Document Type : Original Article
Authors
1
Department of Agricultural Biotechnology, Faculty of Agricultural Sciences, University Campus 2, University of Guilan, Rasht, Iran
2
Department of Agricultural Biotechnology, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran
3
Rice Research Institute of Iran, Agricultural Reaserch, Education and Extension Organization (AREEO), Rasht, Iran
4
Rice Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Amol, Iran
20.1001.1.23831367.1399.7.1.3.0
Abstract
Mutagenesis has been one of the important sources of genetic diversity and Plant mutants can be important
bio-resources for crop breeding and functional genomics studies. Breeding conventional methods for
generating of genetic variability are of low efficiency. We showed that treatment of seeds of rice(Hashemi
cultivar) with 0.8% EMS for 8 h caused visible phenotypic variations on M2 rice mutant genotypes
including flowering date, plant height, number of fertile tiller, panicle length, number of filled and unfilled
grains per panicle, grain width and length, 100 grain weight and grain yield. The phenotypic variation
coefficients of most traits found to be more than the genetic variation coefficients. The number of filled
grains per panicle and seed length had the highest and lowest general heritability, respectivly. The seed
yield had also high heritability. Analysis of correlation between different characteristics in the mutant
genotypes showed that the number of fertile tillers and the number of unfilled grains per panicle had
positive correlation with yield. Also, grain yield exhibited positive and significant correlation with panicle
length, number of tillers and number of filled grains at genotypic level. In multiple regression analysis by
stepwise method, number of tillers, number of filled grains per panicle, 100-grain weight, and grain width
entered into the model, respectively, that explained 96 percent of grain yield variations. Results of grain
yield and its components path coefficient analysis showed that the number of tiller had the highest direct
effect (0.77) through than other traits on grain yield and, therefore it can be considered as major trait in
grain yield improvement in rice. Also, based on results of this research and by using optimal selection
index, mutant genotypes EM 18-17-5 and EM 15-14-1 were selected as superior mutant genotypes. This
mutant population is expected to be serves as a genetical resource for understanding rice biology as well as
for use in genetic improvement of quantitative traits.
Keywords
