Factors affecting in vitro clonal propagation of Prosopis cineraria

Abstract

Genotype, age of tree, nature of explant and size (length and diameter), season of explant collection, explant position on medium, plant growth regulators and certain additives (ascorbic and citric acids, adenine sulphate, L-arginine, glutamine and ammonium citrate), incubation conditions, and subculturing period greatly influenced the in vitro clonal propagation of P. cineraria. The maximum number of lo-12 shoots were induced from the nodal shoot segment from pruned thorny adult trees on Murashige and Skoog's (MS) medium containing 0.1 mgl-' indole-3-acetic acid (IAA) + 2.5 mgl-' benzylaminopurine (BAP) + additives. Higher temperature (31 f 2 "C) and mixed (fluorescent and incandescent) light of 50 pmol me2 s-' photon flux density for 12 h per day photoperiod favoured shoot induction and subsequent growth. Explants from thornless trees produced 6-8 shoots per explant on MS medium containing 0.1 mgll' IAA + 5.0 mgll' BAP + additives. Nodal shoot segments obtained from root and stump sprouts produced multiple shoots. Root segments differentiated into multiple shoots on MS medium containing 0.5 mgll' indolebutyric acid (IBA) + 2.5mgll' BAP.Differentiated shoots multiplied best on MS medium containing 0.1 mgll' naphthalene acetic acid (NAA) + 1 .O mgl-' BAP + additives. To yield multiple shoots the original explant was transferred 6 times on fresh medium after harvesting the differentiated shoots. Shoots were rooted by pulsing with 100 mgll' IBA for 4 h and then culturing on hormone-free half strength MS medium. Initial dark incubation for 5 days at high temperature (33 f 2OC) was found essential for root induction from shoots which was 63% within two weeks. The rooted plantlets contained a consistent number of chromosomes (2 n = 28). It is suggested that the protocol developed could be useful for cloning of mature and tested trees of P. cineraria.

Rapid multiplication of Dalbergia sissoo Roxb.: a timber yielding tree legume through axillary shoot proliferation and ex vitro rooting

“…The old/perennial shoots of unlopped tree, if cultured, did not respond in vitro. It is suggested that the perennial shoots/tissues experience types of stresses like summer heat, severe winter, and extreme drought during the year, and accumulate anti-metabolic substances like phenols and ABA, which inhibit growth in culture (Shekhawat et al 1993). Pruning/lopping/pollarding of mature tree and elimination/removal of aged tissues resulted in the production of reinvigorated shoots during subsequent spring.…”

“…The treatment of explants with chilled, sterile antioxidant solution checked excessive phenolic exudation and browning of tissue and cultures (Phulwaria et al 2012a, b). It has been observed in woody plants that antioxidant solutions may promote growth and development of the shoots particularly at the stage of culture establishment (Shekhawat et al 1993;Sanjaya et al 2006;Rai et al 2010). Explants were cultured on 0.8 % agar-gelled MS medium containing BAP or Kn for shoot bud induction.…”

Micropropagation of commercially cultivated Henna (Lawsonia inermis) using nodal explants

“…1d, Table 2). The repeated transferring has been recommended as a method for rejuvenation of mature explants for micro-clonal propagation of several woody plants (Pierik 1990;Shekhawat et al 1993;Phulwaria et al 2011). The increase in shoot number after repeated transfer of mother explants for different passages may be due to suppression of apical dominance during subculture that induced basal dormant meristametic cells to form new shoots (Tripathi and Kumari 2010).…”

Evaluation of Clonal Variability in Shoot Coppicing Ability and in vitro Responses of Dalbergia sissoo Roxb

“…NORTON and NORTON (1985) observed similar genotype dependent variation for shoot proliferation and plant growth regulator requirement amongst 20 cultivars of Family Ericaceae. Intraspecific variations amongst spiny and spineless genotypes of Prosopis cineraria for their shoot forming ability and phytohormone requirements were also registered (KACKAR et al, 1991;SHEKHAWAT et al, 1993). Coppicing ability of clones and their multiple bud induction capacity seems to exhibit a correlation and there by giving impetus to our belief that said traits are genetically controlled.…”