Effects Of Post-anthesis Different Stages High Temperature Stress And Row Spacing On Yield And Quality

The effect of post-anthesis different stages high temperature stress and row spacing on yield and its composing, photosynthetic characteristics, carbon and nitrogen metabolism,grain quality characters with different spike type of middle gluten wheat cultivar Pingan6 and Yumai49-198 was studied under field condition. The test was did in zhengzhou (Henan Agricultural University, Science and Education Demonstration Garden), Main results are as follows:1.The heat stress conditions in different periods after anthesis and different row spacing have different impact on its production and components,the yield of two Varieties all drop after the heat stress ,and the effects on 1000-grain weight and Grain Yield is By trend-by with a brief delay heat stress after anthesis, there is very significant effect of the Period of heat stress after anthesis on Grain Yield and 1000-grain weight,different row spacing has only Very significant effects on kernels per spike and significant effects on Grain Yield and little effects on spikes ,spikelets and sterilities.2. Post-anthesis different stages high temperature stress and row spacing had regulatory effect on wheat carbon and nitrogen metabolism.In normal condition, wide-narrow row planting was beneficial to the accumulated dry matter and nitrogen in different organ of large-spike cultivar transporting to the grain,but it was opposite to multi spike cultivar.After high temperature stress,yield and nitrogen content decreased,which were the lowest in later stage,and wide–narrow row was higher than equal row.Wide-narrow row planting could relief the negative influence caused by high temperature stress to some extent,which had great practical significance.3. Effects of post-anthesis different stages high temperature stress and row spacing on photosynthetic characteristics in flag leaf was obviously. The results indicated that,effects of high temperature stress over 24 hours on chlorophyll contents(a+b), net photosynthetic rate(Pn),and PSⅡactivity ( Fv/Fo ) ,the maximal quantum efficiency of PSⅡphotochemistry(Fv/Fm),non-photochemical quenching co-efficient(qN)of flag leaves were different by cultivar,stress stage and row spacing. the effects on photosynthetic parameters of flag leaves were large in early and middle grain filling stage,but they were decreased later. Under the same temperature,the effects of high temperature stress on large-spike wheat cultivar were greatest in early grain filling stage,and multi-spike cultivar were in middle. We can adopt the broad line and narrow line cultivation to reduce the effects of high temperature on flag leaf photosynthesis.4. Effects of post-anthesis different stages high temperature stress and row spacing on wheat quality were big. Moderate high temperature could improve the content of protein and starch to some extent.Wide-narrow row planting was beneficial to improving the protein content and flour yield,but it went against the starch content improving.high temperature stress decreased paste parameters,which went against improving the processing quality to which earlier stage stress of large-spke did large harm and middle stage of multi spike did large harm.Wide-narrow row planting could improve farinograph parameters under the same density,which was beneficial to the improve of the processing quality.