Characteristics Of High-yield Winter Wheat Cultivars In Hilly Dryland Region Of Sichuan

The yield level of wheat in Sichuan is lower compared to other region in China.The low and unstable wheat yield in hilly dryland is the bottleneck restricting the overall production increase in this region.The characteristics of high-yield wheat cultivars suitable for dryland in Sichuan hilly are unknown.In view of this,32 typical wheat cultivars from different ages in Southwest China were adopted to explore the yield and yield components and evaluate the photosynthetic characteristics,dry matter accumulation characteristics and nitrogen utilization.The aim of this to screen out high-yielding wheat cultivars suitable for hilly dryland in Sichuan,reveal the characteristics of high-yielding wheat cultivars and provide theoretical basis and variety support for high-yield cultivation and breeding.The specific results are as follows:1.Two-year research results show that the average yield of high-yield species is 5210.0kg·hm^-2,which is 70.1%higher than that of low-yield cultivars;its tillering power is 0.83,the number of spikelets is 17.39,and the effective panicle is 292.05×10⁴ No·hm^-2.The number of grains was 36.33,the grain volume was 1.1×10⁴ grains·m^-2,and the 1000-grain weight was 53.05 g,which was 221.7%,20.7%,1.6%,40.1%,39.4%,and 15.6%,respectively.Path analysis showed that the number of grains per unit area contributed the most to the yield,followed by the number of grains per spike,indicating that increasing the number of grains per unit area or the number of grains per ear in the future under the premise of ensuring a certain effective panicle is the key to achieving high yield in the hilly dryland of Sichuan.2.The high-yield flowering period has a high net photosynthetic rate and light energy interception rate,high chlorophyll content and long green leaves in the upper layer.The net photosynthetic rate of flag leaf high in flowering stage was 17.97?mol·m^-2·s^-1,the lower the product height was 52.4%;the photosynthetic effective radiation intercept rate was81.8%;the lower product variety was 2.8 percentage point higher;The SPAD values of flowering stage,20d after flowering and 30d after flowering were significantly higher than those of low-yield type.The SPAD value of flag leaf was 46.91 and the second-generation SPAD value of 42.50 was lower than the lower yield type of 14.7%and 18.3,respectively.The SPAD value of flag leaf and inverted leaf of flowering stage was significantly positively correlated with yield,which could be used as a high-yield indicator for field identification.3.From the perspective of material production,high-yield cultivars have the characteristics of fast accumulation of dry matter before and after flowering,high accumulation of dry matter,large proportion of dry matter and heavy grain distribution,and high harvest index.The dry matter accumulation rate of high-yield cultivars before flowering was 59.76 kg·hm^-2·d^-1,and the accumulation amount of 8278.14 kg·hm^-2 was12.0%and 18.7%higher,respectively.The contribution rate of dry matter before flowering reached 46.07%.The lower yield type was 79.6 percentage points higher;the dry matter accumulation rate after flowering was kg·hm^-2·d^-1,and the accumulation amount was2531.85 kg·hm^-2.The lower yield types were 32.2%and 23.5%higher,respectively;At the time,the dry matter content of the grain reached 44.09%,which was 36.4%higher than that of the low-yield type,and the harvest index reached 0.48,which was 41.2%higher than the low-yield type.4.Nitrogen absorption efficiency,nitrogen utilization efficiency and nitrogen production efficiency of high-yield cultivars were higher in high-yield type.Nitrogen absorption efficiency 0.99 kg·kg^-1,nitrogen use efficiency 34.72 kg·kg^-1 and nitrogen production efficiency 34.21 kg·kg^-1 were 41.0%,35.8%and 88.0%lower than that of low-yield type,respectively.The nitrogen accumulation after flowering stage was 55.62 kg·hm^-2 and which was 138.6%higher than that of low-yield type.In summary,the characteristics of high-yielding wheat cultivars suitable for hilly dryland are:net photosynthetic rate of flag leaves at the flowering stage is 16.49¹7.97?mol·m^-2·s^-,and light energy interception rate is suitable for 79.28%-83.21%.SPAD>50 and inverted two-leaf SPAD 49.27⁵0.83 are large and have a long green time;at the same time,the dry matter contribution rate before flowering is high 38.2%⁵6.8%,and the dry matter accumulation rate after flowering is fast 39.27⁶4.81 kg·hm^-2·d^-1,the harvest index is large 0.46⁰.50;it also has high nitrogen absorption rate 0.91¹.04 kg·kg^-1,and the characteristics of nitrogen accumulation after flowering are large;high-yield type The yield components of the cultivar were characterized by effective panicle 263.14׳15.92×10⁴ No·hm^-2,grain number 35.34³7.68,and 1000 grain weight 45.99⁵7.36g.The Chuanyu 25,Changmai 34,Mianmai 1419,and Chuanmai 98 is suitable for hilly dry land in Sichuan.