Softwood shoots were produced from 40 cm long stem segments placed horizontally in flat trays containing sterilized sand under natural light or shade conditions for subsequent rooting and micropropagation studies in t...Softwood shoots were produced from 40 cm long stem segments placed horizontally in flat trays containing sterilized sand under natural light or shade conditions for subsequent rooting and micropropagation studies in teak （Tectona grand＆ L.）. Higher number of shoots （6.17） per log was produced under natural light as compared to shade conditions. Forcing was also better in natural light as compared to shade in terms of shoot length, number of nodes or leaves. For rooting, 2-4 cm long softwood shoots were excised and treated with either indole-3-butyric acid （IBA） or α-naphthyl acetic acid （NAA） at 0, 1000, 2000 or 3000 μmol.L^-1 each or with combinations （1000 ＋ 1000, 2000 ＋ 2000 or 3000 ＋ 3000 μmol.L^-1） and then placed in flat trays containing autoclaved sand at 25 ± 2℃ in 16 h photoperiod at 35 μmol.m^-2.s^-1. After 28 days, softwood cuttings treated with IBA ＋ NAA （3000 ＋ 3000 μmol.L^-1） had highest rooting percentage （89.3%） with 5.5 mean roots. Shoot apex and nodal explants of softwood cuttings were pretreated with 0.1% （w/v） ascorbic acid, boric acid, activated charcoal, citric acid, glutamine or polyvinylpolypyrollidone （PVP） for 24 h to remove phenolic compounds before surface disinfestation. Glutamine （G1） and PVP were equally effective resulting in 60% establishment of shoot apices on MS medium supplemented with 10 μmol.L^-1 6-benzylaminopurine （BAP） ＋ 5 μmol.L^-1 NAA. Using shoot apices, highest （42.80） number of multiple shoots with 54.33 mm shoot length were obtained on MS ＋ BAP （8.8 p.mol.L 1） ＋ IBA （2 μmol.L^-1） after 45 days. Shoots were successfully rooted and acclimatized to greenhouse conditions.展开更多
The present study highlights an efficient plant regeneration system in teak(Tectona grandis L.) using forced softwood shoots as an initial plant material. Forced softwood shoots of teak were cut to prepare shoot tip, ...The present study highlights an efficient plant regeneration system in teak(Tectona grandis L.) using forced softwood shoots as an initial plant material. Forced softwood shoots of teak were cut to prepare shoot tip, nodal and internodal explants and cultured on Murashige and Skoog(MS) medium + NAA(1, 3, 6, 10, and 15 μmol · L-1) or TDZ(0.001, 0.01, 0.1, 1, 4, 8, 10, 12 μmol · L-1) for callus induction. Such calluses were further grown on the same levels of TDZ or 0.4, 1, 4, 8, 10 μmol · L-1 BA + 1 μmol · L-1 IBA or GA3. Callus induction was the highest with4.55 cm3 callus volume and 5.75 g dry weight at 0.1 μmol · L-1 TDZ from shoot tips after 35 days. Embryogenic calluses were then shifted to 6, 8 or12 μmol · L-1 TDZ + 2 μmol · L-1 BA or IBA along with 5 mmol · L-1 ascorbic acid(AA) for shoot regeneration from embryogenic cultures. The highest embryogenesis(100%) with 36.4 globular and 5.5 heart-shaped embryo-like structures was obtained at 8 μmol · L-1 TDZ + 2 μmol · L-1 BA after 63 days. Such cultures when further maintained on the same medium up to 150 days resulted in 100% shoot regeneration with 16.4 mean shoots.Shoots were elongated up to 50 mm on agar medium + 8 μmol · L-1 BA + 1 μmol · L-1 GA3. An efficient rooting response(70%) was achieved having4.50 mean number and 49.10 mm root length at 8 μmol · L-1 IBA + 8 μmol · L-1 NAA + 0.1% activated charcoal after 36 days. Rooted shoots were acclimatized in glasshouse, achieving 56.6% plantlet survival.展开更多
文摘Softwood shoots were produced from 40 cm long stem segments placed horizontally in flat trays containing sterilized sand under natural light or shade conditions for subsequent rooting and micropropagation studies in teak （Tectona grand＆ L.）. Higher number of shoots （6.17） per log was produced under natural light as compared to shade conditions. Forcing was also better in natural light as compared to shade in terms of shoot length, number of nodes or leaves. For rooting, 2-4 cm long softwood shoots were excised and treated with either indole-3-butyric acid （IBA） or α-naphthyl acetic acid （NAA） at 0, 1000, 2000 or 3000 μmol.L^-1 each or with combinations （1000 ＋ 1000, 2000 ＋ 2000 or 3000 ＋ 3000 μmol.L^-1） and then placed in flat trays containing autoclaved sand at 25 ± 2℃ in 16 h photoperiod at 35 μmol.m^-2.s^-1. After 28 days, softwood cuttings treated with IBA ＋ NAA （3000 ＋ 3000 μmol.L^-1） had highest rooting percentage （89.3%） with 5.5 mean roots. Shoot apex and nodal explants of softwood cuttings were pretreated with 0.1% （w/v） ascorbic acid, boric acid, activated charcoal, citric acid, glutamine or polyvinylpolypyrollidone （PVP） for 24 h to remove phenolic compounds before surface disinfestation. Glutamine （G1） and PVP were equally effective resulting in 60% establishment of shoot apices on MS medium supplemented with 10 μmol.L^-1 6-benzylaminopurine （BAP） ＋ 5 μmol.L^-1 NAA. Using shoot apices, highest （42.80） number of multiple shoots with 54.33 mm shoot length were obtained on MS ＋ BAP （8.8 p.mol.L 1） ＋ IBA （2 μmol.L^-1） after 45 days. Shoots were successfully rooted and acclimatized to greenhouse conditions.
基金supported by Higher Education Commission (HEC), Islamabad, Pakistan through a Project grant (20-1155/ R&D/08) awarded to FA
文摘The present study highlights an efficient plant regeneration system in teak(Tectona grandis L.) using forced softwood shoots as an initial plant material. Forced softwood shoots of teak were cut to prepare shoot tip, nodal and internodal explants and cultured on Murashige and Skoog(MS) medium + NAA(1, 3, 6, 10, and 15 μmol · L-1) or TDZ(0.001, 0.01, 0.1, 1, 4, 8, 10, 12 μmol · L-1) for callus induction. Such calluses were further grown on the same levels of TDZ or 0.4, 1, 4, 8, 10 μmol · L-1 BA + 1 μmol · L-1 IBA or GA3. Callus induction was the highest with4.55 cm3 callus volume and 5.75 g dry weight at 0.1 μmol · L-1 TDZ from shoot tips after 35 days. Embryogenic calluses were then shifted to 6, 8 or12 μmol · L-1 TDZ + 2 μmol · L-1 BA or IBA along with 5 mmol · L-1 ascorbic acid(AA) for shoot regeneration from embryogenic cultures. The highest embryogenesis(100%) with 36.4 globular and 5.5 heart-shaped embryo-like structures was obtained at 8 μmol · L-1 TDZ + 2 μmol · L-1 BA after 63 days. Such cultures when further maintained on the same medium up to 150 days resulted in 100% shoot regeneration with 16.4 mean shoots.Shoots were elongated up to 50 mm on agar medium + 8 μmol · L-1 BA + 1 μmol · L-1 GA3. An efficient rooting response(70%) was achieved having4.50 mean number and 49.10 mm root length at 8 μmol · L-1 IBA + 8 μmol · L-1 NAA + 0.1% activated charcoal after 36 days. Rooted shoots were acclimatized in glasshouse, achieving 56.6% plantlet survival.
