玉米苗期耐低鐵品種篩選及其機(jī)理研究
發(fā)布時間：2019-06-03 11:14
【摘要】：以不同供鐵水平對玉米苗期的影響研究,篩選了玉米苗期最適鐵濃度：然后,對23個玉米品種在苗期進(jìn)行低鐵脅迫處理,研究低鐵脅迫對玉米生長發(fā)育和生理特性的影響,對供試玉米品種的耐低鐵能力進(jìn)行了綜合評價。從中選擇兩個有代表性的較耐低鐵品種正紅2號和不耐低鐵的玉米品種川單418,進(jìn)行輕、中、重三種程度的低鐵脅迫,研究了低鐵脅迫對兩種玉米品種苗期植株的生長發(fā)育、光合特性、鐵代謝、抗逆和根系生理特性的影響,以期揭示苗期耐低鐵玉米品種對低鐵脅迫的響應(yīng)機(jī)制,主要結(jié)果如下：(1)低濃度供Fe3+抑制玉米地上部莖葉的生長,高濃度供Fe3+則明顯抑制地下部根系的生長；玉米苗期生長最為適宜的供Fe3+濃度為100μmol/L；10μmol/LFe3+可作為低鐵脅迫苗期篩選濃度。葉片活性鐵和葉綠素含量均隨供鐵濃度增加而增加,二者相關(guān)性達(dá)到極顯著水平,與供鐵濃度符合邏輯斯蒂函數(shù)模型,并且與植株生長狀態(tài)(苗高、莖粗、葉面積、莖葉重量等)相關(guān)性也達(dá)到顯著水平,可將活性鐵含量和葉綠素含量作為玉米早期潛在性缺鐵診斷的綜合指標(biāo)。(2)以西南地區(qū)生產(chǎn)上推廣應(yīng)用的23個品種為材料,以15個性狀的相對值(低鐵處理與對照處理的比值)為評價指標(biāo),通過主成分分析、聚類分析、隸屬函數(shù)分析和逐步回歸分析,從15個性狀指標(biāo)中篩選出展葉數(shù)、葉面積、根長、根干重、鐵積累量等5個耐低鐵能力評價指標(biāo),并建立了玉米苗期耐低鐵能力的回歸模型：D=(=384.23+2.71X4+2.50X5+3.22X6+1.70X9+4.86X14)×10-3,篩選出邡玉1號、�？涤�909、正大619、正紅102、福得2號、正紅2號等耐低鐵能力較強(qiáng)的品種。(3)低鐵脅迫影響玉米的正常生長,引起幼苗的苗高、莖粗、可見葉、展葉、根長、根體積、葉面積變小,脅迫程度越嚴(yán)重,脅迫時間越長,效應(yīng)越明顯。總體而言,低鐵脅迫對地上部生長的影響相對較小,對地下部生長的影響相對較大；對正紅2號的影響較小,對川單418的影響較大。(4)低鐵脅迫不僅降低玉米苗期的葉面積,還會降低葉片的葉綠素含量和光合速率,從而影響干物質(zhì)積累,單株干重與鐵濃度呈顯著正相關(guān)關(guān)系,其中正紅2號與川單418相比,單株干重(y)受鐵濃度(x)的影響較小,與鐵濃度的線性回歸方程的斜率較低。(5)隨著鐵濃度的降低,玉米苗的根系活力和單株溶鐵能力(麥根酸分泌量)降低,導(dǎo)致地上、地下部鐵含量和積累量也降低,但鐵素向地上部轉(zhuǎn)移分配能力增強(qiáng),鐵素的生理效率提高,這可能是玉米適應(yīng)低鐵脅迫的重要生理機(jī)制之一。正紅2號與川418相比,單株鐵積累量較高,受鐵濃度影響較小,而且低鐵條件下所吸收鐵的生理效率較高,這是其耐低鐵能力較強(qiáng)的重要原因。(6)營養(yǎng)液中鐵濃度對玉米苗期葉片POD活性的影響較小,對CAT活性較大,低鐵脅迫使CAT活性降低,活性氧清除能力下降,但細(xì)胞內(nèi)滲透調(diào)節(jié)物質(zhì)可溶性蛋白含量升高,其中正紅2號的CAT酶活性和可溶性蛋白質(zhì)含量均高于川單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.
【學(xué)位授予單位】：四川農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：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.
【學(xué)位授予單位】：四川農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S513
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1 付錦艷;楊安強(qiáng);劉烈剛;劉e，
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