Background: Among all abiotic stresses, salinity is the
second most widespread soil problem in rice-growing countries of the world
after drought, which continues due to climate change and poor irrigation
practices. Rice is highly sensitive to salinity, particularly at the seedling
and reproductive stages. Identifying rice genotypes tolerating salinity both at
the seedling and at reproductive stages that maintain stable yield in coastal
saline soils requires an understanding of genetic variability and trait
relationships in terms of direct and indirect effects to develop salt-tolerant
rice varieties.
Aim: The aim of this study is to assess phenotypic
performance and to estimate genetic variability for salt tolerance in both the
seedling and reproductive stages of rice under coastal saline soils.
Methodology: The present study was conducted at the natural
coastal saline soils of Acharya N. G Ranga Agricultural University (ANGRAU)-
Agricultural Research Station (ARS), Machilipatnam, during Kharif (June to
November) 2024. A field experiment was carried out to evaluate Recombinant
Inbred lines (RILs) derived from the cross MCM 109/BRR 0119 for salt tolerance
in an Alpha-lattice design. Here, 150 RILs at F5 generation were studied at pH
8.4, and EC 7.2 dSm-1 and data on yield and salinity traits were collected.
Salt tolerance was evaluated at the seedling and reproductive stages using the
standard evaluation system (SES), with scores from 1 (highly tolerant) to 9
(highly susceptible) based on growth, leaf symptoms, and spikelet sterility.
Statistical analysis was performed using PBIB.test, GCV, PCV, heritability and
GA as per cent of the mean were drawn from the variability package of R
software.
Results: The analysis of variance (ANOVA) for 12 characters
attributed significant differences among 150 RILs studied under salinity
(P<0.01). The traits ear bearing tillers hill-1, salinity scoring at
reproductive stage, shoot Na+/K+ ratio at harvesting stage, and grain yield per
plant (g) exhibited high estimates of GCV, PCV, heritability and genetic
advance as per cent of the mean, suggesting additive gene action. While the
traits plant survival (%), plant height (cm), panicle length (cm), number of
filled grains per panicle, spikelet fertility % and hundred grain weight (g)
exhibited moderate PCV and GCV values with high heritability and genetic advance,
indicating substantial genetic variability for effective selection.
Conclusion: Selecting RILs based on variability traits
results in the development of salt-tolerant, high-yielding varieties suitable
for coastal saline soils. RILs F5 112 and F5 248 can be released as
high-yielding saline-tolerant varieties after evaluation in salinity trials and
multi-location trials, whereas RILs F5 122 and F5 202 can be registered as
genetic stocks for highly tolerant coastal saline conditions.
Author(s) Details
Vinutna Vinnakota
Department of Genetics and Plant Breeding, Agricultural College, Bapatla,
Andhra Pradesh, India.
Girija Rani M
ANGRAU-RARS, Maruteru, West Godavari, India.
Nagendra Rao K
ANGRAU-ARS, Machilipatnam, Krishna, India.
Suneetha K
ICAR-IIRR, Rajendranagar, Hyderabad, India.
Ravi Babu M
ANGRAU-RARS, Anakapalle, Visakhapatnam, India.
Please see the link:- https://doi.org/10.9734/bpi/asti/v6/6807
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