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Combining ability and heterosis studies in a diallel cross of periwinkle (Catharanthus roseus L.)
(Punjab Agricultural University, Ludhiana, 2022) Bolagam Ravikumar; Dhatt, K. K.
The current investigation entitled "Combining ability and heterosis studies in a diallel cross of periwinkle (Catharanthus roseus L.)" was investigated at the Floriculture Research Farm of Punjab Agricultural University, Ludhiana during the years 2019 to 2022. Six inbred lines of periwinkle namely P1 (Vi-15-1), P2 (Vi-13-2), P3 (Vi-16), P4 (Vi-15-2), P5 (Vi-29) and P6 (Vi-14-3) were crossed in full-diallel fashion with an objective of identifying superior cross-combinations for high specific combining ability and qualitative traits and determine the inheritance of flower colour and size. The six inbred lines and their thirty cross combinations were evaluated for plant height, plant spread, number of primary branches per plant, leaf length, leaf breadth, internode length, corolla tube length, days to flowering, duration of flowering, number of flowers per plant, flower diameter, follicle length and number of seeds per follicle in Randomized Block Design and replicated thrice. Analysis of variance was highly significant for all the vegetative and flowering characters indicating presence of genetic variability in the genotypes. The analysis of variance for combining ability was highly significant for growth and flowering characters indicated presence of both additive and non-additive gene actions. The parents P5 (Vi-29) and P1 (Vi-15-1) were recorded preferable GCA effects for most of the traits. These were considered as good general combiners for crossing programmes. The cross combination of Vi-13-2 × Vi-29 had significant positive maximum SCA effects for plant height, plant spread and number of primary branches per plant. The follicle length and number of seeds per follicle were recorded highly significant positive SCA values in the combination of Vi-29 × Vi-14-3. The high significant positive reciprocal effects were recorded for plant height, leaf breadth, number of flowers per plant and number of seeds for follicle in the cross combination of Vi-14-3 × Vi-29. The plant spread, duration of flowering and corolla tube length were shown high significant positive reciprocal results in cross combination of Vi-14-3 × Vi-13-2. The highly significant positive heterobeltiosis was present in the progenies of Vi-29 × Vi-14-3, Vi-13-2 × Vi-29 and Vi-15-1 × Vi-14-3 for most of the studied traits. High to moderate values for phenotypic and genotypic coefficients of variation were shown for majority of the studied characters, recapitulate the presence of variability. The range of phenotypic and genotypic coefficient of variations among the parental lines was 5.35-34.41% and 3.96-34.02%, respectively. The PCV and GCV was 4.14-25.49% and 4.01-24.94% for the cross combinations, respectively. The heritability varied from 46.74-97.77% and 50.62-98.73% for the parental lines and cross combinations, respectively. It indicated that the traits were highly heritable to following generations. The average genetic advance as per cent mean was observed as 8.00-50.21% and 6.03-69.29% among the inbred lines and cross combinations, respectively. The flower colour and size were segregated with 3:1 (monohybrid), 9:3:4 (supplementary gene action), 9:6:1 (polymeric gene action) and 9:3:3:1 (typical dihybrid) in F2 generation of fifteen selected crosses from diallel crosses.
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Salt stress induced morpho-physiological, biochemical and anatomical changes in ornamental tree species
(Punjab Agricultural University, Ludhiana, 2022) Nagar, Kamal Kishor; Dubey, R. K.
The present investigations entitled “Salt stress induced morpho-physiological, biochemical and anatomical changes in ornamental tree species” were undertaken at Landscape Nursery, Department of Floriculture and Landscaping, Punjab Agricultural University, Ludhiana, during 202022 to screen salinity tolerant ornamental tree species for green of salt affected land. One year old seedlings of fifteen tree species were grown in 10” earthen pots containing soil: FYM (2:1) during first week of February 2020. After one month of transplanting, different concentrations of NaCl viz., 0, 50, 100, 150 and 200 mM were given with irrigation water from March 2020 to January 2022. All the parameters were recorded at four-month interval. The salt treatments significantly (p<0.05) affected the morpho-physiological, biochemical and anatomical parameters of ornamental tree species. On the basis of investigations, the tree species were categorized as salt tolerant and salt sensitive. Salt tolerant trees include Delonix regia, Acacia auriculiformis, Cassia fistula, Pongamia pinnata, Plumeria alba, Mimuspos elengi, Butea monosperma, Callistemon lanceolatus and Erythrina variegata whereas, salt sensitive include Jacaranda mimosifolia, Bauhinia purpurea, Koelreutaria paniculata, Millettia ovalifolia, Lagerstromia speciosa and Putranjiva roxburghii. The growth parameters slightly increased or maintained in tolerant trees, whereas in salt sensitive trees, growth parameters decreased with an increase in salt concentration during January 2021 and January 2022. The maximum per cent increase in number of branches (19.02%), survival percent (94.36%), reducing sugar (16.94%) at the concentration of (100 mM NaCl) and upper epidermis thickness (45 µm), palisade thickness (128.05 µm), lower epidermis thickness (42 µm), palisade cell length (70.23 µm), palisade cell diameter (32 µm), intercellular space (16.4%) was recorded in C. Lanceolatus at 200 mM NaCl, whereas, during May 2020 to January 2022, minimum per cent decrease in fresh and dry weight of leaves (26.50%), fresh and dry weight of root (26.78 %) and fresh and dry weight of stem (11.54%), was also observed in the same species at 200 mM NaCl. During May 2020 to January 2022, the maximum per cent increase plant height (21.23%), lea area (20.94%), phenol (33.33%) and carotenoid (8.91%) was recorded in E. variegata. In C. fistula tree species maximum percent increase number of leaves (10.23%), plant spread (6.36%), protein (8.33%) and starch (17.33%) at the concentration of 50 mM NaCl. RLWC (5.28 %) and proline (12%) was found in P. alba at 200 mM NaCl. The maximum total chlorophyll, carotenoid, proteins, RLWC, starch, reducing sugar and minimum proline and soluble sugars was observed during rainy season. Osmolyte concentration was more during January. As the level of NaCl in soil increased, EC also increased. It is difficult to maintain the EC during rainy season as due to dilution effect as well as leaching of salts, consequently resulted in reduced level of EC. On the basis of morpho-physiological, biochemical and anatomical parameters during the 1st and 2nd year of the experiment, tree species were classified as salt tolerant and susceptible. From these, plants highly salt tolerant and the salt susceptible tree species were planted at PAU regional research station, Bathinda. The maximum increase in plant height (4.08 m) in C. fistula, Number of branches per plant (12.0) C. lanceolatus, Stem girth (150.17 mm) A. auriculiformis, Plant spread (1.92 m) C. lanceolatus and survival percentage (100 %) in C. lanceolatus, Pongamia pinnata and C. fistula was observed in saline water irrigated tree species.
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Studies on genetic diversity in chrysanthemum (Chrysanthemum morifolium Ramat.) through hybridization, cytological and molecular approaches for commercial traits
(Punjab Agricultural University, Ludhiana, 2020) Anu Bala; Madhu Bala
The present investigations entitled “Studies on genetic diversity in chrysanthemum (Chrysanthemum morifolium Ramat.) through hybridization, cytological and molecular approaches for commercial traits” were undertaken at Department of Floriculture and Landscaping, Department of Plant Breeding and Genetics and Fruit Molecular Biotechnology Lab in School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, during 2016-19. The study consisted of genetic diversity analysis of diverse genotypes of chrysanthemum through cytological, molecular studies and hybridization for commercial traits. Thirty chrysanthemum genotypes were selected from chrysanthemum germplasm maintained at PAU, Ludhiana for cytological studies. Young flower buds were used for preparation of slides and a range of ploidy level 2n=52-116 recorded among all selected chrysanthemum cultivars. In molecular characterization SSR markers were used to study genetic diversity of thirty chrysanthemum genotypes. Total 17 SSR‟s were selected and among these 15 markers exhibited polymorphism and remaining two were monomorphic. Fifteen polymorphic markers demonstrated relatively high level of polymorphism as out of total 53 alleles produced, 47 were polymorphic showing 92.22 % polymorphism. Genotypes were clustered into two main clusters based on the variability of 15 polymorphic SSR markers. In hybridization twenty-one crosses were made between cultivars belonging to early and main season group. Among twenty-one crosses seed set was recorded in sixteen crosses and germination per cent was observed in fourteen crosses only. Maximum number of seeds per flower head were found in cross Ratlam Selection x Reagan Emperor (11.00), highest seed germination percentage (40.00 %) was recorded in cross between Basanti x Reagan Emperor and seedling vigour found highest (60.00) in cross between Basanti x Reagan Emperor. Hybrids developed from inter crossing of chrysanthemum genotypes were evaluated for various morphological characters and showed variation with respect to flower colour and flower type can be used for different purposes like for pot culture, exhibition purpose and for loose flower production etc. From the effective positive response in terms of various investigations under study, it can be concluded that chromosomal and molecular study helped to estimate genetic diversity which is the most essential pre-requisite as it plays an important role in developing new and novel desired forms through breeding and selection. Polyploidy found could be further helpful for breeding programmes and new cultivars could be developed by addition or deletion of chromosomes in cultivars with known ploidy level. Hybridization helps in development of segregating population having different range of flower colour and height and can be used for different floricultural purposes.
Open Access
Optimization of protocol for indoor vertical garden using different nutrient formulations and light intensities
(Punjab Agricultural University, Ludhiana, 2019) Gautam, Bharti; Dubey, R.K.
The present investigations entitled “Optimization of protocol for indoor vertical garden using different nutrient formulations and light intensities” were undertaken at Landscape Nursery, Department of Floriculture and Landscaping, Punjab Agricultural University, Ludhiana, during 2017-19. The study consisted of two experiments, the first experiment was initiated to evaluate indoor ornamental plants and determine the optimum nutrient formulations for successful installation of an indoor vertical garden. For this, fifteen indoor ornamental plant species were selected and grown in soilless media consisting of cocopeat, perlite and vermiculite in the ratio 3:1:1 with four concentrations of Hoagland nutrient solution (25 % (NF I), 50 % (NF II), 75 % (NF III) and 100 % (NF IV) of Hoagland‟s solution). The fifth treatment (NF V) included self-composed nutrient formulation (Azeezahmed 2014). The plant species were evaluated on the basis of various growth parameters (survival percentage, plant height, number of leaves, leaf length, leaf thickness, internodal length, plant spread, leaf area, fresh and dry plant biomass, root density, maximum shoot and root length), physiological parameters (leaf chlorophyll content, leaf carotenoid content, relative leaf water content), biochemical parameters (proline content) and plant leaf nutrient analysis (N, P, K, Ca, Mg, S). Experimental design was Factorial Completely Randomized Design keeping three replications in each treatment. NF IV (100 % of the Hoagland‟s solution) was significantly better compared with other treatments in terms of growth, physiological, biochemical characters and nutrient accumulation of the plants under indoor conditions. Best five species screened on the basis of performance of various parameters studied were Schefflera arboricola, Dracaena godseffiana, Philodendron salloum, Syngonium podophyllum and Scindapsis aureus. The results of the first year experiment were further used in the second experiment in which the best nutrient formulation along with the selected plant species were used in the indoor vertical garden under different light intensities. The screened indoor plants were planted in the pots filled with media containing cocopeat : perlite : vermiculite in the ratio 3:1:1 arranged as vertical structures (611” x 43”) aligned to the walls of the interiors of a room. Four such structures were fabricated. Each frame was artificially illuminated with different light intensities i.e. the first frame with the light intensity ranging between 700-1100 lux, second 1100-1500 lux, the third frame 1500-1900 lux and the fourth frame was control with 150-250 lux (no artificial light illumination). These light intensities were PWM controlled. The plant species were evaluated on the basis of their response towards different light intensities w.r.t. growth, physiological, biochemical and plant leaf nutrient parameters. From the most effective positive response in terms of various parameters under study, it can be concluded that Philodendron salloum responded best to LI I (700-1100 lux), Scindapsis aureus and Dracaena godseffiana to LI II (1100-1500 lux) and Schefflera arboricola and Syngonium podophyllum to LI III (1500-1900 lux).
Open Access
Effect of botanicals as growth promoter and fusarium wilt suppressor on gladiolus (Gladiolus grandiflorus L.)
(Punjab Agricultural University, Ludhiana, 2018) Patel, Monika; Dubey, R. K.
The present investigation was conducted on open field grown pot plants of two commercial varieties of gladiolus, White Prosperity and Jacksonville Gold using soil: FYM (2:1) as growing media in Department of Floriculture and Landscaping, Punjab Agricultural University, Ludhiana from September 2016 to April 2018. The statistical design for conducting the experiment was CRD. Some of the plant species have been reported to possess harmless eco-friendly chemicals that have growth promoting effect. In the present studies, botanicals were prepared from the leaves of five locally available plants viz. Callistemon lanceolatus, Eucalyptus teriticornis, Azadirachta indica, Tagetes erecta, Aegle marmelos at 20 % and 40 % concentrations and were used for treating corms before planting and then up to harvesting of spike. The present investigations were conducted to know the growth promoting and fusarium wilt disease suppressing effects of botanicals. Present studies revealed that all the ten treatments showed significant differences in growth, yield, physiological and biochemical parameters of plants as compared to control. On qualitative phytochemical analysis of botanicals, it was confirmed that, all the botanicals have steroids and flavonoids. Forty percent concentration of botanicals had more growth promoting effect on plants than 20% concentration. All these botanicals suppressed the fusarium wilt disease of gladiolus to a variable extent. Eucalyptus teriticornis was found as best botanical for fusarium wilt disease suppression. On GC-MS analysis of E. tereticornis botanical, two major antifungal compounds (α-phellandrene and viridiflorol) were found. Among all treatments; E. tereticornis, A. indica and C. lanceolatus were found more effective in growth promotion as well as disease suppression than T. erecta and A. marmelos.
Open Access
Combining ability analysis for growth and flowering characteristics in pansy (Viola × wittrockiana Gams.)
(Punjab Agricultural University, Ludhiana, 2018) Ravneet Kaur; Dhatt, K. K.
The present studies entitled "Combining ability analysis for growth and flowering characteristics in pansy (Viola × wittrockiana Gams.)" were undertaken at the Floriculture Research Farm of Punjab Agricultural University, Ludhiana during the year 2015-2018. Eight inbred lines of pansy were selected for crossing in half diallel fashion (8x8) to study the general combining ability effects of the parents and specific combining ability of the crosses. Twenty eight hybrids were grown along with their parents in Randomized block design. The results pertaining to the analysis of variance for experimental design and combining ability were highly significant for all the characters. Based on gca effects of parents, the parents Pa-64-1-5-14, Pa-62-4-12-18, Pa-63-1-7-25 and Pa-32-8-7-6 were best general combiners for most of the traits except stalk length and flower size which can be recommended for use in breeding programme to generate genetic variability in desirable direction. Studies on specific combining ability of the crosses indicated that the cross combinations viz.,Pa-64-1-5-14 × Pa-62-4-12-18, Pa-13-1-2-3 × Pa-47-1-3, Pa-11-1-3-7 × Pa-62-4-12-18, Pa-64-1-5-14 × Pa-63-1-7-25, Pa-11-1-3-7 × Pa-64-1-5-14, Pa-32-8-7-6 × Pa-63-1-7-25, Pa-64-1-5-14 × Pa-32-8-7-6 and Pa-11-1-3-7 × Pa-63-1-7-25 were the best specific combiner for most of the vegetative and floral characters viz., plant height, plant spread, branches number, days to flowering, duration of flowering, flowers per plant and pod setting (%). Combining ability analysis revealed that magnitude of gcavariance was greater than sca variance suggesting the predominance of additive gene action for the characters viz., branch count, flower size, days from bud initiation to flowering and flowers per plant. Specific combining ability (sca)variance was greater than gca variance for most of the characters viz., plant height at first flowering (cm), final plant height, plant spread, final plant spread, stalk length, days to flowering, flowering duration and pod setting (%) which indicated predominance of non-additive gene action in their inheritance and heterosis breeding would be the best option for improvement of these traits. Heterosis revealed that majority of the hybrids exhibited heterobeltiosis and mid-heterosis in desirable direction. The hybrids exhibiting high per se performance also showed high mid-heterosis. The hybrids exhibited heterosis over better parent for plant height, plant spread, branches count, stalk length, days from bud initiation to flowering, days to flowering, duration of flowering, flowers per plant were Pa-64-1-5-14 × Pa-63-1-7-25 , Pa-11-1-3-7 × Pa-47-1-3, Pa-32-8-7-6 × Pa-47-1-3, Pa-13-1-2-3 × Pa-47-1-3, Pa-11-1-3-7 × Pa-32-8-7-6, Pa-64-1-5-14 × Pa-32-8-7-6 and Pa-64-1-5-14 × Pa-62-4-12-18. High estimates of PCV and GCV were recorded indicating sufficient variability in the germplasm for most of the characters. PCV and GCV showed a range of variation from 14.25% to 67.50% and 14.10% to 67.29% respectively.High estimates of heritability ranges between 83.55% to 99.37% were obtained for different analysed characters and indicate that though the character was least influenced by the environmental effects. The estimates of genetic advance were varied from 2.25% to 336.80% and from 28.73% to 138.17% for genetic advance as % of mean. High heritability coupled with high genetic advance for the characters viz., number of flowers per plant, branch count and days from bud initiation to flowering were recorded and suggested the role of additive gene action in the inheritance of these characters. Hence, simple selection based on phenotypic performance of these traits would be more effective. The estimates of phenotypic and genotypic correlation revealed that flowers per plant was strongly and positively associated with the characters namely number of branches per plant, plant spread, final plant spread, final plant height and duration of flowering at phenotypic and genotypic level. The result of analysis of variance for F₂ indicated that mean sum of squares due to genotypes were highly significant for all the traits studied. PCV was higher than those of GCV for all the traits which indicated greater genotype x environment interactions for the expression of these characters. The estimates of heritability were more than 72.43 percent for all the characters studied for F₂ genotypes. High heritability along with high genetic advance as % of mean for F₂ population were observed for number of flowers per plant, number of branches per plant and days from bud initiation to flowering hence, amenable for simple selection. The different expected ratios were obtained among twenty eight cross combination of F₂ population of pansy for the inheritance of the flower colour.
Open Access
Flowering response of chrysanthemum (Chrysanthemum morifolium Ramat.) genotypes to different photoperiods and quality of light
(Punjab Agricultural University, Ludhiana, 2018) Ranjit Singh; Madhu Bala
The present investigations entitled “Flowering response of chrysanthemum (Chrysanthemum morifolium Ramat.) genotypes to different photoperiods and quality of light” were carried out at the Research Farm, Department of Floriculture and Landscaping, Punjab Agricultural University, Ludhiana, during 2015-18. The experiments were conducted to study the response of standard and spray genotypes to artificial short day conditions. The plants were raised through the rooting of terminal cuttings during February-March and the plants were given short day treatment as night extension using black polythene (100 micron) sheet from civil twilight in the morning to 9 O’clock. The maximum plant height (85.33 cm and 86.00 cm) and plant spread (19.33 cm and 18.67 cm) was exhibited by Boris Becker while number of branches were recorded maximum (5.00 and 5.00) in Punjab Shyamli for both the years. The leaf area index, leaf weight ratio and number of stomata per unit area were not affected significantly. Days to flower bud appearance were recorded minimum (108 and 107.65) in two genotypes viz. Yellow Delight followed by Banglori Local (117 and 110), accordingly early flowering was observed in these genotypes, showing good tolerance towards heat delay. Similar trend was recorded in standard types but none of the genotypes was able to flower early in response to artificial short days. In second experiment different sources of light viz. incandescent bulbs, CFL and LED as night break were used, from 15th August to 31st October, from 10.00 pm to 12.00 midnight to provide long days. Plant spread (25.73 cm and 26.65 cm), days to flower bud appearance (148.34 and 149.25), days to flowering (178.10 and 180.10), flower size (6.85 cm and 7.13 cm) and vase life (12.27 days and 12.55 days) were recorded maximum with LED sources of light as compared to incandescent and CFL. Similarly another experiment was conducted by providing long days with the help of LED lights of red, blue and green colour to investigate the effect of colours of light for night break treatment. The genotypes under red lights exhibited maximum (66.83 cm) plant height, plant spread (18.02 cm), days to bud appearance (142.93 days), days to flowering (170.08 days), flower size (6.69 cm), duration of flowering (31.95 days) whereas stem diameter and vase life was recorded maximum (5.80 mm and 11.27 days, respectively) under blue light. Green lights have resulted in increased content of carotenoids over red and blue LED lights. Similar trend was observed in genotype of standard group. It is thus concluded that the genotypes viz. Yellow Delight and Banglori Local among spray type were suitable for year round flower production as they have exhibited tolerance against heat delay. Among the different sources and colours of light, light emitting diodes (LED) with red colour light were found suitable for effective photoperiodic control for growth and flowering in Chrysanthemum.
Open Access
Effect of growth regulators on in vivo budding in roses (Rosa hybrida L.)
(Punjab Agricultural University, Ludhiana, 2017) Prabhjit Kaur; Grewal, H.S.
The present investigations entitled “Effect of growth regulators on in vivo budding in roses (Rosa hybrida L.)” were carried out on the Research Farm, Department of Floriculture and Landscaping, Punjab Agricultural University, Ludhiana, during 2014-16. The experiments were conducted to study the effect of auxin on the rooting of the budded cuttings and cytokinin on bud take in Rosa hybrida L. in two different cultivars, viz. First Red and Grand Gala. The mature shoots (>1 yr old) of rootstocks, viz. R. indica var. odorata, R. multiflora and R. bourboniana were used for making the stem cuttings. In Experiment I, rootstock cuttings (8-9 inches long, pencil thickness) were treated with different concentrations of IBA for rooting and budded with the scion of rose cvs. First Red and Grand Gala in December- February. In Experiment II, the rootstock cuttings were treated with IBA 1500 mg L-1 for rooting and budded with the scion of rose cvs. First Red and Grand Gala after treating with BAP concentrations in December- February. The type of rootstock and growth regulators treatments significantly (p<0.05) affected the plant growth and flowering of two rose cultivars. The per cent sprouting, survival, shoot length, plant height, number of leaves and flowers per plant were observed the highest in rootstock R. indica var. odorata, whereas, per cent rooting and number of branches were at par in R. indica var. odorata and R. multiflora. The IBA treatment T4 (2000 mg L-1) was found the best regarding per cent sprouting (85.00, 81.67) and rooting of cuttings (91.67, 96.67) survival (68.34, 65.00), shoot length (13.64 cm, 16.29 cm), plant height (20.60, 20.66 cm), number of branches (3.20, 2.84), leaves (9.61, 10.94) and flowers per plant (3.08, 2.07) in rose cv. First Red and Grand Gala, respectively. The best BAP treatment for per cent sprouting (91.66, 88.34), survival (86.67, 86.67), shoot length (15.01 cm, 17.94 cm), plant height (23.01 cm, 24.15 cm), number of branches (3.53, 3.39), leaves (9.95, 11.31) and flowers per plant (2.21, 2.50) was in T4 (BAP 20 mg L-1) in rose cv. First Red and Grand Gala, respectively. It was concluded that the rootstock R. indica var. odorata performed better for First Red and Grand Gala among the different rootstocks tested. The auxin and cytokinin improved the vegetative growth and flowering of the rose plants. The treatment of cuttings with IBA @ 2000 mg L-1 and scion bud with BAP @ 20 mg L-1 were the best for the plant growth and flowering of cv. First Red and Grand Gala budded on R. indica var. odorata rootstock.
Open Access
Induction of mutagenesis in gladiolus through gamma irradiation
(Punjab Agricultural University, Ludhiana, 2017) Dogra, Neha; Dhatt, K. K.
The present investigations entitled “Induction of mutagenesis in gladiolus through gamma irradiation” was undertaken at research farm, Department of Floriculture and Landscaping, Punjab Agricultural University, Ludhiana, during 2014-17. The experiments were conducted to induce variability in gladiolus through gamma irradiation under in vitro and in vivo conditions. The corms of gladiolus variety ‘Punjab Glance’ and ‘Sylvia’ were irradiated with different doses (0, 50,100,125,150 Gy) of gamma rays and planted in October at a spacing of 30x20 cm. The maximum survival per cent, sprouting per cent, plant survival, plant height and leaf number were reported to decrease with the increase in gamma rays dose above 100 Gy. The corms of ‘Punjab Glance’ treated with lowest dose at 50 Gy sprouted after 15.29 days and the same variety at 150 Gy took 23.15 days to sprouting. Maximum spike lengths, florets per spike, floret size were recorded in corms treated with 50 Gy. The shortest spikes with lowest number of florets in small size were recorded at 150 Gy. The corm multiplication in terms of corm and cormels per plant was found to reduce with increased dose of gamma rays. The leaf abnormalities were observed in terms of changes in leaf shape, leaf size, and leaf margin and leaf apex. Total abnormalities in floral characters were higher in 150 Gy. Treatment of corms at 100 Gy resulted in bud fasciation and asymmetrical development of spike in both the varieties. Five mutants were isolated from variety ‘Punjab Glance’ for flower colour under in vivo treatment, one at 100 Gy, two at 125 Gy and two at 150 Gy. The nodal buds of both varieties were raised in MS medium and bud clumps were irradiated with different doses of gamma rays (Co60) 0, 5, 8, 10 and 12 Gy. Irradiated explants were then cultured aseptically on MS basal medium supplemented with 5 mg/l (BAP) + 2mg/l (IBA) and agar-agar to induce shoot and root proliferation. It took 14.27 days for shoot formation, 15.10 days for root and 62.33 days for cormel development at 8 Gy dose. The maximum shoot length (6.19 cm), root length (8.01 cm) and maximum number of shoots and roots per callus were recorded at 8 Gy dose. The gamma rays doses of 5 and 8 Gy were found to be optimum for the induction of mutagenesis under in vitro in gladiolus variety ‘Punjab Glance’ and ‘Sylvia’ with respect to plant sprouting and survival of plant raised from cormels. The cormels raised through in vitro after gamma irradiation were planted in the field and evaluated for morphological parameters. One cormel produced small cormlets within 60 days in both varieties. This study developed a mutagenesis protocol that could be used to develop novel colour mutants in gladiolus.

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