【作者】 张盼盼；

【导师】 冯佰利；

【作者基本信息】 西北农林科技大学 ， 作物栽培学与耕作学， 2013， 博士

【摘要】 建立良好的群体结构，创造适宜的小气候环境是农作物良好生长的基础，不仅有利于其生长发育及产量的提高，也有利于农作物品质的改善。糜子抗旱、耐瘠、水分利用效率高，是北方旱作农区重要的粮食作物和经济作物。探究旱作糜子农田小气候特征及其高产群体生态生理机制，研究和构建合理群体结构，对提高糜子产量，改善产品品质具有重要的指导意义。本试验以强抗旱品种陇糜8号、宁04-339和旱敏感品种晋糜4号、Yym0965为材料，采用田间试验和室内分析相结合的方法，研究了旱地不同施肥水平下，不同糜子品种开花期至成熟期农田小气候特征、干物质积累及转运、光合能力、活性氧代谢、根系活力、产量及产量构成因素的差异，分析评价了糜子农田小气候各因子与生理生态特性、产量及其构成因素的相关关系，得出以下主要结论：（1）与旱敏感品种晋糜4号和Yym0965相比，强抗旱品种陇糜8号和宁04-339的冠层温度两年间持续较低，灌浆结实期间0～25cm土层温度、株间气温、光照度较低，株间相对湿度较高，形成良好的冠层小气候环境，表现出冷湿的特点。增施肥料可以降低糜子群体内冠层温度、株间气温、0～25cm土层温度、株间光照度，不同施肥水平下表现为高肥＜中肥＜低肥＜不施肥，而株间相对湿度表现为高肥＞中肥＞低肥＞不施肥。（2）不同类型品种相比较，强抗旱品种花后同化量对籽粒的贡献率较旱敏感品种高17.8%，但输出量对籽粒的贡献率较旱敏感品种低4.4%，且成熟期地上部干物质剩余量较旱敏感品种高1.4%。增施肥料可以提高糜子花后同化量和花前干物质在籽粒灌浆结实期间的输出量。与不施肥相比，低肥、中肥、高肥下糜子花后同化量分别高16.2%、14.9%、46.0%，花前干物质输出量分别高13.9%、11.1%、25.6%。（3）强抗旱品种旗叶净光合速率、蒸腾速率、气孔导度、胞间CO₂浓度较旱敏感品种分别高17.2%、9.4%、16.9%、15.4%，旗叶可溶性蛋白含量较高，防御活性氧伤害的非酶系统ASA、GSH含量以及保护酶系统SOD、CAT活性也较高，且下降较慢，细胞膜脂过氧化程度较低，整个生育期MDA含量和O₂^-.含量较旱敏感品种分别低18.0%、13.5%，根系伤流强度较旱敏感品种高17.0%，表明强抗旱品种生育后期净光合速率仍能保持较高，根系活力较强，有效地延长了叶片光合功能期，从而有利于制造出较多的光合产物。（4）增施肥料可以提高糜子旗叶净光合速率、蒸腾速率、气孔导度、胞间CO₂浓度、叶绿素相对含量、叶面积和叶面积指数，增加糜子叶片可溶性蛋白含量、ASA和GSH含量，提高SOD和CAT活性，降低MDA和O₂^-.积累量，增加有效穗数，提高产量。与不施肥相比，低肥、中肥、高肥处理下的平均旗叶净光合速率、蒸腾速率、气孔导度、胞间CO₂浓度、叶绿素相对含量、叶面积和叶面积指数分别高14.7%、13.3%、12.3%、6.9%、11.1%、25.9%、50.1%，SOD和CAT活性分别高13.1%、14.0%，MDA和O₂^-.积累量分别低8.3%、9.2%。（5）不同类型糜子灌浆结实期的冠层温度、株间气温与净光合速率、胞间CO₂浓度、可溶性蛋白、SOD、CAT、ASA、GSH、根系伤流强度、有效穗数、穗粒数、产量呈显著或极显著负相关（P＜0.05，P＜0.01）；与POD、MDA、O₂^-.、千粒重呈显著或极显著正相关（P＜0.05，P＜0.01）。说明农田小气候因子与强抗旱糜子较强的生理代谢功能是密切相关的，可以作为筛选强抗旱品种的外部生态指标。（6）不同施肥水平下糜子整个生育后期冠层温度、土壤温度、株间气温、光照度与光合能力各指标、SOD、ASA、GSH、根系伤流强度、有效穗数、穗粒数、产量呈显著或极显著负相关（P＜0.05，P＜0.01），与MDA、O₂^-.、千粒重呈显著或极显著正相关（P＜0.05，P＜0.01）；相对湿度与光合能力各指标、根系伤流强度、SOD、有效穗数、穗粒数、产量呈显著或极显著正相关（P＜0.05，P＜0.01）；与POD、MDA、O₂^-.、千粒重呈极显著或极显著负相关（P＜0.05，P＜0.01）。说明不同施肥处理下优良的生物学性状与农田小气候因子相联系，进一步说明农田冷湿的特点必与合理的施肥措施相关联。更多还原

【Abstract】 To establish a good population structure and to create a suitable microclimate is the basisfor good crop growth, which is not only promote crop growth and yield but also improvequality. Broomcorn millet （Panicum miliaceum L.） is an important grain and cash crops inarid agriculture areas of Northern China, with the characteristic of drought resistance, barrentolerance, high water use efficiency. Therefore, broomcorn millet field microclimate andeco-physiological mechanism of high-yield population in dryland broomcorn millet areexplored, and good population structure are studied and established, which will be greatimportance for increasing yield and improving quality. In this paper, strong drought-resistantvarieties （DRV: Longmi8and Ning04-339） and drought-sensitive varieties （DSV: Jinmi4and Yym0965） were used as materials. The difference of field microclimate, dry matteraccumulation and transport, photosynthetic capacity, active oxygen metabolism, root vigor,yield and yield components of different broomcorn millet varieties from anthesis to maturitywere studied, and the correlation between field microclimate and physiological and ecologicalcharacteristics, yield and its components were analyzed under the low（D）, mid（Z）, high（G）fertility condition. The main results showed as follows:（1） Compared with DSV, DRV had lower canopy temperature,0²5cm soil temperature,air temperature, illumination during grain filling, higher relative humidity, which formed agood canopy microclimate, showing the characteristics of the cold wet, and thus had strongadaptability to drought. Fertility reduced canopy temperature, air temperature,0²5cm soiltemperature, illumination among broomcorn millet plants. These indexes in differentfertilization treatments showed G＜Z＜D＜CK. But relative humidity showed G＞Z＞D＞CK.（2） The contribute rate to grain dry weight of the assimilation of the DRV was17.8%higher than that of DSV after anthesis. But the contribute rate to grain dry weight of theoutput of the DRV was4.4%lower than that of DSV, and the dry matter residues of above-ground were higher those of DSV at maturity. Fertility could improve the dry matterassimilation of broomcorn millet after anthesis and output of dry matter before anthesisduring the grain filling stage. Dry matter assimilation after anthesis under D, Z, G fertilizationwere16.2%,14.9%,46.0%higher than those of CK, and output of dry matter before anthesis were13.9%,11.1%,25.6%than that of CK.（3） Net photosynthetic rate（Pn）, transpiration rate（Tr）, stomatal conductance（Gs）,intercellular CO₂concentration（Ci） of DRV were17.2%、9.4%、16.9%、15.4%higher thanthose of DSV, and soluble protein content （SP）, ASA content, GSH content, SOD activity andCAT activity of flag leaves in DRV were higher than DSV, and their decrease degree werelower than DSV. Moreover, MDA and O₂^-.content of DRV in the whole later growth stagewere18.0%、13.5%lower than those of DSV, root bleeding intensity of DRV was17.0%higher than DRV, indicating that DRV remained higher Pn, root vigor to effectively extendleaf duration, and thus produced more photosynthetic products.（4） Fertility could improve Pn, Tr, Gs, Ci, chlorophyll relative content（SPAD）, leafareas（FLA）, SOD activity, CAT activity of the flag leaves and leaf area index（LAI） ofbroomcorn millet, increase SP, ASA and GSH content, and decrease MDA and O₂^-.content.Moreover, fertility could increase effective spikes, ultimately grain higher yield. Comparedwith CK, the average Pn, Tr, Gs, Ci, SPAD, FLA, LAI of flag leaves under three fertilitytreatments were14.7%,13.3%,12.3%,6.9%,11.1%,25.9%,50.1%higher, SOD, CATactivity were13.1%,14.0%higher, and MDA and O₂^-.Content were8.3%,9.2%lower.（5） There were significant or extremely significant negative correlation between canopytemperature, air temperature and Pn, Ci, SP, SOD, CAT, ASA, GSH, root vigor, effectivespikes, grains per spike, yield in different broomcorn millet types（P＜0.05, P＜0.01）. Therewere significant or extremely significant positive correlation between canopy temperature, airtemperature and POD, MDA, O₂^-.,1000-grain weight in different broomcorn millet types（P＜0.05，P＜0.01）, indicating that field microclimatic factors were close related with strongphysiological and metabolic functions of DRV, and so they were used for screening DRV.（6） Canopy temperature, soil temperature, air temperature, illumination were significantor extremely significant negative correlated with photosynthetic capacity, SOD, CAT, ASA,GSH, root bleeding intensity, effective spikes, grains per spike, yield among differentfertilization treatments（P＜0.05, P＜0.01）. And they were significant or extremely significantpositive correlated with MDA, O₂^-.,1000-grain weight（P＜0.05, P＜0.01）. Relative humiditywas significant or extremely significant positive correlated with photosynthetic capacity, rootbleeding intensity, SOD, effective spikes, grains per spike, yield（P＜0.05, P＜0.01）.Moreover, it was significant or extremely significant negative correlated with POD, MDA,O₂^-.,1000-grain weight（P＜0.05, P＜0.01）. These results showed that excellent biologicalproperties were related with field microclimatic factors to further illustrate the cold and wetfarmland features would be associated with reasonable fertilization measures.更多还原