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1.
The major objective of the research is to identify and locate quantitative trait loci (QTLs) in the Yugoslav maize population. The plants (F2) were selected for the analysis at seedling stage and were selfed to obtain F3 generation. The analysis covered about 15 enzymes controlled by about 30 loci. The seeds of F3 family planted in the greenhouse for measuring some quantitative traits, recorded tasselling and silking during vegetation. At the end of vegetation grain yield, and some other quantitative traits of grain in F3 family were assessed. The relationship between marker loci and the loci for quantitative traits (QTLs) were estimated by computerized statistical method. 相似文献
2.
Curtis M. Wilson 《Biochemical genetics》1985,23(1-2):115-124
Isoelectric focusing of zein in agarose gels gives sharp separations of at least 25 bands noted among 25 corn-belt inbreds. Six inbreds provided standard bands which were used to construct a pattern map. A method is provided for comparing bands, identified by distance from the cathode, which differ only slightly in position. The 25 inbreds were separated into five groups on the basis of pattern similarity. Some groups contained inbreds derived from widely different sources. Zein isoelectric focusing in agarose should be useful for genotype identification and for determination of varietal purity. 相似文献
3.
Phosphoglucomutase (PGM; EC 2.7.5.1) isozyme variants were studied in a large number of inbred lines, crosses, and races of maize (Zea mays L.). Patterns of Mendelian inheritance demonstrated for PGM isozyme variants indicated that they are encoded by nuclear genes. Two unlinked loci, Pgm1 and Pgm2, located on the long arm of chromosome 1 and the short arm of chromosome 5, respectively, specify the observed electrophoretic variation on starch gels. No intra- or interlocus hybrid bands were found, suggesting that each isozyme band consists of a single polypeptide. PGM isozymes were present in all plant parts studied and the activity specified by both loci appears to reside in the cytoplasm. In studies of 520 racial collections of maize from Latin America, a single allele at each locus predominated in most collections. Likewise, the same alleles predominated in a set of 406 inbred lines of maize from the United States and Canada.This work was supported in part by NIH Research Grant GM 11546.Paper No. 8496 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, North Carolina. 相似文献
4.
Response of root system architecture to nutrient availability in soils is an essential way for plants to adapt to soil environments.
Nitrate can affect root development either as a result of changes in the external concentration, or through changes in the
internal nutrient status of the plant. Nevertheless, less is known about the physiological mechanisms. In the present study,
two maize (Zea mays L.) inbred lines (478 and Wu312) were used to study a possible role of cytokinin in nitrate-mediated root growth in nutrient
solutions. Root elongation of 478 was more sensitive to high nitrate supply than that of Wu312. Medium high nitrate (5 mM) inhibited root elongation in 478, while, root elongation in Wu312 was only inhibited at high NO
3
−
supply (20 mM). Under high nitrate supply, the root elongation zone in 478 became swollen and the site of lateral root elongation was close
towards the root tip. Both of the phenomena are typical of root growth induced by exogenous cytokinin treatments. Correspondingly,
zeatin and zeatin nucleotide (Z + ZR) concentrations were increased at higher nitrate supply in 478, whereas they were constant
in Wu312. Furthermore, exogenous cytokinin 6-benzylaminopurine (6-BA) completely reversed the stimulatory effect of low nitrate
on root elongation. Therefore, it is supposed that the inhibitory effect of high concentration of nitrate on root elongation
is, at least in part, mediated by increased cytokinin level in roots. High nitrate supply may have negative influences on
root apex activity by affecting cytokinin metabolism so that root apical dominance is weakened and, therefore, root elongation
is suppressed and lateral roots grow closer to the root apex. Nitrate suppressed lateral root elongation in Wu312 at concentration
higher than 5 mM. In 478, however, this phenomenon was not significant even at 20 mM nitrate. Although exogenous 6-BA (20 nM) could suppress lateral root elongation as well, the inhibitory effect of high NO
3
−
concentration of nitrate on lateral root growth cannot be explained by changes in endogenous cytokinin alone. 相似文献
5.
Zinc deficiency decreased pollen viability in maize (Zea mays L. cv. G2) grown in sand culture. On restoring normal zinc supply to zinc-deficient plants before the pollen mother cell stage of anther development, the vegetative yield of plants and pollen fertility could be recovered to a large extent, but the recovery treatment was not effective when given after the release of microspores from the tetrads. If zinc deficiency was induced prior to microsporogenesis it did not significantly affect vegetative yield and ovule fertility, but decreased the fertility of pollen grains, even of those which visibly appeared normal. If the deficiency was induced after the release of microspores from the tetrads, not only vegetative yield and ovule fertility but pollen fertility also remained unaffected. 相似文献
6.
利用RFLP、SSR、AFLP和RAPD标记分析玉米自交系遗传多样性的比较研究 总被引:112,自引:3,他引:112
利用 RFLP、SSR.AFLP和RAPD 4种分子标记方法研究了 15个玉米(Zea mays L.)自交系的遗传多样性,同时对4种标记系统进行比较。在供试材料中筛选到具多态性的RFLP探针酶组合56个,66对SSR引物,20个RAPD引物和9个AFLP引物组合,分别检测到多态性带167、201、87和108条。SSR标记位点的平均多态性信息量(PIC)最大(0.54),AFLP标记位点最小(0.36),但AFLP标记具有最高的多态性检测效率(Ai,32.2)。4种分子标记所得遗传相似系数相关性显著,比较相关系数表明 RAPD可靠性较低。依据 4种分子标记结果将 15个供试自交系划分为塘四平头、旅大红骨、兰卡斯特、瑞德和PN共5个类群,与系谱分析基本一致。认为SSR和RFLP两种分子标记方法适合进行玉米种质遗传多样性的研究。 相似文献
7.
Effect of Zero Tillage and Residues Conservation on Continuous Maize Cropping in a Subtropical Environment (Mexico) 总被引:12,自引:0,他引:12
The effects of zero tillage and residue conservation in continuous maize-cropping systems are poorly documented, especially
in the tropics, and are expected to vary highly with climatic conditions and nitrogen availability. In the present study,
maize was cultivated during the wet and dry seasons in central Mexico for three consecutive years, under different treatments
combining tillage with residue management techniques and with nitrogen rates. In some treatments, maize was also intercropped
with jackbean, Canavalia ensiformis L. (DC). Yield and yield components as well as physiological traits and soil characteristics were assessed during the wet
and dry seasons for the third year of cultivation. During the wet season, zero tillage was associated with less biomass and
grain yield. Leaf chlorophyll concentration was smaller under zero tillage, suggesting less nitrogen uptake. Both zero tillage
and residue conservation reduced early growth and strongly increased ear rot. During the dry season, zero tillage was associated
with greater root mass, as measured by electrical capacitance. Residue conservation decreased the anthesis-silking interval,
suggesting better water uptake. There was, however, no significant effect of tillage or residue management practices on yield.
Zero tillage was found to be associated with increased soil bulk density, nitrogen concentration and microbial biomass organic
carbon. Residue conservation increased soil carbon concentration as well as microbial biomass organic carbon. Intercropping
with jackbean and conservation of its residues in addition to maize residues increased soil nitrogen concentration. Further
investigation may provide more information on the factors related to zero tillage and residue conservation that affect maize
early growth, and determine to which extent the observed modifications of soil chemical and physical properties induced by
conservation tillage will further affect maize yield. 相似文献
8.
Two maize lines differing in drought resistance were grown at different drought stress induced by polyethylene glycol (PEG 10 000) solutions with osmotic potentials of –0.20, –0.40 and –0.80 MPa in the semipermeable membrane system. During the five days soil water content decreased (from 0.43 to 0.29, 0.25 and 0.23 g cm–3 for three PEG solutions, respectively) as well as leaf water potentials (w; from – 0.54 to –0.76, –1.06 and –1.46 MPa). These values were not significantly different between the investigated lines, indicating that a controlled and consistent soil moisture stress was achieved. Soil drying induced an increase in the ABA content of leaves and xylem of both lines and the effects on stomatal conductance were greater in drought susceptible line (B-432) compared to drought resistant line (ZPBL-1304). To test possible difference in stomatal sensitivity to xylem ABA between lines and to assess any ABA vs. w interaction, roots were fed with 10, 50 and 100 mmol m–3 ABA solutions in another set of experiments. These results showed that manipulation of xylem ABA affected stomata of both lines similarly. Comparison of stomatal sensitivity to drought-induced and applied ABA demonstrated that drought treatment affected stomata of investigated lines by differentially increasing their sensitivity to xylem ABA, thus confirming an interaction between chemical signalling and hydraulic signalling. 相似文献
9.
Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was used for monitoring Al-induced changes in polypeptide composition of membrane proteins isolated from 3-d-old maize seedlings subjected to aluminium stress. Analysis of peripheral membrane proteins isolated from maize root showed an Al-induced increase in accumulation of 14 polypeptides with apparent molecular mass from 10 to 135 kDa. Qualitative differences were found between peripheral membrane proteins isolated from root tip (increased accumulation of 4 polypeptides with Mr 42 000 – 135 000) and from root base (increased accumulation of 10 polypeptides with Mr 10 000 – 59 000). On the other hand, no Al-induced changes were observed in peripheral membrane proteins isolated from maize coleoptile and integral membrane proteins isolated either from root or coleoptile. These results indicate that peripheral membrane proteins undergo considerable changes during 24-h Al treatment while integral membrane proteins pattern is stable. 相似文献
10.
Effect of Osmotic Stress on Abscisic Acid Efflux and Compartmentation in the Roots of Two Maize Lines Differing in Drought Susceptibility 总被引:1,自引:0,他引:1
Roots of two Zea mays L. lines (drought-resistant Polj 17, and drought-susceptible F-2) were exposed to osmotic stress induced by sorbitol (osmotic potential –1.0 MPa). The following parameters were determined in cortex cells: membrane permeability for abscisic acid (ABA), ABA fluxes across membranes, pH values and ABA content in cytoplasm and vacuole. Osmotic stress induced different distribution of ABA within cell compartments in the investigated lines. ABA transport in the F-2 line occurred according to the intracellular pH gradient and the anion trap concept. In Polj 17, however, osmotic stress did not cause any significant effect on pH gradient and compartmental ABA content, but had a stimulating effect on ABA efflux from cytoplasm to apoplast and than via xylem to the leaf. These findings indicate different mechanisms of ABA transport between the investigated lines in response to osmotic stress. 相似文献
11.
Young plants of maize inbred lines CE777, CE704, and CE810 and their F1 hybrids displaying a positive heterotic effect in various photosynthetic characteristics were exposed to low temperature
during their early growth developmental stage. The photochemical activity of isolated mesophyll chloroplasts and the contents
of photosynthetic pigments in leaves of stressed and non-stressed plants were compared with the aim to find out the possible
changes in the relationship between parents and hybrids, and to determine the genetic basis of heterosis in F1 generation. Strong decrease in the content of chlorophylls was observed for all genotypes examined when plants were subjected
to low growth temperature. Similar change was recorded for Hill reaction activity (HRA) of inbred lines but not of their F1 hybrids, and no significant response at all was found for photosystem 1 (PS1) activity or the total carotenoids content.
The intraspecific variation due to differences between genotypes was found for most of photosynthetic characteristics examined.
This variation was caused by the additive and dominance genetic effects. Positive dominance was the main cause of positive
heterosis in HRA and in the contents of photosynthetic pigments and was much more pronounced in the stressed plants compared
to the non-stressed ones. The maternal additive effects participated in the inheritance of contents of photosynthetic pigments
in plants exposed to low temperature, too.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
12.
玉米自交系遗传变异的RFLP分析 总被引:10,自引:0,他引:10
利用RFLP标记研究了13个玉米(Zca nays L.)自交系的遗传变异。从30对探针/酶组合中筛选出杂交带型清晰、稳定、重复性好的24对组合,在13个自交系中获得85个等位基因杂交片段,平均每个位点为3.3条,平均多态性指数为0.499。13个自交系之间的遗传相似系数为0.523-0.802,平均为0.649。UPGMA聚类分析表明,供试自交系共分为5个类群,分群结果与其系谱关系基本吻合;表明 相似文献
13.
Genetic similarities of 13 inbred lines of maize (Zea mays L.) were analyzed by restriction fragment length polymorphisms (RFLPs). The objectives of the study were to detect genetic similarities among 13 inbreds and to assign them to heterotic groups. By means of 24 probe-enzyme combinations (PECs) selected for locus specificity, clear patterns and reproducibility, 85 alleles were found with an average of 3.3 alleles per locus. The allelic frequency data were used to estimate genetic similarities among lines, and as a result the diversity index of 0.499 was obtained. Genetic similarities between the pairs of 13 lines ranged from 0.523 up to 0.802 with an average of 0.649. The UPGMA clustering algorithm analysis classified the 13 lines into five groups, which generally corresponded to known maize heterotic groups based on pedigree information. The authors concluded that RFLP-based markers could be used for investigating genetic relationships between maize inbred lines and assigning them to heterotic groups, but it seemed that a large number of PECs were needed to obtain reliable estimates of genetic similarity. 相似文献
14.
Maize and pigweed response to nitrogen supply and form 总被引:1,自引:0,他引:1
As nitrogen management practices change to achieve economic and environmental goals, effects on weed-crop competition must
be examined. Two greenhouse experiments investigated the influence of N amount and form on growth of maize and redroot pigweed
(Amaranthus retroflexus L.).
In Experiment 1, maize and pigweed were grown together in a replacement series (maize: pigweed ratios of 0:4, 1:3, 2:2, 3:1,
4:0) under three NH4NO3-N supplies (0, 110, and 220 mg N kg-1 soil). Maize was planted into established pigweed and plants were harvested 24 days after maize germination. Pigweed responded
more to supplemental N than maize and accumulated 2.5 times as much N in shoots at the high N supply. Competition effects
were not significant.
Maize and pigweed were grown separately in Experiment 2 and supplied 220 mg N kg-1 as either Ca(NO3)2 or (NH4)2SO4 plus a nitrification inhibitor (enhanced ammonium supply, EAS). In maize, EAS treatment did not affect shoot growth and reduced
root growth 25% relative to the NO3-N treatment. In pigweed, shoot and root growth were restricted 23 and 86% by EAS treatment, respectively. Total plant N accumulation
under EAS treatment was higher in maize, less in pigweed. Under EAS treatment, pigweed leaves were crinkled and chlorotic;
leaf disks extracted in 70% ethanol, pH 3, contained less malate and oxalate but more NH4
+ compared to the NO3-N treatment. Maize leaf disk malate levels were generally higher compared to pigweed but were less due to EAS treatment.
Ammonium level in maize leaf disks was unaffected by N form and EAS treatment increased oxalate levels. Final bulk soil pH
was generally lower in pots where pigweed were grown and tended to be lower due to EAS. Leaf disk malate levels and soil pH
were positively associated.
Results indicate that pigweed is more likely to compete with maize when high levels of NO3-N are provided. Enhancing the proportion of N supplied as NH4
+ should restrict the growth of NH4
+-sensitive pigweed. 相似文献
15.
内复制是影响玉米胚乳发育的关键因素。通过降低CDK(周期蛋白依赖性激酶)活性,胚乳细胞可实现有丝分裂向内复制转变,进而推动籽粒快速灌浆。该研究以玉米微染色体维持蛋白ZmMCM基因家族为对象,对其基本生物信息学特征和非生物胁迫条件下的表达特征进行系统分析,并对其中低温胁迫响应明显的ZmMCM2通过转基因和酵母双杂的方法进行功能验证和分子互作分析。结果表明:(1)在玉米基因组中共鉴定到17个MCM家族成员,分布于6条染色体,而且部分基因间存在串联重复基因和片段复制基因;不同物种MCM蛋白的系统进化树可分为6个亚组,玉米、水稻和拟南芥的MCM2蛋白同属于第Ⅳ亚组;启动子序列分析显示,MCM家族基因启动子序列含有许多与激素响应、胁迫应答以及生长发育调节相关的顺式作用元件。(2)逆境胁迫响应分析表明,MCM基因表达受到NaCl和ABA抑制,对PEG、高温以及低温表现出不同程度的应答,尤其对低温具有明显响应。(3)ZmMCM2基因的过表达会对内复制产生一定的抑制作用,进而导致拟南芥植株矮小、莲座叶数减少以及种子体积缩小。(4)亚细胞定位结果显示,ZmMCM2基因定位于细胞核内;cDNA文库筛选和回转验证发现,MCM2与CDC73相互作用。该研究结果为进一步深入了解MCM2蛋白的分子作用机理奠定了基础。 相似文献
16.
Mitochondria isolated from root tissue of maize plants grown on a modified Knop solution containing 10.9 mM nitrate ± 7.2 mM ammonium were purified on the discontinuous Percoll density gradient with polyvinylpyrrolidone (PVP) added. The presence of PVP allowed separation of several mitochondrial fractions of a different density. Contrary to mitochondria isolated from plants grown in the presence of nitrate alone, revealing only two fractions, the mitochondria from NH4
+/NO3
–-plants were distributed in four fractions. Total amount of mitochondria, as well as specific activities of some nitrogen metabolism enzymes and tricarboxylic acid (TCA) cycle enzymes of all mitochondrial fractions, and respiratory activities of two lower density fractions isolated from plants grown on mixed nitrogen were higher in comparison to mitochondria from nitrate-grown plants. 相似文献
17.
A. L. Kahler A. R. Hallauer C. O. Gardner 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,72(5):592-601
Summary Twelve U.S. Corn Belt open-pollinated and five adapted exotic populations of maize (Zea mays L.) were assayed for allozyme (allele) variation at 13 enzyme marker loci. Extensive allozyme variability was observed in all populations studied. No locus was monomorphic over all populations. Each of the lociIdh2, Got1, Mdh2, Pgd1, andPgd2 expressed two allozymes over all populations,Adh1, Acp1, Prx1, andEst1 each had three allozymes present,Est4, Glu1, andEnp1 had five allozymes, andAcp4 had six allozymes present. Significant deviations of genotypic frequencies were detected from Hardy-Weinberg equilibrium frequencies and 94% of average Fixation Index values indicated heterozygote deficiencies, which suggested that nonrandom mating and/or natural selection favoring homozygotes were possible factors affecting the maintenance or loss of genetic variability marked by these enzyme loci. Genetic distance and cluster analyses indicated that the observed genetic variability at the 13 enzyme loci was closely related to Dent and Flint types of maize. 相似文献
18.
Evaluating the Induced-Odour Emission of a Bt Maize and its Attractiveness to Parasitic Wasps 总被引:3,自引:0,他引:3
The current discussion on the safety of transgenic crops includes their effects on beneficial insects, such as parasitoids
and predators of pest insects. One important plant trait to consider in this context is the emission of volatiles in response
to herbivory. Natural enemies use the odours that result from these emissions as cues to locate their herbivorous prey and
any significant change in these plant-provided signals may disrupt their search efficiency. There is a need for practical
and reliable methods to evaluate transgenic crops for this and other important plant traits. Moreover, it is imperative that
such evaluations are done in the context of variability for these traits among conventional genotypes of a crop. For maize
and the induction of volatile emissions by caterpillar feeding this variability is known and realistic comparisons can therefore
be made. Here we used a six-arm olfactometer that permits the simultaneous collection of volatiles emitted by multiple plants
and testing of their attractiveness to insects. With this apparatus we measured the induced odour emissions of Bt maize (Bt11,
N4640Bt) and its near-isogenic line (N4640) and the attractiveness of these odours to Cotesia marginiventris and Microplitis rufiventris, two important larval parasitoids of common lepidopteran pests. Both parasitoid species were strongly attracted to induced
maize odour and neither wasp distinguished between the odours of the transgenic and the isogenic line. Also wasps that had
previously experienced one of the odours during a successful oviposition divided their choices equally between the two odours.
However, chemical analyses of collected odours revealed significant quantitative differences. The same 11 compounds dominated
the blends of both genotypes, but the isogenic line released a larger amount of most of these. These differences may be due
to altered resource allocation in the transgenic line, but it had no measurable effect on the wasps’ behaviour. All compounds
identified here had been previously reported for maize and the differential quantities in which they were released fall well
within the range of variability observed for other maize genotypes. 相似文献
19.
Milena de Luna Alves Lima Cláudio Lopes de Souza Jr Dyeme Antonio Vieira Bento Anete Pereira de Souza Luciana Aparecida Carlini-Garcia 《Molecular breeding : new strategies in plant improvement》2006,17(3):227-239
The vast majority of reported QTL mapping for maize (Zea mays L.) traits are from temperate germplasm and, also, QTL by environment interaction (QTL × E) has not been thoroughly evaluated
and analyzed in most of these papers. The maize growing areas in tropical regions are more prone to environmental variability
than in temperate areas, and, therefore, genotype by environment interaction is of great concern for maize breeders. The objectives
of this study were to map QTL and to test their interaction with environments for several traits in a tropical maize population.
Two-hundred and fifty-six F2:3 families evaluated in five environments, a genetic map with 139 microsatellites markers, and the multiple-environment joint
analysis (mCIM) were used to map QTL and to test QTL × E interaction. Sixteen, eight, six, six, nine, and two QTL were mapped
for grain yield, ears per plant, plant lodging, plant height, ear height, and number of leaves, respectively. Most of these
QTL interacted significantly with environments, most of them displayed overdominance for all traits, and genetic correlated
traits had a low number of QTL mapped in the same genomic regions. Few of the QTL mapped had already been reported in both
temperate and tropical germplasm. The low number of stable QTL across environments imposes additional challenges to design
marker-assisted selection in tropical areas, unless the breeding programs could be directed towards specific target areas. 相似文献
20.
H. Kato-Noguchi 《Biologia Plantarum》2000,43(4):621-624
Maize (Zea mays L.) seedlings were exposed to osmotic stress, and alcohol dehydrogenase (ADH) activity and abscisic acid (ABA) concentration were determined. The osmotic stress increased ADH activities in both roots and shoots, whereas the increase was 2-fold greater in roots than the shoots. The stress also increased ABA concentration in both roots and shoots and the increase was greater in the roots than in the shoots. 相似文献