Characterization of Chromosomes and Main Phenotypes of Rice Plants from Plant Breeding in Kedungbondo Region, Bojonegoro Regency

Abstract

Indonesia is a countries with the second largest production of rice (Oryza sativa) in Southeast Asia. Increasing the productivity is an important effort to supporting community food security. This research is a descriptive observational study by describing the purpose of characterizing chromosomes in rice varieties of ciherang, IR 64, and K90 based on mitotic time, number of chromosomes, and phenotypic characterization. Observation of mitotic time and chromosome number was carried out using the squash method. Phenotypic characterization was carried out based on plant height, stem diameter, stem shape, stem color, stem surface, leaf vein shape, leaf tip, leaf edge, leaf color, leaf surface, leaf midrib color, bract length, bract width, panicle length, number of productive tillers, and the number of grains per panicle. The results showed that there were differences in the optimum time of cell division, iherang variety occurred at 12.00 WIB with a proportion of 6.94%, the IR 64 variety occurred at 09.00 WIB with a proportion of 23.58%, and the new variety K90 occurred at 09.00 WIB with a the proportion of 6.85%. The number of chromosomes of the three rice varieties is the same, namely diploid chromosomes. Phenotypic characterization showed that new variety K90 rice plants had superior characters in terms of plant height, stem diameter, bract length, panicle length, and number of grains produced per panicle which could improve productivity. The results of the characterization can be used in efforts to cultivate and utilize new superior varieties of rice, as well as help increase the quantity and quality of rice plant productivity.