INDUCED MACROMUTATION IN ANDROGRAPHIS PANICULATA (BURM. F.) NEES

Fourteen viable macromutants (viridis, lax branching, bushy, unbranched I and II, dark green leaf, broad leaf I and II, narrow leaf I and II, drooping leaf I and II, dwarf and early maturity) were induced in Andrographis paniculata (Burm. F.) Nees (Family: Acanthaceae) at M2 following EMS (Ethyl methanesulfonate) and dES (Diethyl sulfate) treatments (0.25, 0.50 and 1.00% for 2h and 4h durations) to dry seeds (moisture content 11.55%). Mutation frequency over M2 population was 2.82% and lax branching mutant was maximum (0.51%). EMS induced relatively higher (3.12%, spectrum 1 to 4) frequency of mutation than dES (2.46%, spectrum 1 to 3). The mutant trait(s) were monogenic recessive mostly (viridis showed digenic mode of inheritance). All mutants bred true at M4. Meiotic analysis revealed 2n=50 chromosomes always in the plant types (control: 24.92II+0.51I/cell; mutants: 24.80II+0.40I to 25II/cell at MI; AI cells were cytologically balanced in all cases). Pollen fertility (control: 80.63%, mutants: 21.28% to 89.25%) and viability (control: 72.24%, mutants: 27.55% to 59.04%) were also assessed. DAPI staining was performed to assess pollen nuclei composition (3-nucleate stage) in dark green leaf, broad leaf I and drooping leaf II as the mutants showed considerably lower pollen fertility and viability than normal plants. Results indicated that pollen developmental phase may be significant for reproductive outcome. Andrographolide (estimated from matured leaves by HPTLC) content (control: 3.41%, mutants: 0.03 to 3.99%) was significantly higher in bushy and broad leaf I and II than normal plants. The mutants induced were considered to be important genetic resources in the plant species.