Comparison of in vitro regeneration pathways in Punica granatum L.

Abstract

When cotyledonary explants, excised from in vitro germinated seedlings, of pomegranate (Punica granatum L.) were incubated on solid Murashige and Skoog (1962) medium supplemented with 21 lM naptheleneacetic acid (NAA) and 9 lM 6-benzyladenine (BA), 80% of explants developed callus. A high frequency of shoot organogensis was obtained when explants were incubated on MS medium supplemented with 8 lM BA, 6 lM NAA, and 6 lM giberrellic acid (GA 3 ). However, adding 24 lM silver nitrate (AgNO 3 ) to this medium markedly enhanced shoot regeneration frequency (63%) and mean number of shoots per explant (11.26) and length of shoots (2.22 cm). Highest frequency of in vitro rooting, mean number of roots/shoot (4.32), and mean root length (2.71 cm) were obtained when regenerated shoots were transferred to halfstrength MS medium supplemented with 0.02% activated charcoal. Well-rooted plantlets were acclimatized, and then transferred to soil medium. Moreover, when zygotic embryos of P. granatum, excised from seeds collected at 16 weeks following full bloom, were incubated on MS medium containing 30 g l -1 sucrose, 15% coconut water, 21 lM NAA, and 9 lM BA, they developed the highest frequency of embryogenic callus, clumps with globular embryos, and mean number of both globular and heartshaped embryos per callus clump. Subjecting zygotic embryo explants to six-week dark incubation period was essential for embryogenic callus induction, and these were subsequently transferred to 16 h photoperiod for further growth and development of somatic embryos. Germination of somatic embryos was observed when these were transferred to MS medium was supplemented with 60 g l -1 sucrose.

Callus Induction and Plant Regeneration in Punica Granatum L. ʻnanaʼ From Leaf Explants

“…These results are in agreement with those of Omura, et al Murkute, et al (2002) reported the highest callus induction (76.4%) and proliferation from cotyledonary explants of pomegranate ʻGaneshʼ when explants were cultured on MS basal medium supplemented with 4.44 µM BA and 2.69 µM NAA. Kanwar, et al (2010) induced callus in wild pomegranate when cotyledonary explants were placed on MS medium containing 21 µM NAA and 9 µM BA and 80% of explants developed callus. In our results NAA was not necessary for callus induction; this may be related to adequate endogenous auxin content in leaf tissue of dwarf pomegranate.…”

Germination inhibits the growth of new roots and seedlings in Eugenia uniflora and Eugenia brasiliensis

“…The balance among sugars, amino acids and growth regulators, for example, has shown effects that are sometimes inducers, sometimes inhibitors of the formation of new embryos (Deo et al, 2010;Kanwar et al, 2010;Karami and Saidi, 2010;Swamy et al, 2010). Thus, in Eugenia seeds, the beginning of the formation of roots or shoots could change the balance of those compounds, which makes an unfavorable medium for differentiation of new seedlings.…”

In vitro propagation of two Iranian commercial pomegranates (Punica granatum L.) cvs. ‘Malas Saveh’ and ‘Yusef Khani’

“…However, this traditional propagation method does not ensure disease-free and healthy plants and it depends on the season. In addition, this method is a very time-consuming and labor-intensive process (Kanwar et al 2010) and a large numbers of cuttings do not survive during plantation. Plant regeneration of pomegranate is also an essential step in the success of generation of transgenic lines and determines the effectiveness of a transformation protocol (Aldwinckle and Malnoy 2009).…”