Direct shoot bud induction and plant regeneration in Capsicum frutescens Mill.: influence of polyamines and polarity

Abstract

Direct shoot bud induction and plant regeneration was achieved in Capsicum frutescens var. KTOC. Aseptically grown seedling explants devoid of roots, apical meristem and cotyledons were inoculated in an inverted position in medium comprising of Murashige and Skoog (Physiol Plant 15:472-497, 1962) basal medium supplemented with 2-(N-morpholine) ethanesulphonic acid buffer along with 2.28 lM indole-3-acetic acid, 10 lM silver nitrate and either of 13.31-89.77 lM benzyl adenine (BA), 9.29-23.23 lM kinetin, 0.91-9.12 lM zeatin, 2.46-9.84 lM 2-isopentenyl adenine. Profuse shoot bud induction was observed only in explants grown on a media supplemented with BA (26.63 lM) as a cytokinin source and 19.4 ± 4.2 shoot buds per explant was obtained in inverted mode under continuous light. Incorporation of polyamine inhibitors in the culture medium completely inhibited shoothoot bud induction. Incorporation of exogenous polyamines improved the induction of shoot buds under 24 h photoperiod. These buds were elongated in MS medium containing 2.8 lM gibberellic acid. Transfer of these shoots to hormone-free MS medium resulted in rooting and rooted plants were transferred to fields. This protocol can be efficiently used for mass propagation and presumably also for regeneration of genetically transformed C. frutescens.

In vitro plant regeneration of 4 Capsicum spp. genotypes using different explant types

“…The significantly higher importance of this factor was clearly revealed in its analysis, independently from other grouping variables (Table 2). A favorable effect of continuous light was also reported by Phillips and Hubstenberger (1985) and Kumar et al (2007). Similarly to our study, these authors applied combinations of BA and IAA as the stimulators of organogenesis in pepper.…”

“…The effectiveness of the 4 factors recommended for that stage of organogenesis was estimated for all the investigated cultivars. We added 1.1 mg L -1 IAA (Joshi and Kothari, 2007) for medium Ua, 0.5 mg L -1 indole-3-butyric acid (IBA) (Sanatombi and Sharma, 2007) for medium Ub, and 3 mg L -1 BA and 2 mg L -1 2,4-dichlorophenoxyacetic acid (2,4-D) (Kintzios et al, 2001) for medium Uc, as well as using a 50% dilution of MS medium (except for agar) (Kumar et al, 2007) for medium ½MS. The effectiveness of rooting was also verified after applying the method of pouring auxin on the growth regulator-free medium.…”

An improved plant regeneration and Agrobacterium - mediated transformation of red pepper (Capsicum annuum L.)

“…All the explants could achieve elongation well irrespective of their genotypic nature. GA 3 alone or in combination with silver nitrate/copper sulphate was found to be efficient for shoot elongation in different genotypes (Hyde and Phillips 1996;Golegaonkar and Kantharajah 2006;Joshi and Kothari 2007;Kumar et al 2007). However, unexpectedly in our work at higher GA 3 concentration (>1 mg/L), the elongated shoots of two cultivars (LCA-235 and Supper) appeared thin and weak which could not survive after hardening.…”

Polyamines and WOX genes in the recalcitrance to plant conversion of somatic embryos of Habanero pepper (Capsicum chinense Jacq.)

“…Polyamines (PAs) are natural occurring compounds in eukaryotic cells and are essential for several processes such as growth and differentiation (Kevers et al, 2000;Kumar et al, 2007;Silveira et al, 2006;Steiner et al, 2007;Takeda et al, 2002;Yadav and Rajam, 1998). In plants, polyamines have been implicated in stress response response, fertilization, senescence, organogenesis and somatic embryogenesis (Kakkar et al, 2000;Slocum, 1991;Takahashi and Kakehi, 2010).…”