No yield penalty under favorable conditions paving the way for successful adoption of flood tolerant rice

Abstract

Flooding is one of the major constraints for rice production in rainfed lowlands, especially in years and areas of high rainfall. Incorporating the Sub1 (Submergence1) gene into high yielding popular varieties has proven to be the most feasible approach to sustain rice production in submergence-prone areas. Introgression of this QTL into popular varieties has resulted in considerable improvement in yield after flooding. However, its impact under non-flooded conditions or years have not been thoroughly evaluated which is important for the farmers to accept and adopt any new version of their popular varieties. The present study was carried out to evaluate the effect of Sub1 on grain yield of rice in different genetic backgrounds, under non-submergence conditions, over years and locations. The study was carried out using head to head trials in farmer’s fields, which enable the farmers to more accurately compare the performance of Sub1 varieties with their recurrent parents under own management. The data generated from different head to head trials revealed that the grain yield of Sub1 varieties was either statistically similar or higher than their non-Sub1 counterparts under non-submergence conditions. Thus, Sub1 rice varieties show no instance of yield penalty of the introgressed gene.

Marker Assisted Breeding to Develop Multiple Stress Tolerant Varieties for Flood and Drought Prone Areas

“…Farmers in drought and submergence prone areas are mainly cultivating the abiotic stress susceptible rice varieties primarily due to their good grain yield potential and market-driven grain quality traits. The performance of these varieties is generally good during the non-drought-submergence affected years (Dar et al 2018). However, during the natural calamities, large reduction in grain yield is observed in these varieties due to their inability to survive and yield under drought or submergence or both.…”

Genetic gain for rice yield in rainfed environments in India

“…In the head-to-head trials, the pair of varieties to be compared were grown in the same field (half of the field for each variety) or in two adjacent fields with similar conditions. The head-to-head trials were conducted using the farmers management practices in the particular locations to assess the extent of yield gain achieved on the farmers’ fields ( Dar et al, 2018 ). The data was analyzed separately for the lowland and shallow-and-medium lowland ecosystems.…”

Genetic strategies for improving crop yields

“…2b). The introduction of SUB1A-1, through marker-assisted breeding, into high-yield varieties now provides an additional week or more of submergence tolerance-without compromising yields under nonsubmergence conditions 52 .…”