Record Details

GENETIC ANALYSIS OF COMPONENTS OF SALINITY TOLERANCE IN RICE (Oryza sativa L.)

KrishiKosh

View Archive Info
 
 
Field Value
 
Title GENETIC ANALYSIS OF COMPONENTS OF SALINITY TOLERANCE IN RICE (Oryza sativa L.)
 
Creator SUDHARANI, M
 
Contributor RAGHAVA REDDY, P
 
Subject yields, developmental stages, grain, tolerance, rice, hybrids, food preservation, planting, genotypes, heterosis
 
Description The present investigation on “Genetic analysis of components of salinity tolerance in rice (Oryza sativa L.)” was carried out at Directorate of Rice Research, Rajendranagar, Hyderabad and Agricultural Research Station, Machilipatnam during rabi, 2009-10 and Kharif 2010 with an aim to evaluate 24 rice genotypes for salinity tolerance, to assess the genetic diversity using microsatellite markers, to estimate heterosis and combining ability involving eight parents and 28 F1s for 16 (including yield and salt tolerance related physiological) traits. Further, the variability and genetic parameters were estimated for physiological, yield and its component traits under coastal saline soil conditions and to understand the relationship of these traits with grain yield.
Through screening at various levels of salt stress at seedling stage, the 24 rice genotypes were categorized into three classes. The cultivars viz., RPBio-226, Swarna, Krishna Hamsa, Sampada, NLR-3042, NLR-145, BPT-5204, Varadan, BPT-2231, BPT-2270 and Dhanarasi were graded as susceptible to salinity, while the genotypes CSR-27, CSR-30, CST7-1, CSRC(S)2-1-7, Santhi, NLR-33359, NLR-3041, NLR-33892 and NLR-34449 were found to be moderately tolerant and the cultivars SR26 B, CSRC(S)5-2-2-5, CSR-4 and SCRC(S) 7-1-4 were identified to be tolerant to salt stress.
The molecular diversity studies using microsatellite markers showed the highest similarity index between RPBio-226 and CSR-27 and the second highest between CST-7-1 and CSRC(S)5-2-2-5, while the lowest similarity index was observed by Swarna with CSR-30. It was also noticed that the hybrid combinations viz., Swarna x CSRC(S)7-1-4, RPBio-226 x CSR-30 and CST-7-1 x CSRC(S)5-2-2-5 which involved parents from distant clusters exhibited direct relation with higher magnitude of heterosis for yield and salt tolerance related traits.
The mean value of the parents indicated that the cultivar SR26 B excelled others by expressing significantly superior mean values for nine traits The next best parent was CSRC(S)7-1-4 for eight traits. The genotypes CSRC(S)5-2-2-5 was also adjudged as desirable for development of salt tolerant varieties coupled with high yield. Among the 28 hybrids studied, SR26 B x CST7-1 and Swarna x CSRC(S)7-1-4
xviii
were superior as they exhibited high mean performance for majority of the characters studied. Estimation of genetic parameters revealed the moderate opportunities to improve grain yield plant-1 and panicle weight in the material studied. Further, the high heritability estimates for number of total tillers plant-1, number of productive tillers plant-1, panicle length, panicle weight, number of filled grains panicle-1, spikelet fertility per cent, 1000- grain weight, grain yield plant-1, SES for visual salt injury and Na+/K+ ratio coupled with high genetic advance as per cent of indicated the scope for rapid improvement these traits through selection under saline soil conditions.
The association analysis revealed that the traits viz., number of tillers plant-1, panicle length, number of filled grains panicle-1, spikelet fertility per cent, 1000-grain weight, harvest index and SPAD readings showed positive and significant association with grain yield plant-1. Hence, selection based on these characters either in combination or alone will help in identifying lines having higher yield potential. The salt tolerance related traits namely, SES score and Na+/K+ ratio had negative associations with yield and most of the yield components, which indicates the need to select plants with less damage score and Na+/K+ ratio to improve the yield coupled with salt tolerance.
The examination of the heterotic trends revealed that the hybrid, Swarna x CSRC(S)7-1-4 manifested significant heterotic expression over mid and better-parents for number of filled grains panicle-1, grain yield plant-1, root / shoot ratio, harvest index, SPAD chlorophyll meter values and desirable negative heterosis for Na+/K+ ratio. Similarly, the hybrid RPBio-226 x CSR-30 was also found to be heterotic over mid and better-parents for number of total tillers plant-1, number of productive tillers plant-1, panicle length, panicle weight, test weight and SPAD chlorophyll meter readings and also showed low inbreeding depression for all traits studied, except for panicle weight.
The GCA and SCA variances revealed the preponderance of non-additive gene action for all the characters under both the environments, except for SPAD chlorophyll meter readings under normal situation and yield reduction per cent under saline conditions, indicating the option of population improvement methods rather the direct selection to breed for salinity tolerance. Based on gca effects, the genotypes viz., CSRC(S)5-2-2-5, SR26 B and CSRC(S)7-1-4 were found to be good combiners for yield attributing as well as salt tolerance related traits (number of tillers plant-1, number of productive tillers plant-1, panicle length, number of filled grains panicle-1, 1000-grain weight, SES for visual salt injury, harvest index, Na+/K+ ratio and yield reduction per cent) including yield. Based on sca effects, the hybrids namely, SR26 B x CST-7-1, RPBio-226 x CSR-30 and CSR-27 x CSRC(S)5-2-2-5 were adjudged as the best hybrids for yield attributes as well as salt for tolerance related physiological traits. Based on per se performance, sca effects and heterobeltiosis, the hybrids viz., Swarna x CSRC(S)7-1-4, RPBio-226 x CSR-30 and CST-7-1 x CSRC(S)5-2-2-5 were identified to be promising.
From the overall investigation it is inferred that there is a greater scope to develop high yielding varieties tolerant to salinity by monitoring parents with genetic diversity and selecting the elite lines based on the traits viz., more number of filled grains panicle-1, higher spikelet fertility per cent, longer panicle with more test weight and low visual salt injury symptoms as well as Na+/K+ ratio and pursuing the cross combination Swarna x CSRC(S)7-1-4 considering to the logical end.
 
Date 2016-06-17T10:25:20Z
2016-06-17T10:25:20Z
2012
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/67502
 
Language en
 
Relation D9360;
 
Format application/pdf
 
Publisher ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY