Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges &
Opportunities during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
raising temperature at post-flowering stage.it experiences both the soil and atmospheric
drought which is one of the major constraints responsible for destabilizing the rabi sorghum
productivity. It has been documented that root growth, leaf area development and osmotic
adjustment under stress are some of the guidelines characterizing for stress tolerance. The
plasticity of root growth and development in response to changing moisture and nutrient status
of the soil provide opportunities for exploring natural variation to identify beneficial root traits
to enhance plant productivity in agricultural systems. Plant roots play an important role in plant
growth by exploiting soil resources via the uptake of water and nutrients. Root traits such as
root length, root volume, root density, and root fresh and dry weight are considered as useful
traits for improving plant productivity under drought conditions.
Methodology
The experiment was conducted at Regional Agricultural Research Station, Vijayapura situated
16°49’N and 76° 34’E with an altitude of678 meters above the mean sea level. The experiment
was conducted in RCBD with three replications with 20 sorghum genotypes for physiological
characterization and identification of key root traits contributing to yield and yield attributing
characters. The water stress was induced by withholding irrigation post-40 days after sowing.
The chlorophyll content was estimated using method suggested by Barnes et al. (1992) while
relative water content was estimated by the method suggested by Barrs and Weatherly (1962).
The membrane injury index was calculated by following the protocol of Kocheva et al. (2004).
The root length was measured physically with a scale, root volume was measured by water
displacement method while the dry mass was measured by drying the roots in the hot air oven
at 70℃ for 72 hours intermittently after taking the fresh weight.
Results
The chlorophyll content of the leaf is expressed from the SPAD index, chlorophyll a,
chlorophyll b and total chlorophyll content. Figure 1 represents the relationships of
physiological parameters with the grain yield. It revealed that the grain yield has significant
positive association with chlorophyll a content (0.99), chlorophyll b content (0.86), total
chlorophyll content (0.98) and SPAD index (0.95). This is representative that the
photoassimilates being produced in the leaf tissues is converted into the grain yield. The total
chlorophyll content has also shown significant positive associations with the yield attributes
such as test weight (0.98) and harvest index (0.94). The chlorophyll content does not show
significant positive association with the panicle weight (0.03). The significant positive
association of the chlorophyll content with the harvest index describes the efficient partitioning
of photoassimilates to the panicle. The relative water content has also shown a significant
positive association with the grain yield (0.97) and the number of grains per plant (0.97). This
is indicative of the plant that a higher water content in the leaf tissues under drought contributes
Managing genetic resources for enhanced stress tolerance
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