Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges &
Opportunities during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
seedlings were at two leaf stage, they were subjected to initial salinity stress of EC=6 dSm -1 by
adding NaCl to nutrient solution and the pH was adjusted to 5.0. After eight days of initial
salinization, the EC was increased to 12 dSm -1 . Initial scoring of the selected individual plants
was recorded at 10 days after initial salinization as per SES of IRRI (1997). The description of
the standard evaluation score of 1 - 9 was presented in Table. The final score was recorded at
16 days after initial salinization.
Standard evaluation score (SES) of visual salt injury at seedling stage
Score Observation Tolerance
1 Normal growth, no leaf symptoms Highly tolerant
3 Nearly normal growth, but leaf tips or few leaves whitish and rolled Tolerant
5 Growth severely retarded, most leaves rolled; only a few are
elongating
Moderately Tolerant
7 Complete cessation of growth; most leaves dry; some plants drying Susceptible
9 Almost all plants dead or dying Highly susceptible
Results
F3:4 families were categorized according to standard evaluation scores recorded and presented in
the Table 1 and Figure. In the present study, 204 F3:4 individuals derived from the cross between
salt tolerant parent MTU1061 and salt susceptible parent MTU1121 were screened for salt
tolerance at seedling stage following hydroponics system at two stress levels (EC=6 dS/m and
EC=12 dS/m). Out of 204 genotypes screened for salt tolerance twelve genotypes showed tolerant
reaction with SES of 3, forty-seven genotypes showed moderately tolerant reaction with a score of
5 and twenty-four genotypes showed highly susceptible reaction with a score of 9. More than
hundred genotypes manifested susceptible reaction with salt evaluation score of 7. Salt tolerance is
governed by multiple factors, tolerant reaction of the genotypes in this study might be attributed by
mechanisms like tissue tolerance, ion exclusion, compartmentalization, activity of different growth
regulators, transcriptional factors and several stress combating pathways (Krishnamurthy et al.,
2020).
Reaction of F 3:4 families against seedling stage salinity
Score Count Salt tolerance
3 12 Tolerant
5 47 Moderately tolerant
7 121 Moderately susceptible
9 24 Highly susceptible
Managing genetic resources for enhanced stress tolerance
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