CO2浓度升高对农作物品质影响的研究进展

农作物品质受农作物遗传发育特征和环境因素的双重影响。在相似的遗传背景条件下，CO2浓度持续升高影响农作物中碳水化合物合成、有益和有害元素吸收的权重逐渐加大，从而引发所谓的“隐形饥饿”和农产品卫生品质下降。本文在回顾国内外有关CO2浓度升高影响农作物中碳水化和物合成、有益和有害成分吸收研究的基础上，结合本团队近年的研究结果，提出：随着产地环境污染由局部向整体扩延，CO2浓度持续升高对农作物卫生品质的潜在影响不断加剧，包括增加或减少农作物对有毒有害物质的吸收；强化农作物对土壤中有益或有害物质的非均衡吸收等。本文还对比了目前国内外CO2浓度升高对农作物品质影响研究的常用手段与方法，并对相关研究结果的差异进行了分析，着重指出这一研究方向今后工作的重点。     

火焰原子吸收光谱法测定湘西莓茶中六种金属元素的含量

运用火焰原子吸收光谱法测定湘西莓茶样品中Fe、Cu、Mg、Ca、Mn、Zn 6种金属元素.采用浓硝酸和双氧水微波消解样品.标准曲线法测定.结果表明,湘西莓茶中含有丰富的人体必需金属元素,方法回收率在98.50%～100.70%之间.本方法简单、准确,测定结果令人满意.     

Fruit Yield,Plant Growth and Nutrient Status in Mango

Abstract

Fruit yield and nutrient concentration of mango (Mangifera indica L.) cultivar ‘Osteen’ were studied in relation to rootstocks Gomera-1 and Gomera-3 for three years. The results indicated that the Gomera-3 root system had higher nutrient uptake and transport towards the scion. Data from grafted and ungrafted Gomera-1 and Gomera-3 trees proved similar with respect to N, P, and K utilization profile, with post-harvest accumulation and a decline during flowering, P and K concentrations significantly decreasing during fruit growth. These trends were largely the opposite for Ca and Mg. The Fe, Zn, Mn, and Cu concentrations rose during dormancy and fell at flowering. Fruit yield was higher with Gomera-1, while Gomera-3 gave fruit with greater weight and width. Tree height, trunk cross-sectional area, canopy diameter and volume were greater in grafted and ungrafted Gomera-3, this rootstock being the most vigorous. The yield efficiency was significantly greater on Gomera-1. Thus, cv. ‘Osteen’ grafted to Gomera-1 offered better yield and required a lower amount of nutrients.     

The Nutritive Value and Yield of Alfalfa Cultivated on Sulphur Postmining Lands

The study was carried out on the reclaimed lands of a bore-hole sulphur mine. The cropping of two succeeding cuts of alfalfa (Medicago sativa L.) was determined and its chemical composition was analyzed. Alfalfa was cultivated on waste lime (flotation tailings), enriched with a humus layer. The levels of basic nutrients, total S, total F, Ca, P, Mg, K, Na, Fe and Mn were determined in alfalfa. The biomass of an average crop was 6830 kg  ha^–1 in the first cut and 14300 kg  ha^–1 in the second one. The yields of dry matter as well as of crude and true proteins were positively correlated with the phosphorus level in the dry matter of alfalfa (P < 0.01). The level of total sulphur was positively linearly correlated with the phosphorus content (P < 0.01). No harmful accumulation of sulphur or fluoride was observed. A deficiency of phosphorus in alfalfa and an abnormal Ca:P weight ratio was found. The S total level was positively correlated with N total concentration. (P < 0.01). The percentage of true protein in crude protein was negatively correlated with total sulphur (P < 0.01). The level of nonprotein nitrogen compounds was positively correlated with S total level (P < 0.01).     

椰子中果皮4种微量元素含量动态规律的研究

对椰子果的中果皮Fe、Cu等4种微量元素的动态变化规律进行研究,并对不同果龄及不同品种间的微量元素含量进行比较和相关性分析。结果表明,椰子果在发育阶段,中果皮Mn、Cu、Zn的含量均呈降低趋势,且与果串发育程度呈显著正相关;所测4种微量元素中Fe含量最高,Cu含量最低。本地高种椰子的中果皮Mn、Cu、Zn含量间均呈极显著的正相关;小黄椰子的中果皮Fe、Mn、Cu、Zn含量间均呈极显著正相关。相同果龄椰子果的中果皮Mn和Zn的含量在2个品种间没有显著差异。     

大气环流指数和地面气象要素对海南省橡胶树白粉病的影响

为探讨大气环流指数和地面气象要素对海南省橡胶树白粉病病情指数的影响,利用1962—2009年逐月大气环流指数和逐日地面气象要素资料,根据橡胶树白粉病病情指数等级,结合因子膨化、相关分析和多元回归等方法,筛选影响橡胶树白粉病病情指数的大气环流指数和地面气象要素,构建等级指标,建立预测模型,并对模型进行检验。结果显示:影响橡胶树白粉病病情指数的大气环流指数依次为北半球副高面积指数、北半球副高强度指数、西太平洋副高西伸脊点、北美区极涡面积指数、亚洲区极涡强度指数和印缅槽,显著影响时段为上年7月至当年4月;地面气象要素有平均最高气温、相对湿度、平均气温≥20℃的日数、小雨日数和平均风速,显著影响时段为上年10月至当年1月;基于大气环流指数、地面气象要素、大气环流与地面气象综合因子的橡胶树白粉病病情指数预测模型准确率分别为74.3%～78.8%、74.7%、94.6%～98.3%,表明基于大气环流和地面气象综合因子的模型准确率较高,可作为海南省橡胶树白粉病的中长期预测模型。     

Improved micropropagation protocol and enhancement in biomass and chlorophyll content in Stevia rebaudiana (Bert.) Bertoni by using high copper levels in the culture medium

Incorporation of a range of higher concentrations of CuSO₄·5H₂O in MS medium [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassay with 240 tobacco tissue cultures. Physiol. Plant 15, 473–497] significantly enhanced direct shoot bud induction and proliferation from cultured leaf and nodal explants taken from mature plants of Stevia rebaudiana. Shoot bud induction medium was supplemented with BAP (2.2 μM) and IAA (2.8 μM). When the concentration of CuSO₄·5H₂O in the induction medium was raised to 0.5 μM (five times the MS level, i.e. 0.1 μM) there was significant increase in percentage response along with increase in shoot bud number per explant. The shoots were healthy, well developed with dark green broader leaves. There was remarkable increase in total biomass and chlorophyll content at increased (0.5 μM) copper level in the medium. During proliferation stage also presence of high copper levels in the medium favoured increase in shoot bud number per explant.     

戏剧化的散文——论余秋雨散文的戏剧化元素

作为戏剧理论家的余秋雨,充分调动多种戏剧元素为散文所用,形成了自己散文创作的独特戏剧化风格。纵观余秋雨散文,从情感基调到句式修辞,从谋篇布局到表现手法,都渗透着丰富的戏剧化元素——悲剧蕴含、戏剧冲突、戏剧悬念、戏剧结构、戏剧情境、鲜明的情感、富于韵律和节奏的语言,等等。戏剧元素的植入,大大拓展了余秋雨散文的文化容量和表现手段,也为当代散文的文体发展开拓了一条新路。     

浅谈园林设计中造形要素

对设计艺术的要素——线、形等进行认识，并探索它们在园林设计中的运用。     

Nitrogen and calcium nutrition of Petunia × hybrida ‘Coral Sea’

The effects of N and Ca nutrition on plant growth and shoot elemental content of Petunia × hybrida Hort. Vilm. - Andr. ‘Coral Sea’ were evaluated. Nitrogen and Ca were applied separately or in combination in three experiments: (1) N at 0, 100, 200 or 400 mg l^?1; (2) Ca at 0, 75, 150 or 300 mg l^?1; (3) N at 0 or 100 mg l^?1 and Ca at 0 or 150 mg l^?1 combined factorially. Shoot and root dry weights, branch length and flower number were highest when plants received 100 mg l^?1 N. Plants treated with 150 mg l^?1 Ca had the highest shoot and root dry weights. Branch length was maximal at 300 mg l^?1 Ca.Nitrogen and Ca interacted to increase shoot dry weights, branch number and length, leaf area and flower number. Increasing N concentrations increased N and decreased P, Mn and Zn shoot contents. Calcium content of shoots increased while N, P and Mg decreased in response to increasing applications of Ca to petunia plants. Minimal N and Ca tissue concentrations for optimal P. × hybrida growth were 3.3 and 0.67%, respectively.