The screening of mutants and construction of mutant library for Oryza sativa cv. Nipponbare via ethyl methane sulphonate inducing

Abstract

Following the sequencing of rice genome, the functional analysis of unidentified genes is gaining wide importance. Mutant isolation is one of the effective ways to isolate and clone the target genes and analyze their functions. To find the various mutants in the same genetic background, seeds of Oryza sativa cv. Nipponbare were treated with ethyl methane sulphonate (EMS). A total of 1056 mutants were screened for five categories in M2 generation with the seedling frequency of 26.29‰ at three-leaf stage, but only 264 mutants were verified in M3 generation with a frequency of 6.57‰. Among the mutants verified in M3 generation, the frequency of leaf mutation was the highest (2.22‰), followed by seedling height (1.74‰) and the abiotic stress tolerance mutant (1.47‰). Nineteen characteristic mutations, including a big group of abiotic stress tolerant mutants such as herbicide resistant, salt tolerant and drought tolerant were identified at this stage. By observation of rice growth characteristics at different developmental stages, another 220 mutants have been isolated and verified in the M3 generation with the mutant frequency of 53.9‰ covering about 28 mutant traits. Among those identified, the highest frequencies were obtained for appearance of brown rice mutant with 18.37‰, followed by panicle mutant with 13.47‰, and grain mutants with 9.06‰. All the mutants screened above were suitable for gene function analysis and for utilization in agronomy.

The screening and preliminary construction of quality mutant population for cultivar “Nipponbare” in japonica rice (Oryza sativa)

“…Thus chemical mutagenesis has been regarded as a reliable method together with mapping and cloning to isolate and characterize genes (Thang et al 2010). …”

“…Nipponbare which the genome sequencing has been completed was selected as the material, and a morphological (but not quality related) mutant library induced by EMS for the variety has been reported (Thang et al 2010). The seeds of this variety were chemically mutagenized for screening the quality mutants and construct a library with different kinds of quality mutants.…”

Water-deficit tolerant classification in mutant lines of indica rice

“…Rice crop (Oryza sativa L.) improvement including conventional breeding program (Jongdee et al, 2006;Venuprasad et al, 2007;Kumar et al, 2008;Ndijiondjop et al, 2010;Guan et al, 2010) and mutant lines (Koh et al, 2007;Jiang et al, 2007;Cairns et al, 2009;Thang et al, 2010) is one of the strategies for water-deficit tolerant trait. Chemical and irradiation techniques are conventionally approached to induce mutation in a large population of mutant lines and pyramiding drought tolerant trait (Cairns et al, 2009;Thang et al, 2010). Plant biochemical changes, such as enhanced accumulation of stress metabolites and increased antioxidant enzymes are evidently expressed in plant responses to water deficit stress.…”

Screening ofChinese cabbage mutants produced by60Co γ‐ray mutagenesis of isolated microspore cultures

“…The alkylating agent ethyl methanesulfonate (EMS) has been widely used in the construction of mutant libraries of Arabidopsis thaliana and rice (Thang et al 2010). Chemical mutagenesis has several benefits.…”