Effects of Colchicine on the Morphology and Agricultural Characteristics of RD.43 Thai Rice Variety

Background: Rice (Oryza sativa L.) is the staple food of the Asian population. Rice breeding will help the rice to withstand unsuitable environmental conditions while providing greater yield and palatability. Induction of rice polyploids can help improve desirable characteristics in rice. The objective of the study was to induce polyploids in Thai rice, which is genetically different from foreign rice. Methods: Colchicine concentrations of 0.0, 0.1, 0.15, 0.2 and 0.25 percent had been applied to 2-day-old germinated rice grains for 2, 4 and 6 hours. After that, rice agronomic characteristics and yield component were studied. To indicate polyploid rice, flow cytometry technique and awn seed characteristics were applied. Result: The results showed that colchicine concentration and exposure time influenced germination and seed abnormalities. Colchicine concentration also influenced leaf number, shoot number, leaf width, leaf length and SPAD value. Exposure time influenced the number of leaves. In light of yield component characteristics, colchicine concentration influenced the total number of seeds, full seed number and seed width. Exposure time influenced number of grains, total number of seeds, number of whole seeds, number of atrophied seeds, full seed weight and seed width. Rice plants that had awn seeds (8.33-58.33 per cent) were grown from the seeds that received colchicine. The experiments had shown that colchicine influenced on morphology and yield component traits. T15 (colchicine 0.25%, exposure time 6 h.) had the most plants with awn seeds, followed by T9 (colchicine 0.5%, exposure time 6 h) and T11 (colchicine 0.2%, exposure time 4 h), respectively.