ROSE BREEDING IN INDIA AND CYTOLOGY OF INDUCED MUTANTS OF H.T. CV 'FOLKLORE'.

Dr. U.S. KAICKER
Scientific Rose breeding in India through conventional breeding techniques started in early thirties when P. Bhattacharji of Bawan Bigha, Deoghar, Bihar made first cross. This got impetus with the work of Dr B.P. Pal, former Director, I.A.R.I., New Delhi, when he released first hybrid 'Rose Sherbat' in 1959. The work got prominence in the former Division of Horticulture since bifurcated into Vegetable and Floriculture and Landscaping Divisions. There are other about 20 amateur Rose breeders who too have contributed to the conventional breeding methods in evolving new rose cvs suited to the varied agroclimatic conditions. Today more than 500 Indian bred roses are available. At I.A.R.I. during the past three and half decades some 200 odd cvs have originated out of which 5 are during 1991 alone, by the conventional and mutation breeding methods. These include those bred by Dr B.P. Pal in his experimental plot at I.A.R.I., these have been well described in his book 'Rose in India'. Earlier work on cytology of 96 cvs of modern roses belonging to dwarf polyanthas, climbers, teas, H.T., floribunda has been done at I.A.R.I. Aneuploidy in a chocolate brown rose Cv 'Mohini' (I.A.R.I., 1973) has been reported earlier with 2n=22 -a hypertriploid raised from a cross 'Sea Pearl' (4n) X 'Shola' (2n). New Cvs have been raised by gamma irradiation of buds/scions with 4–10 KR of gamma-rays of cvs like 'Christian Dior', 'Kiss of Fire', 'Gulzar', etc…, and the budding on the Rosa indica odorata major r.s. In the present study cytology of 12 distinct induced colour mutants obtained by both EMS and gamma-rays and of the control cv. 'Folklore' has been done and found to be 4n, with 2n=28 and the reasons ascribed for these colour mutations. Presence of multivalents including octavalents (0.04 per cell) in 4 mutants, hexvalents in 2 mutants, pentavalents in four mutants as compared to the control have not been reported previously in rose, besides, there is normal presence of quadrivalents and trivalents. The cytology of the varied morphological mutants seems to be responsible for mutations of colour and habit. Meiotic analysis like maximum no. of multivalents per PMC (1.288 ± 0.06) and no. of chromosomes associated as multivalents per PMC (8.50=2.05) have been recorded in 'Solid orange' mutant. There is thus reflection of structural hybridity in the evolutionary complexity of the control and its induced mutants which is at the expense of bivalents or normal pairing while chiasma frequency per cell was variable in mutants 89 % pollen sterility. All these thus cause genic rearrangements responsible for colour changes.
KAICKER, Dr. U.S. (1992). ROSE BREEDING IN INDIA AND CYTOLOGY OF INDUCED MUTANTS OF H.T. CV 'FOLKLORE'.. Acta Hortic. 320, 105-112
DOI: 10.17660/ActaHortic.1992.320.14
https://doi.org/10.17660/ActaHortic.1992.320.14

Acta Horticulturae