Inter ‐annual climate variability constrains rice genetic improvement in China

Twenty-two of the seventy-eight GSR candidate cultivars achieved high grain yield and high NUE with reduced N fertilizer application. There was significant inter-annual variation in grain yield, which was significantly correlated withTmin. Grain yield positively correlated with NUEg (R2 = 0.46) and negatively correlated with protein content (R2 = 0.32), whereas NUEg negatively correlated with protein content (R2 = 0.49).Tmin negatively correlated with grain filling percentage (R2 = 0.95). AbstractYield potential has been significantly increased through hybrid rice breeding in the past, however, the genetic gain in grain yield is becoming marginal in recent years, especially in farmers ’ field. The increase in climate variability is one potential reason for the stagnant rice grain yield. Moreover, overuse of nitrogen fertilizer and poor grain quality of hybrid rice reduce its advantage over inbred rice. The present study evaluated seventy-eight elite hybrid varieties in 2014–2 018 aiming to determine the climate variability and its influences on grain yield, nitrogen use efficiency (NUE), and grain protein content of the newly bred rice hybrid varieties simultaneously. It was found that daily maximum and minimum temperature, daily radiation varied significantly across pla nting years. The extreme differences forTmax,Tmin, and radiation were 2.0 °C, 1.5°C, and 3.6 MJ m−2 d−1, respectively. Overall, grain yield of 22 varieties was significantly increased in ...
Source: Food and Energy Security - Category: Food Science Authors: Tags: ORIGINAL RESEARCH Source Type: research