蜡梅17个品种过氧化物同工酶的研究

采用聚丙烯酰胺凝胶电泳系统,多次进行了蜡梅17个品种的过氧化物同工酶测定。测定结果发现:蜡梅酶谱具有多态特性;蜡梅品种间酶谱差异显著,每个品种均有其特征酶谱,或以其酶带数目、Ff及活性强弱、酶带宽度与其它品种相区别。同时,采用"排序方法"和聚类分析,对蜡酶17个品种酶谱的相似程度进行了研究。研究结果表明,两种方法研究蜡梅品种的酶谱,均可达到定量比较水平,避免单一酶谱谱带确定蜡梅品种的偏阳性,为其品种鉴定与检验提供了新的依据和手段。同时,还表明,聚类分析进行的蜡梅品种酶谱聚类结果,与其形态分类相一致,但与其品种群划分不相吻合,其原因可能与蜡梅品种起源的复杂性和多源性所引起。     

SSR标记揭示的云南地方稻品种遗传多样性及其保育意义

为了探索水稻(Oryza sativa L.)地方品种的遗传多样性及其有效保育方法,对采自云南省17个村寨的82个水稻地方品种和3个国际常用的典型籼稻和粳稻品种进行了微卫星(SSR)分子标记的分析.利用19对SSR引物在85个水稻品种中共扩增出了83个基因型,其分子量变异在100～500 bp之间.基于各品种SSR基因型遗传相似系数聚类分析而获得的UPGMA树状图表明各水稻品种之间存在较大的遗传多样性,其相似系数变异在0.15～0.90之间.但这些地方品种的遗传多样性并非呈均等的地理分布.这85个水稻品种在相似系数为0.52之处分为二组,其中一组包括几乎所有的籼稻品种,而另一组包括全部的粳稻品种,表明SSR标记能很好揭示水稻籼-粳分化.同时,有些来自不同采集地的同名品种表现出一定的遗传差异,说明同名异物的现象存在.云南水稻地方品种具有丰富的遗传多样性,对其有效保育十分重要和迫切,但只有根据遗传多样性的水平和分布特点,采用正确的保育对策和取样方法才能确保对云南水稻地方品种的有效保育.结果进一步表明,选用适当的微卫星引物,可以为准确鉴定籼稻和粳稻品种及研究其进化规律提供有效的分子标记方法,并有利于有目标的水稻遗传资源保育和育种创新.     

SSR标记揭示的云南地方稻品种遗传多样性及其保育意义

为了探索水稻(Oryza　sativa　L.)地方品种的遗传多样性及其有效保育方法,对采自云南省17个村寨的82个水稻地方品种和3个国际常用的典型籼稻和粳稻品种进行了微卫星(SSR)分子标记的分析。利用19对SSR引物在85个水稻品种中共扩增出了83个基因型,其分子量变异在100～500　bp之间。基于各品种SSR基因型遗传相似系数聚类分析而获得的UPGMA树状图表明各水稻品种之间存在较大的遗传多样性,其相似系数变异在0.15～0.90之间。但这些地方品种的遗传多样性并非呈均等的地理分布。这85个水稻品种在相似系数为0.52之处分为二组,其中一组包括几乎所有的籼稻品种,而另一组包括全部的粳稻品种,表明SSR标记能很好揭示水稻籼-粳分化。同时,有些来自不同采集地的同名品种表现出一定的遗传差异,说明同名异物的现象存在。云南水稻地方品种具有丰富的遗传多样性,对其有效保育十分重要和迫切,　但只有根据遗传多样性的水平和分布特点,采用正确的保育对策和取样方法才能确保对云南水稻地方品种的有效保育。结果进一步表明,选用适当的微卫星引物,可以为准确鉴定籼稻和粳稻品种及研究其进化规律提供有效的分子标记方法,并有利于有目标的水稻遗传资源保育和育种创新。     

抗二化螟的水稻品种筛选

【目的】筛选抗二化螟Chilo suppressalis水稻品种资源,明确其抗虫机理,是农业防治的基础。【方法】采用室内人工接虫为害和大田自然受害相结合的方法,鉴定了不同的水稻品种抗性;同时通过目测不同水稻植株外部形态特征、在网罩内供试品种上接入成虫后2 d的产卵量、幼虫孵化后2 d观察稻株内二化螟的存活率,探讨抗虫品种的抗虫机理。【结果】从344个水稻品种资源和当家品种中筛选出"碑田倒"和"银间杂糯"2个抗虫品种,以及"农飞"和"三香糯"等65个中抗品种,进一步对鉴定出的2个抗虫品种和65个中抗品种进行大田验证,发现符合率达88.06%;其中,抗虫品种"碑田倒"和"银间杂糯"稻株叶舌、叶耳紧贴,叶鞘紧包,脉间距较窄,其植株上的产卵量和幼虫存活率显著少于感虫品种"香稻"、"赣南早"、"三粒寸"、"赣优晚"及中抗品种"赛湖早"、"TKM6"。【结论】在籼稻、粳稻和糯稻中均可筛选出抗虫和中抗品种。其中,糯稻中的抗虫品种和中抗品种较多,占糯稻品种的33.3%;粳稻品种次之,中抗品种占20%,籼稻品种较少,为18.83%。其抗虫机理主要是稻株外部形态特征不利于二化螟蚁螟侵入、成虫产卵量少和幼虫生长发育不良、存活率低。     

两个菜用枸杞品种的生长特性及品质分析

对两个菜用枸杞品种的主要生长特性、营养成分及食用性研究表明,大叶品种嫩芽平均产量显著高于小叶品种;大叶品种较耐高温,小叶品种较耐低温;生产上可进行大、小叶品种搭配种植,能有效提早和延长采收期,从而提高单位面积产量和经济效益。此外,小叶品种嫩芽的蛋白质、VitC含量高于大叶品种。两个品种风味各具特色,其适宜的消费群体亦有所差异。     

水稻品种对稻纵卷叶螟抗性的物理及生化机制

稻纵卷叶螟Cnaphalocrocis medinalis连年大发生,为在其治理中培育和推广抗虫品种,本文应用扫描电镜和生化测定研究了5个常用水稻栽培品种扬辐粳8号、扬稻6号、扬粳9538、淮稻9号和宁梗1号叶片中的硅含量、硅颗粒大小、蜡质含量等物理指标和一些生化指标与抗虫性的关系,并比较了稻纵卷叶螟幼虫危害不同水稻品种后其体内生化反应的差异。结果表明抗虫品种宁梗1号、淮稻9号叶片表面的硅含量显著高于感虫品种,硅颗粒大小在品种间无显著差异。宁粳1号叶片蜡质含量显著高于其他品种。由此表明叶片表面硅和蜡质含量与抗性有关。稻纵卷叶螟幼虫取食后,抗虫品种体内的过氧化物酶（POD）、超氧化物岐化酶（SOD）活性显著高于感虫品种,但丙二醛(MDA)含量低于感虫品种。稻纵卷叶螟幼虫取食不同品种后,其体内一些酶的活性明显不同,取食抗虫品种的幼虫体内POD和谷胱甘肽-S-转移酶(GST)活性显著高于取食其他品种的幼虫,SOD活性显著低于取食感虫品种的幼虫, 表明抗虫品种对稻纵卷叶螟幼虫有毒害作用。     

海南中南部地区旱稻(山兰稻)种质资源及保育模式

山兰稻是一类适应性很强的旱稻品种,对于开发节水性高产稻种具有重要意义。该研究调查了海南中南部地区山兰稻种质资源的组成,并选种5个山兰稻品种开展其农艺性状和生产性状的研究,以期了解山兰稻种质资源在该地区的分布及生产现状,并进一步为其保护模式提供理论基础。结果表明:调查共获得38份山兰稻种质资源,含25个品种,主要分布在保亭、琼中和五指山三个市县,在现有的品种中约有45.0%在种植利用。因此,山兰稻品种资源面临濒危,亟需保护;这25个品种可分为籼稻和粳稻2个类型,共聚成6个类群,不同区域间的种质资源具有亲缘性,其中3个独立聚集的品种有明显区域性分布的特征;5个品种容易种植,生产性状较一致,其全生育期约为138 d,与历史栽培记录时间一致,遗传特性稳定,单位产量为2.0~2.8t·hm-2,平均产量为2.4 t·hm-2。综上说明保护山兰稻品种的成本和技术难度不高,但其育种和栽培技术还需要进一步研究,种质资源的开发模式应结合生态保护、品种保育、社会需求等多角度进行综合考虑。     

抗花叶病烟草种质资源的鉴定与筛选

本研究以不同来源、不同类型的46个烟草品种为试验材料,进行抗烟草普通花叶病（TMV）特性的田间鉴定和分子鉴定,为筛选抗病烟草种质奠定基础。结果表明,22个品种的烟草抗TMV特性田间鉴定结果与前人鉴定结果基本相同,从24个前人未鉴定的烟草品种中初步筛选出14个中抗品种,8个中感品种和2个感病品种;通过抗TMV基因（CN）的特异引物进行扩增,36个烟草品种的基因组DNA具有特异性片段;通过分子鉴定和田间鉴定的结果比较,62.9%的具有CN或其同源基因的烟草品种田间鉴定表现为中抗或高抗,83.3%的具有CN或其同源基因的选育烟草品种田间鉴定表现为中抗或高抗;结合两种方法,初步确定了3个中感品种和11个中抗品种。     

不同甘蓝型油菜及其F1硼效率差异与单糖的关系

在硼高效甘蓝型油菜品种及杂交种中 ,单糖的种类比低效品种多 ;除果糖外 ,其绝对含量也远高于低效品种。果糖和甘露糖能与硼反应形成硼糖络合物 ,在硼高效品种及其杂交种中 ,甘露糖的相对含量和绝对含量都高于低效品种 ,尽管在低效品种和杂交种中果糖的含量比高效品种高 ,但果糖含量低 ,起主导作用的仍是甘露糖 ,这种差别很可能是导致硼效率差异的原因之一。     

DNA导入和系选大豆品种及其亲本遗传关系的SSR标记分析

利用现有品种的变异进行系选并培育新品种是一种重要的育种方法。利用SSR标记, 对系选大豆(Glycine max)新品种和其亲本的遗传组成进行分析, 明确二者的遗传关系, 为大豆系选育种提供依据。使用48对SSR引物对22个大豆品种及其亲本进行分析, 结果表明, 由外源DNA导入育成的3个品种与其亲本的一致性为35.42%–95.83%, 虽然供体相同, 但由于导入的外源DNA不同, 故育成的品种间差异很大。另外19个系选品种与其亲本的一致性为27.08%–89.58%, 其中有6个品种与亲本间的差异小于30%。聚类分析发现, 所有参试品种分为东北春大豆及黄淮和南方大豆2类, 其中有8个品种不能与其亲本聚在一起, 说明系选品种并不完全是由于亲本通过突变获得。此外, 农艺性状与分子标记分析结果差异较大, 说明利用有限的农艺性状评价品种间的遗传关系存在一定的局限性。通过比较系选品种和亲本之间的保守位点发现, 特定等位变异出现次数≥7的位点有14个, 分布在11个连锁群, 其中有7个位点与产量和抗病性等重要农艺性状有关, 说明DNA导入和系选品种在选择变异性状的同时, 使一些与重要农艺性状有关的等位变异得到了保留。     

冷胁迫诱导、咖啡因抑制的水稻根新基因片段的分离及表达分析

利用差异显示（Differential display）及H.Y-Yellow琼脂糖凝胶分离等方法,从冷胁迫和甘露醇共同处理的冷敏感水稻（Wase toitsu）根的总RNA中,分离出冷胁迫诱导的cDNA片段,经过测序和同源比较,发现它是一尚未报道的新基因片段。这一基因的表达对温度具有敏感的反应特性,4℃时表达水平明显增加,在正常温度（25℃）下,其表达水平又可快速降低。当幼苗根用0.5mol/L甘露醇预处理2h后,转入冷胁迫,其低温诱导的表达水平增加更为明显。在甘露醇预处理之前加入咖啡因处理根1h,其表达水平明显降低,几乎与正常温度下的对照相同。据此推测,这一基因可能参与了冷胁迫或水分胁迫诱导的耐冷过程中咖啡因敏感信号的传导。      

Chilling-Induced Heat Evolution in Plants

Increases in respiration, particularly via the alternative pathway, are observed in response to chilling. These increases result in increased heat evolution. We have measured increases in heat evolution in response to chilling in a number of plant species using a microcalorimeter. After 8 h of exposure to 8[deg]C, heat evolution in a variety of chilling-sensitive species increased 47 to 98%. No increase in heat evolution was seen with the extremely chilling-sensitive ornamental Episcia cupreata Hook. Heat evolution increased only 7 to 22% in the chilling-resistant species. Increases in heat evolution were observed when plants were chilled in constant light or in the dark, but not when plants were chilled at high humidity. Increased capacity to produce respiratory heat after exposure to chilling temperatures may contribute to the cold-acclimation process.     

低温弱光胁迫对野生大豆和大豆栽培种光系统功能的影响

以野生大豆和栽培大豆为材料,通过同时测定大豆叶片的叶绿素荧光快速诱导动力学曲线和对820nm光的吸收曲线,以及测定超氧化物歧化酶（SOD）和抗坏血酸过氧化物酶（APX）的活性,分析了低温弱光胁迫及常温弱光恢复下这2种大豆光系统Ⅱ（PSⅡ）和光系统Ⅰ（PSI）功能的变化。结果表明,低温弱光胁迫对这2种大豆的PSI和PSⅡ的功能都造成伤害;在低温弱光胁迫下,维持较高的SOD和APX活性和维持PSI和PSⅡ的协调性是野生大豆比栽培大豆耐低温的一个重要原因。     

Role of the Aquaporin PIP1 Subfamily in the Chilling Tolerance of Rice

Although an association between chilling tolerance and aquaporinshas been reported, the exact mechanisms involved in this relationshipremain unclear. We compared the expression profiles of aquaporingenes between a chilling-tolerant and a low temperature-sensitiverice variety using real-time PCR and identified seven genesthat closely correlated with chilling tolerance. Chemical treatmentexperiments, by which rice plants were induced to lose theirchilling tolerance, implicated the PIP1 (plasma membrane intrinsicprotein 1) subfamily member genes in chilling tolerance. Ofthese members, changes in expression of the OsPIP1;3 gene suggestedthis to be the most closely related to chilling tolerance. AlthoughOsPIP1;3 showed a much lower water permeability than membersof the OsPIP2 family, OsPIP1;3 enhanced the water permeabilityof OsPIP2;2 and OsPIP2;4 when co-expressed with either of theseproteins in oocytes. Transgenic rice plants (OE1) overexpressingOsPIP1;3 showed an enhanced level of chilling tolerance andthe ability to maintain high OsPIP1;3 expression levels underlow temperature treatment, similar to that of chilling-tolerantrice plants. We assume that OsPIP1;3, constitutively overexpressedin the leaf and root of transgenic OE1 plants, interacts withmembers of the OsPIP2 subfamily, thereby improving the plants’water balance under low temperatures and resulting in the observedchilling tolerance of the plants.     

Electrical resistance changes during exposure to low temperature measure chilling and freezing tolerance in olive tree (Olea europaea L.) plants

Electrical resistance changes in different organs of four olive tree (Olea europaea L.) varieties, characterized by different tolerance to chilling and freezing, were examined, during exposure to low temperature. Apparent critical temperatures (CT) and freezing temperatures (T_fr) were identified on the basis of the electrical resistance changes. Both temperatures were lower for the more chilling‐tolerant genotypes. From the apparent critical temperatures, the absolute critical temperature (CT_abs) and the time delay of the chilling signal transduction process were calculated. In shoots, CT_abs varied from 8·8 °C for Ascolana (chilling‐tolerant variety) to 13·6 °C for Coratina (chilling‐sensitive variety). The magnitude of the transduction time was very similar (about 2 min) for the three genotypes that are more sensitive to chilling, whereas it was significantly higher (about 3 min) for the most tolerant genotype. Different freezing temperatures were observed for different organs. It would appear from this experiment that the order of sensitivity is roots > leaves > shoots > vegetative buds. Accord was found between the absolute critical temperature of electrical resistance and the critical temperature of membrane potential. The occurrence of electrical resistance changes in the tissues of the olive trees exposed to low temperature suggests the use of this experimental procedure as a quick, easy and non‐destructive tool to screen plant tissues for chilling tolerance. The strong dependence of the electrical resistance on low temperature, and the critical temperature of around 10 °C, can yield interesting information about the lowest thermal limits for the continuation of normal physiological processes and therefore about the adaptability of plants to particular environments.     

Nuclear Deoxyribonucleic Acid Metabolism and Membrane Fatty Acid Content Related to Chilling Resistance in Germinating Cotton (Gossypium barbadense)

Chilling damage was examined in the chilling-sensitive plant Gossypium barbadense. Between 30 and 36 h of germination at 34°C, the seedlings are extremely sensitive to temperatures below 10°C. The initiation of chilling damage by exposure to 2°C for 5 h during the sensitive period resulted in a large reduction in DNA synthesis. The reduction was correlated with a reduced efficiency of nuclear DNA polymerase activity. Comparing a more chilling resistant genotype to a more sensitive variety indicated that the resistant genotype nuclear DNA polymerase activity is more efficient when exposed to a chilling stress. Resistance was also correlated with a higher degree of unsaturated fatty acid content in the nuclear membranes of the resistant variety.     

Lipids in rye seedlings in relation to vernalization

Increasing the chilling time from 1 to 8 weeks decreased the time to heading of winter rye (Secale cereale var. Sangaste) to approximate that of the spring variety (Prolific). On a dry weight basis, the total phospholipid content of the embryos was higher in Sangaste but declined in both varieties during chilling. The proportions of the individual phospholipid components were similar for both varieties and showed similar responses during the 8-week chilling period. Phosphatidylcholine declined and phosphatidic acid increased in both varieties during the treatment.     

Temperature and chemical shocks induce chilling tolerance in germinating Cucumis sativus (cv. Poinsett 76) seeds

Roots of 24-h-old germinated cucumber ( Cucumis sativus cv. Poinsett 76) seeds were subjected to thermal and chemical stresses, equilibrated at 25°C for 2 h and chilled at 2.5°C for 96 h. The germinated seeds were then held at 25°C for 72 h after they were chilled and the elongation of the primary root was used as a measure of chilling tolerance. Control roots elongated from an initial length of 0.2 cm to a final length of 6.3 cm at the end of 72 h. while chilled roots elongated to a final length of only 0.4 to 0.6 cm. Exposure to 0.4 M ethanol for 4 h or to 40°C for 1 h induced substantial chilling tolerance and the roots had a final length of 4.1 and 3.1 cm. respectively. Exposure to 7.5°C for 3 h conferred less chilling tolerance (elongation to 1.4 cm). while exposure to other chemicals (i.e. aqueous solutions of Ca(NO₃)₂, mannitol. methanol and NaCl) produced less, though still significant increases in chilling tolerance. A more severe chilling treatment of 144 h at 2.5°C was required to consistently induce elevated rates of ion leakage. Only the heat and the ethanol shock treatments significantly reduced chilling-induced ion leakage. Inclusion of the protein synthesis inhibitor cycloheximide negated the protective effects of these shock treatments. It appears that de novo protein synthesis is required for induction of chilling tolerance by a variety of chemical and thermal shock treatments.     

Stomatal behaviour and cuticular properties of maize leaves of different chilling-resistance during cold treatment

Stomatal behaviour and the amount and synthesis of epicuticular waxes were studied in maize leaves of various degrees of chilling resistance in order to investigate the rapid desiccation characteristic of chilling injury. In contrast to the resistant variety (KSC 360), the sensitive line (Lye) failed to close the stomata during chilling treatment. Both, the amount of epicuticular waxes and their degree of labeling by 1-14C-acetate were much higher in the resistant than in the sensitive leaves. Chilling-sensitivity was also related to a suppressed conversion of free fatty acids into free primary alcohols.     

茄子种质资源的耐冷性鉴定

采用低温胁迫下幼苗叶片冷害指数、种子活力指数、叶片电导百分率为指标,对34份不同类型的茄子种质资源进行耐冷性鉴定.结果表明,活力指数与冷害指数、电导百分率均呈极显著负相关,电导百分率与冷害指数呈极显著正相关.通过耐冷隶属函数值和聚类分析,初步筛选出11份耐冷性较强的材料.