Mutation breeding

About: Mutation breeding is a research topic. Over the lifetime, 531 publications have been published within this topic receiving 6730 citations. The topic is also known as: variation breeding.

Frequency and spectrum of chlorophyll mutations in greengram [Vigna radiata (L.) Wilczek].

Abstract: Greengram [ Vigna radiata (L.) Wilczek], popularly known as mungbean, is third most important pulse crop of India. Mungbean is a cheap source of dietary protein for the poor, with high levels of folate and iron compared with many other legumes. Variability is low available in mungbean and hence, to replace conventional breeding, mutation breeding has gained its momentum. Induced mutagenesis thus seems to be an ideal methodology for the induction of desirable genetic variability. Chlorophyll mutations, an important index in the estimation of induced genetic changes in mutagen treated population are most widely employed for assessing the potentialities of mutagens in creating genetic variability. An investigation was carried out in two mungbean genotypes CO (Gg) 7 and NM 65 treated by two mutagens viz ., gamma rays and ethyl methane sulphonate. A wide range of chlorophyll mutations was observed and scored in M 2 generation. The highest frequency rate was noted at 300 Gray and 10 mM on M 1 plant basis and M 2 seedling basis in both the genotypes. The mutant chlorina and xantha occurred in all the treatments of gamma rays and EMS at higher proportions.

Molecular characterization of chemical mutagenesis induced diversity in elite maize germplasm

Abstract: Three classical breeding Iowa Super Stiff Stalk (SSS) inbred lines B37, B73 and B84, one Lancaster inbred Oh43 and mutant lines obtained by chemical mutagenesis followed by mutation breeding as follows: two of B37 and four of Oh43 were selected for molecular characterization. The mutant inbred lines were chosen because in addition to the improved GCA and SCA for grain yield, proven by their predominance in the Bulgarian breeding programs, they showed shifts in the flowering time as compared to the initial inbreds. Molecular markers (micro satellites and other PCR-based DNA markers) were used for characterization of maize genotypes and determination of the induced by chemical mutagenesis genetic variability in maize germplasm. The tested nine SSR markers (umc 1001, umclO14, umcl057, umcll81, umcl0lS, umc 1029. umcl003, umc 1033 and umcl035) can discriminate between the initial classical breeding inbred lines and the originating mutant inbreds. Allelic diversity was also studied by PCR amplification with specifically de-signed primers in the coding regions and flanking sequence of two genes: dwarf8 (d&: chromosome 1, 198.5 cM), and indeterminate l (id1; chromosome 1. 175.0 cM). These are considered candidate genes for variation in plant height and/or flowering time, based on mutant phenotypes and chromosomal locations near major QTLs. Single nucleotide polymorphisms and indels were detected in the region flanking the SH2 domain of dwarf8 gene in some of the mutant inbreds as a result of SSCP and sequencing analyses. However, these polymorphisms could not be associated with the observed variations in flowering time. PCR analysis of the promoter region dwarf8 showed a variant fragment of about 1 kb in the inbred line Oh43 that was not present in any other initial and mutant in-bred lines included in the study. PCR amplification of the 5' end of the Id1 coding sequence revealed polymorphic bands in the mutant lines XM535, XM521, XM250-l, XM98-8 and XM85-105, as well as in the classical breeding line B73. The data, presented here demonstrate the usefulness of chemical mutagenesis for generation of genetic diversity within the elite maize germplasm. Some of this variation may affect the major genes in the QTLs. Our initial data revealed mutagenesis induced polymorphisms in the coding sequences of two important for the determination of flowering time transcription factors. Further molecular analyses of the proposed model systems may complement the trait association efforts and will help to directly identify the major genes in the QTLs.

Development of high yielding aromatic mutants of rice (Oryza sativa L.) from a local aromatic cultivar, Tulaipanji by using gama radiation

Abstract: Mutation induced variability is an important method in plant breeding to create non-existing desirable genotype(s) for crop improvement. In this endeavour, gamma radiation was used to create variability for improving plant type and yield attributing traits in a local aromatic cultivar, Tulaipanji. Eight desirable mutants were identified from M4 generation. All those eight mutants induced from Tulpanji were photoperiod-insensitive, non-lodging, semi-dwarf with high yield potential and retained the aroma. Mutants TP3-2, TP3-4 and TP3-6 showed high increase in yield (>89%) over the control cultivar, Tulpanji. As the mutants were photoperiod insensitive, they may be recommended for cultivation for both boro and kharif seasons after necessary trials and demonstrations.

Mutation Breeding of a N-methyl-N-nitrosourea (MNU)-Induced Rice (Oryza sativa L. ssp. Indica) Population for the Yield Attributing Traits

Abstract: Difficulties in breeding new rice cultivars that have a high yield, are acceptable quality, and are tolerant to environmental stresses have been the major constraint of rice production in many developing countries, as these traits are determined by multiple genes associated with complicated and uncontrollable gene segregations.Furthermore, the gene/QTL (quantitative trait locus) introduced to the cultivar is unstable due to the interaction among the active genes, which determine the phenotypic performance, not yet been well understood or controllable. In this study, the N-methyl-N-nitrosourea (MNU)-induced mutation was applied to the heterozygote of the F1 generation from the cross between TBR1 (female) and KD18 (male parent). The phenotype and genotype of the M2 and M3 generations were evaluated and showed that the mutant population phenotypes, including the plant height, semi-dwarfism, amylose content, protein content, gel consistency, grain yield, and spikelet fertility, varied. Interestingly, no segregation among the genotypes in the M2 and M3 generations was observed, while the genotypes of the control population were either paternally inherited or indeterminable when using 28 polymorphism simple sequence repeat (SSR) markers that were identified on parental lines from 200 markers. The MNU-induced mutation caused maternal inheritance in the segregating populations, as primarily important agronomic traits were maternally succeeded from the female line TBR1. The findings of this study indicated that, through the use of MNU, the breeding of rice cultivars with close genetic backgrounds (similarity coefficient = 0.52) could be shortened by the maternal control of important qualities, such as pest and disease resistance and high yield, thus contributing to sustainable rice production for rice farmers. Further examination of rice cultivars with a greater difference in the genetic background should be subsequently conducted.