Genetic analysis of elite rice breeding lines for allelic status of agronomically important genes and combining ability
| dc.contributor.advisor | Rai, Mayank | |
| dc.contributor.author | Shanmugam A. | |
| dc.date.accessioned | 2023-04-11T06:12:12Z | |
| dc.date.available | 2023-04-11T06:12:12Z | |
| dc.date.issued | 2019 | |
| dc.description.abstract | Rice productivity in the North Eastern (NE) India is significantly lower than the national average. With its unique eco-geographical features, North Eastern (NE) India not only serves as the hotspot for indigenous rice landraces but is also considered to be the centre of diversity for blast pathogen (Magnaporthe grisea). Apart from this biotic factor, soil acidity and phosphorous deficiency are considered as the major constraints for rice production in NE India. Rapid development in genomics in terms of mapping and cloning of several agronomically important genes, marker validation and available plant molecular database has facilitated rice breeding with an aim to develop haplotype having all the favourable combination of resistance/tolerance genes along with high yielding genes. Hence, the present investigation was conducted to study the allelic status of blast resistance (Pi1, Pi12, Pib, Piz, Piz-5, Pi9, Pb1, Pita, Pi20(t), Pikm, Pi38, Pi54, Pi64, qPbm11), phosphorous (P) deficiency tolerance (PsTOL1) and yield related (Gn1a, OsSPL14, SCM2, DEP1, SPIKE, GS5, TGW6) genes in selected elite breeding lines intended to be used as parents in rice improvement programme. The eight parents were also crossed in Line X Tester (3 X 5) design to estimate their combining ability. Parental genotyping was performed using candidate gene-based/ linked SSR, SNP and InDel markers for the above-mentioned genes. Favourable haplotype for Pi1, Pi12, Piz, Pb1, qPbm11, SCM2 and TGW6 alleles were found fixed in the elite lines. None of the parents carried favourable alleles for OsSPL14 and DEP1. Four parents carried favourable allele for PsTOL1. Fifteen F1 hybrids, eight parents and two standard checks were evaluated for yield contributing traits under lowland field condition in randomized block design. Correlation analysis revealed that biological yield, P Use Efficiency (PUE), panicle number and tiller number were significantly correlated with grain yield. Highest GCV (30.60 %) was recorded for spikelet fertility, followed by grain yield. Moderate to high heritability was found for yield attributes indicating that selection for these traits would be effective. Dominant gene action was preponderant for all the traits studied except plant height and spikelet fertility. CAUS 105 (L2) and VL 40387 (T3) were best general combiners. Among the crosses, CAUS 105 x VL 40387 (L2 x T3) was the most prominent specific cross having significant SCA effect with the highest heterotic value (191.39 %) for grain yield followed by CAUS 103 x UPRI-3908-18-2-1-1 (L1 x T1). CAUS 105 and HPR 2921 had the highest P uptake (PUP) and L2 xT3 performed well for PUE. Finally, promising parents, crosses and the marker loci that would be segregating in the progenies of these crosses were identified to facilitate Marker Assisted Selection (MAS) for development of pure lines carrying genes that may enhance rice productivity in the region. | en_US |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810196263 | |
| dc.keywords | haplotype breeding, rice, blast resistance, Line x Tester, PUE, molecular markers. | en_US |
| dc.language.iso | English | en_US |
| dc.pages | 78p. | en_US |
| dc.publisher | College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam | en_US |
| dc.sub | Genetics and Plant Breeding | en_US |
| dc.theme | Academic Research | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | Genetic analysis of elite rice breeding lines for allelic status of agronomically important genes and combining ability | en_US |
| dc.type | Thesis | en_US |