台湾茉莉主要农艺性状调查

调查了台湾茉莉的主要农艺性状。结果表明,台湾茉莉当年生茎枝细软,呈匍匐状,树高70.5～111.4cm,分枝较密,树幅101.1～176.5cm,为直立丛生灌木。叶长6.9～11.5cm,叶宽4.8～7.5cm,叶面积24.2～57.2cm~2,花朵大而饱满,花冠直径为3.0～4.0cm,花瓣12～15枚,百花重37....     

柬埔寨双瓣茉莉全封闭紧贴覆膜扦插繁殖技术研究

为探索不同处理对柬埔寨双瓣茉莉扦插繁殖的影响,以3～4 a生柬埔寨双瓣茉莉植株的当年生枝条为扦插材料,分别探讨了全封闭紧贴覆膜扦插、IBA和NAA的应用、插穗留芽数及留叶片数等对扦插生根及生长的影响.结果表明:采用全封闭紧贴覆膜方式扦插,能维持湿润的扦插环境,有效减少插穗蒸腾失水,较好保持插穗叶片的叶形及叶色,插穗生根...     

通过形态性状鉴别栽培亚麻不同类型和品种的研究

Schilling，Tammes和Plonka等学者在本世纪三十年代到五十年代期间，为了鉴别亚麻的不同类型(野生亚麻、油用亚麻、两用亚麻，纤维用亚麻等)和品种，曾就亚麻的形态性状进行过各有侧重的和不同程度的研究，但未形成系统的鉴别标准和方法。     

双瓣茉莉5个花期挥发性成分GC-MS分析

采用气质联用仪(GC-MS)对福州双瓣茉莉花小花蕾期、大花蕾期、花开12 h开花期、花开24 h开花期和花败期5个时期挥发性成分进行鉴定,并用峰面积归一化法分析各组分含量。结果表明,开花期是挥发性物质集中释放期,花败期含量急剧下降,小花蕾和大花蕾时期仅少量释放,这符合茉莉花为气质花的特性。萜类和酯类挥发性物质是双瓣茉莉花香主要成分,萜类挥发性物质在盛开时大量释放,酯类挥发性物质通常在花开12 h开花期释放量最高。5个不同时期共鉴定出43种挥发性成分,挥发性物质种类和绝大部分挥发性物质含量均是在开花期最高,其中含量较高的乙酸芳樟酯、α-金合欢烯、乙酸苯甲酯、苯甲醇、γ-依兰油烯、乙酸甲酯、反式-法呢醇和β-罗勒烯等是双瓣茉莉挥发性物质的主要成分。结果将为茉莉花精油的提取及茉莉花制茶的采摘时期提供依据,为开展双瓣茉莉花挥发性物质代谢途径的分子调控机理研究奠定基础。     

茉莉酸甲酯对籼粳稻农艺性状及品质性状的影响

以6个常规籼稻和6个常规粳稻品种为试材,比较喷施不同浓度的茉莉酸甲酯（MeJA）对籼、粳稻农艺性状及品质性状影响的差异。结果表明,不同浓度的MeJA对籼、粳稻的穗长、一次枝梗数、二次枝梗数、穗粒数均无显著影响,40μmol/L的MeJA对籼、粳稻的实粒数和瘪粒数的影响也不显著,而4000μmol/L的MeJA可显著降低籼、粳稻的株高,并呈现出减少籼、粳稻实粒数,增加籼、粳稻瘪粒数,降低籼、粳稻结实率的趋势,且对瘪粒数和结实率的影响达到显著水平。4 000μmol/L的MeJA处理下,籼稻实粒数的减少程度和瘪粒数的增加程度均显著大于粳稻。4 000μmol/L的MeJA显著提高了籼、粳稻的蛋白质含量,显著降低籼、粳稻的食味值,对籼、粳稻的品质有明显的负向影响。本研究结果可为MeJA在杂交水稻制种中的有效使用提供一定参考。     

乌龙茶品种（系）花器主要形态性状分析

以18个乌龙茶品种为材料,对其花器的主要形态性状进行调查分析,并对其多样性和显著性进行探讨。结果表明,18个乌龙茶品种的花器性状品种内表现稳定,差异不显著;品种间差异显著,变异幅度较大,多样性丰富。这为今后研究这些品种间的系统发育、遗传、分类和寻找低开花结实的茶树种质提供了参考。     

通过形态性状鉴别栽培亚麻不同类型和品种的研究

Schilling、Tammes和Plonka等学者在本世纪三十年代到五十年代期间,为了鉴别亚麻的不同类型(野生亚麻、油用亚麻、两用亚麻、纤维用亚麻等)和品种,曾就亚麻的形态性状进行过各有侧重的和不同程度的研究,但未形成系统的鉴     

基于DUS测试性状的玉米标准品种形态多样性分析

利用DUS测试指南中的36个形态性状对53份玉米标准品种进行形态性状多样性的分析。结果表明,本研究所选用的玉米标准品种具有较为丰富的形态变异,36个形态性状在53个玉米标准品种中检测到193个等位变异,平均每个性状检测到5.361 1个,有效等位变异平均为3.575 6个(1.121 4~6.834 5),平均Shannon-Weaver多样性指数为1.309 4(0.253 5~2.046 1)。聚类分析结果表明,53个标准品种间的形态性状多样性丰富,相似系数介于0.74~0.85,具有标准品种性状描述的示例和校正作用;取相似系数0.80为阈值,可将53份玉米标准品种分为31类,由此可将标准品种的数量调减为31个。     

小麦形态性状的变频及基因

本文用１万多个小麦品种（系）为试材,分析了１２个形态性状的变异范围及各变异的频数分布,并简单介绍了各性状的基因定位情况,结果表明：①１１种芒色中,拟黄芒品种占６９％,３个黑芒基因已定位,９４％的品种芒色与颖色一致;②无芒品种仅占２．８％,已知５个芒型基因;③主频颖色为拟黄颖（占６６％）,已定位４个颖色基因;④无颖毛品种占９０．５％,毛颖基因Ｈｇ为显性;⑤６５．８％的品种为红粒,粒色基因可能有３个位点,３个红粒基因有加性效应,１个蓝粒基因已定位;⑥已定位２０个降秆基因,倒伏与秆质相关问题应予重视;⑦黄秆品种占７１．８％,紫秆基因Ｐｃ位于７ＢＳ上;⑧８１％的品种表现抗落粒性,估计可能有一抑紧颖基因ＴｇＩ;⑨穗型穗码基因尚未知;①０有叶毛品种仅占０．６％,毛叶基因Ｈ１位于４ＢＬ上。     

苎麻品种资源的类型划分及经济性状的研究

苎麻起源于我国，种植范围辽阔，品种类型丰富，栽培面积和产量居世界首位．新中国成立以来，有关科研单位先后对苎麻品种资源的搜集、保存、鉴定和利用，开展了深入的研究，评选了一大批优良品种材料供生产或育种应用，对发展我国苎麻生产和加速新品种的选育起了积极的作用。近几年来，本所对搜集的数百份品种资源从植物形态学、生育性状和经济性状方面进行了比较系统的研究，现综合整理如下。     

Chemical vine desiccation of two potato cultivars

Russet Burbank and Onaway potato (Solanum tuberosum L.) vines were desiccated with diquat (6,7-dihydrodipyrido (1,2-a:2′1′-c) pyrazinediium ion), ametryn (N-ethyl-N-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine), paraquat (1,1′-dimethyl-4,4′-bipyridinium ion), and endothall (7-oxabicyclo (2.2.1) heptane-2,3-dicarboxylic acid) applied at various rates alone or combined with surfactants, drift retardant, copper, or ammonium sulfate. Diquat and paraquat at 0.28 and 0.56 kg ha^?1 plus nonionic surfactant thoroughly desiccated Onaway and Russet Burbank potato vines. Only Onaway vines were thoroughly desiccated by ametryn at 1.3 and 2.3 kg ha^?1. Endothall at 0.87 kg ha^?1 provided thorough desiccation of Russet Burbank vines. The addition of a drift retardant did not reduce the effectiveness of diquat, while combining either ammonium or copper sulfate with diquat slowed the dieback of potato vines in 1987. Combining copper sulfate with diquat also slowed the dieback of Onaway vines in 1988. Both copper and ammonium sulfate, combined with diquat and nonionic surfactant, slowed the dieback of Russet Burbank vines when evaluated two days after application, but seven days later, no difference in vine dieback was evident. Crushing plants by rolling the field prior to desiccant application quickened vinekill by 18%. Applications of diquat using flat fan nozzles at 333 kPa provided vinekill equivalent to applications using hollow cone nozzles on a 25 cm spacing at 833 kPa, when spray volume for both applications was 467 L ha^?1. Potato yield, percentage of U.S. No. 1 potatoes, and stemend discoloration were unaffected by chemical desiccation.     

Importance of chlorogenic acid on the oxidative potential of potato tubers of two German cultivars

Summary Two German cultivars differing in blackspot susceptibility were grown in pots in 1998 and 1999 under control and water stress conditions. Blackspot susceptibility of the tubers was defined as oxidative potential. The effect of free tyrosine, cysteine, phenylalanine, chlorogenic and ascorbic acid on the oxidative potential was analyzed. A high concentration of ascorbic acid led to a decrease in the oxidative potential after harvesting in 1998. No correlation was found between oxidative potential and free tyrosine, phenylalanine or cysteine, respectively. Chlorogenic acid content increased during storage and gave a significant correlation with discoloration, showing that it can have an effect on the oxidative potential of the tuber greater than previously thought. Supplementing freeze-dried potato samples with pure chlorogenic acid increased the oxidative potential. Oxidative potential seems to depend on a series of chemical compounds, and their content is affected by factors including annual variations, cultivar, water availability and storage.     

两个栽培大豆品种的体细胞胚胎发生和植株再生研究

通过优化培养条件,即提高植物生长激素浓度和蔗糖浓度,发展了一种再生频率较高的大豆植株再生的方法。从栽培大豆品种幼胚中诱导形成的体细胞胚性愈伤组织和胚状体可以进一步分化出芽和根,发育成完整植株,中黄４号植株再生频率最高可达３９％,早熟１８号仅得到了胚性愈伤组织。     

Response of two sweet potato cultivars to weed interference

Field experiments were conducted at the U.S. Vegetable Laboratory, Charleston, SC, U.S.A in 2000, 2001, and 2004 to assess the effect of different durations of weed interference on two sweet potato cultivars with different shoot growth habits. The cultivars were Beauregard, which has a spreading growth habit that is typical of U.S. sweet potato cultivars and Carolina Bunch, with an erect growth habit. Weed interference treatments included control plots that were maintained weed free throughout the growing season and plots that were maintained weed free for 0, 10, 20, and 30 days after transplanting. In general, Carolina Bunch was more tolerant of weed interference than was Beauregard. In two of three years Carolina Bunch storage root yields were higher than Beauregard yields in plots that received no weeding; whereas, yields of the two cultivars in weed free plots were not different. Weed interference affected shoot growth to a greater extent than it affected storage root production. At the end of the growing season, Carolina Bunch shoot biomass was greater than Beauregard shoot biomass in plots receiving no weeding and in plots that were maintained weed free for 10 days in all three years. Shoot biomasses of the two cultivars were not different in weed-free plots. Weed shoot biomasses were greater in Beauregard plots than in Carolina Bunch plots in several instances. These results demonstrate that sweet potato cultivars with a vigorous, erect shoot growth habit (with shorter stems, greater branching, and a denser and taller canopy early in the growing season) may be less susceptible to weed interference than cultivars with spreading shoot growth. This study also confirmed previous observations that sweet potato productivity is not greatly affected by moderate weed interference; thus, it may not require intense weed management to produce high yields.     

油菜不同类型品种磷效率特性研究

在鄂东南有效磷缺乏的红黄壤稻田土壤条件下，以我国1508份油菜品种资源预选核心品为材料，研究磷营养水平对不同类型油菜生长发育和产量的影响。试验结果表明，低磷条件下不同类型油菜品种苗期植株生长量和籽粒产量差异较大，甘蓝型、白菜型和芥菜型油菜分别只有48％、43％和15％的品种能正常生育获得种籽，50％以上的品种于苗期和生长期死亡或不能正常开花结实。施磷处理的油菜能正常生长收获种籽，但不同类型和不同品种的苗期干物重及籽粒产量差异较大。     

Defence reactions in two potato cultivars following infection with two races ofPhytophthora infestans

Summary The kinetics of accumulation of chitinases, glucanases and phytoalexins were studied in two potato cultivars, differing in their degrees of vertical and horizontal resistance, when infected with two races ofPhytophthora infestans. Tuber disks of cvs Kennebec (susceptible, low horizontal resistance) and Huinkul (tolerant, high horizontal resistance) were infected with either race “0” (avirulent) or “C” (complex, race 1.3.5.7.11) ofPhytophthora infestans. Extracts of tuber tissue (0–7 days) from cv. Kennebec infected with race “0” showed a strong increase in phytoalexin production and in chitinase and glucanase activities when compared with those infected with race “C”. These results indicate that race “C” is able to block defensive reactions. No significant differences were observed in cv. Huinkul infected with both races. The contribution of these reactions to horizontal resistance is unknown, and our results would not support a conclusive role for them in the interaction.     

新老大豆品种叶片光合特性的比较

为了了解大豆品种叶片光合特性与产量的关系，我们对跨越70多年的4个老大豆[Glycine max(L.)Merr.]品种和4个新大豆品种的光合特性和产量进行了研究。研究结果表明：新品种产量比老品种提高了91%，新品种叶片净光合速率、气孔导度、蒸腾速率、水分利用效率、叶绿素含量和比叶重也不同程度高于老品种，其中以净光合速率增加最多(17.3%)，而胞间CO2浓度却低于老品种。在盛花期和盛荚期，新老大豆品种叶片净光合速率与产量呈显著正相关（P﹤0.05），而其它光合特性指标与产量的相关性不稳定。     

Comparison of vegetative development in soybean cultivars for low-latitude environments

Soybean production has been expanded into northern Brazil by the introduction of long-juvenile genes. These genes cause flowering to be delayed but specific changes in the sensitivity of plant development to temperature and photoperiod have not been resolved in these commercial cultivars. This study was undertaken to resolve possible changes in long-juvenile plants associated with rates of plant emergence, leaf appearance, and flowering. Eight cultivars, including three long-juvenile cultivars, were sown each week throughout a year in a plastic greenhouse so that the plants would develop under differing temperature and photoperiod. While there were differences among cultivars in the cumulative temperature required for plant emergence and the rate of leaf appearance, these differences were not necessarily associated with the long-juvenile trait. An extended duration to flowering was confirmed for the three long-juvenile cultivars but this delay was not associated with any difference in sensitivity to temperature and photoperiod. The trait that distinguished the long-juvenile cultivars was a much lower maximum development rate towards flowering than that found in the other cultivars. However, cultivar differences were identified among the long-juvenile cultivars indicating the possibility of further selection of genotypes to fit specific environments in low-latitude regions.     

Differential interaction between two potato cultivars and two isolates ofPhoma exigua var.foveata

Summary In experiments carried out over two years at two sites, a differential interaction between two potato varieties and two isolates ofP. exigua var.foveata was demonstrated in the cortical tissue.     

Nitrogen fertilization and irrigation affects tuber characteristics of two potato cultivars

Nitrogen fertilization, irrigation, and cultivars affect tuber characteristics such as tuber size, specific gravity, and N concentration. Few studies, however, have investigated the interaction of irrigation and N fertilization on the tuber characteristics of potato cultivars, particularly in Atlantic Canada. The objective of this on-farm study, conducted at four sites in each of three years, 1995 to 1997, was to determine the effects of supplemental irrigation and six rates of N fertilization (0-250 kg N ha^-1) on the number of tubers per plant, the average fresh tuber weight, tuber N concentration, nitrate (NO₃-N) concentration, and specific gravity of the cultivars Shepody and Russet Burbank. Nitrogen fertilization increased the average fresh tuber weight, tuber N and N0₃-N concentrations, and decreased specific gravity. Effects of increasing N fertilization on tuber characteristics were often more pronounced for Shepody than for Russet Burbank, and for irrigated than for non-irrigated conditions. Shepody had greater average fresh tuber weight and tuber N concentration, lower specific gravity, and fewer tubers per plant than Russet Burbank. Supplemental irrigation increased the average fresh tuber weight and the number of tubers per plant, but it had a limited effect on specific gravity and tuber N and NO₃-N concentrations. Tuber NO₃-N con centration and specific gravity were strongly related to tuber N concentration, which in turn depended primarily on N fertilization. Incidents of lowest specific gravity and highest NO₃-N concentration occurred with a relative yield close to or equal to 1.0. We conclude that the risks of low specific gravity and high tuber NO₃-N concentration are greater when fertilization exceeds the N requirements to reach maximum tuber yield.