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11.
将类型Ⅱ愈伤组织从固体培养基转入悬浮培养,发现在改良1/2MN培养基,1.0-2.0mg/L的2,4-D浓度及1000mg/L肌醇存在下,适合所有不同基因型玉米自交系悬浮细胞的生长和细胞成活率的提高.悬浮培养5-6天继代1次是适宜的.大量元素减半和0.5-1.0mg/L的2,4-D浓度用于玉米单细胞培养,能获得良好的细胞分裂和生长.细胞悬浮培养获得了愈伤组织. 相似文献
12.
Ten terminal or subterminal RFLP markers belonging to linkage groups 1, 3, 5, 6, and 10 in maize RFLP map were physically
locted onto maize mitotic chromosomes with in situ hybridization. All biotinylated probes from 600 to 2 250 bp were detected
by DAB staining. The markers belonging to linkage groups 1, 3, 5, 6, and 10 correspondingly located at the chromosomes 1,
3, 5, 6, and 10. All of the tested markers except bnl6.25 and umc44 were duplicated sequences. Each of them was also labeled
on another chromosome besides on the chromosome corresponding to its linkage group. The marker bnl3. 04 was triplicated sequences
and the signals were detected on three nonhomologous chromosomes. In the tested ten markers, there were only four located
at the ends of corresponding chromosomes. Others were located at sites midway along the chromosome arms or near the centromeres.
The region covered by two terminal or subterminal markers in each of linkage groups 1, 3, 5, and 6 occupied 80.02%, 38.25%,
82.30% and 51.16% of the region of both short and long arms in chromosomes 1, 3, 5, and 6 respectively. Only two terminal
markers of linkage group 10 covered the whole chromosome 10. In some linkage groups, two terminal or subterminal markers covered
a short genetic distance but were physically distant, while two covering a longer genetic distance were physically closer.
Supported by The National Natural Science Foundation of China and the Doctorate Vesting Point Foundation of the Education
Committec of the People's Republic of China
Mao Ninghui: born in 1986, used to be an MS student of Wuhan University in 1992–1995 and now is working in Fudan University,
Shanghai 200433 相似文献
13.
A series of comparative studies was carried out on the genetic effects of 25 alien cytoplasms of wheat on the growth potential,
heading stage, fertility, resistance against diseases, important agronomic traits and its heterosis of 125 nuclei-cytoplasmic
hybrids of wheat. The results indicated that there were clearly effects of alien cytoplasms on some characteristics, but the
nucleus still exerted main effect on other characteristics. The effect of interactions between nucleus and cytoplasm was comparative
obvious in some combination. Consequently, when we utilize the effects of alien cytoplasms, we should pay full attention to
the facts such as the characteristic to be improved, the effects of cytoplasm, nucleus, the nucleus-cytoplasm interactions
on that characteristics. From the preliminary studies, we believed that the cytoplasmic types of M0, S1, Sv, D2, D and B, and the nucleo-cytoplasmic hybrids of (Ae. sharonensis)-B174, (Ae. squarrosa)-352-35 (Ae. cylindrica)-352-35, (Ae. cylindria)-E EN-1, (Ae. cylindrica)-NPFP, and (Ae. speltoides)-352-35 would have some utilization potentiality in cultivar improvement.
Foundation item: supported by the Foundation of National 8th Five-year-plan of China
Biography: CHEN Jun-ying, (1964-), male, lecturer, and now worked in Henan Agricultural University, Zhengzhou 450002, China 相似文献
14.
本文研究了磁场对玉米产量及其穗粒形状的影响.实验发现5分钟磁处理为使玉米增产的最佳条件。而瞬间磁处理为使玉米增产的较佳条件。测量了磁场处理过的各组玉米种子及第一代玉米籽粒中的核酸含量.并对磁场处理使玉米增产的机理作了初步探讨。 相似文献
15.
Elevated blood pressure (BP) is of special clinical significance because of its association with pathophysiologies such as heart disease, renal failure, and stroke. We described the development of a protocol for use with hypertensive rats in which prepubertal exposure to a high salt (8% NaCl) diet results in a pathophysiological syndrome including rapid increase in BP, failure to maintain normal weight gain, renal damage, cerebrovascular lesions, and early mortality. These phenomena are described for the inbred spontaneously hypertensive rat (SHR), and for reciprocal F1 hybrids of a cross between SHR and the Dahl salt-sensitive (SS/Jr) inbred strain. The study with reciprocal F1s revealed striking effects of maternal environment on pathophysiological response to a high salt diet. F1s nurtured by SHR mothers weighed less at 35 days of age, and after exposure to the high salt diet suffered more rapid BP increases, greater incidence of stroke, body weight loss, and mortality, than F1s nurtured by SS/Jr dams. These results suggest that maternal mediation of the nutritional status of the animal may play an important role in determining susceptibility to elevated BP and subsequent pathophysiology associated with exposure to a high salt diet. The implication of these findings for human hypertension is briefly discussed. 相似文献
16.
M. C. Marden L. Kiger C. Poyart S. J. Edelstein 《Cellular and molecular life sciences : CMLS》1998,54(12):1365-1384
While most researchers agree on the global features of cooperative ligand binding to haemoglobin (Hb), the internal mechanisms
remain open to debate. This is not due to inaccurate measurements, but is rather a consequence of the cooperative ligand binding
that decreases the equilibrium populations of the partially liganded states and makes observation of the transitions between
these substates more difficult. For example, the equilibrium population of the doubly liganded tetramers is typically less
than 5% of the total Hb. As a result many models with widely varying mechanisms may fit the oxygen equilibrium curve, but
may not be consistent with observations of other parameters, such as ligand-binding kinetics or subunit association equilibria.
The wide range of methods and models has led to divergent conclusions about the properties of specific substates. One notable
debate concerns the properties of the doubly liganded forms. The simple two-state model predicts a shift in the allosteric
equilibrium based on the number of ligands bound, but not on their distribution within the tetramer. From studies of dimer-tetramer
equilibria of various pure and hybrid forms, it was concluded that a tetramer with two ligands bound on the same α
β dimer (species 21, an asymmetric hybrid) shows an enhanced tetramer stability, similar to singly liganded Hb, relative to
the other three types of doubly liganded tetramers which resemble the triply liganded forms [Ackers et al. (1992), Science
255: 54–63]. The implications of this model and the relevant experiments will be reviewed here.
Received 27 April 1998; received after revision 17 July 1998; accepted 10 August 1998 相似文献
17.
以西辽河平原主推品种郑单958、先玉335、金山27和伟科702为试验材料,研究玉米农艺性状对种植密度的响应.结果表明,随着玉米种植密度增加,4个品种的株高和穗位高均先升后降,在密度9.0万株/hm2时达到最大.株高以先玉335最高,其它3个品种差异不大.穗位高金山27最高,伟科702最低.穗位节节间先玉335最长,其它3个品种相差甚微.各品种茎粗均随种植密度增加而减小. 相似文献
18.
19.
阮俊 《西昌学院学报(自然科学版)》1999,(3)
本文对凉山州玉米生产的现状、限制因素、潜力及优势等进行了分析,针对问题提出了发展玉米生产应采取的措施。 相似文献
20.
西昌地区玉米杂交种单株产量与主要农艺性状相关性分析 总被引:3,自引:0,他引:3
对130个玉米杂交种的株高、百粒重、穗行数等12个农艺性状与单株产量进行了相关分析,结果表明,单株产量与穗重、行粒数、穗粗、百粒重、穗长均呈极显著正相关,相关系数分别为0.98403、0.70197、0.70007、0.65396、0.52793;而穗重与穗粗、行粒数、百粒重、穗长也呈极显著正相关。进一步通径分析表明,各性状对产量的直接效应依次为穗重>穗长>行粒数>穗轴粗>穗行数>穗位高>百粒重>穗粗>穗位叶宽。因此,在西昌地区玉米育种工作中,增大穗长和行粒数,提高穗位高和穗位叶宽,并注重其他性状的选择,是获得玉米高产的科学有效办法。 相似文献