感染赤霉病菌后小麦穗组织蛋白的氧化交联

为探究细胞壁组成蛋白在抗赤霉病中的作用，对接种赤霉病茵后小麦抗、感品种穗组织中离子结合型蛋白进行了分析。样品过氧化物酶比活力测定结果显示，高抗品种苏麦3号和望水白在接种赤霉病茵孢子后的6d内，过氧化物酶(POD)比活力明显高于对照，中抗品种扬麦158比对照也略有增加，而感病品种宁麦6号和安农8455则与对照无差异。用凝胶层析的方法分析了抗赤霉病程度不同的5个小麦品种穗组织盐溶成份。结果表明，2个高抗品种在接种病原物或过氧化氢处理后．洗脱体积为8ml的蛋白质(P8)的吸收峰明显增高．而在感病品种中P8蛋白变化不明显。高抗品种的对照样品在过氧化氢水浴(35℃)处理后，P8峰有所提高，表现出与赤霉病茵接种处理一致的趋势。     

Differences in leaf yield and indigo precursors production in woad (Isatis tinctoria L.) and Chinese woad (Isatis indigotica Fort.) genotypes

Isatis tinctoria L. (woad) is one of the earliest known sources of indigo in Europe where it was cultivated since the Middle Ages. Isatisindigotica Fort. (Chinese woad), widely distributed in China, had been used from ancient times as indigo-producing plant and medicinal plant. Both species produce indigo precursors indican (indoxyl β-d glucoside) and isatan B (indoxyl ketogluconate) in their leaves. In order to identify new suitable crops for indigo production in Italy, 17 woad lines were studied under field conditions in Central Italy (Pisa, 43°40′N, 10°19′E) from 2001 to 2003. We analyzed the effects of year, genotype, and harvest times together with their reciprocal interactions on leaf yield and indigo precursors production. Woad lines were then compared with seven I. indigotica lines in a field crop experiment set up in 2003. Extraction and quantification of indigo precursors were accomplished by HPLC-ELSD. Isatan B and indican content, as well as equivalent indigo and fresh/dry leaf yield, were compared between species and among genotypes.     

A multi-gene phylogeny for species of Mycosphaerella occurring on Eucalyptus leaves

Species of the ascomycete genus Mycosphaerella are regarded as some of the most destructive leaf pathogens of a large number of economically important crop plants. Amongst these, approximately 60 Mycosphaerella spp. have been identified from various Eucalyptus spp. where they cause leaf diseases collectively known as Mycosphaerella Leaf Disease (MLD). Species concepts for this group of fungi remain confused, and hence their species identification is notoriously difficult. Thus, the introduction of DNA sequence comparisons has become the definitive characteristic used to distinguish species of Mycosphaerella. Sequences of the Internal Transcribed Spacer (ITS) region of the ribosomal RNA operon have most commonly been used to consider species boundaries in Mycosphaerella. However, sequences for this gene region do not always provide sufficient resolution for cryptic taxa. The aim of this study was, therefore, to use DNA sequences for three loci, ITS, Elongation factor 1-alpha (EF-1α) and Actin (ACT) to reconsider species boundaries for Mycosphaerella spp. from Eucalyptus. A further aim was to study the anamorph concepts and resolve the deeper nodes of Mycosphaerella, for which part of the Large Subunit (LSU) of the nuclear rRNA operon was sequenced. The ITS and EF-1α gene regions were found to be useful, but the ACT gene region did not provide species-level resolution in Mycosphaerella. A phylogeny of the combined DNA datasets showed that species of Mycosphaerella from Eucalyptus cluster in two distinct groups, which might ultimately represent discrete genera.     

河南71个重要小麦生产品种的抗叶锈性鉴定

为给防治中国小麦叶锈病和培育抗叶锈病小麦品种奠定基础,本研究以36个携带已知抗病基因的载体品种和71个河南主栽小麦品种为材料,在苗期接种16个小麦叶锈菌生理小种进行基因推导,并利用系谱分析和分子标记检测对推导结果进行验证,于2014－2015年度在河北保定小麦试验田及2014－2015和2015－2016两年度在河南周口黄泛区农场进行田间成株期抗叶锈性鉴定。结果发现,71个河南小麦品种中,36个品种在苗期共鉴定出7个抗叶锈病基因（ Lr1 、 Lr2b 、 Lr10 、 Lr26 、 Lr17 、 Lr34 和 Lr39 ）,其中27个品种含有 Lr26 ,4个品种含有 Lr39 ,2个品种含有 Lr10 ,含有 Lr1 和 Lr17 的品种各有8个,含有 Lr2b 和 Lr34的品种各有1个。成株期抗叶锈性鉴定结果表明,仅有7个品种具有成株期慢锈性,可能含有成株期抗性基因,可进一步用于培育抗叶锈病品种和抗叶锈病基因的合理布局。     

剑麻叶片纤维细胞形态结构差异分析

观察分析剑麻叶片纤维细胞形态结构特征,及明确取样部位,为深入研究剑麻纤维细胞发育机制及形态提供基础性和实验性的参考。根据剑麻叶片及植株植物学特征确定取样部位,利用透射电镜（TEM）观察2个生长时期成熟叶片的不同区域和3个成熟度叶近轴端纤维细胞形态结构的差异。由电镜图片可知,剑麻不同生长时期叶片的中部和近轴端纤维细胞紧密相连、大小不一,但叶片中部区域多为不含原生质体的细胞壁结构,而近轴端细胞中存在含有细胞器的原生质体。进一步观察了3个成熟度叶片近轴端的纤维细胞形态,发现叶片纤维细胞中的各种细胞器被液泡挤压到细胞边缘,叶绿体为最突出的细胞器。幼年叶和成熟叶中的叶绿体多呈梭形,外膜完整,可见较清晰的片层结构和垛叠区,稚嫩叶的细胞中叶绿体出现皱缩及片层结构排列较紊乱,线粒体肿胀,胞浆内出现空泡,存在细胞核中异染色质增多和质壁分离的现象。综合分析图像信息推测,剑麻叶片纤维细胞生长发育活跃部位位于叶片近轴端,是观察剑麻纤维细胞结构的理想区域。     

低温胁迫对2种主要砧穗组合砂糖橘幼树抗寒性的影响北大核心CSCD

【目的】探究广东肇庆主要使用的2种砧木对砂糖橘(Citrus reticulata‘Shatangju’)抗寒性的影响,为优化其引种栽培和苗木繁育提供科学支撑。【方法】以枳壳[Poncirus trifoliata(L.)Raf.]砧、酸橘(C.sunki Hort.exTanaka)砧3年生砂糖橘为试材,在人工气候室中48 h内从10℃梯次降温至(3±0.5)℃、(-3±0.5)℃分别胁迫24 h,然后,经48 h梯次升温至10℃,24 h后转移至塑料温室中常规栽培90 d,期间调查测定落叶量、生长量、生物量,定期测试分析抗寒生理特性。【结果】在(3±0.5)℃、(-3±0.5)℃胁迫后栽培的90 d中,砂糖橘酸橘砧植株单株落叶数量减小幅度较枳壳砧植株分别大412.2%、134.5%,落叶质量减小幅度较枳壳砧植株分别大546.6%、1098.0%;胁迫后90 d酸橘砧植株株高降低幅度较枳壳砧植株分别大5.0%、16.3%,地径减小幅度较枳壳砧植株分别大75.0%、8.8%,冠幅减小幅度较枳壳砧植株分别大231.6%、52.2%,全株生物量减小幅度较枳壳砧植株分别大465.4%、45.6%。(3±0.5)℃、(-3±0.5)℃胁迫后90 d,酸橘砧植株叶片叶绿素含量(Chl c)降低幅度较枳壳砧植株分别大101.1%、27.0%,光合速率(Pn)降低幅度分别大65.8%、52.2%,叶片蒸腾速率(Tr)升高幅度较枳壳砧植株分别大44.1%、99.9%,叶片气孔导度(Gs)升高幅度较枳壳砧植株分别大41.3%、39.7%。低温胁迫导致砂糖橘叶片碳同化关键酶(Rubisco)、FBP、Ald及PEPC的活性均较同期对照显著降低,叶片水分饱和亏缺(WSD)显著加重、丙二醛(MDA)含量显著升高,枳壳砧植株的变化幅度显著小于酸橘砧植株。【结论】砂糖橘枳壳砧植株抗寒性显著强于酸橘砧植株,其机制主要在于低温胁迫下落叶程度轻,根系较发达,叶片较厚重,光合效率较高,叶片抗脱水、抗膜脂过氧化能力强。     

喂食桑叶粉对黄粉虫生长发育情况的影响

为了降低饲养黄粉虫经济成本,提高桑叶利用率,以不同比例的桑叶粉添加入黄粉虫饲料,探讨桑叶粉添加对黄粉虫幼虫生长发育及体内粗蛋白、粗脂肪、水分等的影响。饲料中桑叶粉添加量小于25%时,可促进黄粉虫幼虫体重增长和缩短幼虫生长周期,桑叶粉添加量超过25%会抑制其生长发育。其中,添加7.5%比例桑叶粉可显著提高黄粉虫幼虫体重和粗蛋白含量,降低其体内粗脂肪的含量。饲料中添加桑叶粉不影响黄粉虫幼虫水分含量。适量添加桑叶粉能促进黄粉虫幼虫生长发育、粗蛋白的积累,但不利于体内粗脂肪的积累。     

不同采收方式对烤烟上部叶片生长及烟碱含量的影响

2005年在长沙以K326为材料研究了一次性采收和分次采收方式对烤烟上部叶生长和烟碱含量的影响，结果表明：不同采收处理对烤烟上部烟叶的生物学特性有一定的影响，同时对烟碱在不同叶位上的积累也有着一定的调控作用。上部烟叶采收次数的增加和留叶数的减少不利于对上部烟叶烟碱的控制，而烤烟上部6叶整体一次性采收，能有效地控制上部烟叶尤其是顶叶烟碱含量过高的问题。     

灌溉对春小麦蒸腾速率的影响及其生理原因

为了揭示灌溉对小麦蒸腾作用的影响及其与其他因子的相互关系，我们采用英国PPS公司CIRAS-1型光合作用综合测定仪测定了春小麦孕穗期不同灌溉量的蒸腾速率、净光合速率、气孔阻力等因子的日变化，同时测定了小麦叶温、有效辐射、气温、湿度和田间微环境风速。研究结果表明，不同灌溉量与春小麦叶片蒸腾速率关系密切。在900m^3/hm^2以下，随灌水量的增加，春小科叶片蒸腾速率明显增大。在影响叶片蒸腾速率的诸要素中，光合有交辐射、叶温、水汽压差和气孔导度对叶片蒸腾速率都存在一定的相互联系和规律。叶片蒸腾速度与细胞内外水汽压差存在着相关关系，与气孔阻力呈显著负相关。本研究可为春小麦节水灌溉提供理论依据。     

Effect of nitrogen and sulphur fertilizers and seed inoculation with rhizobium phaseoli on the nitrogen‐sulphur relationships of bean (phaseolus vulgaris L.)

A greenhouse experiment with beans (Phaseolus vulgaris L.) was performed in order to investigate the effect of nitrogen and sulphur application and seed inoculation on the yield, leaf area, distribution of different nitrogen and sulphur fractions and N/S ratio in shoot, fruit and root.

Inoculation of plants together with nitrogen or sulphur application produces an increase in the concentration of total nitrogen and a decrease in the accumulation of nitrate‐nitrogen and sulphate‐sulphur in shoot, fruit and root. Leaf area increased more with nitrogen than with sulphur application while the highest amounts of fruit dry matter were obtained with sulphur application.

N: S ratios obtained were different according to the part of the plant tested. Sulphur fertilization decreased the N: S ratios in shoot, fruit and root. The data obtained indicate that and adequate N: S ratio can insure maximum production of yield.