High efficiency in vitro plant regeneration from epicotyl explants of Ponkan Mandarin (Citrus reticulata Blanco)

Abstract

Ponkan mandarin (Citrus reticulata Blanco) is one of the most important commercial cultivars of mandarin orange in China. This study reports an improved and efficient protocol for in vitro plant regeneration of Ponkan mandarin. Epicotyl segments, which were cut longitudinally into two halves, were used as explants. The shoot regeneration frequency was significantly increased by longitudinal cutting. A 100% shoot regeneration frequency and 13.2 shoots per explant were obtained when cultures were maintained in darkness for 20 d before being transferred to light conditions, with bud induction by indirect organogenesis. A 72.5% shoot regeneration frequency and 7.8 shoots per explant were obtained when explants were incubated under a 16-h light photoperiod continuously with buds differentiating directly from the cutting wound surface. The optimal medium for shoot formation was Murashige and Tucker basal medium supplemented with 2 mgL −1 BA and 30 gL −1 sucrose both under light conditions. The addition of the auxin NAA reduced the frequency of regeneration. A "filterpaper bridge" technique was used for rooting in this study. The basal portion of regenerated shoots was dipped into 1,000 mgL −1 IBA solution for 15 min before placement on a filter-paper bridge that was maintained in 1/2 MS liquid medium supplemented with 10 gL −1 sucrose. Eighty percent of the shoots rooted, and an average of 2.0 roots per shoot were achieved. Survival rate through acclimatization was 100%.

Direct Shoot Organogenesis in Murraya paniculata (L.) Jack: A Prerequisite for Genetic Transformation

“…Yang et al (2006) found that kumquat (Fortunella crassifolia Swingle) epicotyl segments have the strongest regeneration potency followed by hypocotyl segments, but no shoots could be regenerated from cotyledons. A significant effect of longitudinal sectioning of explants was observed on shoot organogenesis in Ponkan mandarin (Citrus reticulata Blanco) by Zeng et al (2009). When compared with epicotyls that were not cut longitudinally, shoot regeneration efficiency of cut epicotyls was much higher (25.3% vs. 72.5%).…”

PRECONDITIONING OF PLUMULAR APICES EXPLANTS OF PEANUT (Arachis hypogeae) WITH 6-BENZYLAMINOPURINE

“…Shan et al (2009) also reported increased number of shoots with increased concentration of BAP with NAA. Similarly, Zeng et al (2009) reported similar response of epicotyl explants of ponkan mandarin to BAP-NAA concentrations. These findings are contrarily to the previous reports given by Aasim et al (2012Aasim et al ( , 2013 which might be due to late shoot induction from callus in this study which was not observed in chickpea previously.…”

In vitro Plant Regeneration in Cleopatra (Citrus reshni Hort. ex Tan.) by Direct Organogenesis

“…The regenerated shoots were placed on the improved filter-paper bridges for root induction. Similar filter paper bridge technique was used by Zeng et al (2009). The maximum rooting percentage (78.88 ) was observed on MS supplemented with BAP (0.5 mg/l) and IAA (0.5 mg/l) and it was significantly higher over control and all other treatments (Table 4, Fig.…”