生长延缓剂对槟榔苗期叶绿素含量与叶绿素荧光参数的影响

为探讨生长延缓剂对槟榔苗期矮壮的光合特性。于2006年6-11月以移栽45天后海南槟榔为材料,通过喷施250mg/L与500mg/L多效唑、40mg/L和80 mg/L烯效唑及清水5个处理,研究其对槟榔苗期叶绿素含量及叶绿素荧光参数的影响。结果表明：喷施多效唑与烯效唑均能显著增加苗期槟榔叶绿素含量,且使叶绿素荧光参数Fv/Fo,Fv/Fm,qP显著增加,而降低qN、NPQ非光化学猝灭系数,并以250mg/L多效唑处理效果较明显。说明适当浓度的多效唑处理可增加PSII反应中心开放比例,推动光合电子传递,提高槟榔叶片光合性能,起到壮苗目的。     

中国“槟榔黄化病”研究40年——病原、防控措施新进展

自1981年海南省屯昌县首次发现槟榔黄化病（yellow leaf disease of areca palm, YLD）以来,槟榔黄化问题日趋严重,现已成为制约中国槟榔产业可持续发展的最重要的因素。同时,鉴于生产中除槟榔黄化病外,炭疽病、细菌性叶斑病、椰心叶甲、干旱等一些其他因素也可引起槟榔黄化,以及“槟榔黄化病”病原或病因认识上存在混淆的问题,学界暂用“槟榔黄化现象”的表述。近年来,针对上述问题开展了一系列深入研究并取得突破性进展。本文首先简要回顾了中国槟榔黄化病的发生及病原方面的研究进展,介绍了另一种致黄关键新病害——由槟榔隐症病毒1（Areca palm velarivirus 1, APV1）引起的槟榔黄叶病毒病（areca palm leaf yellowing virus disease, ALYVD）,以及其他2种新发现的病毒病害——槟榔坏死环斑病毒病和槟榔坏死环斑病毒病的研究进展。对6个示范基地的病原检测结果表明,部分黄化植株被槟榔黄化植原体（areca palm yellow leaf phytoplasma, AYLP）或APV1单独感染,部分植株被AYLP和APV1复合感染。本文还探讨了槟榔黄化病研究中存在的病原分布不均、含量低引起的检测困难和田间诊断易混淆等问题,并对YLD、ALYVD、叶斑类病害、根腐病害、芽腐病、椰心叶甲、干旱、寒害、除草剂药害等9类因子引起的黄化症状特征进行了总结。进而分析了YLD和ALYVD 防控中存在的问题以及现阶段面临的紧迫形势,从防控策略和具体措施解读了《槟榔“黄化病“防控明白纸》,并指出了其有待进一步完善之处及防控中亟待解决的问题。最后,展望了YLD和ALYVD 2种致黄关键病害综合防控中亟待实施的措施。本文旨在让广大科研工作者和农技人员更好地了解槟榔“黄化病”方面的最新成果。     

Domestication of Irvingia gabonensis: 3. Phenotypic variation of fruits andkernels in a Nigerian village

Domestication of Irvingia gabonensis, a fruit tree grown in agroforestry systems in West and Central Africa, offers considerable scope for enhancing the nutritional and economic security of subsistence farmers in the region. Assessments of phenotypic variation in ten fruit, nut and kernel traits were made on twenty-four ripe fruits from 100 Irvingia gabonensis trees in Ugwuaji village in southeast Nigeria, a center of genetic diversity for this species. There were important differences between the young planted trees of this study and the older unplanted trees of a similar study in Cameroon. Significant and continuous tree-to-tree variation was found in fruit mass(69.0–419.8 g), flesh mass (59.5–388.8 g), nut mass (9.5–40.6 g), shell mass (4.9–30.9 g) and kernel mass (0.41–7.58 g); fruit length (49.2–89.3 mm) and width (46.2–100.5 mm) and flesh depth (12.9–31.4 mm), as well as considerable variation in flesh colour, skin colour, fruit taste and fibrosity. Some fruits were considerably bigger than those found in Cameroon. These quantitative results will help in the development of cultivars within participatory approaches to agroforestry tree domestication, and so promote poverty alleviation and sustainable agriculture. This revised version was published online in June 2006 with corrections to the Cover Date.     

空气湿度对澳洲坚果开花座果和果实生长的影响

花期的澳洲坚果植株随着空气湿度的降低,其花粉育性降低、座果率及光合产物(叶绿素含量、总糖含量和淀粉含量)下降、幼果生长速度减慢。试验结果表明:空气湿度的降低导致叶片光合作用能力下降,干物质积累少,生物产量降低,花粉萌发率低、花粉管生长速度慢,造成花期不遇、授粉受精不良、座果率低,最后造成产量降低。不同品种受空气湿度胁迫的影响程度不同,品种的内部生理特性、花粉育性以及产量都存在差异。澳洲坚果生长的适宜空气湿度为日平均空气湿度在50%以上。     

含铜氮配键腰果酚醛缩聚物的特性及表征

腰果酚醛树脂中含有较活泼的酚羟基，略显酸性，易受碱的腐蚀。先由共缩聚法得到以苯胺改性的腰果酚醛缩聚物，再使之与CuCl2反应，合成含铜一氮配键腰果酚醛缩聚物。用IR、动态粘弹谱(DMTA)、TG和其他手段对产物的结构和理化性能进行表征。结果表明，金属铜离子与苯胺分子中氮原子形成配位健，增大了涂膜内部的交联度，使分子链间形成更大的网状结构。因此，含铜-氮配键腰果酚醛涂膜的物理机械性能、热稳定性、耐化学介质尤其是耐碱性能得到很大的改善。     

旱坡地不同植苗处理对澳洲坚果定植成活率的影响

为解决贵州南亚热区冬春季干旱澳洲坚果植苗成活率低、种苗浪费严重、建园成本高等问题,以澳洲坚果Hinde(H2)嫁接苗为试验材料,采用田间试验方法研究了植苗时间、植苗方法和苗木类型对澳洲坚果植苗成活率的影响。结果表明:用2年生营养袋苗于9月采用树盘作集水盘浇定根水加覆盖地膜方法植苗,苗木成活率可达94%以上。该方法建园植苗成活率高,可有效降低新建园生产成本,提高嫁接苗利用率。     

PVX病毒载体介导2种马铃薯Y病毒科病毒VPg蛋白表达诱导烟草叶片系统坏死的研究

芜菁花叶病毒(Turnip mosaic virus,TuMV)和槟榔坏死环斑病毒(Areca plam necrotic ringspot virus,ANRSV)是马铃薯Y病毒科(Potyviridae)中分别可诱导十字花科作物和槟榔产生坏死病症的2种不同属病毒.VPg(Viral protein genome l...     

Allelopathic Effect of Eucalyptus globulus Labill. on Cyperus rotundus L. and Cynodon dactylon L. Pers.

The allelopathic potential of Eucalyptus globulus Labill. (gum tree) fresh and dried leaf leachates was studied using two perennial weeds, viz. purple nutsedge (Cyperus rotundus L.) and bermuda grass (Cynodon dactylon L. Pers) as test weeds. Aqueous leachate of fresh leaves of eucalyptus significantly suppressed the establishment of vegetative propagules and early seedling growth of the weeds. Leachate of fresh leaf cuttings had growth inhibitory effect on bermuda grass but showed growth promotion effect on purple nutsedge. Similarly the leachate of dried leaves of eucalyptus had differential influence on the growth of the two weeds. There is a possibility to harness the allelochemicals of eucalyptus leaves as herbicides for the management of these perennial weeds.     

松仁乳专用乳化稳定剂优选及其产品稳定性的研究

对松仁乳专用乳化稳定剂进行优选,并对松仁乳产品稳定性进行研究。结果表明,松仁乳专用乳化稳定剂的最佳配比为:单甘脂0.12%,蔗糖酯0.08%,黄原胶0.02%.瓜尔豆胶0.03%,PURFIYGUM0.02%,海藻酸钠0.02%。松仁乳的HLB值为6,【Ca+】≤1mmol/L,在80℃-85℃,pH值6.5-7.5,40MPa均质两次,松仁乳产品具有较好的稳定性。