农学与生物技术专业毕业设计论文-不同玉米品种的根系活力与产量性状关系的初步研究

农学与生物技术专业毕业设计论文-不同玉米品种的根系活力与产量性状关系的初步研究内容摘要：

Yan（ Beijing Agricultural University, Beijing100094) Abstract:Systematic electrophoresis analysis of albumins and globulins of the inbred and hybrid corn ( Zea mays) seeds was carried out on an improved lactatepoly acry lamide gel electrophoresis, a method with high resolving power , good reproducibility and stability. The elect roph regram w as classified into four groups designated as , and! Respectively。 Each inbred or hybrid had its own unique band pattern distinguishable from the others, regarding as its fingerprint . T he band pat tern of the whole kernel was basically similar to that of its embryo, except t hat of the endosperm showing less bands wit h weaker staining intensity。 and most of the patterns overlapped wit h t hose of the embryo. T he band number of the F1 hybrid w as exactly equivalent t o the number of t he mon bands and the specific bands of t he two parent s, indicating that the difference of band patterns w as a geic trait controlled by t he nuclear genes. T he F1 elect rophoregram could be predicted by t hose of the two parent s. T he band pattern of t he F 1 11 hybrids was identical with t hat produced from me chanically mixed extract of t he two parent procedure could be used in corn cultivar identification and as a test f or geic purity. Key words： Corn。 Albumin。 Globulin。 Polyacrylamide gel electrophoresis。 Varietal identification Zein is the main ponent of corn seed proteins. It consists of a number of polypeptides of similar molecular weight but with considerable heterogeneity in bioelectric point, so electrophoresis especially isoelectric focusing ( IEF) analysis of the zein family had been extensively used f or corn cultivar identification. Different genotypes containing between 8 to 15 ponents has been identified from t heir zein bandpatterns on the isoelectric focusing electrophoregram. The zein IEF pat tern has been regarded as a geic marker. The IEF w as also used in mapping of genes coding for zein. However, t he zein IEF pattern does not have enough capacity in differentiating between hybrids and their female inbred parents. Certain band differences could be detected among the inbred by using SDSPAGE procedure to analyze proteins extracted from t he seeds and seedlings, but this difference was influenced by t he buffer solution. From the prehensive survey of irony me variability in corn inbred and hybrids using SGE to fractionate proteins from 5day old coleoptiles tissue and staining f or 12 is enzymes, 88 out of 113 ( 80% ) public inbred being utilized in Canadian hybrids and 146 out of 155 ( 94% ) mercial hybrids w ere distinguished by using SDSPAGE procedures. T he heterogeneity of the album ins and goblins of corn seeds w as also used t o identify part of the corn inbred and hybrids. All of t he abovementioned electrophoresis procedures were carried out under basic pH condition. Wang et al. first used t he gradient palmary limed eagle electrophoresis to analyses the 1 mol/ L urea ex tract able proteins of corn seeds under acid pH condition and had been highly praised f or t he possible validity of t his method f or corn seed purity testing. An acid lactatePAGE procedure has been developed in our laboratory as a basic method of w heat cultivar electrophoresis identification. T his procedure was preliminarily proved t o be suit able for separating corn albumin and globulin fractions. The aim of t his study was to evaluate the feasibility of this procedure in distinguishing different corn genotypes, its resolving power, stability, reproducibility and t he geic expression of parent inbred in term s of band patterns in their F1 hybrids, so as t o explore the possibility of its application on corn geic purity testing and cultivar identification. 1 MATERIALS AND METHODS Sample preparation A tot al of 141 inbred and 153 hybrids of corn ( Zea mays) were studied. T he former prised of 9 high oil inbred developed from Illinois high oil ( IHO) C80, 14 high oil inbred from Alexon high oil synthetic C23, and 6 sweet corn inbred from a mercial single 12 cross of Rogers Seed Co. T he latter prised of 26 hybrids w it h on female parents but different male parent s, and 16 w it h mon male but different female parents. All seed samples were provided by our own laboratory . A single corn seed w as ground w it h a sing le seed mill or soaked in tap water under 0 ℃ overnig ht , after which t he embryo and endosperm w ere dissected with a razor blade. After naturally dried, the embryo or endosperm was g round separately. T he ground powder w as put into 2. 5mL centrifuge tube, w it h t he addition of equalvolume of ex tract ion solution( 0. 5 mol/ L NaCl, containing 15% sucrose and 0. 05% methyl green) , mixed thoroughly and extracted for 1 h at room temperature, then centrifuged at 4000 r/ min f or 5 min. The supernatants were used f or electrophoresis. Preparation of the working solutions T he stock solution, tank buffer, separation gel and concentration gel w ere prepared according t o the proportion and volume in T able 1. Table 1 Recipes for stock, extraction and buffer solutions Stock solutions Mixed ratio 1 .A crylamide 95 g, Bisacrylamide 3. 8 g, distilled water 500mL 2. Sodium lactate2. 81mL+lacticacid to pH。