甜菜碱在盐生植物中的作用

甜菜碱是植物重要的有机渗透调节物质之一,甜菜碱合成酶基因被认为是最重要和最有希望的胁迫抗性基因之一.阐述了甜菜碱在盐生植物中的功能、基因工程操作现状,并展望了该领域的研究方向.     

盐生植物海蓬子的利用价值与开发前景

介绍了新兴保健蔬菜海蓬子的生长习性、营养价值、医疗保健作用及在食品、饲料等行业中的应用,并阐述了其开发前景。     

伴生盐生植物对胡杨幼苗的脱盐效应及其生理生态效应

为了筛选适于胡杨(Populus euphratica)幼苗最佳脱盐效果的盐生植物,以1年生胡杨幼苗为试验材料,采用盆栽控盐胁迫的方法,选取新疆常见盐生植物碱蓬(Suaeda glauca(Bunge)Bunge)、盐角草(Salicornia europaea)和盐节木(Halocnermum str)作为伴生植物进行脱盐试验,通过测定胡杨幼苗生理生态指标探讨脱盐作用对其影响规律。结果表明:与对照(CK)相比,胡杨幼苗在伴生盐生植物脱盐作用下株高和地径均增加,且能够保持一定水平的根冠比、根质量比和根宽深比,其中,株高最大增幅由大到小为盐角草(11 g/L)、碱蓬(5 g/L)、盐角草(5 g/L)、CK;地径增量由大到小为盐角草(11 g/L)、盐节木(11 g/L)、碱蓬(5 g/L)、CK;根冠比增幅由大到小为盐角草(11 g/L)、盐节木(11 g/L)、碱蓬(5 g/L)、CK;根质量比较CK(0.48)差异均不大;根宽深比较CK均有所减少。幼苗表观量子效率(α)、最大净光合速率(Pnmax)、暗呼吸速率(Rd)、光饱和点(LSP)较之于CK均升高,光补偿点(LCP)呈相反的趋势;各处理下CO2响应参数相较于CK总体升高,但CO2补偿点则减小。综合各项生理生态指标,3种伴生盐生植物在60 d的时间产生了较为显著的脱盐效果,低盐质量浓度(5 g/L)条件下,伴生碱蓬对胡杨幼苗脱盐效果最佳;中(11 g/L)、高(15 g/L)盐质量浓度条件下伴生盐角草脱盐效果最佳。     

Puccinellia tenuiflora Exhibits Stronger Selectivity for K+ over Na+ than Wheat

Abstract

The characteristics of selectivity for K⁺ over Na⁺ by the roots of the halophyte Puccinellia tenuiflora were investigated in comparison with the glycophyte wheat (Triticum aestivum). Under various NaCl concentrations, the concentrations of K⁺ in the shoots of P. tenuiflora were 16–24% lower than those of wheat, whereas the concentrations of K⁺ in Puccinellia roots were 2.8–4.0 times higher than those of wheat. In 200 mM NaCl, the concentrations of Na⁺ in shoots of P. tenuiflora and wheat were similar under high K⁺ levels, but the concentrations of Na⁺ in wheat were 1.6 times higher than those in Puccinellia under low K⁺ levels. The concentrations of K⁺ in roots of P. tenuiflora were 1.5–2.0 times higher than those of wheat under low K⁺ levels. Formulas are given for calculating net selective absorption (SA) capacity and selective transport (ST) capacity by roots for K⁺ over Na⁺. We interpret SA as the net capacity of selectively absorbing K⁺ over Na⁺ by epidermal and cortical cells of whole plant roots into the root symplast. ST could reflect the net capacity of selection for K⁺ over Na⁺ transport from whole root stelar symplast to the xylem vessels. The lower ST value of P. tenuiflora might be the reason for accumulation of K⁺ in its roots. The SA values of P. tenuiflora and wheat were approximately equivalent in the low-affinity K⁺ uptake range. The SA values of the former were about two times higher than that of the latter in the high-affinity K⁺ uptake range, showing the root high-affinity K⁺ uptake system of the halophyte P. tenuiflora has a stronger capacity for K⁺ uptake.     

Effect of Salinity on Growth of Twelve Cultivars of the United Arab Emirates Date Palm

To successfully use salt water for crop production and start a breeding program, more information is needed about the response of salt‐tolerant plants to saline environments. The objective of this experiment was to test the growth of 12 cultivars of the United Arab Emirates date palm seeds at four sodium chloride (NaCl) levels. The experiment was a randomized complete block design with three replicates. Optimal growth was found at control and 3000 ppm of NaCl. Relative growth rate (RGR), biomass, and number of leaves (NL) decreased significantly by increasing salinity. Increased NaCl leads to significant decreases in potassium (K⁺), magnesium (Mg²⁺), and calcium (Ca²⁺) contents of plants. The Na/K ratios were lower in shoots than in roots. ‘Lulu,’ ‘Fard,’ ‘Khnaizi,’ ‘Nabtat Safi,’ and ‘Razez’ cultivars showed greater RGR and biomasses, whereas ‘Khnaizi,’ ‘Mesally,’ and ‘Safri’ had greater Na/K ratios than others in the control indicating greater Na⁺ discriminations from plant parts.     

环渤海缺水区盐碱地改良利用技术研究

针对淡水资源匮乏制约盐碱地改良利用难题,自1982年以来,中国科学院遗传与发育生物学研究所农业资源研究中心在环渤海低平原和滨海平原开展了缺水盐渍区盐碱地改良利用研究与示范工作,取得了以下研究成果:1)研究明确了低平原缺水盐渍区盐碱地改良的浅层地下水埋深调控深度,建立了井灌代排、蓄雨淋盐的盐碱地改良技术模式;2)揭示了咸水结冰融水咸淡水分离在滨海盐土的入渗规律,发明了冬季咸水结冰灌溉改良滨海重盐碱地技术;3)提出了耦合盐碱区土壤水盐运移-气候条件-植物生长发育规律的盐碱地改良思路,建立了微域降盐、秸秆隔盐的盐碱地农艺改良技术模式;4)探讨了盐生植物适应盐渍环境的机理,建立了滨海盐碱地盐渍资源高效利用技术模式。形成了以咸水、雨水、耐盐植物高效利用为核心的工程措施、农艺措施与生物措施相结合的盐碱地改良利用技术体系,为环渤海缺水盐渍区农业发展和生态环境建设提供了科技支撑。     

Molybdenum as an essential element for improving total yield in seawater-grown Salicornia europaea L.

The growth of crop plants on full-strength seawater constitutes a major challenge because of the high salt content and the limited availability of essential microelements such as molybdenum. For cultivation of the halophyte Salicornia as seawater-grown crop, the effect of molybdate application on total yield production and the activities of the two molybdenum containing enzymes, nitrate reductase (NR) and xanthine dehydrogenase (XDH) was investigated. Increasing molybdate levels in the growth medium supplemented with nitrate or ammonium enhanced yield during multiple shoot removal. Similarly, NR and XDH activities were enhanced with increasing molybdate, indicating that the activity of both enzymes may play an important role in facilitating yield accumulation. Notably, XDH activity in the roots was high and the levels of ureides were low, whereas in the shoot tips ureides were higher and XDH activity was lower. Considering that XDH is a key enzyme in the biosynthesis of the low C/N ratio ureides, these suggest a source–sink relationship between the roots and shoot tips for efficient transport of root-generated ureides to the young growing shoot tips. Our results imply that the supply of molybdenum to Salicornia grown in seawater enhances plant biomass accumulation by increasing the activities of NR and XDH, thereby stimulating a more efficient remobilization of ureides to the newly grown shoot tips after periodic shoot removal.     

植物响应盐分胁迫的重要蛋白质群组变化规律

综述了甜土植物和盐生植物应对盐分胁迫的重要蛋白质群组变化规律,为耐盐植物品种的选育提供了理论依据。     

浅析节约型园林建设

当今社会提倡低碳生活方式,建设节约型园林成为园林建设的新宠。提出从建设观念、能源利用、合理利用中水资源、普及节约浇灌技术等方面进行变革,推进节约型园林建设的发展。