Genetic Behavior of Five Induced Dwarf Mutants in an Indica Rice Cultivar¹

Abstract

The genetic control of dwarfism was studied in the mutants induced by the chemical mutagen ethyl methanesultanate in a tall indica rice (Oryza sativa L.) cultivar, ‘Tellakathera’. The five dwarfs were, dwarf‐6(d0), dwarf‐ 7(d7), dwarf‐8(d8), dwarf‐9(d9), and dwarf‐10(d10). In crosses of the dwarfs with the tall parent, F1 plants were tall and the F2 plants segregated three tall to one dwarf, suggesting that each of these dwarfs is controlled by a single recessive gene. Crosses among the dwarfs produced tall F1, plants and a dihybrid segregation pattern of nine tall to seven dwarf plants in F2, indicating these five dwarfing gene loci were nonallelic to each other.

Seed viability, germination and seedling growth of canola (Brassica napus L.) as influenced by chemical mutagens

“…In their study, the optimum dosages for mutation induction were 0.7 to 0.9% EMS as determined by the LD 50 criterion. The optimum dosage of EMS for rice was 8 h treatment with 1% EMS according to Padma and Reddy (1977). Compared to the control, treatment with the 12 mM ENU solution for eight hours and non-soaking pre-treatment induced 50% reduction in germination percentage in canola seeds (Table 3) and this treatment would, hence, be an optimal dose of ENU in mutagenic studies.…”

“…Chemical mutagenesis has a number of inherent attractions such as the ability to use different mutagens, change mutagen doses and to easily scale the size of the mutagenesis procedure. Optimization of the mutation induction conditions in each plant species plays a critical role in the successful employment of the mutagenic events (Padma and Reddy, 1977). Breeders must be aware of the genetic structure and responses of plant genotype to a mutagen because frequency and type of induced mutation depends on plant genotypic background, mutagen concentration and pre and post-treatment conditions.…”

Determinación de la DL50 de Metanosulfonato de Etilo (EMS) para la inducción de cambios morfológicos y fisiológicos en plántulas de Plukenetia volubilis

“…Para el empleo de agentes mutagénicos la optimización de las condiciones de inducción varía en cada especie de planta, constituyéndose un paso crítico para el éxito de los eventos mutagénicos (Padma & Reddy, 1977). En tal sentido, es necesario determinar la dosis letal 50 (DL50), la cual se usará como criterio para definir la dosis mutagénica óptima, que contribuyen al 50 de letalidad.…”