玉米苗期耐低铁品种筛选及其机理研究
发布时间：2019-06-03 11:14
【摘要】：以不同供铁水平对玉米苗期的影响研究,筛选了玉米苗期最适铁浓度：然后,对23个玉米品种在苗期进行低铁胁迫处理,研究低铁胁迫对玉米生长发育和生理特性的影响,对供试玉米品种的耐低铁能力进行了综合评价。从中选择两个有代表性的较耐低铁品种正红2号和不耐低铁的玉米品种川单418,进行轻、中、重三种程度的低铁胁迫,研究了低铁胁迫对两种玉米品种苗期植株的生长发育、光合特性、铁代谢、抗逆和根系生理特性的影响,以期揭示苗期耐低铁玉米品种对低铁胁迫的响应机制,主要结果如下：(1)低浓度供Fe3+抑制玉米地上部茎叶的生长,高浓度供Fe3+则明显抑制地下部根系的生长；玉米苗期生长最为适宜的供Fe3+浓度为100μmol/L；10μmol/LFe3+可作为低铁胁迫苗期筛选浓度。叶片活性铁和叶绿素含量均随供铁浓度增加而增加,二者相关性达到极显著水平,与供铁浓度符合逻辑斯蒂函数模型,并且与植株生长状态(苗高、茎粗、叶面积、茎叶重量等)相关性也达到显著水平,可将活性铁含量和叶绿素含量作为玉米早期潜在性缺铁诊断的综合指标。(2)以西南地区生产上推广应用的23个品种为材料,以15个性状的相对值(低铁处理与对照处理的比值)为评价指标,通过主成分分析、聚类分析、隶属函数分析和逐步回归分析,从15个性状指标中筛选出展叶数、叶面积、根长、根干重、铁积累量等5个耐低铁能力评价指标,并建立了玉米苗期耐低铁能力的回归模型：D=(=384.23+2.71X4+2.50X5+3.22X6+1.70X9+4.86X14)×10-3,筛选出邡玉1号、福康玉909、正大619、正红102、福得2号、正红2号等耐低铁能力较强的品种。(3)低铁胁迫影响玉米的正常生长,引起幼苗的苗高、茎粗、可见叶、展叶、根长、根体积、叶面积变小,胁迫程度越严重,胁迫时间越长,效应越明显。总体而言,低铁胁迫对地上部生长的影响相对较小,对地下部生长的影响相对较大；对正红2号的影响较小,对川单418的影响较大。(4)低铁胁迫不仅降低玉米苗期的叶面积,还会降低叶片的叶绿素含量和光合速率,从而影响干物质积累,单株干重与铁浓度呈显著正相关关系,其中正红2号与川单418相比,单株干重(y)受铁浓度(x)的影响较小,与铁浓度的线性回归方程的斜率较低。(5)随着铁浓度的降低,玉米苗的根系活力和单株溶铁能力(麦根酸分泌量)降低,导致地上、地下部铁含量和积累量也降低,但铁素向地上部转移分配能力增强,铁素的生理效率提高,这可能是玉米适应低铁胁迫的重要生理机制之一。正红2号与川418相比,单株铁积累量较高,受铁浓度影响较小,而且低铁条件下所吸收铁的生理效率较高,这是其耐低铁能力较强的重要原因。(6)营养液中铁浓度对玉米苗期叶片POD活性的影响较小,对CAT活性较大,低铁胁迫使CAT活性降低,活性氧清除能力下降,但细胞内渗透调节物质可溶性蛋白含量升高,其中正红2号的CAT酶活性和可溶性蛋白质含量均高于川单418。
[Abstract]:The effect of different iron supply levels on the seedling stage of maize was studied, and the optimum iron concentration in the seedling stage was selected: then, the effect of low iron stress on the growth and the physiological characteristics of the corn was studied. The low iron capacity of the tested corn variety was comprehensively evaluated. Two representative lower iron-resistant and low-iron-resistant corn varieties, Sichuan-418, were selected for light, medium and three levels of low-iron stress, and the growth and development, photosynthetic characteristics and iron metabolism of two maize varieties at the seedling stage of low iron stress were studied. The main results are as follows: (1) the low concentration of Fe3 + inhibits the growth of the upper stem and leaf of the corn, and the high concentration of the Fe3 + is obviously inhibited from the growth of the lower root system; The optimum concentration of Fe ~ (3 +) was 100 & mu; mol/ L, and the concentration of Fe ~ (3 +) was 100 & mu; mol/ L, and the concentration of Fe ~ (3 +) was 10 & mu; mol/ L ~ (3 +). the content of the active iron and the chlorophyll of the leaves is increased with the increase of the iron supply, the correlation of the two is very significant, and the concentration of the iron and the chlorophyll is in line with the logistic function model, and the correlation with the growth state of the plant (the seedling height, the length of the stem, the leaf area, the weight of the stem and the leaf, etc.) also reaches a significant level, The active iron content and the chlorophyll content can be used as a comprehensive index of early potential iron deficiency diagnosis of the corn. (2)23 varieties used in the production of Southwest China are the materials, and the relative values of 15 characters (the ratio of the low iron treatment and the control process) are the evaluation indexes, and the main component analysis, the cluster analysis, the membership function analysis and the stepwise regression analysis are adopted. Five low-iron capacity evaluation indexes such as leaf number, leaf area, root length, root dry weight and iron accumulation amount were selected from 15 character indexes, and a regression model of low iron capacity in the seedling stage was established. D = (= 384.23 + 2.71 X4 + 2.50 X5 + 3.22X6 + 1.70X9 + 4.86X14) and 10-3, and screened out the 1, Fukangyu 909, Zhengda 619 and Zhenghong 102. No.2, Zhenghong No.2, and other low-iron-resistant varieties. (3) Under the condition of low iron stress, the normal growth of the corn is affected, and the seedling height, the thick stem, the visible leaf, the spread leaf, the root length, the root volume, the leaf area of the leaves, the more severe the stress degree and the longer the stress time, the more obvious the effect. In general, the effect of low iron stress on the growth of the ground part is relatively small, the effect on the growth of the lower part is relatively large, the effect on the positive red 2 is small, and the effect on the Sichuan single 418 is large. (4) The low iron stress not only reduces the leaf area at the seedling stage of the corn, but also reduces the chlorophyll content and the photosynthetic rate of the leaves, thus affecting the dry matter accumulation, the dry weight of the single plant is positively related to the iron concentration, The dry weight of the single plant (y) is less affected by the iron concentration (x), and the slope of the linear regression equation with the iron concentration is lower. (5) With the decrease of the iron concentration, the root activity of the corn seedling and the capacity of the single plant dissolved iron (the amount of wheat root acid secretion) are reduced, and the iron content and the accumulation amount of the ground and the ground are also reduced, but the transfer and distribution ability of the iron to the ground part is enhanced, and the physiological efficiency of the iron element is improved, This may be one of the most important physiological mechanisms for maize to adapt to low iron stress. Compared with Sichuan 418, the number of iron accumulation in the single plant is high, the influence of iron concentration is small, and the physiological efficiency of the iron absorbed under the condition of low iron is higher, which is an important reason for its high iron-resistant ability. and (6) the effect of the iron concentration on the POD activity of the leaves at the seedling stage of the corn is small, the activity of the CAT is large, the activity of the CAT is reduced by the low iron stress, the scavenging capacity of the active oxygen is reduced, the content of the soluble protein of the osmotic adjusting substance in the cell is increased, The activity of CAT and the content of soluble protein in Zhenghong No.2 were higher than that of Sichuan single 418.
【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S513
[Abstract]:The effect of different iron supply levels on the seedling stage of maize was studied, and the optimum iron concentration in the seedling stage was selected: then, the effect of low iron stress on the growth and the physiological characteristics of the corn was studied. The low iron capacity of the tested corn variety was comprehensively evaluated. Two representative lower iron-resistant and low-iron-resistant corn varieties, Sichuan-418, were selected for light, medium and three levels of low-iron stress, and the growth and development, photosynthetic characteristics and iron metabolism of two maize varieties at the seedling stage of low iron stress were studied. The main results are as follows: (1) the low concentration of Fe3 + inhibits the growth of the upper stem and leaf of the corn, and the high concentration of the Fe3 + is obviously inhibited from the growth of the lower root system; The optimum concentration of Fe ~ (3 +) was 100 & mu; mol/ L, and the concentration of Fe ~ (3 +) was 100 & mu; mol/ L, and the concentration of Fe ~ (3 +) was 10 & mu; mol/ L ~ (3 +). the content of the active iron and the chlorophyll of the leaves is increased with the increase of the iron supply, the correlation of the two is very significant, and the concentration of the iron and the chlorophyll is in line with the logistic function model, and the correlation with the growth state of the plant (the seedling height, the length of the stem, the leaf area, the weight of the stem and the leaf, etc.) also reaches a significant level, The active iron content and the chlorophyll content can be used as a comprehensive index of early potential iron deficiency diagnosis of the corn. (2)23 varieties used in the production of Southwest China are the materials, and the relative values of 15 characters (the ratio of the low iron treatment and the control process) are the evaluation indexes, and the main component analysis, the cluster analysis, the membership function analysis and the stepwise regression analysis are adopted. Five low-iron capacity evaluation indexes such as leaf number, leaf area, root length, root dry weight and iron accumulation amount were selected from 15 character indexes, and a regression model of low iron capacity in the seedling stage was established. D = (= 384.23 + 2.71 X4 + 2.50 X5 + 3.22X6 + 1.70X9 + 4.86X14) and 10-3, and screened out the 1, Fukangyu 909, Zhengda 619 and Zhenghong 102. No.2, Zhenghong No.2, and other low-iron-resistant varieties. (3) Under the condition of low iron stress, the normal growth of the corn is affected, and the seedling height, the thick stem, the visible leaf, the spread leaf, the root length, the root volume, the leaf area of the leaves, the more severe the stress degree and the longer the stress time, the more obvious the effect. In general, the effect of low iron stress on the growth of the ground part is relatively small, the effect on the growth of the lower part is relatively large, the effect on the positive red 2 is small, and the effect on the Sichuan single 418 is large. (4) The low iron stress not only reduces the leaf area at the seedling stage of the corn, but also reduces the chlorophyll content and the photosynthetic rate of the leaves, thus affecting the dry matter accumulation, the dry weight of the single plant is positively related to the iron concentration, The dry weight of the single plant (y) is less affected by the iron concentration (x), and the slope of the linear regression equation with the iron concentration is lower. (5) With the decrease of the iron concentration, the root activity of the corn seedling and the capacity of the single plant dissolved iron (the amount of wheat root acid secretion) are reduced, and the iron content and the accumulation amount of the ground and the ground are also reduced, but the transfer and distribution ability of the iron to the ground part is enhanced, and the physiological efficiency of the iron element is improved, This may be one of the most important physiological mechanisms for maize to adapt to low iron stress. Compared with Sichuan 418, the number of iron accumulation in the single plant is high, the influence of iron concentration is small, and the physiological efficiency of the iron absorbed under the condition of low iron is higher, which is an important reason for its high iron-resistant ability. and (6) the effect of the iron concentration on the POD activity of the leaves at the seedling stage of the corn is small, the activity of the CAT is large, the activity of the CAT is reduced by the low iron stress, the scavenging capacity of the active oxygen is reduced, the content of the soluble protein of the osmotic adjusting substance in the cell is increased, The activity of CAT and the content of soluble protein in Zhenghong No.2 were higher than that of Sichuan single 418.
【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S513
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