Effect of Growth Regulators on in Vitro Micropropagation and Morpho-molecular Characterization in Carnation (Dianthus Caryophyllus L.)

Abstract

An investigation was carried out to assess the “effect of growth regulators on in vitro micropropagation and morpho-molecular characterization in carnation (Dianthus caryophyllus L.)” during the year 2016-17. Among all the tested media combinations for shoot induction, best results were recorded on culture media MS-19 supplemented with MS basal medium + 1.5 mgL-1 BAP + 0.25 mgL-1 TDZ + 0.5 mgL-1 AgNO3. The culture media MS-3 supplemented with 0.5 mg/L NAA and 1.0 mg/L IBA exhibited best rooting responses in carnation vr. Irene. The minimum hyperhydricity rates were recorded on culture media MS-7 consisting of 36 mgL-1 AgNO3. The studies indicated that AgNO3 can be used for decrease hyperhydricity problem in carnation tissue culture raised plantlets. Genetic stability analysis indicated that both primers (SSR and ISSR) exhibited the monomorphic nature of DNA banding patterns. The absence of polymorphism confirms the true to type nature of in vitro raised carnation plantlets. Studied 25 carnation varieties were characterized on the basis of various morphological characters. The morphological data showed that the maximum plant height (70.11cm), stem length (66.85 cm), leaf pairs per stem (14.13), flower diameter (5.90) was recorded in cv. Rebra, while, maximum flower duration (13.15 days) was recorded in cv. Irene. However minimum days taken to bud appearance (91.17 days) were found in cv. Tabor and days taken to bud opening were recorded with cv. Irene (108.12 days). High heritability coupled with high genetic advance expressed as per cent of mean were observed for leaf pair /stem, flower duration, days taken to bud appearance and stem length. This indicated the influence of additive gene action for expression of these characters. Flower diameter showed positive and significant correlation with flower duration, leaf pair/stem, stem length and plant height at both genotypic and phenotypic level which indicated that by improving these traits, improvement in flower diameter could be achieved under selection. Flower duration and days taken to bud appearance displayed high order of direct effect on flower diameter at both phenotypic and genotypic levels. Twenty five genotypes of carnation were grouped into 3 different clusters. Clustering pattern in this situation exhibited considerable differences which indicated that it would be logical to examine genetic divergence in this environment individually for genetically reliable information. The present study exhibit the potential role of SSR and ISSR markers for discriminating of 25 carnation varieties. Moderate genetic diversity was recorded in studied carnation varieties. Among 25 carnation varieties, only 5 varieties including Golern, Liberty, Gaudina, Lavender-Lace and Domingo were found to be highly diverse. These varieties could be used as parent in breeding programme for introgressing of desirable economic trait in carnation improvement.