| Abstract: | A procedure has been established for high frequency, long-term plant regeneration from leaf sheath-derived callus cultures a- Citronella Java, variety ‘Jorhat’. A total of 600 plants were successfully transferred to the glass house, and subsequently 500 of these were shifted to the field in TWO batches of 250 plants each. From amongst 230 plants of the firs; hatch, on which data were recorded, extensive somaclonal variations were observed for seven agronomic traits, viz., herbage yield, tiller number, diameter of the bush, length and area of the longest leaf, fresh and’ dry weight ratio and oil content. In addition, variations were also recorded for six major constituents of the essential oil pool, i.e., citronellal, citronellol, geraniol, citronellyl acetate, geranyl acetate and elemol. Correlation analysis between agronomic traits revealed a significant negative correlation between oil content and herbage yield. Haw-ever, plants with higher herbage yield (> 3 fold) and oil content (> 1.5–2.0 fold) than the parent variety could be selected from amongst the variants. Furthermore, plants could be recovered with improved oil quality, possessing higher levels (> 1.5 fold) of desirable constituents of the oil like citronellal, citronellol, geraniol and geranyl acetate together with a reduced level (> 5 fold) of elemol which is an undesirable component of the citronella oil. Out of the 19 selected somaclones that were evaluated in a replicated trial with the donor parent as control, 5 lines have been further placed under multitocational trials for stability assessment. The scope of sormaclonal variation is discussed in the improvement of vegetatively propagated aromatic grasses that have a narrow genetic base. |
