ESTIMATING STABILITY PARAMETERS AND STRESS INDICES USING ELITE SALT TOLERANT RICE GENOTYPES

Simple item page
dc.contributor.advisorM.GIRIJA RANI
dc.contributor.authorDASARI SRI TEJASWI
dc.date.accessioned2023-12-04T13:30:19Z
dc.date.available2023-12-04T13:30:19Z
dc.date.issued2023-12-04
dc.description.abstractSalinity is one of the major constraints for rice productivity. Yield enhancement in saline soils is herculean task as it is controlled by polygenes. The present investigation was carried out to estimate stability parameters and stress indices using elite salt tolerant rice genotypes in three environments viz., Normal soil (Pedana) and two saline soils (Chitipalem and Machilipatnam). Assessment of stability of rice genotypes, genetic parameters and magnitude of variability, association of yield related traits are the prime objectives of the present study under salinity. The 24 rice genotypes were evaluated in Randomized Block Design with two replications during Kharif 2021. Observations on plant survival %, seedling and reproductive stages salinity score under saline and days to 50 per cent flowering, plant height (cm), ear bearing tillers plant-1, panicle length (cm), number of filled grains panicle-1, spikelet fertility %, 1000 grain weight (g), grain yield (kg/ha), harvesting index, Na/K ratio were recorded in all the three environments. The 24 elite salt tolerant rice genotypes were screened with QTL/gene specific salinity tolerance linked 28 SSR markers. The analysis of variance showed significant differences between the genotypes for yield and its components in individual environment and combined analysis of two saline environments implied that the genotypes have sufficient genetic variation. The AMMI analysis revealed significant mean squares due to genotypes, environments, and genotype x environment interactions for grain yield and yield component traits in present study, except for 1000 grain weight where only genotypes were significant. This can be attributed as there is significant variation among the genotypes studied in addition to considerable environmental variation. The genotypes MCM 144-25-1-1-3, MCM 208-14-1-1, MCM 100, MCM 208-7-1-1, MCM 148-2-1-1-1, MCM 141, MCM 103, MCM 140, MCM 139, MCM 142-1-1-1-1, MCM 125 and MCM 153-1-1-1-1 are stable high yielding salt tolerant genotypes based on AMMI I and II biplots, stability parameters of AMMI, BLUP and non-parametric SSI. xvii Studies on variability, heritability and genetic advance as per cent mean revealed moderate to high estimates of genotypic and phenotypic coefficient of variation with high heritability and high genetic advance as per cent of mean were recorded for seedling and reproductive stages salinity score, days to 50 per cent flowering, number of filled grains panicle-1, 1000 grain weight (g), grain yield (kg/ha), Na/K ratio indicating the preponderance of additive gene action, thus, direct selection for these traits may be effective for improvement of these characters. Further, the results on character associations indicated that selection of genotypes with minimal Na/K ratio, moderate plant height, fertile spikelets and more filled grains is helpful in evolving salt tolerant genotypes. Studies on stress tolerance index, PCA and molecular diversity analysis revealed MCM 125 and FL 478 can be selected as parents for evolving high yielding salt tolerant rice varieties. High salt tolerant index for spikelet fertility %, plant height from MCM 125 and early duration, bold grain genotypes with higher harvesting index from FL 478 can be choosen as parents for future breeding programmes. Molecular characterisation using gene specific markers revealed that salt tolerant genotypes MCM 109 for QTL (qTSP7.1s), (Qph8), MCM 103 for (qPT7), MCM 100 for (QNa/kr1), (qSKC-1), (qGY4.1s) and MCM 159-1-2-2, MCM 148-2-1-1-1 for (qSSISFH-8.1) showed positive alleles. The genotypes FL 478 and MCM 258-8-2-1 exhibited maximum positive alleles for Saltol QTL that these genotypes can be further exploited for favourable alleles for enhancing rice productivity under salinity conditions. The genotypes MCM 208-14-1-1, MCM 100, MCM 208-14-1-1, MCM 148-2-1-1-1, MCM 139, MCM 103, MCM 140, MCM 142-1-1-1-1, MCM 125 and MCM 153-1-1-1-1 were identified as stable high yielding with moderate tolerance at seedling and reproductive stages and possessing low Na/K ratio by taking low Na uptake from soil with maximum positive alleles of Saltol QTL. The genotypes MCM 144-25-1-1-3 and MCM 141 are high yielding stable genotypes with moderate salinity tolerance and high Na/K ratio and salt tolerance might be due to sodium exclusion mechanism. The stable high yielding salt tolerant genotypes identified in the present study can be released as varieties for salt affected areas and also can be used as genetic stocks in future breeding programmes.
dc.identifier.otherD6433
dc.identifier.urihttps://krishikosh.egranth.ac.in/handle/1/5810202146
dc.keywordsSTABILITY PARAMETERS
dc.keywordsSTRESS INDICES
dc.keywordsELITE SALT
dc.language.isoEnglish
dc.pages198
dc.publisherAcharya N G Ranga Agricultural University
dc.relation.ispartofseriesD6433; D6433
dc.subGenetics and Plant Breeding
dc.themeESTIMATING STABILITY PARAMETERS AND STRESS INDICES USING ELITE SALT TOLERANT RICE GENOTYPES
dc.these.typeM.Sc
dc.titleESTIMATING STABILITY PARAMETERS AND STRESS INDICES USING ELITE SALT TOLERANT RICE GENOTYPES
dc.typeThesis
Files
Original bundle
Now showing 1 - 2 of 2
Thumbnail Image
Name:
SRI TEJASWI BAM-2020-25.pdf
Size:
4.57 MB
Format:
Adobe Portable Document Format
Download
Thumbnail Image
Name:
SRI TEJASWI BAM-2020-25.pdf
Size:
4.57 MB
Format:
Adobe Portable Document Format
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Theses