000			04980nam a22001697a 4500
999			_c161871 _d161871
082			_a660.6 _bAFN/SO
100			_aAfnamol O P
245			_aSomatic embryogenesis in black pepper (Piper nigrum L.)
260			_aVellayani _bDepartment of Plant Biotechnology, College of Agriculture _c2018
300			_a102p
502			_aMSc
520	3		_aThe study entitled “Somatic embryogenesis in black pepper (Piper nigrum L.)” was conducted at the Department of Plant Biotechnology, College of Agriculture, Vellayani, Thiruvananthapuram during 2015-2017, with an objective to standardise a protocol for somatic embryogenesis in black pepper (Piper nigrum L.) var. Panniyur 5. Regeneration through somatic embryogenesis is the most appealing technology in in vitro propagation since it produces large number of somatic embryos from single explants, and also acts as a suitable system for crop improvement through genetic modification. Earlier studies reported that regeneration in black pepper is highly influenced by genotypes. Somatic embryogenesis mediated protocol is not yet reported in any of the Panniyur varieties. In the present study, explants (shoot tip, node and leaf) from field grown and in vitro raised seedlings were used. Systemic contaminants and polyphenols are the major problems associated with in vitro culture of black pepper. Pretreatments of the explants taken from the field grown plants with 250 mg L-1 ascorbic acid for 50 minutes and 50 mg L-1 of PVP for 1 hour reduced the phenolic exudation. Dipping explants in 300 mg L-1 of cefotaxime for 1 hour and addition of 15 mg L-1 of CuSO4 in the medium were found to be effective in controlling the systemic contaminants. Percentage of callus induction varied among type of explants as well as the medium used. Leaf tissue from in vitro raised plants was found to be most responsive to the callus induction (68.75% in 40 days) in MS medium supplemented with1.5 mg L-1 of picloram (Pic). The same concentration of Pic in SH medium produced 57.4% callus induction from leaf. Shoot tip and node taken from in vitro raised raised seedling showed the highest callus induction in MS medium supplemented with mg L-1 of Pic (57.14% and 42.85% respectively). Among the explants collected from the field grown plants, the maximum callus induction occurred in leaves (37%). Calli obtained from leaf, shoot tip and node did not show embryogenesis in any of the 50 treatments and the calli turned black and dried. As there was no response on the somatic embryo induction from shoot tip ,stem node and leaf, somatic embryogenesis was tried in fully ripened seeds of Panniyur-5.Out of 48 treatments tried (MS and SH media, with different combination of 2,4- D,BA,IAA,NAA,TDZ and Pic), only seven treatments responded. In 46% of the seeds, somatic embryos emerged directly from the micropylar region of the seed (SH with 1.5 or 3% sucrose and half strength SH with 3% sucrose) and callus induction was occurred in the rest. The calli initiated from seeds inoculated in MS and SH media supplemented with 1.5 and 2 mg L-1 Pic and 3% sucrose produced somatic embryos in the same medium. Somatic embryogenesis was early in SH medium (40 days) compared to MS medium (60 days). The somatic embryos produced from the calli, failed to produce secondary embryos in any of the 42 treatments tried, however, they germinated to produce plantlets. Somatic embryos directly formed (SH with 3% sucrose) from the seed showed secondary embryo formation from the root pole of the primary embryo (20%) in the same medium itself. The primary embryos formed in SH medium with 1.5% sucrose produced the maximum (51.4%) secondary embryos in semi solid SH medium with 1.5% sucrose medium. Secondary formed in SH+3.5% sucrose got regenerated in to plantlets in the same medium. Secondary embryos from semi solid SH medium were regenerated only when transferred to liquid SH medium with different concentration of sucrose (1.5% and 3.5%) with continuous shaking (110 rpm). Plantlets regeneration was early (48.73 days) in liquid SHmedium with 3.5% sucrose. Somatic embryogenesis was confirmed by visualizing the different developmental stages of the somatic embryos viz. globular, heart, torpedo and cotyledonary stages under the stereo microscope. Histological studies of the embryos confirmed their origin from micropylar tissue and not from zygotic tissue. It showed the presence of secondary embryos from primary embryos as well as the emergence of globular structure from the callus. The present study was successful in developing a somatic embryogenesis mediated regeneration protocol in black pepper var. Panniyur 5 which can be used for the in vitro propagation and genetic modification based crop improvement programmes
650			_aPlant Biotechnology
700			_aSoni, K B (Guide)
856			_uhttp://krishikosh.egranth.ac.in/handle/1/5810148267
942			_2ddc _cTH