House Plant And Gifts Plant

Tr. Comrtzrc Book  Of Roses

rays on four rose cultivar viz. 'Raktagandha', 'Raja Surender Singh of Nalagarh', 'Jantar Menke and 'Neelam barii. In all six types, flower color mutants were isolated. Analysis of their pigments indicated that change in flower color was always associated with corresponding change in the cyanidin contents of the petals.

Bud wood of 35 rose cultivars viz. Hybrid Tea 22, Floribunda 9, Grandiflora 2 and Miniature 2 were irradiated with 2.4 and 5 Krad of gamma rays and budded on rootstock of Rasa indica var Murata for further growth Cultivars belong to different group were differentially sensitive to Gamma irradiation. Radiosensitivity of all the cultivars were studied in detail and it was determined from the result that radiosensitivity was genotypically different. LD,,, dose varied horn cultivar to cultivar (Data, 1991b). In another experiment bud wood of rose cultivar 'Zorina' were irradiated with different doses of gamma rays for induction of somatic flower color mutation. Data (1995a) isolated pink color mutant trans rose cultivar 'Zorina' which is Grenadine Red in color. Casts (1994a) induced creamish yellow flower color mutant from ruse cultivar Salmon Beauty' by irradiating bud wood with 4 Krail of Gamma rays.

Mutagenic effects of acute irradiation on Miniature roses have also been studied by the target theory approach. Miniature rose cultivar Rose hybrid bushes of 'Blue Blood' (PD),' Mountie'(MT), 'Dark Red Mountie(DM) and Tot Luck' (PL) were irradiated with 50,100 and 200 of Gamma rays to induce mutation. The relation between plant height (II) reduction and absorbed dose (D) could be described as = A. BD + CD2 in accordance with the production of the multi-hit target theory when A, II and C are constant. The total numbers of mutations were highest in Pl.. The irradiated plants remained ferkik. The range in color increased substantially for all the cultivars. The number of flowers in an inflorescence decreased for PL, BB and DM but not for MT.

CHEMICAL MUTAGEN

For use of chemical mutagens following three processes are achoped (Carla, 2006)

(i) About 2.5 cm of a budwood containing 2-4 axillary buds can be dipped in a desired concenration of mutagen for a specific period.

(ii) Axillary buds are removed and dipped in desired concentration of chemical mutagen for a disked time.

(in) Shoot apex or axillary buds are covered with cotton and chemical mutagen is applied periodically up to the desired time and then cotton is removed.

lieslot (1968) stated that chemical mutagen on vegetative buds of rose proved mutagenic in diploid and polyploid cultivars, he opines that there are better chances of high frequency of mutants in case of spontaneous periclinal chimera. Gupta and Deka (1983a) treated bud wood of rose cultivar 'Contempt,' (Orange with yellow eye at the base of petal) with 0. 025 and 0. 125% colchicines for four hours. Reduction in sprouting, survival, sprout height and branch and flower number were recorded after colchicines treatment Somatic mutation in flower color was induced. The mutant color was Tangerine Orange and Empire Yellow. Data and Gupta (19830 carefully operated eyes from bud Wooti of rose cultivar 'Contempo' and treated them with 0.2525% and 0. 12598 aqueous solution of colchkines for four hours.