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91.
黄瓜核心种质遗传多样性的苗期和初花期形态标记分析 总被引:1,自引:0,他引:1
对92份黄瓜核心种质进行苗期和初花期形态学标记分析,以评价供试核心种质资源的遗传多样性水平。结果表明:供试黄瓜核心种质的苗期和初花期性状存在明显的遗传变异,不同种质间各性状的平均变异系数为31.0%,其中第一雌花节位的变异系数最大,为59.4%;始花期最小,为14.2%。聚类分析表明,在Pearson相关系数为6.5时,把92份黄瓜核心种质划分为3大类群;Pearson相关系数为3.5时,把92份黄瓜核心种质划分为8个类群。本研究结果丰富了黄瓜种质资源的评价体系,为今后优异基因资源的挖掘与利用提供了科学参考。 相似文献
92.
Vladan Ondřej Božena Navrátilová Aleš Lebeda 《Plant Cell, Tissue and Organ Culture》2009,96(2):229-234
The protoplast cultures of Cucumis sativus in two culture systems were used to study heterochromatin reassembly during dedifferentiation of isolated protoplasts and
their subsequent differentiation into calli and proembryos. Here we show that dedifferentiation of the cucumber mesophyll
cells is accompanied by a dramatic reduction in size and numbers of nuclear chromocenters. Although chromocenters were newly
established during protoplast culture, the measured relative heterochromatin content differed according to the culture system
used. Protoplast culture leading to proembryo formation displayed a lower level of relative heterochromatin content than cultures
resulting in calli and the relative heterochromatin content reached values close to those estimated for somatic embryos. 相似文献
93.
镉是植物生长的非必需元素,它具有很大的生物毒性,与其它重金属相比,更易被植物吸收积累。通过采用营养液水培试验的方法,研究了外源一氧化氮(Nitric oxide,NO)对不同浓度Cd^2+(100μmol L^-1.300μmol L^-1,500μmol L^-1)胁迫下黄瓜幼苗生长、叶片光合特性以及活性氧代谢的影响。结果表明:300μmol L^-1NO供体硝普钠(Sodium nitrop russide,SNP)能显著缓解镉胁迫时黄瓜植株造成的伤害,对300μmol L^-1 Cd^2+处理的黄瓜幼苗缓解效果最好,可提高幼苗的生长量,增强幼苗叶片超氧物歧化酶(SOD)、过氧化物酶(POD)活性;提高了叶片叶绿素和脯氨酸(Pro)含量;降低了叶片内二醛(MDA)含量。 相似文献
94.
95.
Dingman DW 《Journal of invertebrate pathology》2009,100(1):16-21
Failure to identify correctly the milky disease bacteria, Paenibacillus popilliae and Paenibacillus lentimorbus, has resulted in published research errors and commercial production problems. A DNA fingerprinting procedure, using PCR amplification of the 16S-23S rDNA intergenic transcribed spacer (ITS) regions, has been shown to easily and accurately identify isolates of milky disease bacteria. Using 34 P. popilliae and 15 P. lentimorbus strains, PCR amplification of different ITS regions produced three DNA fingerprints. For P. lentimorbus phylogenic group 2 strains and for all P. popilliae strains tested, electrophoresis of amplified DNA produced a migratory pattern (i.e., ITS-PCR fingerprint) exhibiting three DNA bands. P. lentimorbus group 1 strains also produced this ITS-PCR fingerprint. However, the fingerprint was phase-shifted toward larger DNA sizes. Alignment of the respective P. popilliae and P. lentimorbus group 1 ITS DNA sequences showed extensive homology, except for a 108 bp insert in all P. lentimorbus ITS regions. This insert occurred at the same location relative to the 23S rDNA and accounted for the phase-shift difference in P. lentimorbus group 1 DNA fingerprints. At present, there is no explanation for this 108 bp insert. The third ITS-PCR fingerprint, produced by P. lentimorbus group 3 strains, exhibited approximately eight DNA bands. Comparison of the three fingerprints of milky disease bacteria to the ITS-PCR fingerprints of other Paenibacillus species demonstrated uniqueness. ITS-PCR fingerprinting successfully identified eight unknown isolates as milky disease bacteria. Therefore, this procedure can serve as a standard protocol to identify P. popilliae and P. lentimorbus. 相似文献
96.
The effects of 24-epibrassinolide (EBR) added to nutrient solution on growth of cucumber (Cucumis sativus L.) under root-zone hypoxia were investigated. Cucumber seedlings were hydroponically grown for 8 days in normoxic and hypoxic
nutrient solutions with and without addition of EBR at 1 μg l−1. EBR exerted little influence on plant performance in the normoxic nutrient solution, while the chemical alleviated root-zone
hypoxia-induced inhibition of root and shoot growth and net photosynthetic rate (Pn). EBR added to hypoxic nutrient solution
caused an increase in the concentration of fructose, sucrose, and total soluble sugars in the roots but not in the leaves.
Root-zone hypoxia enhanced the activities of lactate dehydrogenase (LDH), alcohol dehydrogenase (ADH), and pyruvate decarboxylase
in the roots. Interestingly, EBR further enhanced ADH activity but lowered LDH activity in hypoxic roots. These results suggest
that EBR added to hypoxic nutrient solution may stimulate the photosynthate allocation down to roots and the shift from lactate
fermentation to alcohol fermentation in hypoxic roots, resulting in the increase in ATP production through glycolysis and
the avoidance of cytosolic acidosis and eventually enhanced tolerance of cucumber plants to root-zone hypoxia. 相似文献
97.
98.
99.
Selection of appropriate reference genes for gene expression studies by quantitative real-time polymerase chain reaction in cucumber 总被引:6,自引:0,他引:6
Quantitative real-time polymerase chain reaction (QRT-PCR) has become one of the most widely used methods for gene expression analysis. However, the expression profile of a target gene may be misinterpreted due to unstable expression of the reference genes under different experimental conditions. Thus, a systematic evaluation of these reference genes is necessary before experiments are performed. In this study, 10 putative reference genes were chosen for identifying expression stability using geNorm, NormFinder, and BestKeeper statistical algorithms in 12 different cucumber sample pools, including those from different plant tissues and from plants treated with hormones and abiotic stresses. EF1α and UBI-ep exhibited the most stable expression across all of the tested cucumber samples. In different tissues, in addition to expression of EF1α and UBI-ep, the expression of TUA was also stable and was considered as an appropriate reference gene. Evaluation of samples treated with different hormones revealed that TUA and UBI-ep were the most stably expressed genes. However, for abiotic stress treatments, only EF1α showed a relatively stable expression level. In conclusion, TUA, UBI-ep, and EF1α will be particularly helpful for reliable QRT-PCR data normalization in these types of samples. This study also provides guidelines for selecting different reference genes under different conditions. 相似文献
100.
The phytotoxic effect of four glycoalkaloids and two 6-O-sulfated glycoalkaloid derivatives were evaluated by testing their inhibition of cucumber root growth. The bioassays were performed using both compounds singly and in equimolar mixtures, respectively. Cucumber root growth was reduced by chaconine (C), solanine (S), solamargine (SM) and solasonine (SS) with IC50 values of 260 (C), 380 (S), 530 (SM), and 610 μM (SS). The inhibitory effect was concentration-dependent. 6-O-sulfated chaconine and 6-O-sulfated solamargine had no inhibitory effects, which indicated that the carbohydrate moieties play an important role in inhibiting cucumber root growth. The equimolar mixtures of paired glycoalkaloids, both chaconine/solanine and solamargine/solasonine, produced synergistic effects on inhibition of cucumber root growth. By contrast, mixtures of unpaired glycoalkaloids from different plants had no obviously synergistic effects. The growth inhibited plant roots lacked hairs, which implied that inhibition was perhaps at the level of root hair growth. 相似文献