不同水稻品种在Cd、As和Hg胁迫下的吸收积累特性

为筛选籽粒中Cd、As和Hg低吸收或低积累的品种或育种中间材料,采用人工添加 Cd(CdCl2·2.5H2O)、As(NaAsO2)和 Hg[Hg(NO3)2·0.5H2O]等重金属化合物的方法污粢土壤,研究不同水稻品种对Cd、As 和 Hg 胁迫的吸收积累特性.结果表明,Cd、As 和 Hg 胁迫时,水稻茎叶、稻谷和精米中均会增加相应重金属的含量;As 和 Hg 主要在茎叶中积累,而籽粒中的含量较低;精米中 Cd 的含量与稻谷和茎叶中的含量差异较小.茎叶中 Cd、As 和Hg 的含量显著或极显著高于稻谷和精米,而精米中相应重金属的含量与稻谷中含量的差异均不显著.南粳 41、金陵香糯、武育粳3号、华粳3号、02428、龙睛4号和云南新团黑谷等7个品种精米中Cd和As的含量均达到绿色食品大米标准;所有品种精米中Hg的含量均未达到无公害食品大米标准.     

Studies on some Drought Resistant Traits of Pearl Millet Cultivars and their Association with Grain Production under Natural Drought

A field experiment was conducted to evaluate the performance of hybrid (BJ 104, MBH 110, CM 46 and GHB 27) and composites (PSB 3, PSB 8, WCC 75 and Local) of pearl-millet on the soils (pH 7.1, Organic carbon 0.5 %, P₂O₅ 9.6 kg/ha, K₂O 80 kg/ha, soil depth 65 cm and profile moisture 8.6 cm) of Indian Grassland and Fodder Research Institute, Jhansi under extreme drought condition (340 mm total precipitation during the crop season). It was observed that hybrids, by and large, gave higher production than composites and local variety even failed to bloom. Further the highest yield from hybrid MBH 110 was due to its drought escaping character (earliness), drought enduring capacity (CSI-12), efficient translocation and better sink strength. BJ 104 and CM 46, though were also drought escaping and possessed capacity to endure drought but inferior to MBH 110 in sink strength which was ultimately reflected in production.
An appraisal of the various agro-physiological traits revealed that earliness, high harvest index, low CSI value (chlorophyll stability index) and high sink strength were directly correlated with productivity of cultivars under drought condition which could be used as a guide lines for breeding drought resistant cultivars of pearl millet.     

不同品种荔枝果实制汁特性比较研究

以13个荔枝品种的果实为试材,利用常规的加工特性分析方法,进行了果实的理化指标和营养成分的分析。结果表明,13个荔枝品种中妃子笑色泽较好,具有典型的荔枝风味、糖酸比适宜、热处理褐变程度轻,是最适宜加工果汁的优良品种。     

Comparative Study on the Zinc and Cadmium Tolerance Potential of Twelve Prominent Rice Cultivars

Heavy metal pollution being a potential threat to agriculture raising rice cultivars with heavy metal tolerance is a promising strategy for remediation of heavy metal polluted agricultural lands. We present here a comprehensive study describing the differences in physiological and biochemical responses of 12 prominent high-yielding rice cultivars to increasing ZnSO₄ concentrations (0, 2, 6, and 10 mM) and CdCl₂ concentrations (0, 1, 2, and 3 mM). Even though Zinc (Zn) is an essential element required for the normal growth and development process of plants, a higher concentration of Zn has an antagonistic effect. Cadmium (Cd) is detrimental to plants and is found in soils contaminated with heavy metals. The effects of Zn and Cd on rice seedlings were a reduction in shoot length, greater chlorophyll and carotenoid loss, higher malondialdehyde content, proline accumulation, and an increased level of sugar and amino acids when treated with CdCl₂ and ZnSO₄. The CdCl₂ and ZnSO₄ stress-induced biochemical changes displayed major differences in the 12 rice cultivars in terms of tolerance to Zn and Cd toxicity. Our data provides evidence that the cultivar Varsha showed the highest tolerance and cultivar JY showed the least tolerance towards Cd and Zn toxicity.     

褪黑素引发对盐胁迫敖汉苜蓿种子发芽特性的影响

褪黑素(MT)是植物体内存在的一种抗氧化剂,具有调节生长发育和缓解非生物胁迫的作用。试验采用MT溶液(50,100μmmol·L^-1)对敖汉苜蓿种子引发6 h和12 h后,进行盐溶液胁迫处理,筛选MT缓解盐胁迫的适宜引发时间和浓度,研究种子发芽能力和幼苗生长的变化规律。利用NaCl、Na 2SO 4、NaHCO 3、Na 2CO 3配制0,25,50,100,150 mmol·L^-1混合盐溶液(记为ck、25 S、50 S、100 S、150 S),NaHCO 3、Na 2CO 3混合配制0,25,50,100,150 mmol·L^-1碱性盐溶液(记为ck、25 J、50 J、100 J、150 J)。结果表明,低浓度盐溶液(处理25 S)可以显著(p<0.05)提高苜蓿种子发芽率,当盐胁迫浓度超过100 mmol·L^-1时,种子发芽率降至最低,且碱性盐(pH>11.0)显著(p<0.05)抑制种子的发芽。在不同浓度MT引发6 h和12 h时,处理25 S种子发芽率最高,50 J最低。100μmmol·L^-1 MT引发12 h可以显著(p<0.05)提高处理25 S、50 S、50 J种子发芽率。平均发芽时间(MGT)随着盐胁迫浓度的增加,逐渐延长,在100μmmol·L^-1 MT引发12 h时可以显著(p<0.05)缩短处理50 S和50 J种子的MGT。种苗长度和鲜重随着盐浓度的增加呈逐渐下降趋势,均在处理50 J时降到最低,且MT引发12 h时后各处理种苗长度均显著(p<0.05)增加,但种苗鲜重均无显著(p>0.05)差异。确定100μmmol·L^-1 MT引发12 h时,可以有效缓解50 mmol·L^-1混合盐溶液和高pH盐溶液(pH>11.0)的胁迫作用。     

Growth and Distribution of Dry Matter in a Drought Tolerant and a Susceptible Potato Cultivar under Normal and Water Deficit Condition

The growth behaviour of Dekama (drought tolerant) and Kufri Jyoti (drought susceptible) was studied using potted plants maintained at well watered condition and water deficit condition respectively. Periodic harvestings were done starting from 50 days after planting till maturity. Recordings of plant height, leaf area, dry weights of different plant parts, the proportion of thinner and thicker roots, stomatal conductance and water saturation deficit were obtained. The plant height, leaf area and dry weight of shoot decreased to nearly the same extent in both the cultivars under stress. The stomatal conductance decreased by 61.7 % in Dekama and by 64 % in Kufri Jyoti due to water stress. Water saturation deficit increased by about 80 % in both the cultivars. The ratios of root to shoot and that of thinner to thicker root increased due to stress in both cultivars and this increase was 85 % and 71 % in Dekama and 64 % and 19 % in Kufri Jyoti respectively. The distribution of dry matter to leaf, stem, root were more at the expense of tuber under stress conditions in both cultivars. However, the tolerant cultivar Dekama got adjusted to the stress condition, with more dry matter partitioned to tubers in the last two samplings. The study points out the factors responsible for better drought tolerance of Dekama compared to Kufri Jyoti and the possible physiological traits useful for selecting drought tolerant cultivars.     

Water Stress Tolerance of Wheat (Triticum aestivum L.): Variations in Hydrogen Peroxide Accumulation and Antioxidant Activity in Tolerant and Susceptible Genotypes

An experiment was conducted on five wheat ( Triticum aestivum L.) cultivars, C 306, PBW 175 (tolerant to water stress), DL 153-2 (moderately tolerant to water stress), HD 2428 and HD 2329 (recommended for irrigated conditions, susceptible to water stress), under pot culture conditions to study the effect of water stress on oxidative injury and antioxidant activity. Water stress significantly decreased relative water content (RWC), ascorbic acid content and membrane stability, and increased hydrogen peroxide and malondialdehyde content, a measure of lipid peroxidation, and activities of antioxidant enzymes in all the genotypes at 7, 17 and 27 days after anthesis (DAA). Water stress tolerant genotypes C 306 and PBW 175, closely followed by DL 153-2, were superior to HD 2428 and HD 2329 in maintaining high RWC, ascorbic acid content and membrane stability and lower hydrogen peroxide content and lipid peroxidation (malondialdehyde content) under water stress at the three stages. The highest activities of glutathione reductase and catalase under water stress were observed in C 306, PBW 175 and DL 153-2 and the lowest activities in HD 2428 and HD 2329 at all the stages. Superoxide dismutase activity at all stages under irrigated conditions and at the first and second stages under water stress conditions did not show significant variation among the different genotypes, but at the last stage under water stress the enzyme activity was highest in C 306, closely followed by PBW 175 and DL 153-2, and lowest in HD 2428 and HD 2329. It is apparent that water stress induces an increase in hydrogen peroxide content and consequently lipid peroxidation and membrane injury (reduced membrane stability). The degree of oxidative stress and antioxidant activity seems to be closely associated with the tolerance/susceptibility of a genotype to water stress.     

棉花抗黄萎病品种选育的轮回选择研究——基础群体的构建

利用我国发现并鉴定的陆地棉核雄性不育系—洞Ａ为工具,将国内外现有的十多个抗（耐）棉花黄萎病的品种（系）和种质系导入到二个轮回群体中,拓建了棉花抗黄萎病轮回选择基础群体。从而为同步提高棉花的产量、品质和抗病性打下基础。     

PEG-8000模拟干旱胁迫对11个马铃薯品种的组培苗生长指标的影响

为了明确聚乙二醇（ PEG-8000）模拟干旱胁迫对马铃薯组培苗的影响,以11个马铃薯主栽品种的脱毒组培苗为试验材料,研究比较了在固体培养基中分别添加5％,10％,15％,20％的 PEG-8000模拟干旱胁迫和对照处理下（不含PEG-8000）组培苗生长指标的变化,对供试品种组培苗的株高、最大根长、茎鲜质量、根鲜质量、茎干质量、根干质量和植物水分含量共7个生长指标进行测定和分析。结果表明,随着胁迫处理PEG-8000浓度的增加,所有材料的组培苗表现出受干旱胁迫现象越严重,当固体培养基中PEG-8000浓度为15％时,11个品种间的差异最大,所测的7个指标值均显著低于对照,是鉴定马铃薯品种组培苗对干旱胁迫反应的最佳浓度。在该胁迫浓度下,供试马铃薯材料的平均相对根鲜质量为26．9％,变异系数为50．6％,是下降幅度和变异系数最大的一个指标,表明根鲜质量更易受到干旱胁迫的影响。利用6个相对指标值,对11个马铃薯品种的干旱敏感性进行聚类分析,在欧氏距离为40处,11个马铃薯品种可分为3类,Ⅰ类包括坝薯10号、高原7号、克新1号和晋薯2号;Ⅱ类包括中薯2号和中薯20号;Ⅲ类包括中薯3号、大西洋、夏坡蒂、费乌瑞它和疫不加,3个类群受干旱胁迫的影响逐渐加重。综合聚类分析和植株含水量的结果,筛选到坝薯10号和高原7号2个耐旱品种。     

Effect of Nitrogen and Phosphorus Levels on Barley Cultivars Grown in Semi-arid Conditions

Most farmers in the rainfed parts of Jordan who use fertilizers use less than optimum rates of N and P because of the uncertainties associated with rainfall. Research results obtained by the national program indicated that the use of improved barley cultivars and fertilizers would result in substantial yield increases. The objective of the present investigation was to determine the optimum combination level of N and P for newly promising cultivars. The effect of 0–0, 5–10, 10–20 and 15–30 kg.ha⁻¹ of nitrogen (N) and phosphorus (P) levels on barley cultivas Rum, Giza, Fun, Harmel and Arta under rainfed conditions in the Mediterranean climate was studied during two cropping seasons, 1994-95 and 1995–96. Increased grain and straw yields, total N and P uptake and RUE were recorded with increasing N and P levels for almost all cultivars. Rum was significantly (P = 0.05) the highest grain and straw producer and highest RUE at the 10 N- and 20 P kg.ha⁻¹ level. The cultivar × fertility level (N–P) interactions were not significant for both grain and straw yields and for total N and P uptake.     

有机酸对Pb^2＋胁迫下水稻愈伤组织诱导和生长的影响

以水稻种子为外植体,研究了pb2+胁迫对水稻愈伤组织诱导和生长的影响以及不同有机酸对Pb2+胁迫的影响.结果表明:不同浓度(250～1 000μmol/L)Pb2+对MS培养基下水稻愈伤组织诱导与生长均有明显的抑制作用,并且随着Pb2+胁迫浓度的升高,毒害程度加深,pb2+胁迫浓度为1 000μmol/L时,表现为生长的愈伤组织块较小,颗粒表面干燥,质地较硬.而添加不同有机酸(抗坏血酸、柠檬酸和草酸)均可明显改善Pb2+胁迫下愈伤组织的生长,尤以750μmol/L柠檬酸对Pb2+毒害的缓解效果最佳,其愈伤组织块颜色浅黄,表面湿润,愈伤组织成活率高,与对照愈伤组形态较接近.柠檬酸不能较好抑制Pb2+胁迫下水稻愈伤组织的褐变现象.     

黄淮海平原旱作条件耐旱苜蓿品种筛选的试验研究

黄淮海平原是中国重要农区,农业生产在中国占有举足轻重的地位。在当前的农业结构调整中,苜蓿已经全面引入该区农业系统中,具有广阔的发展空间。但该区人均水资源占有量及亩均水资源占有量分别是全国的16%和18%,水资源严重不足问题在该区将长期存在。筛选适应该区旱作条件下的苜蓿新品种无疑具有重要意义。通过引进国内外10个苜蓿品种,完全旱作条件下开展3年的品种比较试验,结果表明,在旱作条件下产量较高的苜蓿品种分别是RS、中苜一号、BG-1和R-1,3年干草平均产量分别为6761.4kg/hm2、5991.8kg/hm2、6103.6kg/hm2和5980.2kg/hm2,分别比对照敖汉苜蓿增产55.5%、37.8%、40.3%和37.5%。     

水稻BZIP类转录因子在逆境胁迫下的作用

BZIP类转录因子在植物的逆境胁迫下起着重要作用。本研究构建水稻转录因子OsBZIP88过量表达载体pHB-Osbzip88和干涉载体RNAi-Osbzip88,通过遗传转化获得转基因植株,并对转基因植株在逆境胁迫下的表型鉴定。结果表明,过表达转基因植株抗胁迫能力高于野生型和干涉转基因植株。对OsBZIP88定量表达实验表明:OsBZIP88在水稻各组织中均有不同程度表达,且在叶片中表达量最高。本研究初步探明水稻转录因子OsBZIP88在水稻逆境胁迫应答中具有重要的作用,过量表达转录因子OsBZIP88能够增强水稻的抗逆能力。研究结果为进一步了解BZIP类家族基因和挖掘水稻抗逆基因提供了一定的依据。     

有机酸对Cu2+胁迫下水稻愈伤组织诱导和生长的缓解作用

以水稻种子为外植体,研究了Cu2+胁迫对水稻愈伤组织诱导和生长的影响以及不同有机酸对Cu2+胁迫的缓解效果.结果表明:不同浓度(250～1 000μmol/L)Cu2+对MS培养基下水稻愈伤组织的诱导与生长均有明显的抑制作用,并且随着Cu2+胁迫浓度的升高,毒害程度加深.当Cu2+浓度为1 000μmol/L时,表现为生长的愈伤组织块较小,颗粒表面干燥,质地较硬.而添加不同有机酸(抗坏血酸、柠檬酸和草酸)均可明显改善Cu2+胁迫下愈伤组织的生长,尤以250μmol/L抗坏血酸对Cu2+毒害的缓解效果最佳,其愈伤组织块颜色浅黄,表面湿润,愈伤组织成活率高,与对照愈伤组织形态较接近.抗坏血酸且能较好抑制Cu2+胁迫下水稻愈伤组织的褐变现象.     

Effect of the Russian Wheat Aphid on the Composition and Synthesis of Water Soluble Proteins in Resistant and Susceptible Wheat

The effect of Russian wheat aphid ( Diuraphis noxia) infestation on polypeptide composition and protein synthesis in the presence or absence of chloramphenicol and cycloheximide were studied in genetically comparable wheat ( Triticum aestvum) resistant (cv. PI 137739/5* Tugela) and susceptible (cv. Tugela) to the aphid. The aim is to gain information of molecular nature on the resistance phenomenon which may promote future breeding programmes. In the absence of feeding aphids polypeptide profiles of the two wheat lines were similar indicating the absence or presence at low levels of a constitutive resistance factor. Aphid infestation induced enhanced expression of certain genes in the resistant wheat only. A 100 kD nuclear encoded polypeptide is strongly induced in the resistant wheat. It is also evident that the synthesis of a 56 kD organel encoded polypeptide is suppressed by the feeding aphids in the susceptible wheat.     

镉胁迫对不同水稻品种苗期光合特性与生理生化特性的影响

为了研究镉抗性不同的水稻品种对镉胁迫的生理生化响应差异,采用水培法,以对镉胁迫相对敏感的水稻品种28占和对镉胁迫相对耐受的水稻品种黄粤占为材料,研究了0(蒸馏水,对照),0.05,0.10,0.20 mmol/L 4种不同镉胁迫浓度对该2个水稻品种种子萌发幼苗期的生物学性状、光合特性和生理生化指标的影响。结果表明:不同镉胁迫处理浓度下,2个供试水稻品种28占和黄粤占的苗高、根长、幼苗鲜质量与幼苗干质量均随镉胁迫处理浓度的增大而减小,其中28占减小相对较显著;镉胁迫条件下,水稻叶片的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和胞间CO2浓度(Ci)均呈不同程度的下降趋势。耐镉水稻品种黄粤占Pn、Gs、Tr和Ci的下降均低于镉敏感型水稻品种28占;气孔限制百分率(Ls)呈增加趋势,且品种间差异不显著。随着镉胁迫处理浓度的增加,2个供试水稻品种28占和黄粤占的幼苗叶片叶绿素含量呈下降趋势,而MDA含量、SOD、POD和CAT等抗氧化酶的活性均随着镉胁迫处理浓度的升高而增大,且镉胁迫处理下黄粤占的MDA含量与各抗氧化酶活性较对照的相对增加值小于28占。结果表明,水稻品种黄粤占种子萌发幼苗期对镉胁迫具有较好的抗性。     

高温逆境下嫁接辣椒耐热性的研究

试验以野生辣椒威壮贝尔为砧木,辣椒品种科椒二号为接穗进行嫁接,研究了嫁接和自根辣椒对夏季温室中高温的抵御能力,为设施辣椒耐热栽培及生产提供依据。结果表明,高温对辣椒叶片各项指标影响比亚高温明显;不论是在高温还是亚高温条件下,嫁接辣椒叶片的脯氨酸(Pro)含量、过氧化物酶(POD)活性都明显高于自根苗,而嫁接苗的相对电导率、丙二醛(MDA)含量、超氧阴离子产生速率低于自根苗。明确嫁接能显著提高辣椒的抗热性。     

Selection of Semidwarf, Early Maturing and Blast Resistant Mutants after Mutagenic Seed Treatment in Two Locally Adapted Indian Rice Cultivars

The objective of this study was to induce semidwarf, early maturing and blast resistant mutants in two adapted Indian rice cultivars. Seeds of the rice cultivars ‘Madhu Malti’ and ‘Phul Patas 72’ were treated with gamma rays and ethyl methane sulfonate (EMS) as well as a combination of gamma rays and EMS. A total of 96 dwarf (< 75 cm) and semidwarf (< 100 cm) and 104 early flowering/maturing M₂ plants were identified among the 18,060 M₂ plants observed. Sixty-eight blast resistant M₂ plants were also identified. The true mutant status of these plants has yet to be determined in progeny tests. The induction of desired mutant types in locally adapted cultivars could prove to be superior over their introduction from non-adapted foreign materials via backcrossing in that the important agronomic characteristics of adaptation to the local environment are retained in the mutants.     

亚砷酸盐胁迫下水稻microRNA的应答功能及调控通路分析

为明确砷胁迫下microRNA的应答功能及调控通路,本研究利用miRNA芯片检测水稻幼苗在亚砷酸盐胁迫后miRNA的表达差异。结果发现11个miRNA表达显著下调,7个显著上调,并采用RT-PCR验证了9个miRNA的差异表达。差异miRNA靶基因多编码转录因子以及重金属响应网络中的蛋白。基因本体(GO)和KEGG通路富集表明,砷胁迫下miRNA主要介导调控激素信号转导、硫代谢、氨基酸代谢和抗氧化防御。利用PLACE数据库发现miRNA上游启动子区密集分布多种金属应答元件。本研究有助于阐明水稻中砷转运和积累的分子机制,为水稻抗逆育种提供理论参考。     

Pb2+胁迫对水稻种子萌发及幼苗生长影响的研究

研究了不同浓度Pb^2＋离子胁迫下水稻种子萌发及幼苗生长状况，结果表明：在Pb^2＋浓度不高于100mg／L时对水稻种子的发芽率短期内有一定的促进作用，但所有处理的种子的简化活力指数均低于对照，随着浓度的提高，Pb^2＋离子胁迫对水稻种子萌发的抑制作用越大，水稻种子的简化活力指数、幼苗高度、幼苗鲜重、根鲜重明显降低；Pb^2＋离子胁迫下对水稻种子根生长的抑制作用大于芽。