cause many infections. The Dutch and Malays use leaf and young fruit extracts to eradicate intestinal worms and treat boils [9] . Traditional African medicine also uses papaya organs in its treatments.…”

“…In Ghana, infusion of the dry leaves, administered as a purge, treats gastric disorders. The decoction of the same leaves is used for genitourinary problems in Côte d'Ivoire [9]. The processing of this fruit, as well as its direct consumption, results in large quantities of waste, such as the skin and seeds.…”