鄂东北枫香林更新演替研究

实地调查了红安天台山的枫香(Liquidambar formosana)纯林、枫香-锐齿槲栎(Quercus aliena var.acuteserrata Maxim)等阔叶混交林、枫香-马尾松(Pinus massoniana Lamb.)针阔混交林3种森林类型的12个样地,分别选用特卡钦科法、分层频度法评价各森林类型的更新等级和演替趋势。结果表明,3种森林群落的优势树种更新较差,幼苗数量比较少,主要受郁闭度、坡向、坡度和坡位的影响。阔叶纯林(枫香林)将演替为以枫香、锐齿槲栎和化香(Platycarya strobilacea Sieb.et Zucc.)为主要组成树种的阔叶混交林;以枫香为主的阔叶混交林在一定时期内将演替为阔叶混交林;而针阔混交林将演替为阔叶混交林。     

利用农杆菌介导法获得RNAi转基因枫香的研究

随着我国林业生态工程和退耕还林的开展，木材生产与需求之间的矛盾愈加严重，培育速生优质大径材的研究更加重要。基于LEAFY基因在植物生长发育中的特性，利用PCR和Gateway技术构建了含有LEAFY基因保守序列的RNA干涉植物表达载体LFY-RI，利用根瘤农杆菌Agrobacterium tumefaciems介导法获得转基因植株，利用RNA干涉技术抑制转基因植株中LEAFY基因的表达，从而获得枫香Liquidambar formosana不育转基因植株。并利用聚合酶链式反应（PCR）技术和PCR-Southern杂交技术检测了转基因植株中外源基因整合情况。共获得了5株枫香转基因植株，分子检测表明，其中4株为转基因阳性植株。由于转基因植株还比较幼嫩，对它们生长发育以及木材品质的变化尚处于在观察中。图5参12     

杂交枫香胚性愈伤组织遗传转化体系研究

目的杂交枫香是我国重要的用材和观赏树种资源,但其遗传转化体系尚未建立。建立杂交枫香遗传转化体系为杂交枫香性状改良和基因功能研究提供了方法。方法本研究基于杂交枫香高效的体细胞胚胎发生技术,用根癌农杆菌介导的遗传转化法对其胚性愈伤组织进行遗传转化,对潮霉素选择压、菌液浓度、侵染时间、共培养时间、以及共培养温度等影响因素采用...     

Tobacco anionic peroxidase often increases resistance to insects in different dicotyledonous species

Different species and strains of tobacco (Nicotiana spp), tomato (Lycopersicon esculentum) and sweetgum (Liquidambar styraciflua) that had total peroxidase activity enhanced by a few- to over 100-fold through the expression of a tobacco anionic peroxidase gene driven by a cauliflower mosaic promoter were compared with wild-type plants for resistance to relevant insects. Reduced levels of feeding were generally noticed for leaves, stems and fruit, but the age of tissues and insects influenced the response. Enhanced resistance to Helicoverpa zea and Manduca sexta were noted for tobacco and tomato, and resistance to Hyphantria cunea and Lymantria dispar were noted for sweetgum. In several cases increased mortality and/or reduced growth rates were noted for the high-peroxidase plants. Although many modes of action are possible, indirect comparisons and gravitational nutritional studies suggest peroxidase-enhanced rates of production of compounds toxic to the insects are the most important.     

枫香树脂浅色化工艺试验

应用水蒸气蒸馏工艺,通过添加抗氧化剂,研究制备浅色化枫香树脂的方法。试验表明:对枫香脂的前处理可有效的提高枫香树脂的颜色等级,同时添加抗氧化剂也可有效防止枫香树脂在蒸馏过程中的颜色加深。适宜的工艺条件为:枫脂精油做溶解油,溶解油加入量与枫脂质量比为2∶1,蒸馏水洗4次,单次洗涤水的用量与枫脂质量比为4∶1,常压水蒸气蒸馏温度为130~140℃,蒸馏时间为30 min,减压蒸馏时间为10 min,所得枫香树脂的颜色等级由简单直接蒸馏的12(加纳级)上升为6(加纳级),软化点为131℃,酸值为53 mg/g,皂化值为104 mg KOH/g。     

漆酶活化木材产生活性氧类自由基的处理条件研究

自由基对漆酶活化木材产生胶合力起着关键性的作用。通过试验分析反应体系pH值、处理温度、酶用量、处理时间及树种等因子，对漆酶处理木粉产生的活性氧类自由基的相对浓度的影响。研究结果表明：5个因子均对活性氧类自由基相对浓度有极显著影响。当采用思茅松心材木粉、处理4h、反应体系pH值为4、酶用量为1．5u／g木粉、处理温度为60℃时，漆酶活化木材产生的活性氧类自由基的相对浓度最高。     

Effects of plant essential oils and components from Oriental sweetgum (Liquidambar orientalis) on growth and morphogenesis of three phytopathogenic fungi

Commercial plant essential oils obtained from 40 plant species were tested for their antifungal activity against Phytophthora cactorum, Cryphonectria parasitica, and Fusarium circinatum. Strong antifungal activity against Phytophthora cactorum was achieved with the essential oil derived from Oriental sweetgum, Liquidambar orientalis at 28 × 10⁻³ mg/mL air concentration. In a test with C. parasitica, inhibition rate of patchouli was 51.0%, whereas the other essential oils showed weak activity. Essential oils of manuka (Leptospermum scoparium) and patchouli (Pagostemon patchouli) showed moderate activity against F. circinatum. Analysis by gas chromatography-mass spectrometry led to identification of 11 compounds in the oil of L. orientalis. The antifungal activity of identified compounds was tested singularly by using standard or synthesized compounds. Inhibition rates of cinnamyl aldehyde and benzaldehyde were 100% against P. cactorum at 28 × 10⁻³ mg/mL air concentration. There was a significant morphological alternation in three phytopathogenic fungi after oil or compound treatment.