IMPROVING FORAGE PRODUCTION OF ELEPHANT GRASS (Pennixetum purpureum) AND SORGHUM (Sorghum bicolor) THROUGH INDUCED MUTATION

Abstract

Elephant grass and sorghum plants have long been cultivated in the tropics as feed crops. In some areas, sorghum is also cultivated as food crops while its by products are used for feeding. Researches on breeding these plants have been carried out at PAIR-BATAN with the objective to improve their forage production for ruminant feed. Genetic variability of the plants were induced through mutations using gamma irradiation treatments from Cobalt-60 source to the vegetative parts
of elephant grass and to the seeds of local sorghum variety Keris. The irradiation dose up to 0.5 kg with the dose rate of about 39 gy/minute was used. The first generations of the treated plant (M1) were grown in the greenhouse. The M2 and M3 plants were planted individually in the experimental stations nearby using completely randomized design. Samples of about 200 plants were chosen
randomly for each population in the M2 and M3. The sample plants were cut 20 cm above ground surface at 40 days afier planting/sowing. Two weeks later observations were done for the ability of plants to produce new buds or tillers. The stem/leaf ratio and the plant total biomass, measured by its dry weight, were observed 40 days after cutting. Plants having superior attributes for bud (tiller)
production, stem/leaf ratio, and biomass production in the M2 were selected and replarrted in the M3. Some promising lines were formd to have better attributes than the control plants, but they seemingly segregated in the M3. Research on breeding these segregated lines would be continued until they become homozygotes. Feed quality (nutrition values, digestibility, and palatability) will
be analysed for the homozygote plants.