谢谢阿呀呀的鼓励.我正努力翻译这篇论文的正文部分.好长哦.那些表格不好办哦.

Introduction
一 绪论
Eucalyptus nitens (Deane and Maiden) is an important, fast growing eucalypt planted commercially in several southern hemisphere countries (Tibbits et al. 1997). The species is well adapted to the range of environmental conditions encountered at cold, high altitude sites in the summer rainfall region of South Africa (Swain and Gardner 2003), and is, therefore, currently the most favoured eucalypt for commercial pulpwood production in such areas (Clarke 2000, Little et al. 2002). The erratic and sparse flowering tendency of E. nitens has hampered genetic improvement and commercial seed production efforts of this species (Reid et al. 1995). In South Africa, seedling and grafted trees rarely flower before the age of ten years (Eldridge et al. 1993, Swain and Chiappero 1998), and personal experience has shown that, even then, flowering only occurs at select high altitude sites following exceptionally cold winters. In other southern hemisphere countries (Australia and Chile), E. nitens flowers far more consistently and prolifically (Moncur and Hasan 1994, Gardner 2001).
亮果桉(Deane and Maiden) 生长快速，作为桉树的一个重要的经济树种，在南半球很多国家进行种植(Tibbits et al. 1997)。南非夏季降雨地区的高纬度寒冷区域所会遇到的各种环境条件，这种桉树都能很好地适应(Swain and Gardner 2003)，也因此在这些地区成为目前最受欢迎的桉树林浆经济树种(Clarke 2000, Little et al. 2002)。亮果桉变化无常且稀疏的成花习性阻碍了它的基因改良和商业制种成果 (Reid et al. 1995)。在南非，少有以秧苗和嫁接方式繁殖的桉树在十年树龄前开花的情况(Eldridge et al. 1993, Swain and Chiappero 1998)，即便到了那时候，以我的个人经验，也只是在异常冷冬过后的个别高纬度林址看得到开花现象。南半球的其他一些国家如澳大利亚和智利，亮果桉开花连续得多也多得多(Moncur and Hasan 1994, Gardner 2001)。
During the past decade, considerable progress has been made towards identifying the triggers controlling flowering in E. nitens and developing a management system for enhancing flower and seed production in the species (Moncur and Boland 2000). A range of environmental conditions and cultural techniques have been implicated in the induction of flowering in eucalypts (Moncur and Boland 2000), yet, until now, cold and the triazole-type plant growth retardant paclobutrazol ((2RS, 3RS)-1-(4-chlorophenyl)-4,4- dimethyl-2-1, 2,4-triazol-1-yl-pentan-3-ol) appear to be the most effective treatments in temperate species such as E. nitens and E. globulus (Moncur and Boland 2000, Williams et al. 2003). Other possible stimuli for floral induction, such as photoperiod, have been found to play no role in the induction of flowering, neither in the temperate ornamental eucalypt E. lansdowneana nor in the commercial timber species E. nitens (Moncur 1992, Moncur and Hasan 1994). Pryor (1976) reported no indication of photoperiodic regulation of flowering in E. tereticornis, – a species with the highest latitudinal range among eucalypts (8°S to 38°S latitude (Boland et al. 1992)). Drought stress is known to stimulate floral induction in a range of evergreen tree crops including lychee (Litchi sinensis Sonn.) (Menzel 1983) and Citrus spp. (Krajewski and Rabe 1995), and in certain conifers and broadleaf forestry tree species (Philipson 1990). However, drought stress has not been conclusively linked to floral induction in temperate eucalypt species, including E. nitens (Moncur 1992, Moncur and Boland 2000).
过去十年里，在确定控制亮果桉开花因素方面，在形成加强开花结果的管理系统方面，都取得了显著的成果(Moncur and Boland 2000)。诱发桉树开花的一系列环境条件已经和培育技术紧密结合, 然而直至如今，低温和三氮杂茂类植物生长延缓剂多效唑 ((2RS, 3RS)-1-(4-chlorophenyl)-4,4- dimethyl-2-1, 2,4-triazol-1-yl-pentan-3-ol)依然是对付诸如亮果桉和蓝桉这类温带桉树最有效的方法(Moncur and Boland 2000, Williams et al. 2003)。其他可用的花芽诱因，无论是对于观赏树种的E. lansdowneana还是经济径材树种的亮果桉都毫无诱发开花的作用，光周期就是一种(Moncur 1992, Moncur and Hasan 1994)。Pryor (1976)曾在报告中称， 细叶桉没有光周期的开花规律。在所有桉树中，它具有最高纬度生长范围 (南纬8°~ 38°(Boland et al. 1992))。众所周知，干旱胁迫是一种花芽诱因，能够作用于一系列常绿木本作物，包括荔枝(Litchi sinensis Sonn.) (Menzel 1983)和柑橘柚橙类(Krajewski and Rabe 1995)，还能作用于一些特定的针叶林及阔叶林树种(Philipson 1990)。然而，干旱胁迫与包括亮果桉在内的温带桉树的花芽萌发之间尚未有结论性的联系(Moncur 1992, Moncur and Boland 2000)。
(to be continued)

Although a period of cold appears obligatory for floral induction in E. nitens, paclobutrazol treatment, in conjunction with sufficient winter cold, can significantly enhance floral bud production and subsequent seed crop size (Moncur and Hasan 1994, Williams et al. 1999). For this reason, paclobutrazol treatment has become an extremely popular tool in E. nitens breeding and seed production programmes worldwide. In South Africa, due to apparently unfavourable climatic conditions for flowering, tree breeders and commercial seed producers are currently almost completely reliant on paclobutrazol application to obtain a significant amount of flower and seed production in E. nitens (Swain and Chiappero 1998, Swain and Gardner 2002). This practice, however, is far from the ideal, as, apart from the high cost of the chemical, paclobutrazol persists actively in the soil for several years, the latter feature attracting increasing pressure from environmentalists to discontinue such practice (Reid et al. 1995, Moncur 1998). It is thus highly desirable to investigate more economical and environmentally sustainable ways of stimulating seed production in E. nitens.
虽然一段时期的低温是亮果桉花芽萌发必不可少的条件，但是足够的冬季冷量加上多效唑处理就能显著促进花芽发育并进而提高种子产量(Moncur and Hasan 1994, Williams et al. 1999)。出于此因，在全世界范围内，多效唑处理成为了亮果桉繁育和制种过程中极其普及的手段。目前在南非，无论是树木繁育还是商业制种，因为气候条件显然对开花不利，人们几乎完全依仗多效唑处理来取得可观的开花量和结籽量(Swain and Chiappero 1998, Swain and Gardner 2002)。然而，这种做法是很不理想的，除了化肥的高成本外，多效唑会在土壤中存留多年。这第二点特性就不断招致环保人士施加压力，要求终止使用该手段(Reid et al. 1995, Moncur 1998)。因此，迫切需要研发出更经济且有利于环境可持续性的方式来促进亮果桉结籽。
(to be continued)

Conditions favouring floral induction in E. nitens have yet to be intensively investigated in South Africa. In SE Australia (Canberra, ACT) floral initiation in E. nitens occurs in late winter (August to early September) (Moncur et al. 1994a). Although winter cold has been identified as an important stimulus for floral induction, little is known about the timing of inductive cold events for flowering in E. nitens. It is unclear as to whether cold acts as a floral stimulus in one single inductive event or cumulatively over a series of events (Moncur and Hasan 1994, Meilan 1997). Observations of flowering patterns in E. nitens in South Africa tend to indicate that the latter is more likely. At certain high altitude, exposed sites in the summer rainfall forestry belt, trees of E. nitens flower more consistently and profusely than at nearby sites of similar annual total precipitation, altitude, aspect, soil type and soil depth. Both ‘good flowering’ sites and ‘poor flowering’ sites occur above 1 400 metres above mean sea level (amsl) and are not drought-prone due to high mean annual precipitation (MAP) (>950mm) and deep soils (>1.0m). Our experience indicates that the main environmental difference between the two site types pertains to the degree of topographical relief and associated winter day/night temperature amplitudes. The ‘good flowering’ sites are always in exposed positions on crests or southwest to east-facing up-slopes where air drainage is good and winter day/night temperature amplitudes are low, whereas the ‘poor flowering’ sites occur on flatter terrain where winter day/night temperature amplitudes are relatively high. This phenomenon suggests that uniform cool conditions in winter are more promotive of flowering in E. nitens than extremely varying temperature conditions. Hence, a cumulative cold requirement may be implicated in floral induction in E. nitens.
南非已经开始深入研究亮果桉花芽萌发的有利条件。在澳大利亚东南部（堪培拉，首都直辖区），亮果桉花芽萌发始于晚冬（八月至九月初）(Moncur et al. 1994a)。尽管冬季低温已被确定为花芽萌发的重要促进因素，关于如何选择诱发亮果桉开花的寒冷事件的时机人们却知之甚少。低温是在单次事件中就能诱发花芽，还是需要在一系列事件中进行积累方能生效，这尚未清楚(Moncur and Hasan 1994, Meilan 1997)。南非的亮果桉开花习性或多或少说明，后者可能性大些。在夏季降雨林带一些特定高纬度的裸露林址，对比附近在年降水量、纬度、朝向、土壤类型和土壤深度等方面近似的其他地方，生长在那里的亮果桉开花更连续更繁盛。“开花好”和“开花差”的林址都处在平均海拔(amsl)1 400米以上，年平均降水量(MAP) (>950mm)高，土壤深(>1.0m)，没有干旱可能。以我们的经验，在两类林址之间造成环境差异的是地形起伏程度和相关的冬季昼夜温幅。“开花好”的林址总是处在山脊或西南向到东向山坡上，那里下降风好，冬季昼夜温幅小；相反，“开花差”的林址则处于平坦地形，冬季昼夜温幅相对大。这种现象说明，冬季均匀的冷凉条件比极端波动的温度条件更能促使亮果桉开花。因此，亮果桉的花芽萌发也许需要一定的低温累积。
(to be continued)

In South Africa, currently E. nitens commercial seed orchards (and indeed the bulk of the plantations of this species) are located in ‘warm temperate’ areas of the summer rainfall region, between latitudes 25.5 and 31°S, where large day/night temperature amplitudes regularly occur during the winter months (May to September) (Schulze 1997, Swain and Gardner 2003). Winter daytime temperatures commonly exceed 20°C whilst night-time temperatures descend below –5°C, resulting in day/night amplitudes exceeding 25°C (Richardson and McMahon 1992). Such extreme temperature conditions in winter are antagonistic towards chilling accumulation and bud endodormancy release in temperate fruit crops (Couvillon and Erez 1985). In contrast, ‘uniformly cool’ conditions associated with cloudy and foggy weather in winter enhance chilling accumulation (Erez 2000).
目前在南非，亮果桉商业种子园（事实上是这种树的大片人工林）地处夏季降水地区的“温暖”区域，介乎南纬25.5°到31°之间，那里昼夜大温差的出现在冬季月份（五月到九月）里是有规律的(Schulze 1997, Swain and Gardner 2003)。冬季白天的温度常常高于20°C，而晚上则降至–5°C以下，导致超过25°C的昼夜温差(Richardson and McMahon 1992)。如此极端的冬季温度条件对低温累积和温带果树芽休眠释放极为不利(Couvillon and Erez 1985)。与之相反的是，冬季因多云和有雾天气产生的均匀冷凉条件促进了低温累积 (Erez 2000)。
Therefore, chill models used to quantify the effect of such winter chilling on bud dormancy release in temperate fruit crops (George and Erez 2000, Halgryn et al. 2001) could provide a useful tool to estimate floral bud production in E. nitens. In order to characterise ‘effective’ cold for floral induction in E. nitens, this study evaluated three such chill models to determine whether accumulated winter chilling was related to E. nitens floral bud production. Information arising from such an investigation would not only add to the limited knowledge of optimal temperatures for floral induction in E. nitens, but may also assist in the siting of E. nitens seed orchards.
于是，用于量化如此冬季低温对温带果树芽休眠释放的作用的低温模型(George and Erez 2000, Halgryn et al. 2001)就能作为一个有用的工具，估算亮果桉的的花芽萌发情况。为了说明怎样的低温才是对亮果桉花芽萌发 “有效”，本项研究对三个这样的低温模型进行评估，确定冬季累积低温是否与亮果桉花芽萌发相关。从这样的研究中得出的信息不仅丰富了有限的亮果桉花芽萌发最佳温度的知识，还将为亮果桉种子园的选址提供帮助。
(to be continued)

Material and Methods
A series of four field trials was established across a range of high altitude sites in the summer rainfall forestry belt during 1996. The main aim of the series was to subject E. nitens trees to a range of winter cold conditions and to investigate whether flower bud production was related to amount of winter chilling received by the trees during the previous winter. In the process, the suitability of each of the three different chill models could be evaluated. The effects of ‘propagule type’ (seedling or graft), ‘E. nitens family’ and ‘paclobutrazol application’ on tree growth and floral bud production were also determined, as these were treatments relevant to then-current E. nitens seed orchard practices in South Africa (Swain et al. 1998, Jones 2002).
二 材料和方法
1996年间，在夏季降雨林带某高纬度范围的林址展开了一系列的四场实验，系列实验的目的是把亮果桉作为实验对象，放到某个范围的冬季低温条件中去，研究花芽萌发是否与树木在上年冬季接收到的冷量有关。实验过程当中，三个不同的低温模型中每一个的适应能力将被给予评价。“繁殖体”（秧苗或嫁接）、“亮果桉家系”和“多效唑应用”对树木生长和花芽萌发所起的作用得到确定，因为这些方式与当时南非的亮果桉种子园的惯常做法有关(Swain et al. 1998, Jones 2002)。
Plant material
Propagules used to establish trees for the experiments were derived from three E. nitens provenances, the origins of which are briefly described in Table 1. The seedling trees were produced as follows: In October 1995, four separate seedlots were sown and raised in a nursery. The seedlots were four selected families from the three provenances listed in Table 1, each seedlot consisting of seed from a different, single mother tree in a natural stand in New South Wales, Australia.
1 植物材料
实验用源自亮果桉三个种源的繁殖体进行种植，表1简略描述了种源的背景。实生树的产生如下：1995年10月，四个不同批次的种子下种并在苗圃进行培养。它们是从表1所列的三个种源中挑选出来的家系，每一批次里的种子来自澳大利亚新南威尔士天然环境中的一株单雌株，批次间各不相同。

Table 1: Australian origins of the Eucalyptus nitens provenances and families in the field trials
Provenance Family State Latitude Longitude Altitude (metres amsl*)
Barren Mountain 32091 New South Wales 30°25‘ 152°28‘ 1 505
Barren Mountain 32097 New South Wales 30°24‘ 152°29‘ 1 535
Barrington Tops 34838 New South Wales 31°55‘ 151°30‘ 1 450
Tallaganda 37255 New South Wales 35°54‘ 149°30‘ 1 290
*amsl, above mean sea level

表1: 试验田中来自澳大利亚的亮果桉种源和家系
种源    家系    州    纬度    经度    海拔(平均海拔  米)
Barren Mountain    32091    新南威尔士    30°25‘    152°28‘    1 505
Barren Mountain    32097    新南威尔士    30°24‘    152°29‘    1 535
Barrington Tops    34838    新南威尔士    31°55‘    151°30‘    1 450
Tallaganda    37255    新南威尔士    35°54‘    149°30‘    1 290
(to be continued)

谢谢鼓励.既然开始了,我会把它完成.尽管不容易.

The grafted trees were produced as follows. In August 1995, scions were cut from four different three-year-old grafted ramets in a clonal orchard, and grafted onto six-month-old, potted seedling rootstocks. At the time of cutting the scions, none of the ramets had previously produced flower buds. The rootstocks were grown from South African open-pollinated orchard seed of mixed provenance background. The above four ramets were originally produced by grafting scions from six year old ‘plus’ trees of the same families (and provenances) as the seedlings (Table 1). Seedling trees and grafted trees of the same families therefore were half-siblings. Hence, each of the four ‘seedling’ treatments consisted of many genotypes, whereas each of the four ‘graft’ treatments consisted of only one genotype.
嫁接树产生如下：1995年8月，从无性系林中四个不同的三年生嫁接分株上切得接穗，嫁接到六月生盆栽秧苗的砧木上。在切取接穗时，任何一个分株此前都没有萌发过花芽。砧木是由来自南非自由授粉得到的有种源混交背景的种子生长得来。上述的四个分株最初是通过从六年生同一家系（及种源）的实生（表1）优株上切取接穗嫁接得到。因此，同一家族的实生树和嫁接树是半亲。所以，四个“实生”的试验对象之中每一个都由多个基因型组成，而“嫁接”的每一个都只由一个基因型组成。

Environmental conditions
To test the effect of winter chilling on floral bud production in E. nitens, a gradient in chilling was created by selecting trial sites at four separate localities based on altitude and latitude (Table 2). However, sites varied only slightly in daylength, with a maximum of 27min difference in daylength between sites at the shortest day (21st June) and a maximum of 5min difference in daylength between sites at the longest day (30th September) of the cold accumulation period (Schulze 1997). Mean annual temperature (MAT) of the warmest site, Gowan Brae (15.2°C), was below the upper threshold for optimum commercial planting of E. nitens in South Africa (16.0°C), whereas that for the coldest site, Tentkop (12.6°C), was well below the lower threshold (14.0°C) (Swain and Gardner 2003) (Table 2). The other two sites were Mossbank (MAT 14.0°C) and Blyfstaanhoogte (MAT 13.2°C). Although the altitude of Blyfstaanhoogte and Tentkop were similar (1995 and 1920 metres amsl, respectively), the latter was a colder site as it was located further south (Table 2). All sites were similar in aspect (SEto SW-facing) and exposure (mid-slope), and prone to light to moderate frosts in winter. Although the sites were all located in the summer rainfall area where rainfall distribution has a distinct summer maximum, drought conditions were highly unlikely to occur at these sites as MAP was high (>950mm), summer mists frequent and soils deep (>1.0m). Therefore, daylength as well as drought as floral induction stimuli, as reported for a number of woody angiosperms (Meilan 1997) including certain eucalypts (Moncur and Boland 2000), could be excluded.
2 环境条件
为了就冬季低温对亮果桉花芽萌发的影响进行试验，根据所在的经度纬度挑选出来四个不同地点的试验林址营造出一个低温梯度（表2）。不过，在昼长方面，林址之间略有区别。在低温累积时期内，昼长最短的一天（六月21日）林址间最大昼长差值为27 min；昼长最长的一天（九月30日）林址间最大昼长差值为5 min(Schulze 1997)。Gowan Brae (15.2°C)是最温暖的林址，年平均温度(MAT)低于南非亮果桉最佳经济种植的上阀值(16.0°C)；而最寒冷的林址在Tentkop (12.6°C)，低于下阀值(14.0°C) (Swain and Gardner 2003) (表 2)。另外两个林址分别是Mossbank (MAT 14.0°C) 和 Blyfstaanhoogte (MAT 13.2°C)。尽管Blyfstaanhoogte和Tentkop有着相近的海拔高度（分别是平均海拔1995米和1920米），后者因为更往南而较寒冷（表2）。所有的林址在朝向方面相近（东南向到西南向），在裸露程度上相似（中坡度），在冬季都易受低到中等霜冻。尽管这些林址都处在夏季降雨地区，最大夏季降雨量截然不同，干旱情况在这些地方却极不容易发生，归因于高的年平均降水量(>950mm)、频繁的夏雾和深厚的土壤(>1.0m)。因此，正如报告所称，许多木本被子植物(Meilan 1997)，包括特定的桉树(Moncur and Boland 2000)，可以排除昼长和干旱胁迫作为花芽诱因的情况。
(to be continued)

Paclobutrazol treatment
A suspension of Cultar® (formulation 250g.l–1 paclobutrazol; ICI Agrochemicals) was applied as a soil drench during early April 1998 at a rate of 0.25g a.i. per cm b.s.c.. Method and timing were based on treatments reportedly successful in inducing flowering in E. nitens and E. globulus (Griffin et al. 1992, Moncur et al. 1994b). B.s.c. represented the circumference at the narrowest point along the stem between graft union (in the case of grafts) or root collar (in the case of seedlings) and first primary lateral (branch). The paclobutrazol dose for each tree was dispersed in 2 litres of water and applied evenly to the soil surface in a 1.0m radius around the base of each tree.
3 多效唑处理
1998年4月初，以土壤灌溉方式施用Cultar®悬液(配方 250g.l–1 多效唑；ICI 农药)，比率0.25g a.i./ cm b.s.c.。方法和时机的根据是据称成功诱发了亮果桉和蓝桉开花的处理方法(Griffin et al. 1992, Moncur et al. 1994b) 。b.s.c.表示的是结合区（用于嫁接方式）或地径（用于实生方式）与第一原生侧枝之间沿主茎上的最近点的胸径。每棵树的多效唑剂量用2升水冲散，在树的基部1米半径范围的土壤表面均匀施用。
(to be continued)