Source-sink Relationship and Their Influence on Yield Performance of YAU Promising Rice Lines

Abstract

Fifty YAU promising rice genotypes were used to evaluate source-sink relationship and yield performance in 2017 dry season. The experiment was conducted in the experimental field of Yezin Agricultural University, Nay Pyi Taw, Myanmar. The spacing was 20 cm between row and 20 cm between plants in a randomized complete block design with three replications. The data on physiological traits, yield and yield component traits were collected and analyzed by using STAR and R program. Growth duration1 is positively and significantly correlated with the number of grains panicle-1, filled grains percentage, grain yield, panicle weight, dry weight at heading and harvesting, straw weight and LAI at harvesting, and increase of dry weight from heading to harvesting. Significant positive correlation was found between growth duration2 and decrease of LAI from heading to harvesting indicating that these traits are strongly influenced by source before heading. Significant correlations between yield and physiological and yield component traits were observed except LAI at harvesting and 1000-grain weight. Therefore, yield variation among YAU promising rice lines is more related with source size than with sink size. Decrease of LAI from heading to harvesting and dry weight at maturity exhibited positive direct effect on 1000-grain weight, filled grains percentage and grain number m-2 meaning the relative contribution of source components to the sink. The contribution of the decrease of LAI from heading to harvesting to the grain yield was much higher than that of number of grains, panicle weight and 1000-grain weight. This research finding will be useful for the plant breeder to consider the improvement of yield supporting traits in the breeding program.