Genotypic variation in spatiotemporal distribution of canopy light interception in relation to yield formation in cotton

摘要

Background:Within-canopy interception of photosynthetically active radiation (PAR) impacts yield and other agronomic traits in cotton (Gossypium hirsutum L.).Field experiments were conducted to investigate the influence of 6 cotton varieties (they belong to 3 different plant types) on yield,yield distribution,light interception (LI),LIdistribution and the relationship between yield formation and LI in Anyang,Henan,in 2014 and 2015.Result:The results showed that cotton cultivars with long branches (loose-type) intercepted more LI than did cuitivars with short branches (compact-type),due to increased LI in the middle and upper canopy.Although loose-type varieties had greater LI,they did not yield significantly higher than compact-type varieties,due to decreased harvest index.Therefore,improving the harvest index by adjusting the source-to-sink relationship may further increase cotton yield for loose-type cotton.In addition,there was a positive relationship between reproductive organ biomass accumulation and canopy-accumulated LI,indicating that enhancing LI is important for yield improvement for each cultivar.Furthermore,yield distribution within the canopy was significantly linearly related to vertical LI distribution.Conclusion:Therefore,optimizing canopy structure of different plant type and subsequently optimizing LI distribution within the cotton canopy can effectively enhance the yield.