【作者】 张敏；

【导师】 王锁民；

【作者基本信息】 兰州大学 ， 农学.农村与区域发展， 2017， 硕士

【摘要】 紫花苜蓿不仅可以作为高产优质的饲料创造经济效益,还可以作为绿色屏障防风固沙创造生态效益。我国紫花苜蓿的种植区域主要分布在西北地区,但该区气候干旱、土壤贫瘠且盐渍化严重,种植紫花苜蓿所需要的水肥条件差、种植成本较高。在目前实施“粮-经-草”的三元种植结构和立草为业的大背景下,培育抗逆性强的紫花苜蓿品种势在必行。液泡膜Na+/H+逆向转运蛋白(NHX)和H+-焦磷酸酶(VP)在植物细胞阳离子区域化中起着重要作用,超表达NHX或VP均可显著提高植株Na+的区域化能力从而增强其耐盐性和抗旱性。生长在干旱覆沙地上的强旱生植物霸王(Zygophyllum xanthoxylum)正是因为具有极强的Na+区域化能力,所以能适应极端干旱环境。因此,本文以成功转入霸王阳离子区域化基因ZxNHX和Zx VP1-1的转基因新疆大叶紫花苜蓿(GM)和其野生型植株(WT)为实验材料,通过进行大田双因素裂区实验设计,比较未施肥、减半施肥和正常施肥3种不同施肥处理下WT和GM的株高、冠幅、分枝数、地上部干重以及水分利用率(WUE)、气孔导度(Gs)、蒸腾速率(Tr)、净光合速率(Pn)、叶绿素含量和粗蛋白含量等营养指标,以此来评价GM的田间生产性能及营养品质,为其今后的推广建立初步依据。主要结果如下:1.随着施肥量的增加,GM的株高、地上部干重均显著增加;在各处理下,GM植株的株高、分枝数均显著高于WT植株。与WT植株相比,GM植株具有更强的生长和田间生产性能。2.WT的冠幅在减半施肥和未施肥处理下均显著大于GM,说明WT植株倾向于匍匐生长;而GM植株冠幅小,植株高大、倾向于直立生长。3.大田干旱条件下,相较于WT植株,GM植株体内能积累更多的叶绿素;正常施肥处理下,GM的WUE、Tr、Pn比WT分别高15.3%、20%和12.0%。随着施肥量的增加,GM和WT植株的Pn均显著升高;与减半施肥和未施肥处理相比下,正常施肥处理下GM的Pn分别升高了35.5%和54%;正常施肥处理下WT的Pn比减半施肥和未施肥处理高31.4%和56%。说明相较于WT,GM具有更强的光合作用能力。4.随着施肥量的增加,GM和WT植株的粗蛋白、粗灰分积累量也呈上升趋势;减半施肥和正常施肥条件下GM的粗灰分含量均显著高于WT;GM植株内粗蛋白含量在减半施肥处理和正常施肥处理下分别比比WT高11.8%和7.1%,说明在减半施肥处理下,GM植株作为饲料可以为家畜的生长发育提供更充足的蛋白质。5.酸性洗涤纤维(ADF)和中性洗涤纤维(NDF)含量随着施肥量的增加呈下降趋势,减半施肥和正常施肥处理下GM植株体内的NDF含量比相同处理下的WT低19.2%和10.4%;在未施肥和减半施肥条件下,GM植株ADF的含量比WT低11.9%和22.5%,正常施肥处理下差异不显著。未施肥处理下,WT和GM的RFV差异不显著,在减半施肥和正常施肥处理下,GM的RFV显著高于WT,所以施肥后,与WT相比GM植株作为饲料具有更高的营养价值和营养平衡性能。更多还原

【Abstract】 As a high-yielding and high-quality feed,alfalfa not only has economic value,but also can be used as green barriers to wind and sand to create ecological value.In China,the planting area of alfalfa is mainly in the Northwest,but the soil in Northwest is poor,and the climate is arid.The cost of fertilizer and water needed to grow alfalfa is high.In the current implementation of the policy “grain-by-feeding" ternary planting structure and the establishment of grass for the industry in the form.Cultivating alfalfa with strong stress resistance is more and more attention.Studies showed that vacuolar Na+/H+ antiporter(NHX)and H+-PPase(H+-PPase)play an important role in the ion compartmentalisation of plant cell,and overexpression of N HX or H+-PPase enhanced the salt tolerance and drought resistancein plants.Zygophyllum xanthoxylum is a succulent xerophyte which mainly grows in arid sandy land.As its strong capacity of Na+ compartmentalization,Z.xanthoxylum has a strong salt and drought resistance.Therefore,in this study,transgenic alfalfa(GM),which was successfully transferred ZxNHX and Zx VP1-1 gene and wild type alfalfa(WT)were used as experimental materials.The field experiment was designed to compare the plant height,cro wn width,branch number,yield,water use efficiency,stomatal conductance,transpiration rate,net photosynthetic rate and chlorophyll content of WT and GM under non-fertilization,halved fertilization and normal fertilization condition.In order to study the field production capacity of transgenic alfalfa,as an initial basis for future promotion.The main results are as follows:1.The plant height and shoot dry weight of GM were increased along with the increase of fertilization amount.Plant height and branch number of GM were significantly higher than WT.Thus,the ability of growth and field production about GM is better than WT.2.Under half fertilizer and no fertilizer conditions,crown diameter of WT was higher than corresponding GM plants due to lower nutrient absorption capacity of WT plants.It means that the WT tend to creeping growth and GM on the contrary.3.The content of chlorophyll in GM is accumulated more than WT under drought condition in field.Both of WUE,Gs,and Pn have significant discrepancy between GM and WT under regular fertilizer treatment.Pn of GM is increased 35.5% and 54% under regular fertilizer than half fertilizer and no fertilizer.Pn of WT is increased 31.4%% and 56% under regular fertilizer than other treatments.And the Pn of GM is 12% higher than WT under regular treatment.Compared with WT,the GM has stronger capacity for photosynthesis.4.With the increasing of fertilizer,both content of crude protein and crude ash are increasing gradually.Rude protein content in GM are significantly higher than WT under half fertilizer and regular fertilizer,as well as rude ash.The rude protein content of GM under half fertilizer is 11.8% higher than WT,7.1% under regular fertilizer.It means that GM can provide more protein for livestock than WT when giving half fertilizer.5.Both the content of acid detergent fiber(ADF)and neutral detergent fiber(NDF)are reduced by increasing fertilizer.The NDF of GM is 19.2% and 10.4% less than GM under the treatment of half fertilizer and regular fertilizer.Under the treatment of half fertilizer,the ADF of GM is 22.5% less than WT and is no significantly discrepancy under other treatments.After fertilization the relative feeding value(RFV)of GM is significantly higher than WT witch half fertilizer and regular fertilizer.However,there are no significant difference between GM and WT under no fertilizer.Thus,GM can be a better fodder than WT under half fertilizer and regular fertilizer.更多还原