【作者】 王丹；

【导师】 张永清；

【作者基本信息】 山西师范大学 ， 生态学， 2023， 硕士

【摘要】 根系空间分布影响作物地下部和地上部生长发育能力,合理的根系空间配置及种植密度能有效提高藜麦单位产量。为了探明根系生长空间和种植密度在藜麦生长过程中是否存在根系冗余现象以及对其生理特性和产量的影响,本试验以“陇藜3号”和“陇藜1号”为试验材料,采用根管土柱栽培法进行了两次相关研究:(1)采用等体积不同根土空间构型的2种根管土柱(直径为10 cm、高60 cm的根土空间V1和直径15.2 cm、高26 cm的根土空间V2),5个种植密度(D1:1株/管;D2:2株/管;D3:3株/管;D4:4株/管;D5:5株/管),共10个处理。(2)用直径20 cm的PVC管裁成2种高度的根柱:高60 cm的根土空间H1和高40 cm的根土空间H2,设置4个种植密度(D2:2株/管;D3:3株/管;D4:4株/管;D5:5株/管),共8个处理。主要研究结果如下:(1)相同种植密度条件下,根土空间V1在灌浆期的株高、茎粗、叶面积、根长、根体积、根表面积、地上干物质量、根系干物质量、相对叶绿素含量、SOD酶活、POD酶活和根系活力等分别比根土空间V2平均增加4.78%、10.41%、20.65%、29.04%、7.02%、7.78%、37.40%、48.42%、35.02%、15.80%、56.74%和6.90%,而根冠比和活性吸收面积(%)的趋势与上述指标相反,分别平均下降了9.10%和5.47%。当根土空间(体积、构型)相同时,藜麦的以上指标均随着种植密度的增加呈下降趋势,且表现为D3处理之后,密度增加越大,其各个指标下降幅度就越大。产量则随着种植密度的递增呈先增加后降低的相似变化动态,表现为根土空间V1在种植密度为3株时产量最高,根土空间V2在种植密度为4株时达到极值,但是V1D3的产量比V2D4平均增加了33.00%。其中,相同种植密度处理下,开花期根土空间V2的地上部形态指标株高、茎粗、叶面积和生理指标相对叶绿素含量均显著高于根土空间V1,到灌浆期则反转为V1处理显著高于V2处理。“窄而深”的根土空间V1能促使植株根系向下层深扎,以获取底层的养分,提高单位空间范围内营养物质的贡献率;适当的根土空间和合理的种植密度(V1D3)可以促进藜麦更好的生长,有效减少根系冗余并显著增加单位产量。(2)无论种植密度如何,较大的根土空间均显著促进藜麦生长,与H2处理相比,H1处理的根长、根体积、根系干物质量、根系活力、SOD和POD活性等指标分别平均增加63.86%、50.42%、13.13%、9.83%、13.24%和6.34%,茎秆木质素和纤维素含量分别平均增加8.44%和9.43%。相同根土空间条件下,随着种植密度的增加,对藜麦生长发育的抑制作用加大,表现为随密度的增加,以上各指标下降幅度加大,而根冠比、可溶性糖和可溶性蛋白含量呈相反趋势,均随着种植密度的增大而降低,但H1处理的平均值依旧显著高于H2处理的各项平均值;产量则随着种植密度的递增表现为先上升后下降的趋势,根土空间H1条件下,在种植密度为D4时达到最大值,而H2条件下在D3处理达到最大值;本试验中,H1D4处理的产量达到峰值,相比于H2D3处理,单位产量增加了13.20%,根系单位贡献率最高,能最大程度减少根系冗余,有效提高藜麦单位面积经济收益。根土空间与种植密度互作显著影响藜麦的生长发育和产量的形成,密度胁迫下,增加根土空间可促进藜麦根系生长,当根土空间较小时,可通过减小种植密度缓解藜麦生长压力,达到单位增产最大化。综上所述,根系形态直接影响到作物根系吸收水分、养分的能力,良好根系形态的塑造可提高作物对营养物质的吸收效率,而根土空间是重塑根系形态的关键因素,改良根土空间可有效改变根系分布。与此同时,植株地上部光叶空间也是作物进行光合作用的重要元素,适宜的种植密度可有效利用光源,避免部分叶片重叠无法进行光合过程,也有利于植物枝叶向外延展,增加地上部的空间分布,作物更容易枝繁叶茂。总体而言,科学合理的搭配根土空间和种植密度,有利于藜麦根系形成良好的根系分布汲取营养,以及枝叶进行充分光合作用,为作物生长营造更加适宜的环境,有助于作物向高产优产发展。更多还原

【Abstract】 Root spatial distribution affects the growth and development ability of underground and aboveground parts of crops.Reasonable root spatial distribution and planting density can effectively improve the unit yield of quinoa.In order to find out whether the root growth space and planting density have root redundancy phenomenon in the process of quinoa growth and the impact on its physiological characteristics and yield,this experiment took "Longgui-3" and "Longgui-1" as the experimental materials,and carried out two related studies using root canal soil column cultivation method:(1)two root canal soil columns with equal volume and different soil root -growing space configurations(soil root -growing space V1 with diameter of 10 cm and height of 60 cm and soil root -growing space V2 with diameter of 15.2 cm and height of 26 cm),five planting densities(D1: 1 plant/tube;D2: 2plant/tube;D3: 3 plant/tube;D4: 4 plant/tube;D5: 5 plant/tube),There are 10 treatments in total.(2)Cut PVC pipes with a diameter of 20 cm into two types of root columns: the root soil space H1 with a height of 60 cm and the root soil space H2 with a height of 40 cm.Set four planting densities(D2: 2 plants/pipe;D3: 3 plants/pipe;D4: 4 plants/pipe;D5: 5 plants/pipe),a total of eight treatments.The main findings are as follows:(1)Under the same planting density,the plant height,stem diameter,leaf area,root length,root volume,root surface area,aboveground dry matter mass,root dry matter mass,relative chlorophyll content,SOD enzyme activity,POD enzyme activity and root activity of soil root -growing space V1 increased by 4.78%,10.41%,20.65%,29.04%,7.02%,7.78%,37.40%,48.42%,35.02%,15.80%,56.74% and 6.90% respectively,compared with soil root-growing space V2 at the filling stage,The trend of root-shoot ratio and active absorption area(%)was contrary to the above indicators,with an average decrease of 9.10% and 5.47%respectively.When the soil root -growing space(volume,configuration)is the same,the above indexes of quinoa all show a downward trend with the increase of planting density,and it shows that the greater the density increases after D3 treatment,the greater the decline of each index.The yield showed a similar dynamic of increasing first and then decreasing with the increase of planting density,which showed that the yield of soil root -growing space V1 was the highest when the planting density was 3 plants,and the yield of soil root -growing space V2 reached the extreme value when the planting density was 4 plants,but the yield of V1D3 increased by 33.00% on average compared with V2D4.Among them,under the same planting density treatment,the aboveground morphological indexes of soil root -growing space V2 at flowering stage,plant height,stem diameter,leaf area and relative chlorophyll content of physiological indexes were significantly higher than that of soil root -growing space V1,and at the filling stage,the treatment reversed to V1 was significantly higher than that of V2.The "narrow and deep" soil root -growing space V1 can promote the roots of the plant to penetrate deeper into the lower layer to obtain the nutrients at the bottom and improve the contribution rate of nutrients in the unit space;Proper soil root -growing space and reasonable planting density(V1D3)can promote better growth of quinoa,effectively reduce root redundancy and significantly increase unit yield.(2)Regardless of the planting density,the larger soil root -growing space significantly promoted the growth of quinoa.Compared with H2 treatment,the root length,root volume,root dry matter quality,root activity,SOD and POD activity of H1 treatment increased by 63.86%,50.42%,13.13%,9.83%,13.24% and 6.34% respectively,and the lignin and cellulose content of stem increased by 8.44% and 9.43% respectively.Under the same soil root -growing space conditions,with the increase of planting density,the inhibition effect on the growth and development of quinoa increased,which showed that with the increase of planting density,the decline range of the above indicators increased,while the root-shoot ratio,soluble sugar and soluble protein content showed an opposite trend,which decreased with the increase of planting density,but the average value of H1 treatment was still significantly higher than the average value of H2 treatment;With the increase of planting density,the yield showed a trend of increasing first and then decreasing.Under the condition of soil root-growing space H1,it reached the maximum value at planting density D4,while under the condition of H2,it reached the maximum value at D3;In this experiment,the yield of H1D4 treatment reached the peak.Compared with H2D3 treatment,the unit yield increased by13.20%,and the root unit contribution rate was the highest,which can minimize root redundancy and effectively improve the economic benefits of quinoa per unit area.The interaction between soil root -growing space and planting density significantly affects the growth and yield formation of quinoa.Under density stress,increasing soil root-growing space can promote the root growth of quinoa.When the soil root -growing space is small,the growth pressure of quinoa can be alleviated by reducing planting density to maximize unit yield.To sum up,root morphology directly affects the ability of crop roots to absorb water and nutrients.The shaping of good root morphology can improve the absorption efficiency of crops to nutrients.Soil root -growing space is the key factor to reshape root morphology.Improving soil root -growing space can effectively change root distribution.At the same time,the above-ground light leaf space of the plant is also an important element for the photosynthesis of the crops.The appropriate planting density can effectively use the light source,avoid the overlap of part of the leaves that cannot carry out the photosynthesis process,and is also conducive to the outward extension of the plant branches and leaves,increase the spatial distribution of the above-ground,and make the crops more prone to flourish.In general,scientific and reasonable collocation of soil root -growing space and planting density is conducive to the formation of good root distribution and nutrient absorption of quinoa,as well as full photosynthesis of branches and leaves,creating a more suitable environment for crop growth,and helping the development of crops towards high yield and high yield.更多还原