低浓度蔗糖对黄瓜下胚轴不定根发生有诱导作用

试验比较了低浓度(1 g·L-1)与高浓度(5～50 g·L-1)蔗糖对黄瓜不定根发生的作用.结果表明:不同浓度的蔗糖对植株不定根发生的影响差异显著,低浓度蔗糖能明显促进黄瓜下胚轴切段不定根发生,而高浓度蔗糖则不同程度抑制不定根的发生.     

蔗糖浸种缓解玉米幼苗铜胁迫及其生理指标的灰色关联分析

为探究蔗糖浸种缓解玉米幼苗铜胁迫的能力,采用浸种法研究了342.3 mg·L^-1蔗糖浸种处理对0、100、200、400 mg·L^-1硫酸铜处理玉米幼苗生理生化指标的影响,并进行生理生化指标与玉米铜胁迫恢复指数的灰色关联分析。结果表明,蔗糖浸种可显著提高一定程度铜胁迫下玉米幼苗的株高、根长、相对根长、相对株高、过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性。生理生化指标与蔗糖处理对铜胁迫恢复指数的灰色关联度排序为:相对根长(0.799)>相对株高(0.775)>根长(0.767)>脯氨酸含量(0.749)>POD活性(0.740)>可溶性蛋白含量(0.699)>可溶性糖含量(0.673)>CAT活性(0.664)>叶绿素含量(0.647)>SOD活性(0.601)>株高(0.579)。综上可知,蔗糖浸种在一定程度上能有效缓解玉米幼苗的铜胁迫,抗性鉴定时选择相对根长、相对株高、根长、脯氨酸含量、POD活性、可溶性蛋白含量、可溶性糖含量、CAT活性等强关联指标可以提高选择效率,这为玉米抗性育种提供了参考。     

Effect of High Temperature on Sucrose Content and Sucrose Cleaving Enzyme Activity in Rice Grain During the Filling Stage

Global warming is due to continuous increase in greenhouse effect caused by human productive activities. Much attention has been paid to the influence brought by the increase of temperature on crop growth. Many researches in China and other countries are …     

两种冻干保护剂在禽病疫苗生产中的效果比较

试验证明，含１％的明胶和５％蔗糖液与含５％蔗糖牛奶作鸡新城疫弱毒冻干疫苗和鸡传染性支气管炎弱毒冻干疫苗的冻干保护剂，其免疫效果是相同的，即明胶蔗糖保护剂可以代替蔗糖牛奶保护剂，从而可降低生产成本     

Role of <Emphasis Type="Italic">Cacopsylla pyri</Emphasis> in the epidemiology of pear decline in Spain

The frequency of pear decline-positive insects and transmission of pear decline (PD) phytoplasma by Cacopsylla pyri in Spain has been studied. Psyllids were used for experiments on phytoplasma transmission both to healthy Pyrus communis trees and to an artificial feeding medium. Over a period of 1 year, about 100 psyllids were collected monthly from pear trees, cv. Williams, using the beating tray method, and tested for the presence of PD phytoplasma. Results indicate that the frequency of PD positive psyllids changes through the year and that C. pyri transmits the pear decline associated disease agent. Phytoplasma transmission was also effective under laboratory conditions using a feeding medium. The relationship between PD positive Cacopsylla pyri, Pear decline phytoplasma transmission and the sex of the vector was also evaluated. Although the percentage of PD positive psyllids was similar in both genders, PD phytoplasma transmission by females was significantly higher than by males. Since the sex ratio (male/female) was less than 1:1 for most of the year, these results should be taken into consideration for controlling Pear decline in Mediterranean climates.     

橡胶树‘热研7-33-97’和‘PR107’胶乳和树皮中蔗糖代谢相关的酶活与基因表达研究

对2个产胶水平差异明显的橡胶树品种（‘热研7-33-97’和‘PR107’）产胶旺季时2个与产胶直接相关的碳库（胶乳和茎干树皮）中蔗糖代谢相关的酶活、基因表达以及胶乳生理参数、树皮非结构性碳水化合物（NSC）含量进行了比较研究。结果表明：‘PR107’干胶产量的季节性变动明显大于‘热研7-33-97’,但均在9月底出现一个产胶高峰;2个品种胶乳的总固形物、无机磷和蔗糖含量差异不明显,但‘热研7-33-97’的干胶含量显著高于‘PR107’;树皮NSC的主要成分为可溶性糖（占80%以上）,但品种间的NSC及其相关组分（淀粉、可溶性糖和还原性糖）的差异均不显著;胶乳中,蔗糖合成酶（Sus）主要催化蔗糖合成,品种间的中碱性转化酶（NIN）和Sus酶活差异均不显著;树皮中,‘热研7-33-97’的NIN酶活显著大于‘PR107’,而其他蔗糖代谢相关酶活品种间的差异不显著;在胶乳中,HbSWEET10a基因的表达量高,并且‘热研7-33-97’>‘PR107’,还是唯一在品种间表达显著差异的蔗糖代谢相关基因;在树皮中,‘PR107’的HbSus3和细胞壁转化酶基因HbCIN2的表达显著高于‘热研7-33-97’,HbSUT5显著低于‘热研7-33-97’,而其他4个蔗糖代谢相关基因的表达在品种间差异不显著。本研究结果为深入探究蔗糖代谢调控与胶乳再生的互作奠定了基础。     

Early Influence of Wood Ash Application on the Carbohydrate Reserves and Composition in Needles of Scots pine {Pinus sylvestris)

Abstract

Wood ash treatment can probably increase forest productivity on low fertility sites. However, the resulting effect on the carbohydrate concentration as the main carbon and energy reserve in trees is little studied. In 2000, a square of 0.1 ha sandy soil below a 19-year-old Scots pine (Pinus sylvestris) plantation was treated with raw fly ash (0.5 kg.m^-2); untreated square was used as control. One year after the treatment, carbohydrates (glucose, fructose, sucrose, maltodextrins, starch and excess bound fructose) were analyzed enzymatically from current-year and one-year-old needles. The ratio K/N in needles suggested an improved balance between these elements in treated trees, in which the K concentration was higher. The largest relative differences (50% of control) were observed in glucose and fructose in summer. The squares did not differ in the concentration of the accumulated carbohydrate reserves in needles during low temperature stress in winter and before the growth of new shoots in spring. During the vegetation period decreased levels of soluble carbohydrates and starch were observed (max 70% of the control value around 100 mg total carbohydrates g^-1 dry mass). Because the experiment was designed without true replicates, reasons for the observed differences require further study.     

人工合成六倍体小麦苗期氮、糖代谢关键酶基因的表达

以人工合成异源六倍体小麦为材料,采用RT PCR技术,对六倍体小麦多倍化初期氮、糖代谢关键酶基因（GS1、GS2、G6PD H 、S PS）的表达情况进行了研究。结果表明,六倍体小麦 GS1基因表达水平较其双亲中值（MPV）显著升高,GS2基因表达水平与其亲本基本一致,而 G6PDH基因和S PS基因表达水平较其M PV出现了不同程度的降低。     

糖、硼、钙对大喇叭杜鹃四合花粉萌发的影响

以大喇叭杜鹃（Rhododendron excellens）为研究对象,研究了蔗糖、硼酸及CaCl2单因子及正交试验对其四合花粉萌发和花粉管生长的影响。结果表明,蔗糖、硼酸和CaCl2及3因子交互效应对大喇叭杜鹃的四合花粉萌发率、单花粉粒萌发数量及单花粉粒花粉管长度均有显著影响;最适蔗糖、硼酸和CaCl2溶液浓度分别为80g/L、100mg/L、80mg/L;正交试验的最佳配方组合是：80g/L蔗糖＋50mg/L H3BO3＋40mg/L CaCl2。