柑桔的冻害生理和冻后管理

发展柑桔生产是使农民致富奔小康的好门路，目前扩展很快，效益也很好。但柑桔主要生长在亚热带的较南地区，对于地处亚热带北缘的湖南、江西、浙江的北部，安徽、江苏南部和上海市等地，柑桔往往因冬季寒流频繁的袭击而遭受冻害。柑桔（主要是温州蜜桔）在极端最低气温达到一7aC时，即会有不同程度的伤害，若达到一13C时，则会导致部分或全部死亡。低温持续时间愈长柑桔受害程度愈重。1991年12月下旬长江以南的许多柑桔种植区极端最低气温曾达*5℃—-7℃，并持续了3天之久，有些地区则出现了短时间的-13℃左右的最低气温，致使大面积桔园…     

柑桔矮化砧木的生理生化预选指标研究

以７４－１积、紫花宜昌橙、Ｒｕｓｋ枳橙、Ｔｒｏｙｅｒ枳橙、江南柑、９２号红桔和蟹橙为标准系列砧木,研究了它们的生理生化特征,从中筛选出了茎还原性糖含量、叶片还原性糖含量、叶片氨基酸含量、茎蛋白质含量、叶片过氧化物酶活性５个柑桔矮化预选指标和叶片可溶性糖含量、叶片蛋白质含量２个辅助预选指标。     

峡谷暖区柑桔气候生态的定量研究

作为山地气候[7,8] 类型之一的峡谷地形气候 ,在农业上的应用研究已引起广泛的关注。研究其农业地形气候[10 ] ,特别是对作物气候生态进行定量研究 ,有助于峡谷区域农业气候资源的合理开发与利用。本文所述及的峡谷主要是指鄂西南的长江三峡、清江河谷及香溪河谷。因峡谷地形特别 ,气候的突出特征是峡谷暖区 (因海拔 80 0ｍ附近的冬季气温接近于同纬度的江汉平原而可定为暖区的上限 )的形成 ,其表现为隆冬少有低温冻害 ;难有积雪、雨凇和雾凇 ;风力弱、无偏北大风 ;有效辐射小、净辐射量大。其成因为 :冷空气难进易出 ;西南暖槽的保护作用[2…     

几个气候区木本植物的开花结果物候

分析了我国海南和广东、秦岭、东北等不同森林气候区木本植物开花、结果物候以及果实和种子大小分布的规律。三个区系的开花、结果物候和种子、果实大小分布,都有类似的格局。但随着纬度的升高,一年中植物开花和结果的时间更加集中,海南和广东整年都有木本植物开花,秦岭有10个月左右,而东北仅有7个月。并且随着纬度升高,开花高峰的时间较迟,而结果高峰的时间较早。在海南和广东,热带区系成分和温带区系成分的木本植物,一年中开花和结果物候格局是很一致的。三个区系木本植物的果实和种子大小分布的格局也是很相似的,但海南和广东植物果实和种子大小范围较大,较多样,随着纬度升高,果实和种子大小范围变小,较单调。三个区系木本植物最小的果实的大小都差不多,为0．1cm,但最小的种子的大小却很不相同,随着纬度的升高而增大,开花和结果物候与月均气温及降水量的相关性因不同的区系而不同．鼎湖山常见木本植物果熟期和气候因子的相关性比结果期更显著。     

不同居住条件对中国树鼩生殖生理的影响

目的：探讨不同居住条件对中国树鼩生殖生理的影响。方法：将30只中国树鼩放在大、小不同的笼内临近饲养,分为3组（n=10）：对照组,小笼饲养组和利血平组。给予利血平作为干预措施,饲养180d,用放射免疫法检测血液和组织中激素和核苷酸的水平,光、电镜观察脑和睾丸组织线粒体超微结构变化。结果：实验第180天检测,与对照组比,小笼内中国树鼩血肾上腺素（A）、去甲肾上腺素（NA）、环磷酸腺苷（cAMP）、环磷酸鸟苷（cGMP）含量分别升高了71．71％,46．68％,35．14％,19．24％;睾酮（T）、雌二醇（E2）分别降低了34．33％,9．67％;丘脑（thala．mus）、前额叶皮层（PFC）、海马（Hipp）、睾丸（Testicle）组织中cAMP含量分别升高了31．61％,45．82％,30．17％,28．56％;thalamus、Hipp、Testicle组织细胞线粒体的体密度（VD）增加了172．04％,151．69％,132．79％;数密度（ND）增加了66．27％,69．28％,67．37％;面密度（SD）增加了34．46％,54．83％,31．60％;曲细精管明显萎缩,精原细胞显著减少。利血平组A、NA水平比对照组分别降低了65．95％,77．80％（P〈0．01）,其他成分均接近对照组,差异无统计学意义（P〉0．05）。结论：不同居住条件对中国树鼠鼩生殖生理具有明显的抑制作用。     

矮牵牛花期一些生理指标的变化

选择了 3种颜色的矮牵牛 (PetuniahybridaVilm) :粉红色、杂色和红色 ,将其开花过程分为 4个时期 :未出现花芽、花芽期、花蕾期和开花期 ,测定各时期MDA、可溶性糖、激素水平和多胺含量等指标的变化。结果表明 ,从无花芽期到开花期MDA含量有所升高 ;可溶性糖含量呈现降低的趋势。在粉红色的矮牵牛叶片中 ,IAA含量在开花期升高 ;GA含量在无花芽期和花芽期时较高 ;而ZRs则在花蕾期较低 ,在开花期时含量上升。 3种多胺含量的变化不同 ,腐胺在整个花期略有上升 ,精胺和亚精胺则略有下降     

柑桔隔年结果的生理机制研究进展

柑桔隔年结果是世界上柑桔业的一大问题,严重影响了果实的产量和经济效益。该文对柑桔种类和品种、碳水化合物和氨基酸等代谢产物、核酸和核苷酸、矿质营养、激素、蛋白质及酶等影响柑桔成花和隔年结果的相关因素进行了评述,为今后的研究和生产提供参考依据。     

影响农杆菌介导的柑桔基因转化因素研究

以柑桔（ Ｃｉｔｒｕｓ） 中的枳壳、甜橙、柠檬、四季桔上胚轴为对象, 进行了农杆菌介导的柑桔衰退病病毒外壳蛋白基因转化影响因素研究, 最终将衰退病病毒外壳蛋白基因转入枳壳。研究结果表明： 以卡那霉素为选择试剂, 且外植体水平放置时, 枳壳的选择浓度为５０μｇ／ｍＬ, 其它品种为２０ ～３０μｇ／ｍＬ。外植体与农杆菌的共培养时间３ ｄ 最好, ７０ ～１００μｍｏｌ／Ｌ的酚类化合物（Ａｓ） 的添加对外植体Ｇｕｓ 瞬时表达阳性率有明显促进作用。转化所用外植体年龄以２０ ｄ 最好, 品种之间抗性芽产生率与Ｇｕｓ 阳性芽产生率明显不同。以质粒ＤＮＡＮｃｏⅠ酶切产物为探针, 进行了Ｓｏｕｔｈｅｒｎ ｂｌｏｔ 分析, 结果表明外源基因已稳定整合到了枳壳植株的核基因组中。     

Gender specialization and factors affecting fruit set of the wind-pollinated heterodichogamous Juglans regia

Gender expression, flowering phenology, reproductive performance and factors affecting fruit set (i.e., flowering synchrony, size and distance to the nearest pollen donor) were investigated in a cultivated population of a wind-pollinated self-compatible heterodichogamous Juglans regia (Juglandaceae). Four flowering morphs, (i.e., protandrous, protogynous, male and female) were observed. The sexual functions of the protandrous and protogynous morphs were almost synchronous; however, they were not reciprocal, and the separation of male and female flowering within most monoecious individuals was not complete. Thus, within-morph mating and geitonogamous pollination may be common. The ratio of protandrous versus protogynous morphs was biased towards the protandrous morph, but the fruit set did not differ between the morphs, suggesting that the fruit set of the protandrous morph could be partly compensated by within-morph pollination. The ratio of the female flower number or fruit number to the total male catkin length was higher in the protogynous morph than in the protandrous morph and did not vary with plant size, suggesting that gender variation was not size dependent and that the sexual function of protandrous morphs was more male biased. Fruit set depended on plant size only for protandrous morphs. The fruit set of individual plants decreased with increasing distance to the nearest pollen donor regardless of morph, possibly because of pollen limitation. The fruit set of individual plants increased with flowering synchrony, indicating that flowering synchrony could affect reproductive success.     

A possible role for flowering locus T‐encoding genes in interpreting environmental and internal cues affecting olive (Olea europaea L.) flower induction

Olive (Olea europaea L.) inflorescences, formed in lateral buds, flower in spring. However, there is some debate regarding time of flower induction and inflorescence initiation. Olive juvenility and seasonality of flowering were altered by overexpressing genes encoding flowering locus T (FT). OeFT1 and OeFT2 caused early flowering under short days when expressed in Arabidopsis. Expression of OeFT1/2 in olive leaves and OeFT2 in buds increased in winter, while initiation of inflorescences occurred i n late winter. Trees exposed to an artificial warm winter expressed low levels of OeFT1/2 in leaves and did not flower. Olive flower induction thus seems to be mediated by an increase in FT levels in response to cold winters. Olive flowering is dependent on additional internal factors. It was severely reduced in trees that carried a heavy fruit load the previous season (harvested in November) and in trees without fruit to which cold temperatures were artificially applied in summer. Expression analysis suggested that these internal factors work either by reducing the increase in OeFT1/2 expression or through putative flowering repressors such as TFL1. With expected warmer winters, future consumption of olive oil, as part of a healthy Mediterranean diet, should benefit from better understanding these factors.     

Precocious flowering of juvenile citrus induced by a viral vector based on Citrus leaf blotch virus: a new tool for genetics and breeding

The long juvenile period of citrus trees (often more than 6 years) has hindered genetic improvement by traditional breeding methods and genetic studies. In this work, we have developed a biotechnology tool to promote transition from the vegetative to the reproductive phase in juvenile citrus plants by expression of the Arabidopsis thaliana or citrus FLOWERING LOCUS T (FT) genes using a Citrus leaf blotch virus‐based vector (clbvINpr‐AtFT and clbvINpr‐CiFT, respectively). Citrus plants of different genotypes graft inoculated with either of these vectors started flowering within 4–6 months, with no alteration of the plant architecture, leaf, flower or fruit morphology in comparison with noninoculated adult plants. The vector did not integrate in or recombine with the plant genome nor was it pollen or vector transmissible, albeit seed transmission at low rate was detected. The clbvINpr‐AtFT is very stable, and flowering was observed over a period of at least 5 years. Precocious flowering of juvenile citrus plants after vector infection provides a helpful and safe tool to dramatically speed up genetic studies and breeding programmes.     

影响开花植物物种多样化速率变化的因素探讨

开花植物(被子植物)是目前最为繁荣兴盛的陆地植物,是地球上种类最多、分布最广、适应性最强的优势植物类群。然而,物种多样性在开花植物的谱系中极端不均匀,同时其物种并非匀速增加,而是集中在某些时期快速扩张。这种现象暗示了开花植物的多样性受到某些因素的调控,而揭示影响开花植物多样化速率的机制便是这数十年来植物学家孜孜不倦努力的目标。该文介绍了当前的研究进展。研究显示,那些与类群分类相关的关键性状大多与多样化无关,而早期被视为决定因素的花性状,目前被认为影响较低或是需要多性状联合才产生实际影响。多倍化是一个受到高度关注的候选因素,被认为能提供物种扩张所需的遗传物质,在适当的情况或其他因素的参与下促成物种多样化。然而,许多研究也呈现各类的争议,这些悖论或许代表了多倍化不是决定因素,而是扮演着间接的角色。另外,环境的变异(温度、湿度、空间)也能提高多样性的发生。整体而言,影响开花植物多样化速率的原因,很可能是一种综合因素共同促成的结果,而每个植物类群多样化速率提升的原因亦可能不尽相同。因此,先分别对植物类群进行探讨,再进行整合,或许更能提供一个确实且普遍的模型。     

Probing the role of endogenous ethylene in the degreening of citrus fruit with ethylene antagonists

The ethylene antagonists, 2,5-norbornadiene (NBD) and silver nitrate, were used to probe the involvement of endogenous ethylene in the natural degreening of citrus fruit. Mature-green, detached Shamouti orange (Citrus sinensis L. Osbeck) fruit were treated with NBD vapor or dipped in solutions of silver nitrate. More than 80% of the chlorophyll was lost from control fruit after 8 days. NBD (0.11 mmole/liter) inhibited the loss of chlorophyll by 60%. NBD also antagonized the degreening induced by exogenous ethylene by 50%. Silver nitrate (0.1 mM) inhibited the loss of chlorophyll by 55%. Ethylene evolution of mature, green detached fruit was <2 nl.fruit^-1.h^-1 (ca. 13.5 nl.Kg^-1FW.h^-1) and did not change significantly for 7 days after harvest. NBD concentrations up to 0.22 mmole/liter did not enhance ethylene evolution. Not with-standing the extremely low amounts of ethylene evolved, the inhibition of degreening by NBD and silver nitrate suggests that endogenous ethylene is involved in the control of this process in mature citrus fruit.     

Gibberellic acid causes earlier flowering and synchronizes fruit ripening of coffee

The effect of 100 mgl^–1 gibberellic acid (GA₃) on flowering and fruit ripening synchrony, fruit set, fruit fresh weight, and vegetative growth were studied for different size classes of coffee (Coffea arabica L. cv. Guatemalan) flower buds. Flower buds that were > 4 mm, but not developed to the candle stage at the time of GA₃ treatment, reached anthesis 20 days earlier than the controls, and their development was independent of precipitation, unlike the controls. Fruit from buds that were treated with GA₃ at the candle stage showed earlier and more synchronous ripening than the control, although no differences in flowering were found during anthesis. Buds that were smaller than 4 mm at the time of treatment did not respond to GA₃ applications. Treatment with GA₃ did not affect fruit set, fresh weight of fruits, or vegetative shoot growth.     

开花期枣树茎流与气象因子的关系

阿克苏地区农田灌溉水资源利用率相对较低,大多采用漫灌为主、滴灌为辅,加上环境干旱、水资源紧缺已成为制约当地红枣种植业发展的主要因素,因此迫切需要寻找新型节水灌溉方法。该研究采用美国Dynamax公司生产的Flow-32包裹式茎流计对茎流速率进行连续监测,并在样地内安装HOBO小气候仪同步获取气象数据,将所得数据进行对比分析,探讨了不同灌溉方式下枣树茎流速率的变化规律以及与气象因子之间的关系。结果表明：两种灌溉方式下茎流连日变化呈现明显的昼夜变化规律,茎流速率均为单峰曲线且夜间茎流活动现象明显,早晨茎流启动时间W1早于W20.5 h,峰值前后W1和W2枣树茎流均出现较小幅度的“峰值群”,W1和 W2峰值出现时间分别为13：30－14：30和13：00－14：30,峰值大小分别为2133.33~2724.93 g·h-1和2234.11~2689.40 g·h-1;茎流日累积量变化过程曲线均为“S”形,但W1日茎流总量大于W2;茎流速率变化曲线均与太阳辐射和温度呈现正相关,与空气湿度呈现负相关,与风速相关性较差;太阳辐射表观波形变化趋势与两种灌溉方式下茎流变化曲线均存在异同,启动时间早于W1约0.5 h,W2约1 h,但峰值出现时间却晚于W1和W2。通过相关分析,太阳辐射均为主要影响因子,建立两种灌溉方式下液流速率与气象因子的多元线性模型,经过回归系数和相关系数检验,W1和W2多元线性回归方程均达到了显著水平。该研究结果为新型灌溉方式W1的实用性和优越性提供了科学依据。     

两结实类型柑橘果实铁锰锌铜含量的年周期变化(英文)

对单性结实的龟井温州蜜柑和自花授粉结实的鄂柑1号柑橘果实的铁、锰、锌和铜含量的年周期变化进行了测定。结果表明:(1)龟井子房的锌和铜含量在花前至花期居较高,花后趋下降,而鄂柑1号对应值在花期出现明显下降并居较低,花后却有一明显上升;两品种子房(幼果)的铁和锰含量变化却无明显差异,花后呈类似的下降趋势。(2)幼果阶段的果实铁、锰、锌和铜含量均居较高,在果实膨大初期(干旱期)均出现一明显下降,而在果实膨大中期却出现显著上升,之后又趋下降。本文还对果实发育中的微量元素含量动态及其与果实发育之间的关系进行了讨论。