抗坏血酸对苹果组培苗耐热性的生理效应

用0.5 mmol/L抗坏血酸(ASA)处理苹果组培苗,在42℃的条件下进行不同时间高温胁迫处理,研究了ASA 处理对高温胁迫下苹果细胞膜相对透性、丙二醛(MDA)含量、抗氧化酶活性以及抗氧化剂含量的影响。结果表明, ASA处理可以有效地抑制抗氧化酶活性的下降,提高酶活性;同时还抑制ASA含量的下降,延缓了膜透性和丙二醛 含量的增加;但抑制了GSH含量的增加。这些结果说明,ASA处理可以增强苹果的耐热性。     

不同叶龄苹果叶片抗坏血酸含量与其代谢相关酶活性的比较

以‘嘎拉’苹果(Malus domestica Borkh. ‘Gala’) 叶片为试材, 研究了幼叶、展开叶、成熟叶、衰老叶4个不同时期叶片的抗坏血酸(AsA) 含量、合成和代谢相关酶活性及其相互之间的关系。结果表明, 不同叶龄苹果叶片总抗坏血酸和AsA含量的变化趋势一致, 均在成熟期最高, 衰老期开始下降,AsA关键合成酶GalLDH 活性表现出相应的变化。同时, 有助于AsA 再生的脱氢抗坏血酸还原酶(DHAR) 、单脱氢抗坏血酸还原酶(MDHAR) 、谷胱甘肽还原酶(GR) 活性均在叶片衰老期最低, 并伴有抗坏血酸过氧化物酶(APX) 活性的下降和H2O2的大量积累, 使抗坏血酸氧化程度在衰老期也达到最大。     

利用苹果SSR引物分析山楂属植物遗传关系

SSR引物在不同物种间具有通用性,从141对苹果属(Malus spp.)SSR引物中筛选出10对适合于山楂属(Crataegus spp.)植物的SSR引物,并对8个种37份山楂种质资源的遗传关系进行了分析。10对SSR引物共检测到91个多态性谱带,每个位点的等位基因数为3～13个,平均为9.1个。位点杂合度为0.432～0.790,平均为0.688。10对SSR引物可以将20份山楂资源区分开,17份不能区分的资源分为3组,第1组为3个伏山楂品种,第2组和第3组分别包括大果山楂的2个和12个品种。基于SSR标记构建的聚类树状图将供试37份山楂资源分成2个类群,第1类群包括6个山楂野生种,第2类群包括供试的所有伏山楂、山楂和大果山楂资源。该聚类结果与传统形态学分类一致。     

苹果种质资源主要描述标准比较分析

种质资源描述标准是研究和利用种质资源的基础。介绍了国内外7个主要苹果种质资源描述标准的制定国家、发布时间、性状选择以及评价方法,并对其植物学特征和生物学性状进行归纳、整理,比较分析了各标准在描述符性质、层次结构、描述符性状选择以及编码方式等方面的差异。指出我国今后若进一步修订与完善苹果种质资源性状描述标准,可从3个方面进行借鉴:描述性状选择以必选性状为主;样本采集应严格规定取样数量、取样方法及砧木的一致性;性状鉴定以过程控制为主,兼顾结果控制,增加可操作性和可重复性。     

我国苹果种质资源研究现状与展望

简要介绍了近几年国内外苹果生产及贸易现状,并概述了我国4个苹果种质资源圃的建设情况和苹果属植物资源收集、保存工作。从农艺性状、品质性状、矮化性和无融合生殖等方面对苹果种质资源进行了系统的鉴定评价,并利用现代计算机技术,对501份苹果种质资源的性状鉴定和评价数据进行规范化处理,建成苹果种质资源信息数据库。目前苹果种质资源创新及利用主要体现在苹果新品种、矮化砧的选育和苹果无融合生殖利用3个主要方面,并提出今后我国苹果种质资源研究的重点和方向。     

我国杏种质资源及遗传育种研究新进展

简要介绍了杏的起源、分布及种质资源收集、保存情况,着重对杏种质资源的细胞学、孢粉学、授粉生物学、分子生物学、解剖学和抗寒机理方面进行了综述。揭示了国内外杏的最新研究动态、杏起源、演化、分类及抗寒、抗旱机理等,同时论述了国内外杏的育种目标、遗传规律及先进的育种技术,并提出了我国杏今后的发展方向。     

基于遗传算法的苹果产量组合预测模型研究

苹果产量的预测不仅能为社会和经济管理决策提供可靠的依据,也给有关部门编制计划提供重要的数据.首先介绍了指数曲线模型、多元线性回归模型和组合预测模型.通过比较发现,组合预测模型能充分利用单个预测模型的优点,能够有效地减少单个预测模型受随机因素的影响,从而提高预测的精度和稳定性.为此,提出了苹果产量组合预测模型,将指数曲线...     

苹果属种质资源亲缘关系的SSR分析

应用SSR技术对59份苹果属材料进行基因组的多态性分析,从20对引物中筛选出12对SSR引物扩增出176个等位基因,平均每个位点14.7个等位基因。位点杂合度为0.4039～0.7412,遗传多样性指数为0.6156。用3对引物(CH02a04、CH02g04和CH01f03b)即可区分全部供试材料。NTSYS软件进行相似系数计算,UPGMA法聚类分析将59份苹果属材料分为3大类群,即栽培品种、地方品种和新疆的野生苹果、野生种或其变种。栽培品种中具有相同亲本起源的品种被紧密地聚到了一起,相似系数较高;地方品种与新疆的野生苹果的聚类相互交错,呈现出新疆的野生苹果作为东亚基因中心的起源种与中国各地方品种在起源演化上的相关性;各野生种及其变种类型均聚到了一起,与传统的系谱基本一致。     

几个早熟苹果品种果实糖酸组分及风味品质的评价

采用高效毛细管电泳仪分离测定了6个早熟苹果品种果实的糖酸组分,并对早丰甜、贝拉、辽伏3个品种可溶性糖、可滴定酸、糖酸比及主要香气成分含量与风味品质的关系进行了研究.结果表明,(1)所有参试品种均以果糖含量最高,品种间变异系数最小,仅为14.59%,但蔗糖和葡萄糖含量与果糖明显不同,在不同品种间存在较大差异,品种间变异系数分别为67.58%和29.94%,果糖和蔗糖含量是影响早熟苹果品种糖类总含量的主要因素.有机酸中苹果酸含量在不同早熟苹果品种也存在较大差异,最高为6.61 mg/g,最低仅为1.55 mg/g;(2)果实可溶性糖、可滴定酸、糖酸比及3种主要香气成分测定和官能鉴评结论在早丰甜、贝拉和辽伏3个品种间存在显著差异,官能鉴评的这种差异性与糖、酸及香气成分等成分测定结果基本一致,因此,在试验条件下,3个早熟苹果品种风味品质评价指标应包括可溶性糖含量、可滴定酸含量、糖酸比及1-丁醇、(E)-2-己烯醛和乙酸丁酯等3种主要香气成分的总含量.     

Agrobacterium tumefaciens mediated genetic transformation and regeneration of Morus alba L.

An efficient method was established for genetic transformation of Morus alba clone M5 using Agrobacterium tumefaciens mediated gene transfer. Cotyledon explants from in vitro grown seedlings were co-cultivated with disarmed strain LBA 4404 harbouring the binary vector p^BI121 carrying chimeric β-glucuronidase (GUS) and neomycin phosphotransferase (npt II) genes. Maximum transformation frequency of 18.60% was recorded with 48 h of pre-conditioning followed by co-cultivation for the same duration. Expression and presence of transgene was confirmed by histochemical test and polymerase chain reaction. The transgenic plants were micropropagated and successfully acclimatised.     

根癌农杆菌介导寒富苹果转化体系的建立

以寒富苹果组培苗叶片为外植体,利用植物表达载体上含潮霉素抗性基因的根癌农杆菌EHA105(pCAMBI-A1301)和含卡那霉素抗性基因的根癌农杆菌EHA105(pCAMBIA2301)对影响寒富遗传转化效率的因素进行系统研究。结果表明,寒富叶片对潮霉素反应敏感,在附加潮霉素的培养基上寒富叶片褐化较为严重。潮霉素和卡那霉素适宜的筛选质量浓度分别为4 mg.L-1和25 mg.L-1。农杆菌介导寒富苹果转化体系的建立以MS+TDZ 2.0 mg.L-1+NAA 0.5 mg.L-1培养基为叶片离体再生芽培养基。适宜的转化条件为:菌液浓度D 600nm=0.5、叶片外植体在菌液浸泡8 min、共培养时间为3～4 d、推迟4 d进行筛选培养。抗性基因对转化效率具有明显的影响,EHA105(pCAMBIA2301)的平均抗性芽再生率(0.96%)比EHA105(pCAMBIA1301)的平均抗性芽再生率(0.58%)高出几乎50%,EHA105(pCAMBIA2301)的抗性芽再生率最高达1.87%。GUS组织化学染色和PCR鉴定结果表明本研究获得了寒富苹果转基因植株。     

外源抗坏血酸对离体苹果叶片衰老的影响

 以苹果(Malus domestica Borkh. ) 品种‘嘎拉’秋梢成熟叶片为试材, 在5 mmol·L ^{- 1}抗坏血酸(AsA) 培养条件下, 研究了外源AsA 对离体苹果叶片衰老过程( 0 ～72 h) 中抗坏血酸—谷胱甘肽(AsA - GSH) 循环各组分和AsA合成关键酶L - 半乳糖酸- 1, 4 - 内酯脱氢酶(GalLDH) 的影响。结果表明, 外源AsA部分抑制了离体苹果叶片衰老过程中膜脂过氧化, 降低了H2O2含量, 但对表示膜损伤的相对膜透性影响不大。对AsA - GSH循环各组分来说, 外源AsA维持了叶片衰老过程中抗坏血酸过氧化物酶(APX) 和脱氢抗坏血酸还原酶(DAHR) 的高活性, 部分抑制了单脱氢抗坏血酸还原酶(MDHAR) 活性的下降, 同时降低了GSH的氧化程度, 从而提高了AsA含量和再生能力。外源AsA 在衰老前期抑制了GalLDH活性, 降低了AsA的合成能力, 而后期维持了GalLDH的高活性。     

Optimization of saline water level for sustainable Barnea olive and oil production in desert conditions

The main aim of the present study is to evaluate the effects of long-term irrigation with water at three different levels of salinity on Barnea olive trees with a view to optimize vegetative growth, productivity and oil quality. The study was carried out on trees growing in the Negev desert of Israel. The intermediate salinity (4.2 dS m⁻¹ EC) inhibited growth significantly only in the first year after planting, while from the second year onward retardation of vegetative growth as compared with the control treatment (1.2 dS m⁻¹ EC) was slight and non-significant. However, the high salinity (7.5 dS m⁻¹ EC) retarded tree growth significantly. Furthermore, the intermediate treatment led to significant increase in tree productivity relative to the other treatments, and also to an increase in olive oil yield. In conformity with the greater number of fruits produced, the olives of the 4.2 dS m⁻¹ EC treatment tended to be smaller.No significant differences were found between saline- and control-water irrigated trees in terms of olive oil basic quality parameters, such as free fatty acids, peroxide value, and fatty acid profile. The saline treatments increased the levels of certain antioxidant components (polyphenols and Vitamin E) in the oil extracted from the olives as compared with the control. The data obtained clearly show that, of the three water salinities tried, the moderate level of 4.2 dS m⁻¹ EC is best suited for production of olives and olive oil under the conditions prevailing in the central Negev, at least during the first 9 years from planting. The sustainability of Barnea cultivation under moderately saline water is discussed.     

Cryopreservation of Malus cultivars: Comparison of two droplet protocols

Two droplet procedures, droplet-vitrification (PVS2) and droplet (DMSO) were applied for cryopreservation of in vitro cultured apple (Malus domestica Borkh., cvs. Florina, Idared, Colmar and Rebra) plants. The highest post-thaw regrowth rates (70% for cv. Florina, 66% for cv. Idared, 63% for cv. Colmar and 60% for cv. Rebra) were achieved after using the droplet-vitrification (PVS2) protocol. The excised shoot tips (2–3 mm in length) were precultured in 0.5 M sucrose enriched media for 24 h. Subsequently they were transferred in PVS2 vitrification solution for 30 or 40 min (depending on cultivar) at 24 °C and then immersed in liquid nitrogen. Rewarming was performed in liquid MS medium at 24 °C. Plants regenerated from cryopreserved shoot tips did not display any sign of morphological alteration or abnormalities in growth in comparison with control plants.     

刺梨果实和叶片发育过程中抗坏血酸和抗氧化酶的协同变化

 以‘贵农5号’刺梨为材料，研究了果实和叶片发育过程中主要保护酶和抗坏血酸（AsA）的变化。结果表明，刺梨果实和叶片内都具有较高的SOD活性，并在发育过程中呈基本相似的变化模式；总体上看，刺梨叶片中具有较高的POD和CAT等抗氧化酶活性，并呈‘初期升高后期降低’的变化趋势，但AsA含量及其氧化还原态(AsA与AsA库的比值)较低。在果实中，SOD活性和AsA含量高，而POD活性很低，并且在果实发育中、后期降至检测不到的水平，整个生育期都未能检测到CAT活性。这表明刺梨果实和叶片中存在着不同的自由基清除协作机制。     

The use of CPPU for efficient propagation of pineapple

The use of forchlorfenuron (N-(2-chloro-4-pyridyl)-N′-phenylurea) (CPPU) for efficient propagation of pineapples was investigated. About 85% of axillary buds can be forced to sprout by soaking defoliated stem pieces (12 cm in length) in a 2.5 or 5.0 mg l⁻¹ CPPU solution for more than 3 h. The use of old stems taken from the third or fourth ratoon plants had the advantage of less liability to fungal decay, as compared to young stems from the first crop plants. The CPPU treatment combined with the removal of shoots from stems at monthly intervals significantly increased the number of shoots per stem piece (about 15 shoots per piece at 5.0 mg l⁻¹ CPPU), and resulted in a more uniform shoot size (the percentage of shoots within a range of 5–15 cm in length was about 90% at 5.0 mg l⁻¹ CPPU). The rooting of shoots was easily promoted within 1 month by treating the basal portion of shoots with 20 mg l⁻¹ indole-3-butyric acid (IBA) for 15 min. The CPPU method required about 5 months for plantlet propagation. From these results, we found that pineapple plantlets could be efficiently propagated by the following method: (1) soaking defoliated stems in a 2.5–5.0 mg l⁻¹ CPPU solution for more than 3 h; (2) harvest of developed shoots from the stems at regular intervals; and (3) promotion of rooting on the shoots at 20 mg l⁻¹ IBA for 15 min.     

芒果果实冷害过程中谷胱甘肽和抗坏血酸含量的变化

‘紫花’芒果果实（ＭａｎｇｉｆｅｒａｉｎｄｉｃａＬ．ＺｈｉＨｕａ）２℃贮藏１５ｄ时发生严重的冷害。贮藏前期,还原型谷胱甘肽（ＧＳＨ）、还原型维生素Ｃ（ＡｓＡ）含量略有上升,说明短期低温胁迫可促使机体提高清除氧自由基能力,以适应不良环境。随冷害时间延长,ＧＳＨ、ＡｓＡ含量下降;膜脂过氧化产物（ＭＤＡ）、膜透性、氧化型谷胱甘肽（ＧＳＳＧ）和氧化型维生素Ｃ（ＤＨＡ）增加,表明细胞防御能力下降,自由基代谢平衡可能被打破,膜脂过氧化加剧,果实冷害加重。１０℃贮藏的芒果,无冷害症状,２２ｄ时果实启动成熟,贮藏期间ＧＳＨ、ＡｓＡ含量维持较高水平。     

利用分子标记研究苹果资源与基因组的进展

苹果是近年来用分子标记研究较多的果树树种。从苹果品种的鉴定、亲子关系的确定、种质的遗传与变异、重要农艺性状的筛选或遗传机理的研究以及遗传图谱的构建几个方面概述了分子标记在苹果上的应用现状 ,并对进一步的工作提出了相应的建议     

Molecular cloning of three malic acid related genes MdPEPC, MdVHA-A, MdcyME and their expression analysis in apple fruits

Malic acid (MA) in apple fruit is the predominant organic acid associated with taste, flavour and juice quality. In this study, three full-length cDNAs of MdPEPC, MdVHA-A and MdcyME were cloned from apple fruit. They encoded cytosolic phosphoenolpyruvate carboxylase (MdPEPC, EC 4.1.1.31), subunit A of vacuolar H⁺-ATPase (MdVHA, EC 3.6.1.3) and cytosolic NADP-dependent malic enzyme (MdcyME, EC 1.1.1.40), respectively, for MA synthesis, transportation and degradation. Real-time quantitative PCR discovered that the expression levels of three genes varied with development stages, and that their expression patterns differed between low acid (LA) and high acid (HA) genotypes. In addition, enzyme activity assay showed that PEPC and VHA contributed positively to MA accumulation during fruit development both in LA and HA, while cyME did negatively.     

Selection of efficient arbuscular mycorrhizal fungi in the rhizosphere of cashew and their application in the cashew nursery

Mycorrhizal association in cashew (Anacardium occidentale L.) grown in five different plantation areas of South India was investigated. The soil samples were collected from all locations. Physico-chemical properties of rhizosphere soils, arbuscular mycorrhizal fungal spore count and root colonization were recorded. Species isolated were Acaulospora, Gigaspora, Glomus and Scutellospora. The mycorrhizal spore density was maximum at Thanjavur and minimum at Kudumiyamalai. Root colonization percentage oscillated between 20 and 30%. The species of Glomus, G. aggregatum Schenck and Smith, G. fasciculatum (Thaxter) Gerdemann and Trappe and G. mosseae (Nicol. and Gerd.) Gerdemann and Trappe were the most abundant in the majority of the experimental sites. Hence these three species were selected and used for artificial inoculation studies. Of the three mycorrhizal fungi G. fasciculatum significantly increased shoot length, internode number, internode length, number of leaves, stem diameter, root length and root number.