Effects Of Planting Densities On Physiological Characteristics And Grain Yield Of Two Winter Wheat Cultivars With Different Spike Type

Under field experiments,two cultivars including multi-spike and large-spike winter wheat were cultivated in growth season during 2004-2006 at Henan Agricultural University Research Station to evaluate the effects on Photosynthesis Characteristics,physiological characteristics and yield.The main results were as follow:1.There were effects on colony under planting densities of two winter wheat cultivars with different spike type.But it had differences between two cultivars,for yumai49-198,the colony showed increased with the increasing in planting densities before reviving,and then, the highest colony was observed on the B₃ treatment;for lankaoaizao8,the differences was not obviously under planting densities,as increased with the increasing in planting densities before reviving,reviving to booting stage,the lower density treatments were favorable,the colony were higher,when anthesis,the spikes had broken down with the mid-density treatments.The Leaf area index(LAI)increased during procreate period with two spike type winter wheat with the increasing of density(expect for lankaoaizao8 at jointing);at the late filling stage,the surrounding to get worse and the LAI was lower.2.Planting densities had different effects on Ch1,Fv/Fo,Fv/Fm,qP and qN of flag leaf of two spike type winter wheat.For yumai49-198,the great content of chl was observed on B₁ treatment before 14d after anthesis,during 21-35d after anthesis the chl content were higher under B₂ and B₃ treatments.For lankaoaizao8,the differences was not obviously before 21d after anthesis,but after 28d after anthesis the highest chl content was observed on C₃ treatment and there were significant differences.The Fv/Fo,Fv/Fm and qP of flag leaf decreased during determining periods of two spike type winter wheat,for yumai49-198,the higher Fv/Fo was observed under two mid-level densities treatments as B₂,B₃,the B₁ and B₄ were lower(expect for in the early of filling stage);for lankaoaizao8,the mid-level densities were favorable before anthesis,but after anthesis the Fv/Fo were higher under lower densities.The change of qN increased during determining periods of two spike type winter wheat.For yumai49-198,the qN was lower under the mid-level densities during determining periods,but for lankaoaizao8,the qN was lower under the mid-level density before filling stage,then the qN was higher under the C₃ treatment.3.The activity of SPS and SS in flag leaf showed a single peak-curve,and the curve appeared at 14d after anthesis of two spike type winter wheat.For yumai49-198,The SPS and SS of B₃ treatment was in inferior position after 14d after anthesis,but the B₁ treatment was higher all the time during filling stage;and for lankaoaizao8,the activity of SPS and SS in flag leaf under lower density treatments were favorable in pre-filling stage,and the highest density as C₄ treatment was bad.NR,GS activity in flag leaf decreased with days after flower increasing.And the NR activity at the lowest and highest plant density treatments is higher from the beginning of anthesis to 21 days after anthesis with two spike type winter wheat.And during 28-35d after anthesis the mid-level density treatments were favorzble.The differences of GS under different treatments was not obviously with yumai49-198 before 14 days after anthesis,then the differences was significant;The lankaoaizao8 was similar as yumai49-198.4.The results indicated that the sucrose content and the soluble sugar content in flag leaf showed a single peak-curve,for yumai49-198,the higher content was observed on B₂ treatment,and the lower was B₄ from the beginning of anthesis to 14 days after anthesis,in the late of filling stage the higher-level density as B₃ treatment was favorable;for lankaoaizao8,the higher-level density were better in the whole filling stage.The sucrose content and the soluble sugar content in grains of two wheat cultivars were favorable under the second treatment,and that the rate of using was better.For yumai49-198,the sugar content was plenitude under the highest planting density as B₄ treatment,but it was not favorable to the transform;and the lowest planting density as B₁,not only the content was not plenitude but also the transform was bad.As for lankaoaozao8,both the sugar content and the rate of using were advantageous under lower density treatments.5.The starch content in grains of two wheat cultivars increased in grain filling stage, and the rate of starch accumulation showed a single-peak curve,and the peak value appeared during 21-28d after anthesis.Planting densities had effects on starch content and its component:Yumai49-198,a multi-spikes cultivar,the highest starch content in grains when mature and the proper rate of starch accumulation were observed on B₃ treatment(225×10⁴/hm²);and lankaoaizao8,a large-spike cultivar,the highest starch content was obtained on C₁ treatment(300×10⁴/hm²);There were differences among treatments with two spike type winter wheat,but the differences were not significant.The soluble protein content in grains under different density showed that:B₄＞B₃＞B₁＞B₂ with Yumai49-198,and C₁＞C₄＞C₃＞C₂ with lankaoaizao8.6.Under this experiment,the highest yield was observed on the second level of density with both the two cultivars.And the grains per spike and 1000-grain weight were promoted obviously.And that the worst treatments for yield were B₄ and C₃,for B₄,the spikes/hm² was higher,but the grains per spike was lower;for C₃,both the spikes/hm2 and grains per spike were bad.Then with the spikes/hm²,it showed increased when density increasing with ynmai49-198,but the change of lankaoaizao8 was not obviously;The grains per spike decreased with increasing of density;And the 1000-grain weight was best under the second treatments,and the highest density was disadvantageous,but the differences among treatments were not significant.Based on the results of this experiment,we established the suitable planting density to high yield and high quality.That was,to multi-spike wheat yumai49-198 the basic seedlings was 150×104/hm²,and the basic seedlings at 375×104/hm² with large-spike wheat lankaoaizao8 were better.And these two treatments,the colony structure and photosynthesis characters index was better,the yield was higher.