Browsing by Author "Padmini Swain"

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Depth of soil compaction predominantly affects rice yield reduction by reproductive-stage drought at varietal screening sites in Bangladesh, India, and Nepal
(Springer International Publishing, 2017) Suresh Prasad Singh; Abhinav Jain; M.S. Anantha; Santosh Tripathi; Subarna Sharma; Santosh Kumar; Archana Prasad; Bhawana Sharma; Biswajit Karmakar; Rudra Bhattarai; Sankar Prasad Das; Shravan K. Singh; Vinay Shenoy; R. Chandra Babu; S. Robin; Padmini Swain; J.L. Dwivedi; Ram Baran Yadaw; Nimai P. Mandal; T. Ram; Krishna Kumar Mishra; S.B. Verulkar; Tamal Aditya; Krishna Prasad; Puvvada Perraju; Ram Krishna Mahato; Sheetal Sharma; K. Anitha Raman; Arvind Kumar; Amelia Henry
Aims: Drought is the major constraint to rainfed rice productivity in South Asia, but few reports provide detailed characterization of the soil properties related to drought stress severity in the region. The aim of the study was to provide a compilation of drought breeding network sites and their respective levels of drought stress, and to relate soil parameters with yield reduction by drought. Methods: This study characterized levels of drought stress and soil nutrient and physical properties at 18 geographically distributed research station sites involved in rice varietal screening in Bangladesh, India, and Nepal, as well as at farmers’ fields located near the research stations. Results: Based on soil resistance to penetration profiles, a hardpan was surprisingly absent at about half of the sites characterized. Significant relationships of depth of compaction and yield reduction by drought indicated the effects of soil puddling on susceptibility to cracking, rather than water retention by hardpans, on plant water availability in this region. The main difference between research stations and nearby farmers’ fields was in terms of soil compaction. Conclusions: These results present an initiative for understanding the range of severities of reproductive-stage drought stress in drought-prone rainfed lowland rice-growing areas in South Asia. © 2017, The Author(s).
Rice breeding for yield under drought has selected for longer flag leaves and lower stomatal density
(Oxford University Press, 2021) Santosh Kumar; Santosh Tripathi; Suresh Prasad Singh; Archana Prasad; Fahamida Akter; Md Abu Syed; Jyothi Badri; Sankar Prasad Das; Rudra Bhattarai; Mignon A Natividad; Marinell Quintana; Challa Venkateshwarlu; Anitha Raman; Shailesh Yadav; Shravan K Singh; Padmini Swain; A Anandan; Ram Baran Yadaw; Nimai P Mandal; S. B Verulkar; Arvind Kumar; Amelia Henry
Direct selection for yield under drought has resulted in the release of a number of drought-tolerant rice varieties across Asia. In this study, we characterized the physiological traits that have been affected by this strategy in breeding trials across sites in Bangladesh, India, and Nepal. Drought- breeding lines and drought-tolerant varieties showed consistently longer flag leaves and lower stomatal density than our drought-susceptible check variety, IR64. The influence of environmental parameters other than drought treatments on leaf traits was evidenced by close grouping of treatments within a site. Flag-leaf length and width appeared to be regulated by different environmental parameters. In separate trials in the Philippines, the same breeding lines studied in South Asia showed that canopy temperature under drought and harvest index across treatments were most correlated with grain yield. Both atmospheric and soil stress strengthened the relationships between leaf traits and yield. The stable expression of leaf traits among genotypes and the identification of the environmental conditions in which they contribute to yield, as well as the observation that some breeding lines showed longer time to flowering and higher canopy temperature than IR64, suggest that selection for additional physiological traits may result in further improvements of this breeding pool. © 2021 The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Experimental Biology.
Unlocking the Nexus between Leaf-Level Water Use Efficiency and Root Traits Together with Gas Exchange Measurements in Rice (Oryza sativa L.)
(MDPI, 2022) Ramasamy Gobu; Goutam Kumar Dash; Jai Prakash Lal; Padmini Swain; Anumalla Mahender; Annamalai Anandan; Jauhar Ali
Drought stress severely affects plant growth and development, causing significant yield loss in rice. This study demonstrates the relevance of water use efficiency with deeper rooting along with other root traits and gas exchange parameters. Forty-nine rice genotypes were evaluated in the basket method to examine leaf-level water use efficiency (WUEi) variation and its relation to root traits. Significant variation in WUEi was observed (from 2.29 to 7.39 µmol CO2 mmol−1 H2 O) under drought stress. Regression analysis revealed that high WUEi was associated with higher biomass accumulation, low transpiration rate, and deep rooting ratio. The ratio of deep rooting was also associated with low internal CO2 concentration. The association of deep rooting with lower root number and root dry weight suggests that an ideal drought-tolerant genotype with higher water use efficiency should have deeper rooting (>30% RDR) with moderate root number and root dry weight to be sustained under drought for a longer period. The study also revealed that, under drought stress conditions, landraces are more water-use efficient with superior root traits than improved genotypes. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.