Candidate gene markers based molecular profiling for grain zinc accumulation in rice
| dc.contributor.advisor | Sharma, V.K. | |
| dc.contributor.author | Kumari, Kumkum | |
| dc.date.accessioned | 2020-02-10T10:21:42Z | |
| dc.date.available | 2020-02-10T10:21:42Z | |
| dc.date.issued | 2018 | |
| dc.description.abstract | A study was conducted to determine the genetic variation and divergence in relation to grain zinc accumulation amongst rice varieties using candidate gene based panel of reported primers and to examine the genetic importance of zinc transporter candidate gene based panel of designed primers in discrimination for differential zinc accumulation amongst rice varieties. Twenty-eight locally adapted varieties and advanced breeding lines of rice were evaluated in randomized block design with three replications and the seeds collected after harvesting of the crop were utilized for determination of zinc content in unpolished grains. Eighteen entries selected from the two extremes of grain zinc distribution range constituted the final experimental material and utilized during molecular characterization. Genomic DNA was extracted from two to three weeks old seedlings of purposefully selected set of 18 varieties and then targeted amplification of the genomic DNA was achieved by using a panel of 14 candidate gene specific 14 reported primers and 14 designed primers. Exploitable extent of variability was observed with respect to grain zinc accumulation amongst the set of 28 rice varieties initially evaluated as experimental materials. Zinc content, which varied from 8.18 ppm to 21.53 ppm, was found to be considerably higher in unpolished grains of RAU 3036, Sanwal Basmati, Rajendra Nilam and Rajendra Bha gwati. Using a panel of 14 candidate genes specific 14 reported primer pairs, reproducible amplification was successfully achieved with 12 primer pairs amongst which only eight primer pairs generated polymorphic amplified products. Successful amplification with two candidate genes specific reported primers, namely, OsNAC and OsNRAMP6a was notachieved. Contrarily, each of the 14 designed primer pairs exhibited reproducible amplification, but polymorphic amplified products were generated with only eight primer pairs. Appearance of amplified products in the form of bands at different positions on the gel revealed differential migration due to differences in overall size of the products generated from targeted amplification of specific region of genome. Molecular level genetic polymorphism among the entries was recognized on the basis of variation in respect of position of bands. Ample genetic differentiation and divergence was revealed at the molecular level amongst the rice varieties subjected to molecular characterization using the candidate genes specific and polymorphic panels of reported as well as designed primer pairs. Results from reported primers and designed primers based analysis were in well agreement with each other. Furthermore, hierarchical classification pattern of rice varieties was almost completely corroborated by principal coordinate analysis based spatial distribution pattern of genetic profiles of rice varieties. Hierarchical cluster analysis as well as principal coordinate analysis based on a combination of polymorphic and informative eight reported and eight designed primer pairs provided better expression of differentiation and divergence amongst the rice varieties subjected to molecular characterization. Thus, the use of 14 candidate genes specific 16 polymorphic markers in the genetic analysis exhibited a remarkably higher level of genetic polymorphism, which allowed unique genotyping of eighteen entries included in the analysis. Hence, these markers can be effectively and efficiently utilized for grain zinc accumulation related discrimination of rice genotypes and selection of parental genotypes for genetic improvement in relation to grain zinc biofortification. Microsatellites were detected within the candidate genes and within the amplicons, thereby providing a basis to deduce that the variation present in candidate genes, as observed in terms of differences in the molecular size of the genomic regions spanned by the primer pairs, may be a role player in the differential grain zinc accumulation in rice varieties. Single marker analysis established the association of four markers, namely, OsNACK, OsZIP1-1, OsNRAMP7 and OsNRAMP7K with grain zinc accumulation. These four markers can be effectively used in marker-assisted selection program for grain zinc biofortification in rice. Inter-crossing diverse genotypes from different clusters can lead to successful pyramiding of desirable alleles through molecular breeding program. Parental genetic diversity will undoubtedly increase the probability of identifying desirable recombinants during screening for improvement in relation to grain zinc biofortification. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810142817 | |
| dc.keywords | Agriculture, Plant Breeding, Grain, Rice, Genetics, DNA, | en_US |
| dc.language.iso | en | en_US |
| dc.pages | 61p. ; ix(Bibliography) | en_US |
| dc.publisher | Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur | en_US |
| dc.sub | Agricultural Biotechnology | en_US |
| dc.subject | null | en_US |
| dc.theme | Candidate gene markers based molecular profiling for grain zinc accumulation in rice | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | Candidate gene markers based molecular profiling for grain zinc accumulation in rice | en_US |
| dc.type | Thesis | en_US |