CLONAL PROPAGATION OF BANANA CV. AMRITA SAGAR AND BARI Kola -I

Abstract

he stud) \\as undertaken with a v icw lo establish a method for in vttro culture and plant regeneration from shoot tip cxplants of two cultivars Amritasagar and B/\RI kola-I or Banana (J'vlusa S'pp.) Shoot tips excised from field grown plants were used as experimental materials and this experiment was setup at PROS! llK/\ Tissue Culture Centre Trust (PTCCT) Laboratory, Koitta, Manikgonj during the period from February 2006 to April 2007. Studies were done to identify and optimize the cxplants sterilization techniques, establishment or in vitro shoot proliferation, effects of phytohormoncs on in vitro shoot proliferation and root induction and its ex-vitro establishment. In the present study, different auxins(!/\/\, 113/\, N/\/\) and cytokinins (13/\P. KIN) and organic supplements (coconut water) have been used in different concentration and combinations to optim izc the clonal propagation. Lxplants were sterilized by 0.1 % I lgCl2 for 14 minutes and shoot tips or both cultivars were found free from contamination and survived cent percent. Less than 14 minutes showed in vitro contamination and more than 14 minutes treatment, percentage or survival declined considerably. Types imd concentration of different cytokinins had remarkable effect on primary establishment of' ex plants. B/\P 5.0 mg/I was found the best and 1.0 mg/I 13/\P showed lowest performance for primary establishment of' shoot tips and its subsequent in vitro growth. Synergistic effects of 8/\P and KIN (0.5mg/l 13/\P I 0.5mg/l KIN) were round superior for single shoot proliferation. The best performance were observed in MS 1 5.0 mg/I 13/\ P 12.0 mg/I KI t 2.0 mg/I I/\/\, MS t 4.0 mg/I 13/\P t-2.0 mg/I 113/\+2.0 mg/I I/\/\ and 0.5 mg/I 13/\P I 0.Smg/l KIN and 13% Coconut Water (CW) and the lowest performances were observed in MS t-3.0 mg/I 13/\P+ 1.0 mg/I KIN t-1.0 mg/I !/\/\, MS t 2.0 mg/I 13/\P t 2.0 mg/I 113/\ 12.0 mg/I I/\/\ and 1.5 mg/I 13/\P t 0.5mg/l KIN and I O'Yo CW for multiple shoot proliferation. Maximum number or shoot 8.17 and the highest length of shoot 5.50 cm was recorded in 0.5 mg/I 13/\P 10.5mg/J KIN and 13% CW. Combine effect or 11/\P & KIN were observed on leaf' development. The best performance was observed in MS +4.0 mg/I 13/\P 1- 1.0mg/l J/\/\ for both the cultivars, Maximum number of leaves 3.55. 3.20 and largest leaf 2.50cm. 2.23cm were found for both cultivars respectively. The number or subcultures substantially effect on in vitro shoot multiplication. It was observed that the number or multiple shoots per culture was maximized 15.80 and 12.50 respectively up to 7th subculture but beyond that the rate or multiple shoot formation was declined considerably. In vitro derived shoot lets were cultured in MS medium supplemented with lf3/\, N/\/\ & !/\/\ for in vitro root induction. Among the various media composition Yi MS+ I .Omg/l 113/\ proved the best for root induction (shoot rooted I 00% for both the culiivars, number or root per shoot 6.08. 6.13 & root length 4.0J cm. 3.90 cm) for Amritasagar and 13/\RJ Kola-I respectively and Yi MS+5.0mg/l N/\/\ was round the lowest performance Ior root induction (shoot rooted 40% tor the culiivars. number or root per shoot 2.84, 2.68 & root length 1.67 cm, 1.50 cm). Transplanted rooted shoot survived 85.90'Yo in soil and resumed growth. After 6 weeks or transplantation no off type plant was noticed which indicates all the micro- propagated plants were true-to type. From the stated observation it can be concluded that clonal propagation or banana cultivars can be established through i11 vitro techniques for commercial propagation.