Preconditioning effect of cytokinins on in vitro multiplication of embryonic node of grass pea (Lathyrus sativus L.) cultivar Gürbüz

Abstract

Lathyrus sativus L. (grass pea) is an important grain legume crop grown all over the world. It is very recalcitrant and difficult\ud to regenerate under in vitro conditions. The present study determined the effect of preconditioning of cytokinins [10 and 20 mg L–1\ud thidiazuron (TDZ) and 2-isopentenyl adenine (2iP)] and postconditioning of dissimilar levels of TDZ-indole-3-butyric acid (IBA)\ud and 2iP-IBA on in vitro shoot multiplication using embryonic node explants. The results showed that preconditioning followed by\ud postconditioning on Murashige and Skoog (MS) medium with 0.25, 0.50, 0.75, and 1.0 mg L–1 2iP or TDZ combined with 0.10 mg\ud L–1 IBA had positive effects on shoot multiplication. It seemed as if the TDZ-preconditioned and TDZ-IBA–postconditioned explants\ud were more regenerative compared to 2iP-preconditioned or 2iP-IBA–postconditioned explants. Maximum shoot induction (100%) was\ud achieved on MS medium containing 1 mg L–1 TDZ and 0.10 mg L–1 IBA, with a mean number of 31.10 shoots per explant. In comparison\ud to the other cytokinin tested, 2iP-preconditioned and 2iP-IBA–postconditioned explants had longer shoots, with a mean shoot length of\ud 8.10 cm. Root initiation was observed on all cultures 4 weeks after the transfer of shoots with the best rooting on MS medium containing\ud 2 mg L–1 IBA. The rooting response was 76.56% with a mean number of 8.03 roots per shoot and root length of 8.2 cm. The healthy\ud plants were transferred to a greenhouse for acclimatization and exhibited 90% survival. It was concluded that TDZ preconditioning was\ud necessary for grass pea multiplication along with TDZ-IBA postconditioning. This regeneration protocol may facilitate future genetic\ud transformation and breeding studies to reduce β-N-oxalyl-L-α,β-di-amino propionic acid content in grass pea

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

“…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. Similarly, negative effects of inceased BAP concentration with NAA has been reported for preconditioned embryonic node of grass pea (Barpete et al, 2014). The results also confirmed the clear effects of postconditioning concentrations on shoot length and in line with Aasim et al (2009Aasim et al ( , 2010 in cowpea and chickpea (Aasim et al, 2011 and.…”

“…This phenomenon of shoot regeneration from callus is not reported earlier by other researchers worked on preconditioning followed by postconditioning of explants (Aasim et al, 2009(Aasim et al, , 2011(Aasim et al, , 2012(Aasim et al, and 2013Barpete et al, 2014). Analysis of variance showed statistically insignificant effects of preconditioning dosage on callus and 100% shoot regeneration frequency in agreement with (Aasim et al, 2009) and embryonic axis (Aasim et al, 2010) of cowpea, mature embryo and embryonic axis (Aasim et al, 2011) and plumular apices (Aasim et al, 2013) of chickpea, plumular apices of lentil (Aasim et al, 2012) and (Barpete et al, 2014) from embryonic node of lathyrus preconditioned with 20 mg/l TDZ. Contrarily, variable response of cotyledonary node of dwarf chickling pulse treated with cytokinin on callus and shoot induction has been reported by Saglam (2012).…”

“…It is supposed that preconditioning of explants with higher concentraions promoted the cell division in meristematic region of plumular apices explants which ultimately resulted in more shoots. Superiority of preconditioning effects on shoot regeneration from plumular apices of lentil (Aasim et al, 2012), chickpea (Aasim et al, 2013) and embryonic node of grass pea (Barpete et al, 2014) compared to unconditioned explants has been confirmed. Similarly, Madhulatha et al (2004) found 50 mg/l preconditioning of BAP-Kin (1:1) for 60 min for optimum shoot proliferation in banana.…”

“…In this study, we successfully achieved upto 75.67% rooting using different IBA concentrations irrespective of preconditioning concentrations. Successfull rooting of preconditioned explants has been reported in cowpea, grasspea by Aasim et al (2009Aasim et al ( , 2010, and Barpete et al (2014). Low rooting percentages after preconditioning has been reported in chickpea (Aasim et al, 2011) and lentil (Aasim et al, 2012).…”

“…Preconditioning of explants using higher cytokinins concentration for few hours to few days may lead to rapid cell division. Successful shoot regeneration with precondition of explants with different cytokinins and concentrations has been employed successfully for Picea abies (Von Arnold and Tillberg, 1987), banana (Madhulatha et al, 2004), cowpea (Brar et al, 1999); (Aasim et al, 2009 and2010), chickpea (Aasim et al, 2011 and, dwarf chicklings (Saglam, 2012), lentil (Aasim et al, 2012), and grass pea (Barpete et al, 2014). Results of postconditionining concentrations and combinations revealed the insignificant effects on callus induction (%) and shoot regeneration (%) which showed the supremacy of explant compared to reported previously in peanut.…”