Optimizing Winter Wheat Population Building In Saline-Alkali Land By Applying Conditioner

In this experiment,the dynamic development process of wheat tiller on saline-alkali soil was studied to clarify the tuning effect of the conditioner on population construction,and to provide technical support for the construction of reasonable population structure of wheat on saline-alkali soil.In this field experiment,winter wheat varieties Jinan 17（JN17）and Rumai19（RM19）were selected as test materials.Four kinds of conditioners were set up:no conditioner（T0）,silica-calcium,kali-magnesium（Ca O≥18%,K₂O≥2%,Mg O≥5%,Si O₂≥6%,T1）,compound modified zeolite type adjuster（70%T1+30%zeolite powder,T2）,compound modified polymer type adjuster（99%T1+1%polyacrylamide,T3）,the dosage of the adjuster is 2100 kg/ha,The effects of different conditioning agents on nutrient accumulation,salt ion absorption,mineral ion absorption and endogenous hormone contents in tiller and tiller segments of wheat were analyzed and compared,and the tuning effects of conditioning agents on tiller occurrence,development and panicle formation of wheat in saline-alkali soil were clarified.The main research results are as follows:1.Effect of conditioning agent on yield of winter wheatCompared with no conditioner,the application of conditioner significantly increased the grain yield of two winter wheat varieties.The yield of JN17 was the highest under the treatment of T2 modifier,which increased by 76.51%compared with no treatment.The grain yield of RM19 was not significantly different between T2 and T3 conditioner,and the highest value was reached under T3 conditioner,which was 107.6%higher than that without conditioner.The analysis of wheat yield composition showed that the spike number of JN17and RM19 increased significantly after the application of conditioner,the most significantly under T2 conditioner.The main reason for the increase in yield was that the spike number of wheat increased significantly.2.Effects of conditioner on population dynamics and heading rate of winter wheatThe total tiller number per unit area of the two wheat varieties was significantly increased with the modifier treatment compared with without the modifier,and the effect was most significant with the T2 modifier treatment.JN17 total tiller number per unit area was higher than RM19.The total tiller number of JN17 decreased from jointing stage and RM19from rising stage.Compared with no conditioner,the tiller heading rate of the two winter wheat varieties increased significantly after the application of T1,T2 and T3,among which the heading rate of JN17 was 48.78%,47.26%and 46.48%,and the heading rate of RM19was 55.38%,61.82%and 68.8%.3.Effects of conditioning agents on nutrient uptake of tillers and tiller nodes of winter wheatThe contents of N,P and K in each tiller decreased with the increase of tiller position.The contents of N,P and K of each tiller and tiller node increased significantly with conditioner compared with no conditioner.The contents of N,P and K in each tiller and tiller node of JN17 were the highest under T2 conditioner.In particular,the contents of nitrogen,phosphorus and potassium in the third primary tillering were increased by 49.04%,43.63%and 57.60%,respectively,compared with T0 conditioner.The contents of N and P in tillers and tiller nodes of RM19 were the highest under T3 treatment,while the contents of K were the highest under T2 conditioner.In particular,the contents of nitrogen,phosphorus and potassium in the third primary tillering were increased most significantly,which were47.70%,33.83%and 54.31%higher than that of T0 conditioner.The correlation analysis results showed that nitrogen and phosphorus contents were significantly positively correlated with the heading rate,which was conducive to the formation of wheat tillers.4.Effects of conditioner on salt ion content in tillers and tiller nodes of winter wheatCompared with no conditioner,Na⁺accumulation in tillers and tiller joints was significantly reduced with conditioner,and ion toxicity to wheat was reduced.The effects of T2 modifier on both varieties were the most obvious.Compared with T0,the Na⁺content of JN17 main stem,first tiller,second first tiller,third first tiller and tiller node decreased by35.15%,39.88%,38.6%,21.11%and 16.19%,respectively.The content of Na⁺in the main stem,the first primary tiller,the second primary tiller and the tiller node（the third primary tiller did not survive）of RM19 decreased by 27.93%,37.30%,36.23%and 17.90%.According to the random forest model,Na⁺content is the most influential factor on yield change.5.Effects of conditioner on mineral elements content of tillers and tiller nodes of winter wheatCompared with no conditioner,the absorption of mineral elements Ca²⁺,Mg²⁺and Fe²⁺by tillers and tiller nodes of wheat was significantly improved by the addition of conditioner to maintain normal physiological metabolism and growth of wheat.The contents of Ca²⁺,Mg²⁺and Fe²⁺in the third first-order tiller were significantly lower than those in the main stem,the first primary tiller and the second primary tiller,and the lack of mineral nutrient elements made the second and third primary tiller difficult to survive.The correlation analysis between each index and the heading rate showed that the increase of Ca²⁺and Fe²⁺content was significantly positively correlated with the heading rate,which was conducive to the formation of wheat tillers.6.Effects of conditioning agents on the contents of endogenous hormones in tillers and tiller nodes of winter wheatThe contents of defense hormones ABA and JA increased and the contents of SA and Z+ZR decreased in tillers and tiller nodes of wheat after the application of conditioner,compared with that without the application of conditioner.The effects of both varieties were most significant under T2 conditioner.The contents of GA₄and GA₇under T2 conditioner were lower than those of other treatments at greening stage and rising stage,and higher than those of other treatments at jointing stage.With the increase of tillering position,the contents of SA and Z+ZR increased,while the contents of ABA and JA decreased.The contents of GA₄and GA₇in the second and third primary tillers were lower than those in the main stem and the first primary tiller,indicating that the growth rate of the second and third primary tillers gradually slowed down.According to the random forest model,the content of defense hormones ABA and JA is more important to yield change than that of growth hormones Z+ZR,GA₄and GA₇.The second and third primary tillering tillers had less defense hormones ABA and JA,while the higher content of Z+ZR made them less resistant to salt-alkali stress.Therefore,the application of conditioner（the most significant effect of modified zeolite conditioner）can significantly increase the contents of N,P and K in each tiller and tiller node of the two varieties,reduce the content of Na⁺,promote the absorption of mineral ions(Ca²⁺,Mg²⁺,Fe²⁺),maintain the appropriate level of hormones,alleviate the damage of salt stress on each tiller,and improve the tiller formation rate.To ensure higher ear number per unit area,the yield of wheat on saline-alkali land can be increased eventually.