ABSTRACT
In this study, we developed a mutagenesis protocol specifically designed for chrysanthemum cv. "Candid" in order to introduce genetic variation. By subjecting chrysanthemum shoots to different doses of physical and chemical mutagens, we successfully generated a total of 24 mutants, each with unique genetic compositions. We observed that the mortality rate was lowest when the shoots were exposed to 10 Gy gamma irradiation and 1.00% EMS. To assess the diversity and relatedness among the mutants, we employed RAPD and SSR markers. The combination of these markers allowed us to construct a dendrogram that effectively categorized the mutant population into distinct clusters based on the specific mutagen treatments. Interestingly, the mutants induced by 10 Gy gamma irradiation exhibited greater genetic diversity in terms of flower colors. On the other hand, mutants created with 1.00% EMS displayed a higher level of variation and yielded more viable mutants. To determine the optimal markers for studying genetic diversity, we analyzed the polymorphic information content (PIC) of different markers. Among the tested markers, OPA-07 (RAPD) and JH47 (SSR) showed the highest PIC values, indicating their effectiveness in capturing genetic variability within the mutant population. Conversely, the PIC values of OPD-07 and JH20 demonstrated the lowest among the markers tested. Our results revealed a percentage of polymorphism ranging from 81.81% to 100% for RAPD markers and 66.66% to 100% for SSR markers. These findings indicate that physical mutation induced by 10 Gy gamma irradiation can be clearly distinguished from chemical mutation induced by EMS at concentrations of 1% and 0.75% in chrysanthemum cv. "Candid.â³ Overall, this study provides valuable insights into the genetic composition of the generated mutants and highlights their potential for enhancing chrysanthemum-breeding programs. The identified markers, particularly, OPA-07 and JH47, can serve as valuable tools for future studies aimed at exploring and exploiting the genetic diversity within the chrysanthemum population.
ABSTRACT
Present investigation was carried out to arrive at an effective micropropagation protocol for Winter Jasmine (Jasminum nudiflorum) using nodal segments from actively growing plants as explants. Explants were collected from current season shoots during April-May just after the initiation of new flush. Combined sterilization treatment of explants with 1.0% NaOCl2 for 10 min followed by 70% ethanol for 10 s recorded highest culture survival (63.88%) and optimum culture asepsis (63.88%) followed by the treatment containing 0.1% HgCl2 for 10 min followed by 70% ethanol for 10 s with culture survival (61.11%) and culture asepsis (69.44%). Highest culture establishment (80.55%) and minimum days to bud sprouting (7.62 days) was recorded with Benzyl adenine + Kinetin (3.0 + 1.0 mgL-1) but maximum length (4.33 cm) and leaf number (7.78) of established micro shoots was recorded with Benzyl adenine + Kinetin (1.0 + 0.5 mgL-1). Maximum proliferated shoots (2.41) and an optimum proliferation percentage (77.78 %) was recorded with Benzyl adenine + Kinetin (3.0 + 0.5 mgL-1). Minimum size of proliferated shoots (2.02 cm) was recorded with Benzyl adenine + Kinetin (3.0 + 1.0 mgL-1) followed by 2.25 cm recorded with Benzyl adenine + Kinetin (3.0 + 0.5 mgL-1). Highest rooting (63.93%), primary root number/microshoot (4.74) and longest primary roots (34.67 mm) were recorded with IBA (2.0 mgL-1). IBA yielded better results than NAA in terms of higher rooting percentage and root number. However, days to root initiation were found minimum (22.00) with 2.0 mgL-1 of NAA. Highest ex vitro survival of rooted microshoots (89.67%) was recorded with IBA (2.0 mgL-1).
ABSTRACT
Micropropagation protocol of Oriental Hybrid Lilium cv. Ravenna was developed using bulb scale segments (Basal and Tip) as explants. Surface sterilization of healthy bulb scales with carbendazim 200 ppm for 30 min, then 0.1 percent mercuric chloride for 10 min, then 70% ethyl alcohol for 30 s was superior to all other treatments in recording highest culture asepsis (77.08%) and higher explant survival (86.12%). Explant survival was higher in basal segments (88.54%) compared to tip segments (85.52%). Highest culture establishment was recorded in basal scale segments (68.26%) followed by tip scale segments (55.21%). MS medium augmented with 0.50 mgl-1 Naphthalene acetic acid and 2.0 mgl-1. 6-Benzylamino Purine recorded maximum culture establishment (76.17%), highest bulblet number/explant (5.52) with maximum length of shoots (2.20 cm) and number of leaves (3.39). This treatment combination of growth regulators resulted in highest shoot proliferation (83.33%) along with maximum shoot number (2.41explant-1), shoot length (2.35 cm) and leaf number (5.44) of micro shoots during proliferation stage. Rooting of explants was superior with Indole-3-butyric acid compared to Naphthalene acetic acid. Highest rooting of 92.71% along with maximum number of primary roots shoot-1 (12.06), maximum primary root length (3.17 cm) was documented in Murashige and Skoog medium added with Indole-3-butyric acid 1.50 mgl-1 with best ex vitro survival rate (98.96%) of rooted plantlets during primary hardening in perlite + vermiculite (1:1) mixture.
ABSTRACT
An efficient protocol for in-vitro propagation of an important ornamental crop, Petunia hybrida Vilm. Cv. "Bravo" was developed. The explants that were used to carry out the experiment were Leaf segments, nodal segments and shoot tips. Nodal segments recorded highest per cent asepsis followed by shoot tips and leaf segments. Asepsis was found to be highest when the explants were sterilized with Fungicide (Carbendazim) 0.02% for the duration of 30 min followed by 0.1% HgCl2 for duration of 10 min and then ethanol 70% for 10 s. Longer duration of the sterilant treatment showed more necrotic effects on the explants, thus mercuric chloride treatment when given for 5 min proved to be more effective in terms of survival of the explants. Maximum establishment per cent was recorded in Murashige and Skoog (MS) media fortified with BAP (1.5 mg L-1) and IBA (0.5 mg L-1) in shoot tips and nodal segments, i.e. 97.90 and 95.74% respectively. Callus was efficiently induced and developed when PGR amalgamation of BAP (0.1 mg L-1) and 2,4-D (1.5mg L-1) was used. Kinetin at the concentration of 2.0 mg L-1 along with IBA at 0.5mg L-1 recorded highest callus regeneration in both leaf and internodal segment derived callus. Maximum proliferation percent of shoots (97.90%), highest number of shoots (20.50 explant-1) and maximum length of shoot (2.70 cm) was recorded in PGR combination of IBA and BAP both at 0.5 mg L-1 concentration level. Rhizogenesis was recorded to be highest in the MS media containing IBA 1.00 mg L-1. Best hardening media which recorded maximum survival per cent 92.50% was noticed on the media formulation comprised of equal ratio of perlite and vermiculite mix, under poly house conditions.
