Influence of cytokinins, auxins and polyamines on in vitro mass multiplication of cotton (Gossypium hirsutum L. cv. SVPR2).

In the present investigation, the influence of different forms of cytokinins, auxins and polyamines were tested for mass multiplication and regeneration of cotton. Initially, for the identification of effective concentration for multiple shoot induction, various concentrations of BAP, Kin and 2iP along with IAA and NAA were tested. Among tested concentrations, media fortified with MS salts; B5 vitamins; 30 g/l, glucose; 2.0 mg/l, 2iP; 2.0 mg/l, IAA and 0.7 % agar showed best response for multiplication of shoot tip explants (20 shoots per shoot tip explants). In nodal explants, maximum of 18.6 shoots were obtained in the media fortified with MS salts, B5 vitamins, 30 g/l, glucose, 2.0 mg/l, 2iP, 1.0 mg/l, NAA and 0.7 % agar. Effect of different concentrations of polyamines like spermidine and putrescine were also tested along with the above said multiplication media. Among the various treatments, 20 mg/l of putrescine showed best response and the multiple of shoots were increased to 26.5 shoots per shoot tip explants and 24.5 shoots per nodal explants. Elongation of shoots was achieved on multiple shoot induction medium. Significant number of roots were initiated in the medium supplemented with MS salts, vitamin B5 and IBA (2.0 mg/l). The frequency of root induction was increased by addition of, PVP (10 mg/l) along with root induction medium and after 2 weeks, the roots reached the maximum length of 22 cm. Further, these plantlets were hardened by using sand, soil and vermiculate in 1:1:1 ratio. The hardened plants were transferred to the environmental growth chamber for proper acclimatization. The hardened plants were then transferred to field for boll yielding and they exhibited 100% survival.

Accumulation of lead and cadmium in upper parts of mustard (Brassica juncea) seedlings in response to putrescine.

Lead and cadmium accumulation examined in shoot and leaf tissues of seedlings of mustard (Brassica juncea cv RH-30), at 7th day, treated with either putrescine (1 mM), or ammonium nitrate (10 mM) or IAA (10 microM). These were included in the nutrient medium, containing Pb or Cd (0.1 mM and 2 mM). Metal accumulation was more in shoot than in leaf tissues, which was increased manifold under saline conditions. However, Cd accumulation in tissues was higher than Pb. Chemical (putrescine, ammonium nitrate or IAA) treatment of the seedlings, decreased metal accumulation in leaf (10-20%) and in shoot (40 to 60%) tissues, depending upon external metal levels. Putrescine significantly decreased the metal accumulation and translocation under saline conditions.