| The high,middle and low-yield common buckwheat‘cv.Fengtian 1’(FT1),‘cv.Zongtian 2’(ZT2)and‘cv.Xinnong 1’(XN1)were selected to study their root length,root surface area,root volume and average diameter.The relationship between agronomic traits and yield in the aboveground areas identified the best root morphology and plant type for high yield of common buckwheat.By studying the accumulation and distribution of nitrogen,phosphorus and potassium in different organs of common buckwheat,the N,P,K and B fertilizers were regulated to study the regulation of root morphological,agronomic traits and yield of common buckwheat.The main results were as follows:1 The relationship between root morphology,agronomic traits and yield of common buckwheatThe growth period of buckwheat is shorter,and the root growth process showed the basic law of“slow-fast-slow”.Roots grew slowly before flowering,and the root dry weight was the smallest.The root growth rate was highest at the filling stage,and the dry weight of roots was higher.The growth rate of the roots at the maturity stage slowed or even stopped.The root morphology of different common buckwheat cultivars showed different performances at different growth stages.The roots of high-yield common buckwheat cultivars had large roots and developed lateral root systems,which provided the basis for the growth of plant shoots;the roots of middle common buckwheat varieties were second to none.The low-yield of common buckwheat had the smallest root system.The performance of agronomic traits was also different among the three common buckwheat cultivars.The plant height,the number of main stem segments and the number of main stems were all expressed as FT1?XN1?ZT2.The number of branches of the main stem is represented by FT1?ZT2?XN1.The factors affecting the yield were different among the three common buckwheat varieties.The grain weight per plant and the 1000-grain weight of the’cv.Fengtian 1’were significantly higher than those of the’cv.Zongtian 2’and’cv.Xinong 1’,respectively.Grain number per plant,seed length and width did not differ significantly among the three common buckwheat varieties.2 The relationship between dry matter accumulation to N,P and K absorption and distribution in various organs of common buckwheatWith the advancement of the growing period,the dry matter quality of’cv.Fengtian 1’showed an“S”curve change,and the dry matter accumulation of the whole plant and each organ showed the trend of“first increase then decrease”,reaching the maximum at the grain filling stage.The dry matter weight of flowers and seeds accounted for 54.46%of the total dry matter mass.The dry matter accumulation of the whole plant and each organ showed a significant downward trend.The nitrogen,phosphorus and potassium contents of the whole plant were highest during the flowering period.Root dry weight and stem dry weight had a significantly negative correlation with content of K in root,while had a conspicuous negative correlation with stem phosphorus accumulation and leaf phosphorus accumulation of‘cv.Fengtian 1’.The root dry weight and leaf nitrogen accumulation were significantly negative.There was a significant negative correlation between stem weight and nitrogen accumulation in leaves,while there was no significant correlation between leaf dry weight and nitrogen,phosphorus,and potassium levels in various organs.3 Effect of fertilizer control on root system and yield of common buckwheatNitrogen fertilizer can significantly increase the plant height of common buckwheat varieties,increase the number of main stem nodes and branches,improve the root morphology of common buckwheat,and increase yield.The root morphology of’cv.Fengtian 1’and’cv.Xinnong 1’both reached the optimum condition when nitrogen fertilizer was applied at 50 kg/hm~2,and the root growth was inhibited when the nitrogen fertilizer was exceeded;the root morphology of’cv.Zongtian 2’was exceeded.It is best when applying nitrogen fertilizer 100 kg/hm~2.The yields of’cv.Fengtian 1’and’cv.Xinnong 1’reached the highest when treated with nitrogen fertilizer 100 kg/hm ~2,which was 39.84%and 34.32%higher than the control,respectively.The yield of’cv.Zongtian 2’reached the highest when treated with nitrogen fertilizer 50 kg/hm~2,up to 1164.06 kg/hm ~2,which was 34.02%higher than the control.The optimum root morphology of’cv.Fengtian 1’and’cv.Zongtian 2’were all treated with a phosphate fertilizer of 70 kg/hm~2.The optimal root morphology of’cv.Xinnong 1’was in the application of phosphate fertilizer35 kg/hm~2 processing.The yields of’cv.Fengtian 1’,’cv.Zongtian 2’and’cv.Xinong 1’were all highest when treated with 70 kg/hm~2,which increased by 19.65%,14.53%and 39.27%respectively compared to the control.The root morphology of’cv.Fengtian 1’was best when treated with potassium fertilizer 10 kg/hm~2,and the root morphology of’cv.Zongtian 2’and’cv.Xinong 1’was all 5 kg/hm ~2.The yields of’cv.Fengtian 1’and’cv.Zongtian 2’were the highest when treated with 10 kg/hm~2,which was24.36%and 34.76%higher than the control,respectively.The yield of’cv.Xinong 1’was the highest when treated with potassium fertilizer 5kg/hm~2,up to 1056.05kg/hm~2,which was 19.32%higher than the control.After applying boron fertilizer on leaf surface,the root length and surface area of’cv.Fengxian 1’were the largest at the treatment of 24kg/hm~2,and the volume and average diameter were middle;the root length,surface area and volume of’cv.Zongtian 2’were the largest.All of them were maximal at the treatment of 12 kg/hm~2.The root morphology of‘cv.Xinong 1’was decreased after spraying boron fertilizer,and it was the smallest at 24 kg/hm~2 treatment.The yields of the three common buckwheat cultivars were all highest when treated with 24 kg/hm~2,which increased by 29.66%,12.47%and 31.10%compared with the control. |
