Yield And Phosphorus Efficiency Of Different Wheat Varieties In Guanzhong,shaanxi Province

The Guanzhong area in Shaanxi Province is one of the main wheat production areas in China,and it is also one of the traditional bases in breeding wheat varieties.Understanding the differences in phosphorus efficiency among wheat varieties can serve future breeding and improve resource use efficiency.In this study,a two-year field experiment was conducted to investigate wheat biomass paititioning,yield and phosphorus efficiency of 15 wheat varieties（Xiaoyan 22,Xinong 20,Zhoumai 18,Weilong 158,Xinong585,Weilong 121,Xinong 121,Xiaoyan 22,Xinong 20,Zhoumai 18,Weilong 158,Xinong 585,Weilong121,Xiaoyan 58,Weilong 169,Weilong 136,Weilong 123,Weinong 223,Luomai 8,Wunong 148,Weinong979 and Zhongmai 895）currently cultivated in the Guanzhong Plain of Shaanxi Province under two fertilization regimes.The main results and conclusions are as follows:（1）The yields of different wheat varieties were significantly different,and their yields were different under different fertilization conditions.Under the fertilization,the yield of wheat varieties was 3008-8473kg ha^-1.The wheat varieties with higher yields in both years were Weilong 121,Weilong 123,Xiaoyan 58,Weilong 169,Zhongmai 895 and Luomai 8.Under no fertilization,the yield of wheat varieties was 1928-4562 kg ha^-1.The wheat varieties with higher yields in both years were Weilong 169,Weilong 123,Weilong121 and Xinong 20.Wheat yield was most affected by the grain number and was less affected by thousand kernel weight and harvest index.（2）At anthesis,the average proportions of stem dry matter,leaf dry matter,and spike dry matter to above-ground dry matter were 50.3%-69.5%,14.9%-30.7%and 12.3%-26.7%,respectively.At maturity,the average proportions of stem dry matter,leaf dry matter,and chaff dry matter to above-ground dry matter were 20.8%-37.5%,5.8%-13.6%and 8.6%-22.8%,and the average ratio of chaff dry matter to grain dry matter was 18.5%-64.7%.There were significant differences in dry matter partitioning of different organs in different wheat varieties at anthesis and maturity.Among them,the high-yield wheat varieties（Weilong169,Weilong 123 and Weilong 121）had higher stem proportion of dry matter at anthesis,and lower stem proportion of dry matter to above-ground dry matter at maturity.In addition,in 2019-20 year,when there was more rainfall,the proportion of chaff dry matter to above-ground dry matter and ratio of chaff dry matter to grain dry matter at maturity were lower,which was beneficial to the growth of grains.（3）Under both fertilization regimes,the grain traits(the number of grains g^-1 stem dry weight,the number of grains g^-1 spike dry weight and the number of grains g^-1 structural stem dry weight)at anthesis among wheat varieties were significantly different.Among them,Weilong 169 and Weilong 121 had higher number of grains g^-1 spike dry weight at anthesis under fertilization and no fertilization,so they obtained higher grain numbers.In addition,the grain traits(the number of grains g^-1 stem dry weight and the number of grains g^-1 chaff dry weight)at maturity were significantly different for different wheat varieties.（4）Under the fertilization treatment,the spike fertility index of different wheat varieties was（47.57-105.01）ⅹ10³ grains kg^-1 spike dry weight,and the available sources for grain filling was 3105-8668 kg ha^-1.Under no fertilization treatment,the spike fertility index of different wheat varieties was（53.48-127.37）ⅹ10³ grains kg^-1 spike dry weight,and the available sources for grain filling was 1737-4443 kg ha^-1.There were significant differences in spike fertility index and available sources for grain filling among different wheat varieties.The grain number was significantly positively correlated with spike fertility index and available sources for grain filling.（5）The above-ground phosphorus uptake at maturity was 13.68-27.28 kg ha^-1 with fertilization,and6.72-14.86 kg ha^-1 without fertilization.There were significant differences in phosphorus uptake among different wheat varieties,in which Weilong 121,Weilong 123 and Zhongmai 895 had higher phosphorus uptake under fertilization,and Weilong 169 under no fertilization.Phosphorus requirement for producing100 kg grains was 0.266-0.487 kg.The wheat variety with lower phosphorus requirement per 100 kg grain was Xiaoyan 58,and the higher one was Weilong 136.（6）The phosphorus harvest index of different wheat varieties was 0.724-0.938,and the wheat variety with higher phosphorus harvest index was Weilong 169.The phosphorus use efficiency was 206-379 kg kg^-1,and the wheat variety with higher phosphorus use efficiency was also Weilong 169.The phosphorus fertilizer partial productivity of wheat varieties was 65.68-161.88 kg kg^-1,the phosphorus balance index was 0.3-0.5,and there were significant differences among different wheat varieties for these two traits.The phosphorus use efficiency,the phosphorus fertilizer partial productivity and the phosphorus balance index were significantly positively correlated with the ratio of pre-anthesis P uptake under fertilization.In summary,based on the two-year field test,it was found that the high-yield and phosphorus-efficient wheat varieties were Weilong 169 and Xiaoyan 58 under fertilization,and Weilong 121 under no fertilization.In the future,it is recommended to increase the grains number to increase yield and to increase the ratio of pre-anthesis P uptake to improve phosphorus utilization efficiency.