Effects of cadmium and arsenic on growth and metal accumulation of Cd-hyperaccumulator Solanum nigrum L

Remediation of heavy metal contaminated sites using hyperaccumulators presents a promising alternative to current environmental methodologies. In the pot-culture experiment, the effects of Cd, and Cd-As on the growth and its accumulation in the Cd-hyperaccumulator (Solanum nigrum L.) were determined. No reduction in plant height and shoot dry biomass was noted when the plants were grown at Cd concentration of 1.0. The plant can be classified as a Cd-hyperaccumulator. Growing in the presence of 10 mg/kg Cd and 50 mg/kg As, the plant height and shoot dry matter yields did not decrease significantly (p>0.05) compared to that at 10 mg/kg Cd, however the stem Cd content increased by 28%. It was also observed that S. nigrum used exclusion strategy to reduce As uptake in the roots and restricted translocation into the shoots, resulting in As contents of the plant being root>leaf>stem>seed. The Cd accumulation capacity coupled with its relatively high As tolerance ability could make it useful for phytoremediation of sites co-contaminated by Cd and As.     

Endophyte-assisted promotion of biomass production and metal-uptake of energy crop sweet sorghum by plant-growth-promoting endophyte Bacillus sp. SLS18

The effects of Bacillus sp. SLS18, a plant-growth-promoting endophyte, on the biomass production and Mn/Cd uptake of sweet sorghum (Sorghum bicolor L.), Phytolacca acinosa Roxb., and Solanum nigrum L. were investigated. SLS18 displayed multiple heavy metals and antibiotics resistances. The strain also exhibited the capacity of producing indole-3-acetic acid, siderophores, and 1-aminocyclopropane-1-carboxylic acid deaminase. In pot experiments, SLS18 could not only infect plants effectively but also significantly increase the biomass of the three tested plants in the presence of Mn/Cd. The promoting effect order of SLS18 on the biomass of the tested plants was sweet sorghum > P. acinosa > S. nigrum L. In the presence of Mn (2,000 mg kg(-1)) and Cd (50 mg kg(-1)) in vermiculite, the total Mn/Cd uptakes in the aerial parts of sweet sorghum, P. acinosa, and S. nigrum L. were increased by 65.2%/40.0%, 55.2%/31.1%, and 18.6%/25.6%, respectively, compared to the uninoculated controls. This demonstrates that the symbiont of SLS18 and sweet sorghum has the potential of improving sweet sorghum biomass production and its total metal uptake on heavy metal-polluted marginal land. It offers the potential that heavy metal-polluted marginal land could be utilized in planting sweet sorghum as biofuel feedstock for ethanol production, which not only gives a promising phytoremediation strategy but also eases the competition for limited fertile farmland between energy crops and food crops.     

强化龙葵富集镉根际促生菌的分离、筛选与鉴定

【背景】植物-微生物联合修复土壤重金属污染日渐兴起,获取与超富集植物高效互作的微生物是实现联合修复技术进步的关键。龙葵在镉农田污染修复中广泛应用。【目的】筛选可促进龙葵生长及富集镉的耐镉根际促生菌。【方法】从龙葵根际土分离耐镉菌株,筛选具有良好促生特性的菌株,水培试验考察镉胁迫下菌株对植物生长及镉富集能力的影响,确定可促进龙葵生长及富集镉的微生物菌株,通过生理生化特性和16S rRNA基因序列分析进行菌株的初步鉴定。【结果】分离得到NT1、AXY1、AW2和AW1四株强化龙葵富集镉促生菌,经鉴定分别为Lysinibacillus sp.、Beijerinckia fluminensis、Achromobacter animicus和Herbaspirillum huttiense。上述菌株均可有效促进龙葵生长,增加其株高和干物质积累,提高地上部镉富集量。其中,NT1可使株高、地上部干重分别增加31.33%和62.65%,AW2可使地上部镉富集量增加37.29%。【结论】筛选所得菌株可为提高植物修复效率提供实践依据,为研制田间施用生态功能菌剂做铺垫,用于农田镉污染的微生物-龙葵联合原位修复。     

Comparative physiological responses of Solanum nigrum and Solanum torvum to cadmium stress

? Under cadmium (Cd) stress, Solanum nigrum accumulated threefold more Cd in its leaves and was tolerant to Cd, whereas its low Cd-accumulating relative, Solanum torvum, suffered reduced growth and marked oxidative damage. However, the physiological mechanisms that are responsible for differential Cd accumulation and tolerance between the two Solanum species are largely unknown. ? Here, the involvement of antioxidative capacity and the accumulation of organic and amino acids in response to Cd stress in the two Solanum species were assessed. ? Solanum nigrum contains higher antioxidative capacity than does S.?torvum under Cd toxicity. Metabolomics analysis indicated that Cd treatment also markedly increased the production of several organic and amino acids in S.?nigrum. Pretreatment with proline and histidine increased Cd accumulation; moreover, pretreatment with citric acid increased Cd accumulation in leaves but decreased Cd accumulation in roots, which indicates that its biosynthesis could be linked to Cd long-distance transport and accumulation in leaves. ? Our data provide novel metabolite evidence regarding the enhancement of citric acid and amino acid biosynthesis in Cd-treated S.?nigrum, support the role of these metabolites in improving Cd tolerance and accumulation, and may help to provide a better understanding of stress adaptation in other Solanum species.     

镉及其与钙组合对褐脉少花龙葵毛状根生长、抗氧化酶活性和吸收镉的影响

为了探讨利用褐脉少花龙葵毛状根来修复重金属镉(Cd)污染的可能性,采用溶液培养法研究了Cd单独及其与钙(Ca)组合对褐脉少花龙葵毛状根生长、抗氧化酶超氧化物歧化酶(SOD)和过氧化物酶(POD)活性及对Cd吸收的影响。结果表明,Cd≤50μmol/L时能促进毛状根生长,而高于100μmol/LCd则抑制毛状根生长,使其侧根根尖变褐和变短,数目减少。与对照相比,不同浓度Cd培养的毛状根可溶性蛋白含量和SOD活性先升高后逐渐下降;其丙二醛(MDA)含量显著提高;100μmol/LCd使毛状根POD活性逐渐升高,但300μmol/LCd则使毛状根POD活性逐渐降低。与对照(仅添加100μmol/L或300μmol/LCd的毛状根)相比,Cd和10～30mmol/LCaCl2组合培养使毛状根可溶性蛋白含量和MDA含量降低;但提高其SOD活性;而100μmol/LCd和10～30mmol/LCaCl2结合培养的毛状根POD活性均比对照低;而300μmol/LCd和10～30mmol/LCaCl2结合培养的毛状根POD活性则均比对照提高。原子吸收分光光度法测定结果表明,毛状根吸收和吸附的重金属Cd含量随着培养基中Cd浓度的升高而增加。但外源加入10～30mmol/LCaCl2能减少毛状根对Cd的吸收,并调节其抗氧化酶SOD和POD活性,降低其膜脂过氧化水平而解除重金属Cd对毛状根生长的抑制或毒害。     

Chemical-assisted phytoremediation of CD-PAHs contaminated soils using Solanum nigrum L

A well-characterized cadmium (Cd) hyperaccumulating plant Solanum nigrum was grown in Cd and polycyclic aromatic hydrocarbons (PAHs) co-contaminated soil that was repeatedly amended with chemicals, including EDTA, cysteine (CY), salicylic acid (Sa), and Tween 80 (TW80), to test individual and combined treatment effects on phytoremediation of Cd-PAHs contaminated soils. Plant growth was negatively affected by exogenous chemicals except for EDTA. S. nigrum could accumulate Cd in tissues without assistant chemicals, while there was no visible effect on the degradation of PAHs. Cysteine had significant effects on phytoextraction of Cd and the highest metal extraction ratio (1.27%) was observed in 0.9 mmol/kg CY treatment. Both salicylic acid and Tween 80 had stimulative effects on the degradation of PAHs and there was the maximal degradation rate (52.6%) of total PAHs while 0.9 mmol/kg Sa was applied. Furthermore, the combined treatment T(0.1EDTA+0.9CY+0.5TW80) and T(0.5EDTA+0.9CY+03Sa) could not only increase the accumulation of Cd in plant tissues, but also promote the degradation of PAHs. These results indicated that S. nigrum might be effective in phytoextracting Cd and enhancing the biodegradation of PAHs in the co-contaminated soils with assistant chemicals.     

镉胁迫对金银花生理生态特征的影响

采用水培试验方法,研究了不同浓度镉(Cd)(0、5、10、25和50 mg·L^-1) 胁迫条件下藤本植物金银花的生长和生理特性.结果表明: 与对照相比,Cd胁迫对金银花的生长未造成明显影响,在5～50 mg·L^-1 Cd处理下,其生物量无明显差异(P>0.05),在低浓度Cd(5 mg·L^-1)处理下生物量有所增加,叶、根生物量和总生物量分别增加了2.88%、2.33%和1.25%,说明金银花对Cd具有较强的抗性.在低浓度Cd胁迫下,植物各器官的含水量和可溶性蛋白含量均有所降低,而根系和叶片的丙二醛含量分别增加51.90%和23.07%,叶绿素和类胡萝卜素含量则增加15.87%和24.89%,超氧化物歧化酶活性也显著增强.随着Cd浓度的增高,金银花体内的叶绿素和类胡萝卜素含量,以及超氧化物歧化酶活性均有所降低.     

Assessing the potential for cadmium phytoremediation with Calamagrostis epigejos: a pot experiment

A pot experiment was conducted for three vegetation periods on a sandy soil (pH 7.5) to study the uptake and distribution of Cd in plant tissues of Calamagrostis epigejos (L.) Roth. Cadmium was applied as CdCl2 (a total of 11 solution of 0, 20. 100, and 200 mg Cd l(-1)). HNO3- and water-extractable concentrations of Cd in 2- and 20-cm soil depths were correlated with the applied Cd showing that Cd was very mobile in the soil. The uptake of Cd from soil by Calamagrostis epigejos was directly related to the total soil Cd content and to the water-soluble pool of Cd. The concentrations of Cd in plant tissues (roots, rhizomes, leaves) and litter increased with increased applied Cd. Most of the Cd that was taken up was accumulated in roots (range from 1.88+/-0.42 to 40.96+/-16.71 mg kg(-1) dry mass), followed by rhizomes (0.52+/-0.13 to 25.70+/-6.35 mg kg(-1)) and leaves (0.30+/-0.06 to 9.20+/-1.93 mg kg(-1)). Cd concentrations of the litter were about twofold greater than the concentrations in the leaves (0.67+/-0.07 to 18.98+/-7.00 mg kg(-1)). The bioaccumulation factor (leaf/soil concentration ratio) increased significantly from 0.70+/-0.10 (control) to 1.1+/-0.17 (100 mg Cd l(-1)), but decreased again at the highest Cd level (200 mg Cd l(-1)) toward 0.74+/-0.34, which was not significantly different from the control. The low transfer of Cd from soil to above-ground organs at higher soil Cd concentrations indicates an exclusion mechanism. The leaf/root Cd concentration ratio (translocation factor) shows no significant relationship to increasing soil contamination. Only 4-7% of the total plant Cd was accumulated in the above-ground tissues. The phytoextraction potential (total Cd removed from soil) within three growing seasons ranged from 0.11 to 0.25% of the total soil Cd. Total output in above-ground living and dead plant material of C. epigejos would be approximately 20 g ha(-1) a(-1) for the lowest contamination level (+20 mg Cd per pot) and approximately 275 g ha(-1) a(-1) for the highest contamination level (+200 mg Cd per pot). This is within the range where an application for phytoextraction of Cd has been suggested by other authors. However, we conclude that the practical use of C. epigejos for phytoremediation is not mainly in the field of phytoextraction, but phytostabilization. C. epigejos has the capability to structurally stabilize the soil and reduce Cd contamination spread due to erosion. The uptake of the available Cd pool and accumulation in below-ground biomass may further prevent leaching into ground water.     

Bioavailability assessment and accumulation by five garden flower species grown in artificially cadmium-contaminated soils

Many studies have been conducted on phytoextraction; however, non-native hyperaccumulator species are not suitable for the natural environment of Taiwan in many cases. Drawing upon previous results, the growth and heavy metal accumulation in artificially cadmium-contaminated soils were compared for five local garden flower species. The treatments included a control (CK), 9.73 +/- 0.05 mg kg(-1) (Cd-10), and 17.6 +/- 0.8 mg kg(-1) (Cd-20). All plants were harvested at 35 days after transplanting and analyzed for Cd content. Cd accumulation in the shoot of French marigold (Tagetes patula L.) and Impatiens (Impatiens walleriana Hook. f.) grown in Cd-20 treatment were 66.3 +/- 6.5 and 100 +/- 11 mg kg(-1), which equated to a removal of 0.80 +/- 0.11 and 0.60 +/- 0.37 mg Cd plant(-1), respectively. The maximum Cd accumulation of Impatiens reached the threshold value (100 mg kg(-1)) characteristic of a Cd hyperaccumulator and its bioconcentration factor (BCF) and translocation factor (TF) were greater than one. Impatiens therefore has the potential to hyperaccumulate Cd from Cd-contaminated soils. With the exception of Garden verbena, significant relationships were found between Cd concentrations in soil extracted by 0.05 M EDTA, 0.005 M DTPA, and 0.01 M CaCl2 and the concentration of Cd in the shoots of the tested garden flowers.     

A two-year field study of phytoremediation using Solanum nigrum L. in China

A two-year in-situ phytoremediation trial was launched in Shenyang Zhangshi (Sewage) Irrigation Area (SZIA). The phytoremediation efficiency of Solanum nigrum L. was determined, by both monitoring the change of soil Cadmium level in the upper 20 cm of soil, and calculating the plant uptake of soil Cd. After two years experimental, by monitoring the soil Cd concentrations, The Cd concentrations decreased on average from 2.75 mg kg^?1to 2.45 mg kg^?1 in the first year and from 2.33 mg kg^?1 to 1.53 mg kg^?1 in the second year, amounting to a decrease by a factor of 10.6% in the first year and 12% in the second year. After two years phytoremediation by S. nigrum, Cd concentrations of the seven experimental plots with S. nigrum growth decreased from 2.75 mg kg^?1 to 1.53 mg kg^?1, a decrease by a factor of 24.9%. And the soil Cd concentration decreased only 2.1% and 1.7% in the bared experimental plot. And the calculating of Cd uptake by S. nigrum shown that, the plants uptake 4.46% and 5.18% of the total soil Cd in 2008 and 2009, while the soil Cd concentrations decreased by a factor of 10.6% in 2008 and 12.1% in 2009.     

镉胁迫对鸡冠花种子萌发及幼苗生理生化特性的影响

采用水培法和盆栽法测定分析不同浓度Cd(0、50、100、150、200 mg/L)胁迫对鸡冠花种子萌发、幼苗生物量、叶片光合色素、渗透调节物质(可溶性蛋白、可溶性糖、脯氨酸)、丙二醛(MDA)、低分子巯基化合物(GSH、GSSG、Cys、NPT)含量以及抗氧化酶 (SOD、POD、CAT、APX)活性的影响,探讨鸡冠花耐受Cd胁迫的能力及其生理机制,为植物解毒机制提供基础资料。结果显示：(1)鸡冠花种子的发芽势、发芽率和发芽指数在低浓度Cd处理下提高,而活力指数、根长及苗长在各浓度Cd胁迫下均不同程度降低,以上指标均在低浓度(50、100 mg/L)Cd胁迫下受到显著抑制,且根长受抑制程度显著高于苗长;幼苗生物量(整株鲜重、地上部分鲜重及地下部分鲜重)在200 mg/L Cd胁迫时受到显著抑制,较对照分别下降了61.9%、58.4%和72.7%;根冠比及主根长虽未受到显著影响,但总体呈现降低趋势。(2)鸡冠花幼苗叶片叶绿素和类胡萝卜素含量在100~200 mg/L Cd胁迫下均显著降低,叶片可溶性蛋白、可溶性糖和脯氨酸含量在Cd胁迫下总体呈升高趋势,并分别在50、150、200 mg/L时显著升高。(3)鸡冠花幼苗叶片各抗氧化酶活性在Cd胁迫下呈不同变化趋势,POD和APX活性在各浓度Cd胁迫分别增加23.1%~304.2%和160.0%~280.0%;SOD活性在各浓度Cd胁迫均受到抑制,但仅在150 mg/L时显著降低43.2%;CAT活性在50~150 mg/L Cd胁迫下显著增强了46.6%~66.5%,但在200 mg/L Cd胁迫却显著降低59.5%。(4)高浓度(200 mg/L)Cd胁迫下鸡冠花幼苗叶片巯基化合物GSH、GSSG、Cys、NPT含量分别比对照上升了53.2%、164.2%、53.9%和0.79%,而GSH/GSSG比值显著降低。研究发现,鸡冠花种子萌发期和幼苗期对Cd胁迫均具有一定的耐受力,但高浓度Cd胁迫仍致使幼苗部分抗氧化酶活性降低,ROS过量积累,引起膜脂过氧化程度加深,其产物MDA含量逐渐升高;Cd胁迫促进低分子巯基化合物含量呈不同幅度的增加,但GSH/GSSG比值下降,细胞内氧化还原反应(Redox)受到抑制,导致幼苗正常生长代谢受阻,生物量持续降低。     

‘凤丹’生物量分配的季节动态及其受株龄和遮荫的影响

生物量分配动态研究对了解作物产量形成机制具有重要意义。‘凤丹’是以杨山牡丹（Paeonia ostii T.Hong et J.X.Zhang）为原种形成的新型木本油料作物,其产量形成机制尚不明确。本文采取破坏性取样策略,研究不同株龄‘凤丹’生物量分配的季节动态以及遮荫对产量的影响。结果显示,‘凤丹’生物量在果熟期达到最大值,总生物量随株龄增大而增加,但其增长速率趋势则相反。‘凤丹’根和茎的生物量分配在休眠期最大,而叶生物量分配最大值出现在果熟期;繁殖分配仅为3.24%~6.85%,但随株龄增大而增加（4年生果实生物量为（7.74 ±0.31）g/株,8年生果实生物量为（26.81 ±0.44）g/株）。‘凤丹’单株年同化总量为161.21~232.34 g,种子收获指数为2.71%~6.87%,收获指数与株龄呈正相关（R²=0.8178）。‘凤丹’营养生长和总生物量在遮荫条件下有所降低,但繁殖生物量和收获指数在30%遮阳处理中显著增加（种子增产3.66 g/株,产量提高389.36%）。本研究表明‘凤丹’年周期内的源与库结构呈动态变化,株龄对‘凤丹’的生物量分配及产量有明显效应,适度遮荫可提高‘凤丹’的产量。     

Cadmium phytoextraction from loam soil in tropical southern China by Sorghum bicolor

The cadmium (Cd) uptake characteristics by Sorghum bicolor cv. Nengsi 2# and Cowley from the acidic sandy loam soil (pH = 6.1) during the entire growth period (100 days) were investigated in pot outdoors in a tropical district of southern China, Hainan Island. The Cd-spiked levels in soil were set as 3 and 15 mg/kg. Correspondingly, the available Cd levels in soil extracted by Mehlich III solution were 2.71 and 9.41 mg/kg, respectively. Basically, two varieties in a full growth period (100 days) did not show a significant difference in their growth and Cd uptake. Under high Cd stress, the plant growth was inhibited and its biomass weight and height decreased by 38.7–51.5% and 27.6–28.5%, respectively. However, S. bicolor showed higher bioaccumulation capability of Cd from soil to plant [bioconcentration factor (BCF)>4], and higher transfer capability of Cd from roots to shoots [translocation factor (TF)>1] under high Cd stress; Cd contents in the roots, stems, and leaves of S. bicolor reached 43.79–46.07, 63.28–70.60, and 63.10–66.06 mg/kg, respectively. S. bicolor exhibited the potential phytoextraction capability for low or moderate Cd-contamination in acidic sandy loam soil.     

德国鸢尾对Cd胁迫的生理生态响应及积累特性

通过盆栽研究了Cd胁迫下德国鸢尾的生长状况、生态效应、生理特性及吸收和富集Cd的能力.结果表明:德国鸢尾对小于5 mg/kg的Cd有较强的耐性,适用于城区土壤修复;Cd浓度大于5 mg/kg时抑制德国鸢尾生长,降低了其生态效应.随着Cd浓度的增大,德国鸢尾根系活力、叶绿素含量和含水量逐渐降低,游离脯氨酸和可溶性糖含量先升高后降低,细胞膜透性逐渐升高.Cd在德国鸢尾体内分布为根系＞地上部分,随着Cd浓度的增大,德国鸢尾根系和地上部分Cd积累浓度逐渐升高、富集系数和转运系数逐渐降低;Cd浓度为20 mg/kg时德国鸢尾对Cd的积累量最大,为2.122 mg/plant.     

Effects of salinity on growth and survival in five Artemia franciscana (Anostraca: Artemiidae) populations from Mexico Pacific Coast

Salinity is an important factor influencing growth and survival of aquatic organisms such as Artemia, a valuable aquaculture species. This study evaluated the effects of salinity on A. franciscana populations from different water bodies in Mexico's Pacific Coast. With this purpose, five autochthonous bisexual Artemia populations were tested to assess their survival and growth values against salinities of 40, 60, 80, 100 and 120 g/l, under laboratory conditions (25 +/- 2 degrees C; pH 8-10; constant light and aeration). The organisms were fed with 100 mL of rice bran and 2L of Tetraselmis suecica (500 000 cel/ml). The culture experiments were made in 200L plastic tanks, and survival and growth final values were obtained after 21 culture days. Survival and growth curves were determined by a regression analysis (R2). The significant differences between salinities were determined by ANOVA test (p < 0.05). The best survival and growth rates were found at salinities of 100-120 g/l. When the Mexican Artemia populations were cultivated at 40 g/l of salinity, 100% mortality was observed in the juvenile stage. This study determined that survival and growth values of A. franciscana populations increased with salinity. The five A. franciscana populations presented significant differences in their survival rate under various salinity regimes. The studied populations experienced high mortality at salinities under 60 g/l and over 200 g/l, and especially during the metanauplius stage. The present study confirms that growth rates in Mexican A. franciscana populations from Pacific Coast habitats are not inversely proportional to salinity. These A. franciscana populations should be cultured at 100-120 g/l of salinity to obtain better survival and growth rates. This data is useful to improve culture systems in aquaculture biomass production systems.     

镉与萘复合胁迫对红树植物白骨壤幼苗萌芽及生长的影响

为探讨白骨壤(Avicennia marina)幼苗对重金属镉(Cd)和多环芳烃萘(Nap)复合胁迫的响应,采用砂基栽培,对其幼苗的萌芽和生长进行了研究。结果表明,Cd、Nap复合胁迫对白骨壤萌芽的抑制效应较单一胁迫明显,胁迫前期幼苗成活率提高,胁迫后期则降低。胁迫栽培45 d,10 mg L~(–1)的Nap在叶形态、茎高及各器官生物量上能够减轻Cd胁迫的影响,但增强对根长的抑制作用,10 mg L~(–1) Nap-25 mg L~(–1) Cd处理的叶面积、叶长、叶宽、茎高及全株生物量分别比25 mg L~(–1) Cd处理的提高9.6%、7.9%、7.4%、5.1%和20.2%,但根长则比150 mg L~(–1) Cd处理的下降11.1%。至胁迫栽培90 d,各处理间幼苗器官及全株生物量无显著影响,复合胁迫对叶形态、茎高和根长等的抑制作用要强于单一Cd胁迫。因此,随着复合胁迫时间的延长,Cd和Nap对白骨壤幼苗的生长由拮抗效应转变为协同效应。     

Improving rock phosphate availability through feeding, mixing and processing with composting manure

The objective of this study was to improve the availability of phosphorus (P) from rock phosphate (RP) through feeding, mixing and composting manure. The experiment was conducted as a 3 x 2 split-plot design. Manure was collected from 12 Boran steers (200+/-4.5 kg live weight) fed a basal diet of Napier grass (Pennisetum purpureum) at 2.5% body weight on a dry matter (DM) basis. The main plot treatments were (i) manure from steers supplemented with 113 g Busumbu rock phosphate (BRP) per day (FBRP), (ii) manure from steers not supplemented with BRP, feces mixed with 113 g BRP per day (MBRP) and (iii) manure from steers not supplemented with BRP and feces not mixed with BRP (CONT). The sub-plots comprised composting the manure either (i) mixed with 440 g of wheat (Triticum aestivum L.) straw per kg fresh feces (WS) or (ii) without straw (WOS). The manure was composted in 200 L plastic bins for 90 days. After 90 days, P availability was evaluated (i) by aerobic laboratory incubation at 25 degrees C for 1, 2, 4, 8, 12, and 16 weeks and (ii) by greenhouse agronomic evaluation study using maize (Zea Mays L.) as the test crop in either a humic Nitosol or an Andosol. In the laboratory incubation study, resin P was higher (p<0.05) for the WS compost than for the WOS compost; values were higher (p<0.05) for the Andosol than for Nitosol and followed the order of FBRP-WS, Andosol>FBRP-WS, Nitosol>MBRP-WS, Andosol>MBRP-WS, Nitosol>FBRP-WOS, Andosol>FBRP-WOS, Nitosol. In the greenhouse evaluation, maize crops in the WS compost had higher (p<0.05) biomass yield than the reference fertilizer, triple super phosphate, (173% versus 196%; Andosol and Nitosol, respectively). The biomass yield and P uptake relative agronomic effectiveness (RAE) for WS compost was also higher (p<0.05) than that of WOS compost (184 versus 3+/-0.8 and 242 versus 162+/-0.2, WS and WOS, biomass yield and P uptake, respectively). Nitosol biomass yield and P uptake RAE were also higher (p<0.05) than for the Andosol (99 versus 88+/-0.8 and 332 versus 72+/-0.2, Nitosol and Andosol, biomass yield and P uptake, respectively). The results show that P-enriched composting in the presence of wheat straw significantly increased P availability and increased plant growth. However, in terms of plant growth, there was no additional benefit of first feeding the RP to steers before composting the manure because most of the RP fed seem to have been utilized by the animal.     

Resistance to Phytophthora infestans in somatic hybrids of Solanum nigrum L. and diploid potato

In breeding for resistance to late blight, ( Phytophthora infestans Mont. de Bary), an economically important disease affecting potatoes, the search for new sources of durable resistance includes the non-host wild Solanum species. The aim of this work was to evaluate the resistance to P. infestans in the somatic hybrids between S. nigrum L. and diploid potato clone ZEL-1136. Sixteen somatic hybrids, their fusion parents, and three standard potato cultivars were screened for resistance to P. infestans in two types of tests-on whole plants and detached leaves-with two highly aggressive and virulent isolates of P. infestans, US8 and MP322. In the whole plant assay, the foliage of the somatic hybrids showed no symptoms of infection, while the foliage of the potato fusion parent and the standard cultivars was infected with P. infestans. In the detached leaflet assay, the breaking-down of resistance of the S. nigrum L. parent and the variable response of individual hybrid clones were noted. Nine S. nigrum L. (+) ZEL-1136 hybrids showed a resistance that was significantly higher than that of S. nigrum, while six clones expressed a resistance to P. infestans similar to that of S. nigrum. The results confirm the effective transfer of late blight resistance of S. nigrum into its somatic hybrids with potato.     

松嫩平原贝加尔针茅无性系构件的结构及生长规律

采用整个分蘖丛挖掘的取样方法,对松嫩平原栽培条件下贝加尔针茅无性系构件的结构,以及生长与生产规律进行了定量分析.结果表明,在9月末停止生长期,经过2个生长季的营养繁殖,贝加尔针茅无性系的丛径为9.4±3.24 cm.无性系的全体构件数为161.±8.2个.其中,生殖分蘖株为14.6±11.48个,占9.2%;营养分蘖株为146.9±78.70个,占90.7%.全体构件总生物量为3.8±34.22 g,其中生殖分蘖株生物量为2.0±20.34 g,占43.7%;营养分蘖株为28.8±19.43 g,占6.2%.随着丛径的增加,不同构件的数量均具有线性同速生长规律,而不同构件的生物量均具有幂函数异速增长规律.不同构件生物量与无性系全体构件的数量和生物量之间均呈显著(P<0.0)或极显著(P<0.01)的幂函数正相关关系.平均单个生殖分蘖株的生产力约为营养分蘖株的10倍.生殖分蘖株的数量和生物量的表型可塑性普遍大于营养分蘖株.