Fruit Load and Root Development in Field-Grown Loquat Trees (Eriobotrya japonica Lindl)

Photosynthate translocation to the root in loquat trees decreases as fruit develops. Thus, during the most active period of fruit development, that is, from 50 % of its final size to the beginning of fruit color change, which correspond to BBCH growth scale stages 705 and 801, both translocating and reducing carbohydrate concentrations diminish greatly. Concomitantly, the results from our experiment show an increased abscisic acid (ABA) concentration and a decrease in the respiration rate detected by an accumulation of glucose-6-phosphate, which paralleled a reduced indole-3-acetic acid (IAA) concentration in roots. As a consequence, root development was strongly and significantly reduced. Because loquat fruit develops in winter and nonshoot growth takes place at this time, our results show that root development in loquat trees is controlled by the fruit, mediated by competition for carbohydrates and modulated by hormones. The experiment was conducted using field-grown loquat during two consecutive years and by comparing fruiting and defruited trees. Fruits were detached from the trees in the early fruit developmental stage (10 % of final size, 701 BBCH growth scale), and carbohydrate concentrations in leaves, shoot bark, and roots, as well as nitrogen fractions (N–NO₃ ^?, N–NH₄ ⁺, and N–proteinaceous) and hormone (IAA, zeatin, and ABA) concentrations in roots, were analyzed throughout the period of fruit development. Root development was evaluated by counting the emerging lateral root primordia during the fruit developmental stages BBCH growth scale 701–809 (fruit color fully developed).     

Fruit Regulates Bud Sprouting and Vegetative Growth in Field-Grown Loquat Trees (Eriobotrya japonica Lindl.): Nutritional and Hormonal Changes

The effects of fruit on bud sprouting and vegetative growth were compared on fruiting and defruited loquat trees from fruit set onward. Carbohydrate and nitrogen content in leaves and bark tissues and hormone concentrations were studied during the fruit development and vegetative growth periods. On defruited trees, a significant proportion of buds sprouted in winter, whereas buds from fruiting trees sprouted only in the spring when fruit reached its final size. Furthermore, when panicles were completely removed in autumn, the buds also sprouted. In addition, fruit directly affected vegetative growth by reducing shoot length. An effect of sink removal (flower or fruit) promoting bud sprouting, regardless of the season, was then demonstrated. Neither soluble sugar concentration nor nitrogen fraction concentration in leaves or bark tissues was related to bud sprouting, but a certain nutritional imbalance was observed during the most active period of fruit development. Moreover, fruit sink activity significantly modified hormone content by increasing indole-3-acetic acid (IAA) and reducing zeatin concentrations, resulting in a higher IAA/zeatin ratio parallel to the lower bud sprouting intensity. Therefore, these changes caused by fruit removal are all related to vegetative growth, but there is no evidence that they are responsible for bud burst.     

Purification and characterization of a novel (R)-hydroxynitrile lyase from Eriobotrya japonica (Loquat)

A hydroxynitrile lyase was isolated and purified to homogeneity from seeds of Eriobotrya japonica (loquat). The final yield, of 36% with 49-fold purification, was obtained by 30-80% (NH(4))(2)SO(4) fractionation and column chromatography on DEAE-Toyopearl and Concanavalin A Sepharose 4B, which suggested the presence of a carbohydrate side chain. The purified enzyme was a monomer with a molecular mass of 72 kDa as determined by gel filtration, and 62.3 kDa as determined by SDS-gel electrophoresis. The N-terminal sequence is reported. The enzyme was a flavoprotein containing FAD as a prosthetic group, and it exhibited a K(m) of 161 microM and a k(cat)/K(m) of 348 s(-1) mM(-1) for mandelonitrile. The optimum pH and temperature were pH 5.5 and 40 degrees C respectively. The enzyme showed excellent stability with regard to pH and temperature. Metal ions were not required for its activity, while activity was significantly inhibited by CuSO(4), HgCl(2), AgNO(3), FeCl(3), beta-mercaptoethanol, iodoacetic acid, phenylmethylsulfonylfluoride, and diethylpyrocarbonate. The specificity constant (k(cat)/K(m)) of the enzyme was investigated for the first time using various aldehydes as substrates. The enzyme was active toward aromatic and aliphatic aldehydes, and showed a preference for smaller substrates over bulky one.     

枇杷种子的脱水敏感性与膜脂过氧化作用

枇杷种子不耐贮藏,属于脱水敏感的种子。在干燥脱水过程中,子叶和胚轴的超氧物歧化酶（ＳＯＤ） 和过氧化物酶（ＰＯＤ） 活性不断下降,而丙二醛（ ＭＤＡ） 含量及种子浸泡液的电导率不断增加,种子活力逐渐降低。外源０ ．０５ ～０ ．２５ ｍｍｏｌ／Ｌ 的抗坏血酸（ＡＳＡ） ,０ ．０５ ～５ ．０ ｍｍｏｌ／Ｌ 的还原性谷胱甘肽（ＧＳＨ）和０ ．０５ ～０ ．５ ｍｍｏｌ／Ｌ 的Ｃａ２ ＋ 处理能有效地增强种胚防御过氧化的能力,缓解氧自由基对种胚的伤害,提高脱水劣变的种子活力。     

枇杷4-香豆酸CoA连接酶的某些特性

以枇杷品种‘解放钟’果实为试材,用硫酸铵分级盐析方法提取4-香豆酸CoA连接酶,其最适温度为10和40℃,40和10℃下的热稳定性较好;最适pH为8．0且较稳定;最适底物为咖啡酸。     

枇杷果肉有机酸组分及有机酸在果实内的分布

用高效离子交换色谱（HPIC）测定了枇杷（Eriobotrya japonica Lindk）18个品种（小毛枇杷、夹脚、卓南1号、解放钟、富阳、森尾早生、华宝2号、香钟10号、白花、土肥、多宝2号、乌躬白、洛阳青、茂木、早钟6号、白梨、塘头4号和长红3号）的成熟果肉和2个品种（解放钟和早钟6号果）成熟果实不同组织有机酸含量。结果表明,成熟果肉中均含有苹果酸、奎尼酸、柠檬酸、异柠檬酸、α-酮戊二酸、富马酸、草酰乙酸、酒石酸8种有机酸,有的还含有微量的阿魏酸、顺乌头酸和B一香豆酸。大多数品种果肉中苹果酸含量最高,平均含量为4399mg kg^-1 FW,占总酸的62．7％;其次是奎尼酸,其平均含量为2042mgkg—FW,占总酸的29．1％。品种之间可滴定酸和有机酸含量差异很大。通过对果肉可滴定酸进行聚类分析,可把18个枇杷品种分为五个组群：极高酸（小毛枇杷）、高酸（夹脚、卓南1号、解放钟和富阳）、中酸（森尾早生、华宝2号、香钟10号、白花、土肥和多宝2号）、低酸（乌躬白、洛阳青、茂木和早钟6号）和极低酸（白梨、塘头4号和长红3号）。解放钟和早钟6号果肉和果皮的总酸含量及可滴定酸均无显著差异,但果皮和果肉的总酸含量和可滴定酸均大大高于种子。相似于果肉,果皮和种子的主要有机酸也是苹果酸和奎尼酸。果皮中苹果酸含量远高于奎尼酸,但种子中苹果酸含量比奎尼酸稍低。此外,种子中苹果酸和奎尼酸比果肉和果皮中的低得多。     

In Loquat (Eriobotrya japonica Lindl.) Return Bloom Depends on the Time the Fruit Remains on the Tree

In loquat (Eriobotrya japonica Lindl.), the comparison of fruiting trees and defruited trees carried out covering a range of developmental fruit stages reveals a significant reduction in flowering due to fruit from its early stage of development, being higher when it changes color and becomes senescent, which coincides with the floral bud inductive period. This effect occurred both at the tree and at the shoot level. Furthermore, although current shoots almost always develop into panicles, those from fruiting trees develop fewer flowers, suggesting that fruit also affects at the floral bud level. In our experiment, the gibberellin concentration at the floral bud inductive period was significantly higher in bark tissues (periderm, cortex and phloem tissues) of fruiting trees, compared with defruited trees that tend to flower more. The lower concentration of IAA in the bark tissues of defruited trees also contributes to increase their flowering intensity. On the contrary, the zeatin concentration was higher. Accordingly, at bud burst, the IAA/zeatin ratio, an indication of effect on flowering, was significantly higher for fruiting trees. Some disruption in the nitrate reduction process in fruiting tree was also observed. The process of floral bud induction and differentiation was not associated with either reducing or translocating and reserve carbohydrate concentration. Hence, loquat flower intensity depends on the time the fruit is maintained on the tree. The intensity is affected indirectly, by reducing the number of shoots, and directly, by reducing the number of flowers per panicle, and these effects are linked to endogenous plant hormone contents.     

枇杷属植物种质资源及普通枇杷园艺学研究进展(综述)

简述枇杷属植物种质资源的分布及分类,并对主要种——普通枇杷的栽培、育种、繁殖、组织培养技术、生理、分子生物学等园艺学研究进展进行综述。     

枇杷属植物等位酶遗传变异及品种基因型指纹

利用超薄平板微型聚丙烯酰胺凝胶的等电聚焦电泳技术,对国家枇杷种质资源圃所收集保存的113个枇杷（Eriobotrya japonica Lindl．）品种（或株系）和4个野生近缘种[栎叶枇杷（E．prinoides Rehd．et Wils．）、大渡河枇杷（E．prinoides var．daduheensis H．Z．Zhang）、齿叶枇杷（E．serrata Vidal．）、大瑶山枇杷（E．dayaoshanensis Chen．）],共117份材料进行了等位酶遗传变异分析。在12个酶系中共检测到24个清晰位点和59个等位基因,多态位点为21个,位点最大等位基因数为5,体现出枇杷丰富的遗传种质多样性;X^2分析表明等位基因频率在不同产地品种群间存在明显差异,在用于分析的19个多态位点中,有15个位点达到显著或极显著水平;且不同的种材料拥有各自特有等位基因,如Dia-1^c,Dia-2^b,Dia-3^b只存在于大瑶山枇杷中,Est-2^b,Est-3^a只存在于大渡河枇杷中,Idh-1^d仅出现于枇杷品种荔枝枇杷中,体现了枇杷物种间的遗传组成差异;利用11个酶系统22个位点的53个等位基因所构建的枇杷品种（株系）等位酶基因型指纹可以将113个枇杷品种中的111个完全区分,各品种均有自己独特的等位酶基因型指纹,虽然进一步的分析表明,目前所研究的酶系统位点和等位基因变异与枇杷品种果实园艺性状变异间缺乏关联,但等位酶标记仍然不失为枇杷品种鉴别的一种有用工具。     

枇杷成花过程叶片蛋白质变化动态

研究了温室内水分胁迫下盆栽枇杷和大田枇杷的成花和未成花枝梢叶片可溶性蛋白质含量在花芽分化过程中的变化动态,同时对成花和未成花枝梢顶芽进行特异蛋白双向凝胶电泳研究。结果表明,枇杷成花诱导需经历可溶性蛋白质含量一定程度的升高,然后急剧下降的过程,即可溶性蛋白质的升高对应成花诱导,而蛋白质的下降与形态分化紧密相关。成花植株枝梢顶芽与未成花植株枝梢顶芽的2-DE图谱总模式相同,但前者比后者多了两种蛋白质,其分子量和等电点一为MW 14110.5±110.8、pI 5.350±0.008,另一为MW 66446.3±260.9、pI 4.730±0.032,两种蛋白质均呈酸性,可能与枇杷成花密切相关。     

Generation of (2-Nitroethyl)benzene and related benzenoids from L-Phenylalanine; flower scents of the Japanese Loquat Eriobotrya japonica [Rosales: Rosaceae]

ABSTRACT

(2-Nitroethyl)benzene, methyl 4-methoxybenzoate and 4-methoxybenzaldehyde have been known as major scent components in flowers of the Japanese loquat Eriobotrya japonica [Rosales: rosaceae], together with 13 related benzenoids, including Z- and E-2-phenylacetaldoxime and benzyl alcohol. The scents air-trapped from a flowering panicle during 24 h incubation with d₈-L-phenylalanine were composed of 15 deuterium labeled compounds {d₆-styrene, d₅-benzaldehyde, d₇-2-phenylacetaldehyde, methyl d₅-benzoate, d_{7 ?}2-phenylethanol, d₇-2-phenylacetonitrile, d₄-1,4-dimethoxybenzene, d₇-Z-2-phenylacetaldoxime, d₄-4-methoxybenzaldehyde, d₇-E-2-phenylacetaldoxime, d₄-4-methoxybenzyl alcohol, d₇-(2-nitroethyl)benzene, methyl d₄-4-methoxybenzoate, methyl d₆-cinnamate and ethyl d₄-4-methoxybenzoate}. On the other hand, hexane extracts of the flower petal incubate with a mixture of d₅-Z- and d₅-E-2-phenylacetaldoxime after 24 h indicated generation of six d₅-labeld components {d₅-benzaldehyde, d₅-benzyl alcohol, d₅-2-phenylacetaldehyde, methyl d₅-benzoate, d₅-2-phenylethanol, and d₅-(2-nitroethyl)benzene}. By comparing those results, (2-nitroethyl)benzene was concluded as a product directly generated from a mixture of Z- and E-2-phenylacetaldoxime together with six minor benzenoids, while two major compounds (4-methoxybenzaldehyde and methyl 4-methoxybenzoate) together with three minors from L-phenylalanine, presumably via L-tyrosine. The other two minor components were derived from L-phenylalanine.     

Genomic characterization of self-incompatibility ribonucleases (S-RNases) in loquat (Eriobotrya japonica Lindl.) (Rosaceae, Pyrinae)

Loquat (Eriobotrya japonica Lindl.) is a fruit tree species of the Pyrinae subtribe of the Rosaceae that behaves as self incompatible. Since self-incompatibility in the Rosaceae is of the gametophytic type where a stylar ribonuclease (S-RNase) controls the female function of pollen–pistil recognition, consensus primers derived from the alignment of S-RNase sequences from other Pyrinae species were used to search for S-RNases in loquat. As a result, the first four S-RNases were sequenced for this species. The genomic sequences obtained showed the structural features of Pyrinae S-RNases. Moreover, microscopic observations of pollen tube growth in the style confirmed the inter-(in)compatibility relationships predicted from the molecular analyses. Phylogenetic analysis of the deduced amino acid sequences with other Pyrinae S-RNases confirmed that divergence of S-alleles in loquat and the Pyrinae predated speciation. This study reports for the first time the genomic characterization of S-RNases in loquat, providing a sound basis for an appropriate selection of pollinator cultivars and an adequate design of breeding programs.     

Hypotriacylglycerolemic and Antiobesity Properties of a New Fermented Tea Product Obtained by Tea-Rolling Processing of Third-Crop Green Tea (Camellia sinensis) Leaves and Loquat (Eriobotrya japonica) Leaves

We manufactured a new fermented tea by tea-rolling processing of third-crop green tea (Camellia sinensis) leaves and loquat (Eriobotrya japonica) leaves. The mixed fermented tea extract inhibited pancreatic lipase activity in vitro, and effectively suppressed postprandial hypertriacylglycerolemia in rats. Rats fed a diet containing 1% freeze-dried fermented tea extract for 4 weeks had a significantly lower liver triacylglycerol concentration and white adipose tissue weight than those fed the control diet lacking fermented tea extract. The activity of fatty acid synthase in hepatic cytosol markedly decreased in the fermented tea extract group as compared to the control group. The serum and liver triacylglycerol- and body fat-lowering effects of the mixed fermented tea extract were strong relative to the level of dietary supplementation. These results suggest that the new fermented tea product exhibited hypotriacylglycerolemic and antiobesity properties through suppression of both liver fatty acid synthesis and postprandial hypertriacylglycerolemia by inhibition of pancreatic lipase.     

Development of microsatellite markers from loquat, Eriobotrya japonica (Thunb.) Lindl

Loquat (Eriobotrya japonica) is a minor fruit which has become an interesting alternative into the European fruit industry. This interest resulted in a loquat germplasm collection established at the Instituto Valenciano de Investigaciones Agrarias, Valencia, Spain. Currently, it is the main reservoir of this species outside Asia. We developed and characterized the first 21 polymorphic microsatellite loci from a CT/AG-enriched loquat genomic library. The observed heterozygosity ranged between 0.20 and 1.00, expected heterozygosity ranged between 0.17 and 0.81, three markers were multilocus and eight loci departed significantly from Hardy-Weinberg equilibrium. These markers will facilitate diversity and genetic studies into the species.     

枇杷茎尖二步玻璃化法超低温保存的研究

超低温保存是目前植物种质资源长期稳定保存最理想的方法,而近几年发展的玻璃化超低温保存法具有设备要求简单、材料处理步骤简便及效果和重演性好等特点,倍受人们的青睐。国内外用玻璃化法成功地保存许多果树的种质资源。在对枇杷（Eriobotrya japonica Lindl．）花粉超低温保存取得成功的基础上,作者进行了枇杷茎尖玻璃化超低温保存的研究,以期建立枇杷茎尖超低温保存体系,为长期稳定保存枇杷种质资源提供技术支持。     

基于枇杷转录组序列的SSR分子标记引物开发

为获得更多的枇杷SSR引物,对枇杷转录组测序得到的1 kb以上的11 798条Unigenes进行SSR位点搜索。结果在3515 条Unigenes（6.77%）中共获得4438个SSR位点,其中主要重复类型为双碱基重复和三碱基重复,二者占SSR总数的68.27%,而四、五、六碱基重复类型较少,仅占1.42%。对选出的SSR标记采用Primer3进行引物设计,得到7911 对SSR位点特异引物,可用于枇杷遗传多样性分析、分子标记辅助育种、育种群体的建立等研究。     

枇杷叶的化学成分和药理作用研究进展

以近十几年来国内外的文献为依据,从化学成分和药理作用方面综述了枇杷叶的研究进展。枇杷叶含有三萜酸、挥发油、倍半萜、黄酮、糖苷类等成分,具有抗炎止咳、减肥降血糖、抗癌、抗氧化、保肝等作用。枇杷叶化学成分多样,药理作用广泛,具有较高的研究开发价值和广阔的应用前景。     

桂西峰丛岩溶山区大果枇杷引种试验初报

在典型的桂西岩溶区广西都安县三只羊乡进行‘早钟六号’和‘长虹三号’两个大果枇杷品种的引种栽培试验。结果表明,两个品种均能适应引种区的气候和环境,生长良好,而且还具有早实早熟的特性,栽种第三年有80%以上的植株开花结果,单株产量在10kg以上;两个品种每公顷产量分别为7875kg和8400kg,产值为47250元和50400元,净收入为35250元和38400元,果实品质优良。成林的枇杷园增加了林地面积,明显改善局部小气候。在桂西峰丛岩溶山区发展大果枇杷,经济效益、社会效益和生态效益显著。