【作者】 张蓓蓓；

【导师】 刘文兆； Scott X. Chang；

【作者基本信息】 西北农林科技大学 ， 生态学， 2011， 博士

【摘要】 本文从干旱、高温和真菌接种等几种不同环境着手,分析了小麦水分利用效率及其它相关性状应对不同环境的变化特征。其中,黄土塬区的研究内容基于两种试验条件下水分利用效率及茎流和其它气体交换指标的变化,两种试验条件分别为,(1)同一肥力水平下8种冬小麦品种对比试验;(2)同一品种“长武134号”条件下3种磷肥水平施加试验。加拿大的试验包括,(1)控制试验条件下,干旱高温对春小麦水分利用效率的影响及其与品质指标木聚糖之间的关系,干旱胁迫下菌根接种对氮、磷吸收和水分利用效率的影响;(2)加拿大Alberta省西部草原干旱区春小麦在不同菌类接种和磷肥处理下水分利用效率的变化特征。通过分析研究,了解了小麦水分利用效率应对相应试验环境下的变化,同时结合小麦的产量等指标进行综合分析,为小麦品种的筛选、推广种植和栽培模式的选择提供实验依据与技术支撑。其主要结果如下:1.品种对比和磷肥差别供应田间试验(F0,F1和F2)表明,拔节期叶片净光合速率大于开花期;拔节期叶片蒸腾速率也大于开花期。品种试验下拔节期瞬时水分利用效率略大于开花期,而磷肥试验中开花期瞬时水分利用效率略大于拔节期,且两个时期F1的瞬时水分利用效率都是最高,分别为3.04和3.77 umol CO2/mmol H2O,说明适当的磷肥施加可以提高作物的水分利用效率。品种试验中拔节期的SPAD值是洛阳8716最大,与另外七个品种都达到了极显著的差异,开花期各品种差异不显著,最终产量是洛阳8716和陕麦893最高;磷肥试验中F2处理下SPAD最大,且产量最高。2.茎流速率日变化都呈现先升高后下降的趋势;磷肥试验中F0、F1和F2单株茎流速率最高时分别为2.796、3.734和3.873 g/h,随着施肥量的增加茎流量增大;环境因子中的光合有效辐射对茎流变化影响较大;同时对日茎流速率和叶片蒸腾速率进行同步性相关分析得出,茎流速率与叶片蒸腾速率有显著的相关关系,但是相比来说有一定的时间滞后性,说明水容影响了水分的运动过程。3.干旱(拔节期开始,40%田间持水量)和高温(孕穗期开始,32/22℃)处理对两种在加拿大广泛种植的春小麦品种(Superb和AC Crystal)的水分利用效率和木聚糖含量有很大的影响。总体来说,高温下Superb成熟时间比AC Crystal提前了大概10天,说明Superb对高温的敏感性较强;叶片的相对含水量和比叶面积对干旱的敏感性较大。干旱和高温降低了小麦的生物量,所用的水分和产量最终增加了这两种小麦的水分利用效率;稳定性碳同位素分辨率有干旱处理和品种显著性,并且它与水分利用效率呈负相关;高温干旱降低了叶片气体交换指标。高温增加了小麦籽粒木聚糖的含量(特别是水溶性木聚糖);并且木聚糖的含量与水分利用效率呈显著的正相关。4.丛植菌根、氮肥(180 kg/hm2)以及干旱(拔节期开始,40%田间持水量)处理对春小麦Superb的水分利用效率以及氮磷含量的吸收有很大的影响。氮肥施加和菌根接种增大了叶片的相对含水量,而干旱降低了叶片相对含水量的值;干旱降低了叶片的比叶面积,而氮肥施加和菌根接种提高了叶片的比叶面积;干旱处理提高了不同时期小麦的水分利用效率,但在相同氮肥施加下,菌根接种对水分利用效率的影响不大,并且氮肥施加和干旱处理都降低了叶片的稳定性碳同位素分辨率,菌根接种对其影响不大;各处理下籽粒与茎秆的氮含量差异显著,同时不同部位的磷含量随着水分胁迫和菌根接种而增大,氮肥施加间接的影响了茎秆对磷素的吸收,但是对籽粒磷素的吸收影响不大。5.两种真菌(Penicillium和AMF)和不同水平磷肥施加(45 kg/hm~2和90 kg/hm~2)均能增加叶片的气体交换指标,并且在相同的磷肥施加水平下,AMF比Penicillium更能促进叶片的光合性能;丛枝菌根可显著的增加Castor区瞬时水分利用效率;稳定性碳同位素分辨率的含量随着施磷剂量的增加而增大;茎秆和籽粒中磷含量随着真菌接种和施磷而增大,并且AMF的影响最大,;真菌接种和磷肥施加增加了田间的叶面积指数,生物量以及产量。更多还原

【Abstract】 The research of this paper was conducted in drought, high temperature, fungal inoculation and other several different environments to evaluate water use efficiency, photosynthetic characters and other relative items. On the Loess Plateau, （1） 8 varieties were analyzed to see the differences between their water use efficiency, sap flow velocity and gas exchange parameters, （2） using 3 different P levels on another wheat variety Changwu 134 to see the water use efficiency and other characters changes. There were also some experiments conducted in Alberta, Canada, （1） In greenhouse condition, under high temperature and water-deficit treatments the relationship between water use efficiency and arabinoxylan fractions of spring wheat was analyzed; the fungal inoculation to nutrient uptake and water use efficiency change were also analyzed; （2） Under drought field conditions, the inoculation of different fungi and different P levels adding were used to measure the differences of the water use efficiency. Those researches of water use efficiency under these several environments and combined the yields and other characters, which is useful to the wheat variety selection and cultivating model. Main results are as follows:1. The results of photosynthetic characters showed that the value of leaf photosynthesis rate at stem elongation stage was higher than that at flowering stage, and the value of leaf transpiration rate at stem elongation stage was also higher than that at flowering stage. For the results of instantaneous WUE, it showed that under the wheat variety experiment the instantaneous WUE was higher at stem elongation stage than that at flowering stage; but in phosphorus experiment, the instantaneous WUE was a little higher at flowering stage, and the highest value of the WUEi at both stages was under F1 treatment, and it was 3.04 and 3.77 umol CO₂/mmol H₂O respectively. It showed that adding P could increase the instantaneous WUE. The SPAD of LuoYang 8716 at stem elongation stage was the highest and had significant differences among 8 varieties, and the yield of the LuoYang 8716 and Shaan Mai 893 were the highest. Both the SPAD and the yield of F2 was the highest among 3 different phosphorus treatments.2. The results of the sap flow showed that curves of daily sap flow velocity firstly rose up and then dropped down. In phosphorus experiment, the highest sap flow velocity in a day was 2.796、3.734and 3.873 g/h under F0, F1 and F2 respectively, and the sap flow was increased by the P adding. Radiation had a greater impact on sap flow change during many environment factors. The correlation analysis of time synchronization for sap flow velocity and leaf transpiration rate showed that there was a significant positive correlation between them but had the hysteretic nature of the time, and that maybe because the water capacitance had effect on the water movement.3. Under a controlled environment of water-deficit （imposed at the stem elongation stage） and high temperature （imposed at the booting stage）, the water use efficiency （WUE） and arabinoxylan concentration of two spring wheat varieties （‘Superb’and‘AC Crystal’） were analyzed. The temperature treatments were 22/12 （day/night） and 32/22℃. Overall, time to maturity under high temperature was 10 days shorter for‘Superb’than for‘AC Crystal’, indicating that‘Superb’was more sensitive to high temperature stress. Leaf relative water content （RWC） and specific leaf area （SLA） were more sensitive to drought than to high temperature for both varieties. Drought and high temperature decreased （P < 0.05） biomass, water use and grain yield but increased WUE of’Superb’and‘AC Crystal’. Without temperature stress, significant drought and variety effects were found on CID （carbon isotope discrimination） which was negatively correlated with WUE. All gas exchange parameters declined under drought and high temperature. High temperature increased the grain arabinoxylan concentration （especially the water-extractable arabinoxylans）. The different arabinoxylan fractions were positively correlated with WUE suggesting that arabinoxylans can be increased by selecting for increased WUE.4. Arbuscular mycorrhizal fungal inoculation, nitrogen adding （180 kg/hm2） and drought （imposed at the stem elongation stage, 40% filed capacity） were used to analyze changes of the water use efficiency, nitrogen and phosphorus uptake. The nitrogen adding and fungal inoculation can improve the leaf relative water content, but drought decreased it; drought decreased the specific leaf area, but nitrogen adding and fungal inoculation increased it. The water use efficiency was improved by drought, while under the same nitrogen level, fungal inoculation didn’t have much impact on water use efficiency; nitrogen adding and drought all decreased the leaf carbon isotope discrimination. Under different treatments, the leaf and stem nitrogen concentrations were changed a lot and the phosphorus concentrations of different parts were also improved by drought and fungal inoculation, while nitrogen adding indirectly influenced the stem uptake of phosphorus but not seed.5. This experiment evaluated the combined effects of fungal （arbuscular mycorrhizal （AM） and Penicillium） inoculations and phosphorus （P） fertilization （0, 45 and 90 kg/ha） on the net rate of photosynthesis, water use efficiency, P uptake and the growth of spring wheat （Superb） under field conditions at two locations （Castor and Vegreville） in Alberta, Canada. The results showed that both fungal inoculation and P application increased the rate of photosynthesis. Under the same P level, AM inoculation had a greater positive effect on the rate of photosynthesis than Penicillium. The AM inoculation increased the instantaneous water use efficiency （WUEi） of plants at Castor but not at Vegreville. The carbon isotope discrimination (Δ¹³C) of the leaves increased with the rate of P application but was not affected by fungal inoculations. Phosphorus concentrations of stem and seed increased with both fungal inoculation and P application irrespective of location, with AM inoculation showing the largest effects. The interaction between P and fungi was significant for stem P concentration in plants grown in Vegreville. Both Fungal inoculations and P application increased the leaf area index （LAI）, biomass and grain yields at both locations.更多还原