共查询到20条相似文献，搜索用时 31 毫秒
1.
M. Sedgley 《Scientia Horticulturae》1977,7(1):27-36
Pollen tube growth was studied in the pistil of the male floral stage of the avocado. Self-pollination of the male stage occurred but pollen tubes did not reach the ovary. When female and male stages were hand pollinated, fewer pollen tubes were present in the pistil of the male than in the female stage. A tube reached the ovary in only 1 of 110 male stage pistils, as compared with all female stage pistils observed. Flowers pollinated in the female stage were retained on the plant for longer than flowers pollinated in the male stage.Aniline blue-positive and resorcin blue-positive material (callose) was not present in the pistil of flowers in the female stage but occurred in 46% of the aniline blue-stained and 30% of the resorcin blue-stained pistils in the male floral stage. By 42 h after first opening, callose was present in every pistil observed, in association with the cell walls of the stigmatic papillae, the transmitting tissue, the vascular tissue or the cortex and epidermis or a combination of these tissues. Callose occurred earlier in pollinated than in unpollinated pistils, particularly in the transmitting tissue.It is suggested that reduced pollen tube growth in the pistil of the male floral stage of the avocado is associated with the presence of callose. 相似文献
2.
D.J. Tucker 《Scientia Horticulturae》1981,14(3):201-206
The levels of cytokinin-like substances in the roots of tomato plants sown in November and grown in nutrient-film culture or in soil have been compared throughout the growing season. Similar levels of these substances were found in the roots of both crops from January until mid-March. Subsequently, the levels in the roots of plants grown in solution culture rose rapidly to reach a peak concentration 25 weeks after sowing. Over the same period, the levels in the roots of the plants grown in soil remained comparatively low. Stopping the plants 1 month after first anthesis significantly reduced the levels of cytokinins in the roots of both crops. 相似文献
3.
The deposition of calcium in tomato fruit grown at a range of salinities (electrical conductivities between 3 and 17 mS cm“1), with or without IAA-transport inhibitor treatment, was investigated. Calcium (Ca) in the flesh and pulp of tomato fruit was sequentially separated into four fractions: FI soluble in water, FII soluble in 2.5 mol dm“3 NaCl, Fill soluble in 2% acetic acid and FIV soluble in 5% HC1. In mature fruit, grown at 3 mS cm“1, more than half the Ca was in FI, and the Ca concentration was higher in the pulp than in the flesh. FII and Fill each contained less than 20% of the Ca, and the Ca concentration was higher in the flesh than in the pulp. In general, salinity reduced the concentration of Ca in all fractions and slightly altered the proportional distribution of Ca in fractions. The deposition of calcium in young fruit, grown at 3 and 8 mS cm“1, was highest in FII in the flesh or in FI in the pulp. When 45Ca was supplied to detached fruit, the patterns of45 Ca distribution in the fractions were similar to that of total Ca. Treatment with an IAA-transport inhibitor, CME, reduced both the uptake and transport of 45Ca. While the amount of 45Ca in all fractions was significantly reduced by CME, the proportional distribution of 45Ca among fractions was not affected substantially. Although the proportional deposition of Ca in different fractions was not significantly affected by either salinity or CME, further reduction of the intrinsically low deposition of Ca in FII of distal pulp caused by these factors may be the cause of blossom-end rot in tomato fruit. 相似文献
4.
以苹果感病品种‘红星’和抗病品种‘红玉’为材料,研究了苹果与斑点落叶病菌（Alternaria alternata apple pathotype）互作过程中超微结构,细胞Ca2+分布,以及在钙信号转导途径中具有重要作用的钙依赖蛋白激酶基因（CDPK）的表达,探讨钙信号在苹果防御斑点落叶病菌侵染中的作用。结果表明,在未接种状态下,叶肉细胞结构完好,叶绿体呈卵圆形沿细胞边缘排列,Ca2+主要分布在细胞间隙和液泡中,‘红玉’细胞间隙Ca2+密度比‘红星’大。接种斑点落叶病菌8 h,‘红星’叶肉细胞中的Ca2+沉淀主要分布在胞质中,而液泡等细胞器中减少;‘红玉’的Ca2+沉淀主要集中在胞质和筛管分子中,液泡和细胞间隙中减少,且趋向于在细胞壁外围和液泡膜上沉积。接种18 h,‘红星’叶肉细胞间隙Ca2+沉淀密度增加,而‘红玉’中的Ca2+沉淀主要集中在叶肉细胞的胞质和液泡,以及筛管分子中。接种24 h,‘红星’叶肉细胞结构已发生形变,质膜发生裂解,筛管壁木质化加厚,Ca2+沉淀主要分布在液泡中;‘红玉’叶片细胞结构完好,Ca2+沉淀主要分布在液泡和胞质中。接种36 h,‘红星’叶肉细胞受到菌丝入侵,结构和形态遭到破坏,在未受损叶肉细胞中Ca2+沉淀主要集中在液泡中,在受损的细胞中Ca2+沉淀无序地散布在受损细胞周围及细胞间隙;此时‘红玉’叶肉细胞中Ca2+沉淀主要集中在胞质和液泡中,并且能够保持Ca2+动态平衡。在接种后不同阶段,‘红星’和‘红玉’叶片中MdCPKs基因呈现不同的表达特点：大多MdCPKs在‘红玉’中的表达量在24 h达到最高值;‘红星’中在36 h达到表达峰值,且表达量也比‘红玉’中低得多。上述结果表明,钙信号响应斑点落叶病菌侵染,在抗病苹果品种‘红玉’中,Ca2+内流是细胞质Ca2+上升的主要来源;在感病品种‘红星’中,细胞器Ca2+释放是细胞质Ca2+的主要来源。‘红玉’苹果MdCPKs基因响应病菌侵染比‘红星’苹果早而且强烈。 相似文献
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6.
以童期不同的海棠（Malus sp.）植株为试材,使用酶联免疫法（ELISA）测定花芽分化期间
短枝顶芽、幼叶、细根中内源激素含量的变化,以探讨内源激素对花芽分化的影响,为缩短果树童期、
开发利用早实海棠资源奠定基础。结果显示,早实植株与成熟嫁接植株的内源激素含量变化趋势相似。
花芽分化的前期阶段,芽和根中IAA 含量均逐渐减少,到9 月初开始上升,成熟植株含量整体低于未成
熟植株;成熟植株叶中内源IAA 含量高于未成熟植株。芽中GAs 先上升后下降再上升,成熟植株8 月份
达到最低,而未成熟植株9 月份处于最低水平;叶中GAs 含量在成熟植株均保持较低水平;根中GAs 变
化与芽相反。内源ZR 含量在不同器官均有大幅增加,成熟植株均高于未成熟植株,实生早实植株中的变
化幅度最大。成熟植株芽中ABA 含量在160 ~ 170 ng · g-1FW 上下波动,未成熟植株始终低于160
ng · g-1FW;叶和根中的ABA 含量变化趋势一致,即先升高后逐渐下降,9 月之后回升。成熟植株较未成
熟植株在芽与叶中均表现为高比值的ABA/GAs 与ZR/GAs,而根中与此相反。 相似文献
7.
AIM: To study the pathophysiological mechanism of cardiomyopathy, the expression of TGF-β1 and apoptosis in myocardium of diabetic rats were investigated. METHODS:The diabetes models were established by single intravenous injection of streptozotocin (50 mg/kg) in rats. By the method of immunochemistry, the expression of TGF-β1 in the cardiomyocytes was detected as the index to evaluate the degree of fibrosis. The method of TUNEL was used to measure the cardiomyocyte apoptosis as the index to explore its importance in process of diabetic cardiomyopathy. RESULTS:① The weight of diabetic rats was apparently lower than that in the rats before the diabetic model was built (P<0.01), and the increase in weight in diabetic rats within three month was less than that in normal group. ② Compared with control group, the concentration of blood glucose was continually elevated during the experiment. ③ The expression of TGF-β1 in the diabetic cardiac muscle was much more than that in normal group (P<0.01). ④ The apoptosis of myocardium measured by the method of TUNEL was apparent in the diabetic groups than that in normal one (P<0.01). However, no significance was detected in the different courses of diabetic groups. CONCLUSIONS:The apoptosis might play an important role in leading the diabetic cardiomyopathy to heart failure. The expression of TGF-β1 in the myocardium of diabetic rats was more than that in normal and had an increasing trend in the procession of diabetic cardiomyopathy. TGF-β1 might be a significant factor in diabetic myocardium fibrosis. Apoptosis might play an important role in the initial stage of diabetes, which promotes the diabetic cardiomyopathy to heart failure. 相似文献
8.
G.C. Head 《The Journal of Horticultural Science and Biotechnology》2013,88(2):183-187
Measurements in an underground observation laboratory showed that, in 3 years, only small quantities of white root were present in the spring on nitrogen-deficient apple trees growing in grass. N K fertilizer applied in the spring greatly increased the amount of white root within a few weeks. Fertilizer application resulted in no lasting increase in nitrate or ammonium nitrogen in the soil and only a small increase in leaf nitrogen content in one year. It is thus not certain whether the observed effects were due to incipient nitrogen deficiency in the trees, and its correction, or to a direct effect on the root of an alteration in the levels of nitrogen, potassium, or of an unknown biological component in the soil. 相似文献
9.
桃果实和叶片中糖分的季节变化及其与碳代谢酶活性的关系研究 总被引：9，自引：0，他引：9
以晚熟的艳丰一号桃为试材,研究了果实和叶片中可溶性糖、淀粉及相关酶活性的变化。结果表明,在果实生长发育早期,果实和叶片中的可溶性糖主要是还原糖,中后期,还原糖维持在相对较低的水平上,非还原糖大量积累;在整个果实生长发育期间,果实中蔗糖、葡萄糖、果糖含量显著地高于叶片,而叶片中山梨醇和淀粉含量则显著地高于果实;叶片中蔗糖、葡萄糖、果糖含量和果实中山梨醇含量较稳定,在整个生长季节中差异较小;在整个生长发育期间蔗糖在果实中持续积累,尤其是在成熟前急剧增加,果实内葡萄糖和果糖含量在生长发育前期总体呈下降趋势,中后期维持在一个相对较低的水平上;叶片中山梨醇含量在生长前期下降,之后维持在相对稳定状态。在整个果实生长发育期间果实中果糖含量与NI、SS和SDH活性及葡萄糖含量与SS和SDH活性呈显著正相关;叶片中葡萄糖含量与SDH活性呈显著正相关且果糖含量与SS和ADPGPPase活性呈显著负相关,此外叶片中蔗糖含量与SPS活性呈显著正相关,但果实中蔗糖含量与SPS不存在任何相关性。因此认为各主要糖的合成与转化在叶片和果实中可能存在着不同的酶调控机制。 相似文献
10.
AIM:To investigate Nrf2 that regulates the expression of γ-glutamylcysteine synthetase (γ-GCS) in the inflammatory cells in bronchial asthma guinea pig bronchoalveolar lavage fluid (BALF). METHODS:Adult male guinea pigs were randomly divided into control group (group A), asthmatic group (group B) and dexamethasone group (group C). Asthmatic model was established by the method of ovalbumin challenge. MDA concentration in the lung tissue homogenate was detected. The total cell count and the proportion of inflammatory cells in BALF were measured. The methods of immunohistochemistry and in situ hybridization were used for detection of the protein and mRNA expressions of Nrf2, Bach1 and γ-GCS. RESULTS:(1) The proportion of eosinophils (EOS) in BALF and the MDA concentration of the lung tissue in group B were higher than those in group A and group C. (2) The result of in situ hybridization indicated that the A value of γ-GCS was the highest in group A compared to group B and group C, but the A value of Nrf2 and Bach1 in 3 groups has no statistical significance. (3) Immunohistochemistry indicated that the A value of γ-GCS in group B was lower than that in group A. The positive rate in cell nucleus of Nrf2 in group B was lower than that in group A and group C. The positive rate in cell nucleus of Bach1 in group B was higher than that in group A and group C. (4) The mRNA expression of γ-GCS (A value) showed positive correlation with the positive rate in cell nucleus of Nrf2 and negative correlation with the positive rate in cell nucleus. A negative correlation between the proportion of EOS in BALF of group B and the γ-GCS mRNA was observed. CONCLUSION:There is disequilibrium between oxidation and anti-oxidation in bronchial asthma guinea pig. Inflammatory reaction decreases the expression of γ-GCS in the inflammatory cells in bronchial asthma guinea pig. Dexamethasone regulates the nuclear translocation of Nrf2/Bach1 and increases the expression of γ-GCS. 相似文献
11.
JIA Jian-tao ZHANG Hui-ying TIAN Xiao-xia JI Jing-quan ZHANG Li-li LV Min-li WANG Li-min FENG Ming ZHAO Zhong-fu HAN De-wu CHENG Ji 《园艺学报》2011,27(8):1580-1585
AIM: To explore the role of 78 kD glucose-regulated protein (GRP78) in the development of hepatopulmonary syndrome (HPS) in rats and the relation to intestinal endotoxemia (IETM). METHODS: The experimental animals were randomly divided into HPS groups of the 4th week, the 6th week and the 8th week. Normal control groups at the corresponding time points were also set up. The Wistar rat model of HPS produced in the process of liver cirrhosis was induced by employing multiple pathogenic factors to the animals. The rats in normal control group were designed by feeding with standard diet and tap water. Histopathological changes of the lung and liver were observed under microscope with the staining of hematoxylin and eosin (HE). The concentrations of alanine amino transferase (ALT), endotoxin and tumor necrosis factor α (TNF-α) in plasma, the contents of TNF-α and malondialdehyde (MDA) in the lung tissues were detected. The expression of GRP78 at mRNA and protein levels in the lungs was measured by the methods of RT-PCR and Western blotting, respectively. RESULTS: The level of endotoxin in plasma was gradually increased with the HPS development. The expression of GRP78 at mRNA and protein levels was also gradually increased with the HPS development and was significant at every time point. The endotoxin in plasma was positively correlated with the expression of GRP78 protein in the lung tissues of the rats with HPS. With the HPS development, the levels of ALT and TNF-α in plasma and the contents of TNF-α and MDA in the lung tissues were gradually increased. The content of endotoxin in plasma and the protein expression of GRP78 in the lung tissues were positively correlated with the contents of TNF-α in plasma and TNF-α and MDA in the lung tissues. The contents of TNF-α in plasma and GRP78 at mRNA and protein levels and TNF-α in the lung tissues were higher in the rats with HPS at every time point than those in normal control group. At the 6th week and the 8th week, the contents of endotoxin and ALT in plasma and MDA in the lung tissues of the rats with HPS were significantly higher than those in normal control group. CONCLUSION: IETM originated from the liver cirrhosis acts as a critical stressor of endoplasmic reticulum (ER) stress and activates ER stress in the lung by oxidative stress, resulting in increased expression of GRP78. Therefore,the increased expression of GRP78 induced by ER stress may play an important role in the development of HPS in rats. 相似文献
12.
AIM: To investigate the effect of taurine on the expression of glucose transporter 1 (GLUT1) and transporter 3 (GLUT3) in rat brain with diffused brain injury (DBI).METHODS: Sixty-four male Sprague-Dawley rats were randomly divided into 4 groups: sham-operated group, DBI group, low-dose taurine group (200 mg/kg, ig) and high-dose taurine group (300 mg/kg, ig).After fed with the corresponding drugs for 7 days, the animal model of DBI was made, and the rats were executed 24 h after DBI.The expression of GLUT1 and GLUT3 in the brain was detected by the methods of immunohistochemistry and Western blotting.The pathomorphological changes of the cerebral cortex were observed under electron microscope.RESULTS: The expression of GLUT1 was detected in capillary vascular endothelial cells in each group, and cytoplasm-positive cells or the cells with buffy membrane were observed.No significant difference of the GLUT1 expression in brain tissues between DBI group and sham-operated group was detected.Compared with DBI group, the expression of GLUT1 in the brain tissues were significantly increased in low-and high-dose taurine groups (P<0.01).The expression of GLUT1 in the brain tissues in low-dose taurine group were significantly higher than that in high-dose taurine group (P<0.05).The positive staining of GLUT3 only appeared in the periphery of the third ventricle in each group in the cells with buffy membrane or positive cytoplasm.The expression of GLUT3 in the brain tissues in DBI group was significantly higher than that in sham-operated group (P<0.01).The expression of GLUT3 in the brain tissues in low-and high-dose taurine groups was significantly higher than that in DBI group (P<0.01).Compared with low dose taurine group, the expression of GLUT3 in the brain tissues were significantly increased in high-dose taurine group (P<0.01).The pathological damage of cerebral cortex in low-dose taurine group was obviously alleviated.CONCLUSION: Taurine may take part in the neuroprotective mechanisms in DBI by increasing the expression of GLUT1 and GLUT3 at protein level to maintain the energy supply in brain tissues. 相似文献
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以"晋梅杏""凯特""鸡蛋杏""金太阳"一年生休眠枝条和带花枝条为试材,通过不同低温处理,测定膜透性、保护酶活性和渗透调节物质,比较生理指标在低温下的变化以及与抗寒性的关系,分析各指标间的相关性,以期为筛选抗寒新品种提供参考依据。结果表明:随温度降低,枝条相对电导率、枝条丙二醛(MDA)含量、枝条脯氨酸含量、杏花MDA含量、杏花脯氨酸含量呈上升的趋势;枝条超氧化物歧化酶(SOD)活性、花朵SOD活性整体呈先升后降的趋势。"凯特"枝条中MDA含量与其它3个品种差异显著;"金太阳"枝条中脯氨酸含量与其它3个品种差异显著。花朵中MDA含量与4个杏品种的抗寒性呈负相关;除"鸡蛋杏"以外,枝条中脯氨酸含量与抗寒性呈正相关。相对电导率和枝条中SOD活性、枝条中脯氨酸含量、花朵中MDA含量呈极显著正相关,与花朵中脯氨酸含量呈显著负相关。花朵中MDA含量与花朵中SOD活性、花朵中脯氨酸含量呈极显著负相关;花朵中SOD活性与花朵中脯氨酸含量呈极显著正相关。综上所述,4种杏品种抗寒性强弱顺序为"金太阳">"晋梅杏">"鸡蛋杏">"凯特"。 相似文献
15.
JIANG Wei JIANG Hong-feng CAI Da-yong PAN Chun-shui QI Yong-fen PANG Yong-zheng TANG Chao-shu 《园艺学报》2004,20(12):2167-2174
AIM: The activity and expression of neutral endopeptidase (NEP) and the adrenomedullin (ADM) contents in various tissues were observed in septic shock and control rats to study the possible role of NEP in the change of ADM contents in tissues during septic shock. METHODS: The septic shock model of rats were established by cecal ligation and puncture (CLP). ADM contents, NEP activities, level of NEP mRNA and NEP protein were measured. RESULTS: (1) In early septic shock (ES), the ADM contents were generally higher in detected tissues, the NEP activity in left ventricle and small intestine were lower and was higher in blood than those in controls, and in lung, kidney and aorta were similar with the controls. NEP immunoreactive staining were less in lung, left ventricle, endothelium and media of aorta, but more in adventitia of aorta and kidney than those of the controls; (2) In late septic shock (LS), the ADM contents in small intestine was less but in plasma and other tissues were higher, and the NEP activity were less in plasma and other tissues than those in ES. The NEP immunoreactive staining were less in heart, endothelium and media of aorta, lung and kidney than those in ES, and was no significant change in adventitia of aorta compared with those of ES. RT-PCR found that NEP gene expression were significantly less in left ventricle, aortas, lung and small intestine than those in the controls. CONCLUSIONS: In septic shock rats, the NEP activity changes heterogeneously but the ADM contents elevate in most tissues. These results indicate that during the septic shock, the local concentrations and actions of ADM in various tissues may be regulated differently by the NEP. 相似文献
16.
针对宁夏灵武地区枣园绿盲蝽越冬卵在枣枝的分布特征不明等问题，于2018年3月初采用“Z”字形取样法调查了两块枣园样地绿盲蝽越冬卵在枣枝上的产卵位置，并分析了修剪口处越冬卵的数量及形态特征。结果表明，当年休眠期枝剪口处的平均卵量显著高于枣股及其翘皮，且2年生枝与多年生枝剪口卵量显著高于1年生枝剪口；剪口周皮部的平均卵量显著小于髓心部，但带卵率显著大于髓心部；剪口周皮部的越冬卵长度、饱满度均显著大于髓心部，剪口周皮部与髓心部的越冬卵宽度、瘪卵数均差异不显著。在管理精细无杂草的纯枣园中，休眠期修剪口处的周皮部与髓心部是绿盲蝽产卵越冬的主要场所。据此提出封闭剪口与早春整枝修剪是防治绿盲蝽危害的关键措施。 相似文献
17.
R. Goren E.E. Goldschmidt S.P. Monselise 《The Journal of Horticultural Science and Biotechnology》2013,88(4):443-451
Seasonal changes in native auxins, gibberellins and inhibitors in leaves and bark of Shamouti orange trees were studied. In December and February some auxin activity was found in the pH 6.0 ether fraction of leaves. Gibberellins were found mostly in the pH 7.0 water residue, with a peak in December. Large amounts of abscisic acid-like inhibitors were found in the pH 6.0 ether fraction of leaves, and the pH 7.0 water residue contained other inhibitors. Auxin activity in the bark was higher than in leaves, and the amount of inhibiting substances detected in the bark was much lower. Auxins were found in both fractions, whereas gibberellins were found in the pH 7.0 water residue as well as in the pH 3.0 ether fraction.Ringing the trunks of trees in March promoted the accumulation of growth regulators in the bark near the ring and in the leaves. The main effect of ringing in August was an accumulation of acidic gibberellins above the ring during the first three weeks after ringing. 相似文献
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以维多利亚葡萄组培苗为材料,在改良B5培养基不同供氮水平下,研究了葡萄试管苗根、茎、叶对氮素的吸收、利用及对株高、茎粗、根数、根长的影响。结果表明:培养基中氮素越低试管苗氮的利用率越高,过量氮的供给并不能增加试管苗茎、叶对氮的利用。试管苗在不同发育阶段氮的分配不同,全氮含量在根中表现为前期高、后期低,而在茎、叶中则表现为先低后高。35d时减氮处理根中氮最高;标准氮、增氮处理叶中最高;氨态氮以增氮处理在各器官中含量为高;而蛋白质氮则以标准氮处理最高。 相似文献
19.
Joanna Nowak Marian Saniewski R. M. Rudnicki 《The Journal of Horticultural Science and Biotechnology》2013,88(4):383-390
Changes in the content of carbohydrates and in the activity of hydrolytic enzymes were studied in hyacinth bulbs exposed to low temperatures. It was found that the amount of insoluble carbohydrate initially present in the scales and buds of hyacinth bulbs decreased greatly after a prolonged period of low temperature treatment. This decrease was greater in rooted bulbs, held at a low temperature for 63 days in natural conditions, than in unrooted bulbs stored in a refrigerator for the same period. At the same time the levels of soluble mono- and oligosaccharides, and of soluble starch, increased in the scales and buds of chilled bulbs. These changes in sugar level were found to be correlated with changes in the activity of certain hydrolytic enzymes. The activity of these enzymes was higher in rooted bulbs than in those which had not rooted before treatment. The activity of hydrolytic enzymes was found to be considerably higher in the flower buds than in the scales. 相似文献