Regrowth responses to cutting of different cultivars of winter wheat

Source-sink distribution response to cutting of common mid-maturity ('Ningmai5' and 'Longyu4') and late-maturity ('Xifeng27' and 'Longyu1') winter wheat cultivars in Longdong region was analyzed in this study. Leaf area index (LAI) at early regrowth stage, dry matter distribution pattern at anthesis and maturity stages of cut wheat with 2 cm stubble and uncut (the control) wheat were analyzed. The results showed that LAI and photosynthetic products of different cut wheat cultivars were different. Compared with the uncut treatment, cut treatment significantly decreased LAI of 'Ningmai5' and 'Lingyu4' mid-maturity cultivars respectively by 27% and 17%, decreased LAI of 'Xifeng27' late-maturity cultivar by 6%, increased LAI of 'Longyu1' late-maturity cultivar by 7%. Aboveground biomass of cut 'Ningmai5' and 'Lingyu4' mid-maturity cultivars decreased respectively by 18% and 11% while that of cut 'Longyu1' late-maturity cultivar increased by 13% at anthesis stage over the uncut ones. Compared with the uncut treatment, the trend of the belowground biomass of the 4 cultivars under cut treatment pointed downwards with the decreasing trend of late-maturity cultivar higher than that of mid-maturity cultivar. However, belowground biomass of late maturity cultivar gradually increased at maturity stage with a significant increase of 26% in 'Longyu1' wheat cultivar. While carbohydrate content of all the parts of mid- and late-maturity cultivars decreased, that of 'Longyu1' late-maturity cultivar increased by 2%?12%. These suggested enhanced distribution of carbohydrate and dry matter to leaf and spike along with redistribution ability and source-sink coordination, which laid the basis for high grain output. Compared with other cultivars, 'Longyu1' late-maturity cultivar was more suitable for forage utilization at tillering stage and harvestable grain at maturity.