柑橘盐胁迫响应及耐盐机制研究进展

柑橘是一种对盐胁迫十分敏感的园艺作物。综述了不同柑橘资源耐盐性的差异,进一步列举了盐胁迫对柑橘产生的生理伤害,盐胁迫容易造成植株体内的水分亏缺,并导致盐离子尤其是Cl-的积累进而产生离子毒害效应。盐胁迫还影响植株对矿质元素的吸收,使其体内养分失衡。柑橘在长期进化过程中形成了一定的耐盐机制。例如,糖醇类和氨基酸类的合成有助于柑橘的渗透调节,酶促系统和非酶类氧化剂能够降低活性氧对柑橘的伤害。此外,离子转运蛋白如ATP结合盒转运体(ABC)和氯离子通道(CLC)能够参与离子平衡重建过程,这也在柑橘的盐胁迫适应中起重要作用。     

Analysis of xylem water as an indicator of current chloride uptake status in citrus trees

The potential use of stem xylem chloride (Cl⁻) analysis as an indicator for sudden variation in Cl⁻ uptake by the tree was examined. Three extraction techniques (xylem sap extracted by centrifuge, and water extraction of fresh or dry ground xylem) were linearly correlated to each other as well as to soil salinity. Chloride values in xylem sap extracted by centrifugation were about half (3–34 mM) of those found in water extraction of fresh or dry ground xylem (9–84 mM), reflecting some Cl⁻ accumulation by existing living cells. Based on dry ground xylem, xylem Cl⁻ concentration was not affected by time of day; however, when centrifuge extraction was used, daily values were highest at the beginning and end of the day, and lowest during mid-day. Additionally, Cl⁻ concentration was not affected by stem thickness (5–25 mm) using the dry ground extraction method. Rootstock affected xylem Cl⁻ content in the same way it affected leaf Cl⁻ content; xylem Cl⁻ content was highest for trees grafted on salt-sensitive rootstocks and vice versa. As opposed to leaf analysis in which Cl⁻ concentration can only increase with time, xylem Cl⁻ content always followed soil salinity variation, either increasing or decreasing. Thus, analysis of stem xylem water can be a valuable tool for detecting short-term variation in Cl⁻ uptake. This method is important in trees since leaf analysis reflects the cumulative Cl⁻ content and therefore does not always give the current transitory mineral uptake status.     

Mineral nutrition of jojoba explants in vitro under sodium chloride salinity

Jojoba (Simmondsia chinensis (Link) Schneider) explants were cultured in vitro on a basal medium supplemented with sodium chloride up to 169 mM during the proliferation stage. At the second and third month of salinity stress, the mineral nutrition (macro- and micro-elements) of the explants was assessed. Explants accumulated significant amounts of sodium and chloride (jojoba is an ‘includer’) while potassium, manganese, phosphorus and nitrate concentration was reduced. The concentration of the other elements did not exhibit significant changes. Each level of salinity stress affected the nutrient status of the explants distinctively. Jojoba explants tolerate salinity up to a level of sodium chloride concentration (113 mM), without showing any stress symptoms. Above this level, the salinity stress impact was observed as succulence and chlorosis of leaves and shoots.     

The effects of sodium chloride on ornamental shrubs

The use of saline waters is an option for the irrigation of salt tolerant ornamentals as competition for high quality water increases. However, despite the importance of ornamental shrubs in Mediterranean areas, salt tolerance of such species has received little attention. The aims of our investigation were to quantify the growth response and any injury symptom of 12 widely cultivated ornamental shrubs to irrigation with saline water and to investigate any possible relation with the concentration of Na⁺ and Cl⁻ in the plants. Species were irrigated with different salinities (10, 40, and 70 mM NaCl) for a 120-day period. At the end of salt treatment, plants were sampled and dry biomass recorded; the relative growth rate (RGR) was also calculated. Root and leaf samples from each species were used to evaluate Na⁺, K⁺ and Cl⁻ concentrations. Growth rates were significantly reduced in Cotoneaster lacteus, Grevillea juniperina and Pyracantha ‘Harlequin’, which also showed the highest percentage of necrotic leaves. The increasing external NaCl lead to an increase of Na⁺ and Cl⁻ in roots and leaves of the different species, although less Na⁺ was accumulated than Cl⁻: growth reduction well correlated with the concentration of Cl⁻ and/or Na⁺ in the leaves. The most sensitive species (i.e. C. lacteus, G. juniperina and Pyracantha ‘Harlequin’) had high concentrations of Na⁺ and/or Cl⁻ in their leaves and also showed a decrease in their leaf K⁺/Na⁺ ratios. Even though other species (i.e. Bougainvillea glabra, Ceanothus thyrsiflorus, Leptospermum scoparium, Leucophyllum frutescens and Ruttya fruticosa) demonstrated a high ion concentration in their leaves, they could be considered relatively salt tolerant as there was little growth reduction and few symptoms of injury in the leaves. In some other cases (i.e. Cestrum fasciculatum, Escallonia rubra and Viburnum lucidum) the observed tolerance was related to higher ion concentration in the roots compared to the leaves, probably indicative of a limited transport to the shoots. Only in Eugenia myrtifolia was the absence of symptoms associated with a limited Na⁺ and Cl⁻ uptake from the rhizosphere.     

Growth,root morphology and boron uptake by citrus rootstock seedlings differing in boron-deficiency responses

Boron (B) is an essential microelement for higher plants and has important physiological functions in plant growth and development. Citrus plants are frequently exposed to B-deficiency, but knowledge regarding the effects of B-deficiency on rootstock growth, root morphology and genotypic variations in citrus is limited. To evaluate the variations in plant-growth parameters in response to B-deficiency, five citrus rootstocks seedlings that grown in modified 1/2-strength Hoagland's solution that contained 0.25 μM H₃BO₃ (moderate B-level, Control) or 0 μM H₃BO₃ (B-deficiency, −B) were investigated before and 90 days after treatment. There are significant genotypic variations in plant-growth parameters (dry mass, leaf area and seedling height), root-morphological traits and B-concentrations. B-deficiency inhibited plant dry mass and leaf area expansion of Fragrant citrus, Sour orange and Trifoliate orange seedlings significantly (P < 0.05), whereas no effect was found on the total dry mass of Carrizo citrange and Red tangerine seedlings. Further, B-deficiency reduced the root number, root length and root surface area in Fragrant citrus and Trifoliate orange significantly (P < 0.05); however, no significant effect was detected on these root morphological traits of Carrizo citrange and Red tangerine (P > 0.05). In addition, B-deficiency reduced the B-concentration in the leaves of all the five genotypes and the B-concentration in the roots of Fragrant citrus and Sour orange, none effect was observed on the B-concentration in stems of all studied genotypes and roots. However, there were significant relationships between the root-morphological traits and B-uptake efficiency. These results showed that Carrizo citrange and Red tangerine are B-efficient, Trifoliate orange is the moderate B-efficient genotypic rootstocks, whereas Fragrant citrus and Sour orange are B-inefficient genotypic rootstocks. In addition, Trifoliate orange was the moderate B-efficient rootstocks of five genotypes. The root-to-shoot dry mass ratio (R/S) and longer root numbers were higher in the Carrizo citrange and Red tangerine than that of Trifoliate orange, Fragrant citrus and Sour orange genotypes. That is to say, maintaining higher R/S and numerous longer lateral roots is very important in improving the B-efficiency and thus contribute much to the resistance of seedlings to B-deficiency in the Carrizo citrange and Red tangerine genotypes.     

Effect of rootstocks on the leaf mineral content of citrus

Leaves from ‘Valencia’, ‘Hamlin’ and ‘Washington Navel’ oranges grown on ‘Rangpur’ lime, ‘Cleopatra’ mandarin, ‘Sour Orange’, ‘Troyer’ citrange and ‘Rough Lemon’ root-stocks were analzed for N, P, K, Ca, Na, Cl, Fe, Mn, Cu and Zn. Significant differences among rootstocks were obtained for K, Ca, $\text{Ca}\text{K}$, Na and Cl, but not for N, P, Fe, Mn, Zn and Cu. Scion leaves on ‘Cleopatra’ mandarin tended to be low in K and high in $\text{Ca}\text{K}$ and those on ‘Rangpur’ lime were high in K and low in Ca and $\text{Ca}\text{K}$. ‘Troyer’ citrange induced higher uptake of Na and Cl than all other rootstocks. ‘Washington Navel’ leaves contained more Fe, Zn, Cu and Mn, and less Na, than ‘Hamlin’ or ‘Valencia’ leaves. ‘Valencia’ leaves contained more Ca and less K than the other two cultivars. The nutritional status of the trees was slightly low in N, K and Mn, optimum in Fe, Zn and Cu, normal-to-high in P, and contained non-toxic levels of Na and Cl. The statistical interaction of root stock and scion was found non-significant.     

郁闭柑橘园改造对植株光化学反应参数及果实品质的影响

【目的】探明不同整形改造技术对郁闭树体有效光合辐射、叶绿素荧光及果实品质等的影响,为果树冠层微生态环境优化及高产稳产提供理论依据。【方法】以15 a(年)生枳橙砧‘奥林达’夏橙为试材,分别对郁闭植株(CK)进行开心形、篱壁形和变则主干形修剪处理,然后利用CI-110植物冠层分析仪测定植株冠层有效光合辐射分布、利用多功能植物效率分析仪M-PEA测定叶片快速叶绿素荧光的变化。【结果】不同处理植株的光合有效辐射、光合色素含量、快速叶绿素荧光参数在6月至9月差异明显:树体有效光合辐射(PAR)逐月明显下降;叶片光合色素呈先明显上升后略微下降的趋势;在试验测定阶段,植株叶片光系统活性、光能利用率、光合机构性能逐渐提高,叶片放氧复合体(OEC)受到伤害程度降低。几种整形改造方式对树体各项生理指标的影响明显,开心形、篱壁形和主干形等3种处理植株光合有效辐射、光合色素含量、光能利用率及光系统性能等均较对照明显提高。单株产量及果实品质以开心形最优,篱壁形、主干形次之,但均优于对照。【结论】通过树形改造改善了冠层微生态重要因子即光合有效辐射状况,树体的叶片光合色素含量、光合结构性能、光合机构自我保护能力、光合效率、PSI与PSII的协调性等都有极大的提升,明显改善了植株单株产量及果实品质。     

Comparative biology of citrus leaf-miner on different citrus rootstocks and wild hosts

The oviposition by the citrus leaf-miner, Phyllocnistis citrella, was highest on ‘Rangpur’ lime and slightly lower on ‘Jatti Khatti’ and ‘Kharna Khatta’. ‘Cleopatra’ and ‘Troyer’ were moderately preferred, while the lowest number of eggs was recorded on Murraya exotica, followed by Jasminum sambac, but no mining was observed on these two hosts. The mean duration of the egg stage did not vary much on different hosts. The larval duration was highest in ‘Troyer’, indicating prolongation which was possibly due to antibiosis. The minimum larval survival was also recorded in ‘Troyer’, confirming antibiosis. There was not much difference in the pre-pupal stage. The pupal period was prolonged on ‘Troyer’ as compared to other hosts. This further confirms the occurrence of antibiosis in ‘Troyer’ to citrus leaf-miner. In general, the life cycle was short during June and long during February in all the hosts. The general conclusion is that ‘Troyer’ was a less suitable host for citrus leaf-miner compared to other rootstocks.     

Effect of salinity and water table on growth and tolerance of plum and peach

The effects of combinations of salinity (no salt, 2000 p.p.m. or 4000 p.p.m. of CaCl₂ and NaCl, 1:1) and water table (30 cm, 60 cm or 90 cm from the soil surface), on the vegetative growth and tolerance of ‘Golden Japanese’ plum and ‘Mit Ghamre’ and ‘Balady’ peaches were studied. The plants were grown in lysimeters. The growth of the trunk, total shoot length, the increase in shoot length per cm and the fresh weight of top, root and total plant were reduced with increasing salinity of the irrigation water. The effect was accentuated when the plants were maintained at high water table level. The salinity treatments resulted in the death of 43%, 73% and 76% of the plants in the plum, and the ‘Mit Ghamre’ and ‘Balady’ peaches, respectively, indicating that the plum is more tolerant to salinity than the peach. The plants of the salinity treatments showed various symptoms of salt injury, such as leaf burn, defoliation, shoot die-back and finally death. In the peaches, salt injury started to occur in the first growing-season, whereas the salt injury appeared in the plum in the second growing-season. The symptoms were more pronounced in the 4000 p.p.m. treatment than in the 2000 p.p.m. treatment and were more pronounced at the high water table level. The salinity level was the predominant factor and the effect of the water table on the vegetative growth diminished with increase in the salinity level of the irrigation water.     

Demarcating specific ion (NaCl, Cl, Na) and osmotic effects in the response of two citrus rootstocks to salinity

The present work differentiates the effects of NaCl, Cl⁻, Na⁺ and concentrated macronutrients on two citrus species, sour orange (Citrus aurantium L) and Macrophylla (Citrus macrophylla Wester). Plants were grown in a base nutrient solution (0.07 MPa osmotic pressure) for 4 months before applying the treatments that consisted of isotonic solutions of 0.23 MPa osmotic pressure of Na⁺ (40 mM, without Cl⁻), Cl⁻ (40 mM, without Na⁺), NaCl (40 mM) and 3.5 times the concentration of macronutrients of the base solution. Plants were grown in the different treatment for 2 months before being examined for symptoms of toxicity. The two genotypes showed major differences in the extent of Cl⁻ and Na⁺ accumulation in leaves and in their ability to maintain the internal concentrations of essential nutrients in response to the different ionic compositions of the medium. Differences in mineral nutrient accumulation were observed among treatments in both rootstocks. It was concluded that growth response to the different treatments was primarily affected by an osmotic effect, although in Macrophylla, the ionic effects also seem to be present.     

Effect of salinity and water table on the mineral content of plum and peach

The effects of combinations of salinity and water table on the mineral content of plum and peach were studied in lysimeters.Chloride content (Cl) in the leaves and the roots of plum and in the leaves of peach increased with salinity, whereas Cl in peach roots was not affected. Leaves of peach contained higher amounts of Cl than the leaves of plum. The opposite trend was observed in the roots.Sodium content (Na) increased with salinity in plum, whereas in peach it was not affected.The effect of salinity on calcium content (Ca) was not consistent in plum and peach.Potassium content (K) in the leaves of plum and peach decreased with salinity, whereas in the roots it was not affected.The Ca/K ratio in plum leaves increased with salinity, whereas in peaches it decreased in the 4000 p.p.m. treatment.Leaf phosphorus content (P) in the plum and the ‘Balady’ peach decreased with salinity, while in ‘Mit Ghamre’ peach it was not consistently affected. In plum root, P increased with salinity, whereas the effect was the opposite in peach.Magnesium content (Mg) was not significantly affected.The depth of the water table had no consistent effect on the Cl, Na, Ca, K, Ca/K ratio, P and Mg contents in the leaves and roots of plum or peach.The interaction between salinity treatments and water table levels was not significant in most cases.     

柑橘衰退病毒侵染对寄主植物同工酶及酸性病程相关蛋白表达的影响

以柑橘衰退病毒(Citrus tristeza virus,CTV)不同致病力株系接种寄主植物,比较分析了寄主植物体内过氧化物酶(peroxidase,POD)和多酚氧化酶(polyphenol oxidase,PPO)活性变化特点。结果表明,该病毒侵染对这2种酶活性的影响因寄主品种和CTV株系而异,CTV强毒和弱毒株系侵染均导致墨西哥莱檬植株中POD活性明显降低;在甜橙上,CTV强毒株系接种植株中POD活性则显著性提高,而弱毒株系接种对POD的活性无明显影响;在对该病毒具有较高抗性的枳壳中,接种CTV不同株系对POD活性均无明显影响。而在接种强毒株系N25的墨西哥莱檬中PPO活性有所增强,在枳壳上则表现为接种植株的PPO活性降低,在甜橙上PPO活性无明显的变化。POD、PPO和酯酶(esterase,EST)同工酶酶谱分析的结果显示,CTV弱毒株系接种枳壳后诱导产生了2条新的EST同工酶谱带,而在其他CTV接种植株上均未诱导表达新的POD、PPO及EST酶谱。酸性病程相关蛋白分析结果显示,CTV强毒株系在甜橙上诱导产生有6条明显的酸性病程相关蛋白条带。     

开花期追施氯化钾对西瓜的影响

在西瓜开花坐果期,追施氯化钾15kg/667m2,并及时浇水。结果表明:追施1周后,单株鲜茎叶生长量(3年均值)比不追施(对照)的减少275g,西瓜果个、整齐度、瓜皮亮度等外在商品性状均优于对照;3年平均增产西瓜447.8kg/667m2,增幅为37.7%。     

Chloride and sodium excluding capacities of citrus rootstock germplasm introduced to Australia from the People's Republic of China

The responses to root zone salinity (0, 25 and 50 mM NaCl) by 40 citrus rootstock genotypes introduced from the People's Republic of China, measured as shoot chloride (Cl⁻) and sodium (Na⁺) ion accumulation, growth and dry matter accumulation, were investigated under glasshouse conditions. Two experiments, one using aerated nutrient solutions and the other irrigated sand cultures, were conducted with plants grown from rooted cuttings taken from representative trees of different mandarin (Citrus reticulata Blanco and C. erythrosa Hort. ex Tan.), yuzu (C. junos Sieb. ex Tan.), Ichang papeda (C. ichangensis Swing.), sour orange (C. aurantium L.) and trifoliate orange (Poncirus trifoliata (L.) Raf.) genotypes. Two standard genotypes, viz. Rangpur lime (Citrus x limonia Osbeck.) and William's trifoliate orange were included in the experiments as reference controls.     

Effect of soil salinity levels on growth and chemical composition of Syzygium cumini L.

Seedlings of Syzygium cumini were grown in artificially salinized soils of conductivities 0 to 20 mmhos cm^-1 for 19 months. Adverse effects on growth were seen at and above a conductivity level of 16 mmhos cm^-1 of the saturation extract. As the conductivity increased, the adverse effects of growth and the extent of plant injury were intensified As salinity increased, the leaf chlorophyll content at the end of the experiment decreased. The leaf N content did not differ significantly, but the root N content was significantly lower at higher salinity levels. With increased salinity the K, Ca, Mg, Zn and Fe in the leaves and roots lessened, but leaf Na rose in concentration with increasing salinity. The Mn and Cu contents of leaves and roots did not differ significantly.     

抑霉唑硫酸盐在柑橘果实中的降解规律研究

【目的】为柑橘抑霉唑硫酸盐的合理使用提供科学依据,【方法】采用浸果法对抑霉唑硫酸盐在柑橘中消解动态进行了研究。样品中的抑霉唑硫酸盐用甲醇提取,液液分配去除杂质,离子对高效液相色谱检测。【结果】当添加水平为0.10～5.0 mg.kg-1时,添加回收率为73%～91%,相对标准偏差为1.5%～5.8%,最低检测浓度为0.10 mg.kg-1。抑霉唑硫酸盐在柑橘全果和橘皮中的降解动态曲线符合一级动力学方程,半衰期分别为63 d和60 d。【结论】该检测方法的灵敏度、精确度、准确度均满足农药残留检测要求。抑霉唑硫酸盐在柑橘上降解较快。     

Effect of interplanted rice on the growth of tomato in deep solution culture and on the response to salinity

Summary

Tomatoes were grown for 66 d in deep solution culture (a) without aeration, (b) with interplanted rice and (c) with air bubbled through the solution, in factorial combination with two electrical conductivities (4 and 8 mS cm^?1). Root growth was seriously restricted in the poorly aerated solutions (a) and (b). Interplanted rice stimulated shoot growth compared with the un-aerated treatment, and increased the total dry weight, leaf area and fruit yield (fresh weight) by up to 26, 34 and 22% respectively. The total dry weight of plants grown with rice was only 60% of that of the aerated ones but the area of corresponding upper leaves was 73%. Water and nutrient uptake were reduced by poor aeration but, after allowing for the uptake by the interplanted rice, only the uptakes of P and Ca by tomatoes in that treatment were significantly higher than those of the un-aerated plants. The higher salinity reduced growth and the uptake of nutrients. No interaction between aeration and salinity was found.     

Effect of garlicin on sodium channel current in rat ventricular myocytes

AIM: To observe the effect of garlicin on sodium channel(I_Na) in isolated ventricular myocytes of rats. METHODS: The ventricular myocytes of rats were obtained by enzymatic dissociation and treated with different concentrations of garlicin. The change of I_Na was recorded by the technique of whole-cell patch clamp recording.RESULTS: Garlicin decreased the I_Na of isolated ventricular myocytes in a dose- and voltage-dependent manner. The current density was elevated to peak under the condition that the membrane voltage was -40 mV before treated with garlicin. The current density was decreased by 48% from peak after treated with 500 μmol/L garlicin . No significant change of the active curve with the use of garlicin was observed. The median inactive voltages of the inactive curves before and after garlicin treatment were (-88.61±9.60) mV and (-103.03±8.90) mV (P<0.01), respectively, and the slopes were -7.85±0.88 and -7.55±2.75 (P>0.05), respectively, indicating that garlicin made a shift to the negative direction. CONCLUSION: Garlicin treatment induced the current density-voltage curve of I_Na to shift up and significantly decreased the current density. The inactive curve of sodium channel moved to the left, while the current density was not decreased after treated with garlicin. Garlicin blocks sodium channel in its inactive state in a dose- and voltage-dependent manner.     

Effect of a cytochrome P450 inhibitor on abscisic acid biosynthesis and stomatal regulation in citrus trees in water-stressed conditions

The effect of diniconazole, an inhibitor of cytochrome P450, on drought tolerance was examined in ‘Shiranui’ [(Citrus unshiu Marc. × Citrus unshiu Osbeck) × Citrus reticulate Blanco] trees. Diniconazole treatment increased abscisic acid (ABA) concentration in leaves compared with untreated controls in water-stressed conditions after 20 days of water-stress treatment. Diniconazole significantly decreased the stomatal aperture at 9 h after application compared with untreated controls in water-stressed conditions. The photosynthetic rate decreased in water-stressed conditions; however, regardless of the earlier stomatal closure induced by diniconazole application, the decrease of photosynthetic rate was delayed by the application.