马尾松二代无性系种子园的花期同步性

【目的】研究马尾松二代种子园无性系的开花物候特征、花期同步性、结实状况及气候影响因子,评价无性系花期同步性规律,指导种子园经营生产及提高种子遗传品质与产量。【方法】连续2年对浙江省淳安县姥山林场马尾松二代无性系矮化种子园的22个无性系进行花期、花量和结实性状调查,分析其开花物候与花期同步指数。【结果】各无性系雌雄球花整体花期持续时间为8～17天, 2014年始花期相对于2013年滞后约6天,且持续时间缩短约6天。整体水平上,年度内雌球花及雄球花的各花期时长差异较小;无性系的始花期和盛花期的物候特征年度间存在差异, 2014年无性系内雌雄球花开花的同步性更强。无性系的开花物候受气候因素影响较大,这使得无性系间开花同步程度降低,花期同步指数变异增加, 2013年和2014年花期同步指数变化范围分别为0.041～0.556和0.284～0.802,无性系的平均变异系数分别为32.3%和16.8%。各无性系分别作为父、母本时,年度内无性系花期整体同步性水平差异较小,表现出无性系作为父本时的散粉期整体的同步性要高于作为母本时的可授粉期的同步性。年度间无性系作为父、母本及自交的花期同步指数均有极显著差异, 2014年各无性系的花期同步指数在整体水平均高于2013年,但自交指数在年度间无显著差异。相关分析表明,雌球花越多的无性系的球果数越多;而雌球花花期持续时间越长的无性系座果率越高;不同年度的雌球花盛花期和花期的持续时间均与千粒质量指标呈显著或极显著正相关。【结论】浙江姥山林场马尾松二代无性系种子园雌、雄球花的花期具有较好的同步性,无性系间没有出现花期不遇现象。无性系交配组合的雌球花可授粉期和雄球花的散粉期影响了种子园无性系的种实品质及座果率。连续2年的观测表明无性系间花期整体同步性水平存在差异,且这种差异与二代种子园无性系的亲本遗传背景有关。各无性系分别作为父、母本时,表现出无性系作为父本时的散粉期整体的同步性要高于作为母本时的可授粉期的同步性,无性系作为父本和母本时花期同步指数呈负相关,且种子园内存在1/3无性系具有高于异交平均水平的自交可能性,是马尾松二代种子园管理和无性系再选择应综合考虑的因素。     

Phenological observations onLarix principis-rupprechtii Mayr. in primary seed orchard

Through 5 years of phenological observations onLarix principis-rupprechtii Mayr. in primary seed orchard and studies on population and individuals of clones, the annual periodic phenological laws were revealed and the annual phenological periodic table was drawn up. The correlation between various phenophases, the air temperature and active accumulated temperature were analyzed and expounded. The authors also analyzed the similarities and differences of phenophases among clonal individuals as well as the blooming properties of male and female flowers at the same time. This study could provide theoretical reference for working out the production plan of improved varieties and other management measures in seed orchard ofLarix principis-rupprechtii. Biography: ZHANG Xin-bo (1956-), male, senior engineer in Shanxi Academy of Forestry Science and Northern Research Institute of Forestry of China, Taiyuan 030012, P. R. China. Responsible editor: Zhu Hong     

木荷种子园无性系开花物候及同步性分析

[目的]研究种子园无性系的花期物候特征和花期同步性及影响因子对种子园科学管理具有指导意义。[方法]2015年和2016年连续2 a对木荷无性系种子园中19个无性系进行花期物候调查,分析其开花物候与花期同步指数。[结果]木荷种子园各无性系开花持续时间为10~28 d,2016年较2015年晚2 d进入始花期。相关分析结果表明,开花数多的无性系比开花数少的无性系花期更长、座果数更多,花期持续时间长的无性系比持续时间短的无性系座果数更多。无性系组合间花期同步指数有较大差异,2015年和2016年变化范围分别为0.552~0.857和0.406~0.808,平均分别为0.758和0.713,其中花期同步指数大于0.80的无性系分别在50%和40%以上。年度内花期同步指数变异系数分别为12.016%~46.476%和15.375%~51.202%,无性系之间平均花期同步指数存在极显著变异(P0.01)。年度间花期平均同步指数为0.737,平均花期同步指数间不存在显著变异(P0.05)。年度间花期同步指数相关系数为0.229,表明年度间花期同步指数具有一定的相关性,但不显著。[结论]木荷种子园无性系年度间花期同步指数较为稳定,可根据开花物候和花期同步指数对无性系进行筛选和优化,同时辅以人工授粉等措施弥补花期同步性差异,以达到提高种子园种子产量和质量的目的。     

Mating patterns in an indoor miniature <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> seed orchard as revealed by microsatellite markers

To evaluate the practical application of an indoor seed orchard, we compared the seed production, final germination rates and mating patterns of potted Cryptomeria japonica D. Don clones in two miniature seed orchards: one in a glasshouse and the other outdoors. There was no statistically significant difference in total seed production between the orchards (P = 0.275, ANOVA). However, the final germination rate of seeds produced in the indoor orchard was significantly lower than that of seeds produced in the outdoor orchard (P < 0.01, Wilcoxon test). The average self-fertilization rate was higher in the indoor orchard (27.2%) than in the outdoor orchard (5.6%), and this parameter was strongly associated with the reduced final germination rates of the seeds harvested in the glasshouse. Pollen contamination was considerably lower in the indoor seed orchard (48.9% in the outdoor seed orchard and 4.4% in the indoor seed orchard). χ² tests indicated that the paternal contributions of each constituent clone differed significantly in both orchards (P < 0.001 in both cases). The strong variations in paternal contributions among indoor orchard clones was significantly correlated with their respective pollen production capacities (Spearman ρ = 0.693, P < 0.001). To reduce the high self-fertilization rates, we recommend the use of orchard clones with similar pollen production capacity in indoor seed orchards.     

Variation in growth of Heterobasidion annosum among clones of Picea abies incubated for different periods of time

Thirty‐seven 4‐year‐old clones of Picea abies were inoculated with one isolate of the S intersterility group of Heterobasidion annosum in a greenhouse. The dehardened cuttings were organized in three different groups with four to six ramets in each group. All groups were inoculated on the same day shortly after shoot elongation. The groups were sampled for H. annosum growth after 34 (group 1), 83 (group 2) and 182 days (group 3), respectively. Measured parameters were cutting height and diameter, vigour index of the cuttings, infection incidence, mortality rate and fungal growth in the stem. The height of the cuttings was almost constant during the 6 months of incubation, whereas the diameter increased by about 10% during the same period. The proportion of living cuttings containing H. annosum decreased with time (99.5, 93 and 67% infection in groups 1, 2 and 3, respectively) and differed significantly among clones in group 3. Mortality rate increased with time (0.5, 22 and 37% mortality in groups 1, 2 and 3, respectively) and differed significantly among clones in groups 2 and 3; the same clones being most susceptible for both times. Mean fungal growth into the wood was significantly different among groups and among clones within each group. The ranking position for fungal growth was similar in the three groups. The results indicate that frequency of infection success, mortality rate and fungal growth are clone‐dependent factors. Broad sense heritability varied between 0.08 and 0.25 for fungal growth and lesion length at the three incubation periods. Infection success frequency was initially not different among clones but in the longer incubation periods there were significant differences among clones, indicating differences in resistance. Fungal growth in wood differed among separate host clones irrespectively of the length of inoculation period. The vigour of the cuttings seem to influence the length of fungal extension only in the initial stage of the infection.     

Parameters affecting shoot production and rooting of cuttings from lodgepole pine hedges

By propagating lodgepole pine (Pinus contorta) cuttings in vivo, we obtained after 7 growing cycles (ca 3.5 years) in a greenhouse, sufficient number of cuttings from most families to establish clonal progeny tests. Twenty-one full-sib families with approximately 20 clones per family were studied for five years. Years when cuttings were set, families within latitude and clones within families differed significantly in rooting percentages, with the variance components 4.2%, 8.2% and 9.5%, respectively. One way to get a frequent and uniform rooting is to take cuttings from non-leading shoots since they have higher rooting percentage than leading shoots. Neither total length of the cuttings nor length of the primary needles were significantly correlated to rooting percentage. With appropriate management of the ortets and the cuttings during rooting, most clones could be included in a cutting propagation program.     

Resource level as a proximate factor influencing fluctuations in male flower production in Cryptomeria japonica D. Don

Airborne pollen of Cryptomeria japonica causes severe pollinosis, and the number of people suffering from pollinosis has increased rapidly during recent decades. Male flower production in C. japonica shows annual variability; thus, predicting male flower production for the following spring could be a countermeasure against pollinosis. We analyzed factors that explain fluctuations in male flower production of C. japonica according to parameters reflecting internal resource dynamics based on field observations. In addition, we carried out experiments to regulate available resource levels using artificial shading to test the effect of internal resource levels on the number of male flowers produced. We found that temperature and precipitation in the previous summer and a relative increase in male flower production in the previous year were negatively related, whereas sunshine duration in the previous summer and diameter at breast height were positively related to the current year increase in male flower production. The number of male flowers was significantly reduced by the shading treatment and was positively correlated with the amount of total non-structural carbohydrates in the root. These results suggest that understanding the parameters controlling internal resource levels could lead to more accurate predictions of male flower production.     

Morphological and Ecological Variation of Gremmeniella abietina var. abietina in Pinus sylvestris,Pinus contorta and Picea abies Sapling Stands in Northern Finland and the Kola Peninsula

The morphological and ecological variation of two types of Gremmeniella abietina var. abietina causing scleroderris canker on conifers was investigated in Pinus spp. and Picea sp. sapling stands in northern Finland and the Kola Peninsula. Small - tree type (STT or B type) of G. abietina was detected alone in 13 Scots pine, three lodgepole pine and two Norway spruce sapling stands out of 26 stands investigated, both STT and large - tree type (LTT or A type) were observed in six Scots pine stands, and LTT was detected alone in two Scots pine stands. For the first time, G. abietina was found to injure Norway spruce saplings in a respective plantation in northern Fennoscandia. STT isolates produced statistically significantly more conidia in vitro than LTT isolates. Morphological variation in conidia septation revealed that STT produced conidia with more than five septa more frequently than did LTT. There was a greater range in variation in septation in STT than in LTT, with overlapping between the types. Isolates of both types were equally associated with cankers, coloured wood, pycnidia or apothecia in the infected saplings.     

马尾松二代种子园无性系开花物候观测

[目的]在用材林高世代种子园建园材料选择时,最初重点考虑的是其速生性,而对优树的开花物候关注较少。在高世代种子园营建时,无性系的配置常根据其种源在大范围内考虑其开花物候的遗传因素,但即使是小范围内相同种源的无性系,其开花物候也不可能绝对同步。因此,了解种子园无性系的开花物候,可为种子园的集约经营、产量预测、种子遗传品质调控等提供依据。[方法]于2012—2013年,在桂阳县苗圃马尾松二代种子园Ⅰ大区、Ⅴ大区分别随机选取不同类型的无性系10个和25个,对其开花物候进行观测。[结果]表明:不同无性系的雌、雄球花花期起止日期和持续时间均有差异,但无性系间雌、雄球花花期值差异均未达显著水平,35个无性系总体雌、雄球花花期具有一定的同步性;35个无性系雌、雄球花的初花期基本同步,雌、雄球花的盛花期和末花期同步。株间花期差异相对于无性间要大,但雄球花花期较早的植株,其雌球花花期也较早,同一株建园亲本的雌、雄球花花期有一定的同步性。除雌球花的末花期与雄球花的初花期呈微弱负相关外,雌、雄球花的初花期、盛花期、末花期间均呈极显著或显著正相关。各花期的相关性呈现初花期和盛花期的相关盛花期和末花期的相关初花期和末花期的相关,雌球花初花期与雄球花初花期的相关系数最大。坡位对母树的花期有极显著影响,生长在不同坡位的植株,其雌、雄球花花期值差异明显,其大小均为上坡中坡下坡。坡位对花期影响最大的是雌球花的初花期,其次是雄球花的初花期、雌球花的盛花期、雄球花的盛花期,而对雌、雄球花的末花期影响最小。偏北产地无性系的花期相对较早,不同的无性系类型,其雄球花的盛花期和雌球花的初花期的差异显著;雄球花的初花期、末花期以及雌球花的盛花期和末花期差异均不显著。不同的年份,雌、雄球花花期的早晚差异很大,2012年最早初花期较2013年最早初花期早25 d。[结论]桂阳马尾松二代种子园35个无性系总体雌、雄球花花期具有较好的同步性;从开花物候方面考虑,该种子园建园材料选择较合理,对种子园种子产量和遗传品质没有影响。     

Juvenile radiata pine clonal seed orchard management in Galicia (NW Spain)

A juvenile radiata pine clonal seed orchard (Pinus radiata D. Don) in Sergude (northwestern Spain), comprising 57 clones, was evaluated for fertility, offspring diversity and genetic drift during 4 years. Flower and fruit production was used to asses clone fertility in the orchard. Fertility variation measured as “sibling coefficient” was found to be an average of 1.5, having high genetic diversity (0.99) and low coancestry (0.013). The clones varied in fertility from year to year. Effective population size in the orchard was between 35 and 40, indicating that between 60.30 and 69 %, the clones contributed effectively to seed yield. One way to improve seed yield in the orchard is by increasing the effective population size. Thinning and pruning highly reproductive clones of gibberellin application might be useful in increasing effective population size. The orchard’s parental balance showed consistent improvement over time. Cone and seed characteristics were also investigated. The results showed that significant genetic variation exists among clones for cone width and length; total, sound and empty seed number; as well as 100 seed weight. The seed orchard is still in a juvenile phase; moreover, the broad-sense heritability and variation data obtained in this study could be very valuable in the management practices of the existing radiata pine clonal seed orchard and can be also used for better planning of advanced generation of clonal seed orchards in Spain.     

Impact of Fertility Variation on Gene Diversity and Drift in two Clonal Seed Orchards of Teak (Tectona grandis Linn. f.)

Two 25 year old teak clonal seed orchards comprising 15 (CSO-I) and 20 clones (CSO-II), respectively, selected mostly from moist forests of Western Ghats (latitude 10° N) in southern India, were evaluated for fertility, offspring diversity, and genetic drift. The orchards differed in fertility of clones as well as flower and fruit production per ramet. Fertility was highly skewed in CSO-II, where one clone (originating from higher latitude −17° N, in Eastern Ghats of peninsular India) produced 55% of the fruits and 68% of the flowers in the orchard, in contrast to a similar contribution from four most fertile clones in CSO-I. Fertility variation, measured as `sibling coefficient' (1.7 in CSO-I and 8.3 in CSO-II), was high in CSO-II resulting in high coancestry and low effective population size (3 times lower than CSO-I) in the seed crop. In CSO-I, 58% of the clones contributed effectively to seed production compared to only 12% effective contribution resulting in eight times higher genetic drift in CSO-II. Placing limits on how much seed can be collected per clone might be useful in restricting over representation of highly reproductive clones thereby increasing genetic diversity in the seed crop.     

Progeny of Eucalyptus globulus Labill ssp. Globulus

The preliminary assessment of progeny test in a seed orchard of Eucalyptus globulus Labill.ssp.globulus at Yipinglang State Farm of Yunnan Province in China was conducted.The trial was composed of 21 replications,with 2 trees on each plot,15 plots in each incomplete block,and 18 incomplete blocks in each replication,laid out in a α-design of 270 open-pollinated families.The families were of three categories (natural populations,local land race and seed orchard).They were further subdivided into 11 regions.The data from an assessment of growth,stem form and other characteristics of the young trees after being planted 2 years were analyzed.Results are as follows:the different categories differed significantly in their growth,with the families from seed orchards being the best.Regions also differed significantly in their growth.The families from the regions of Westem Victoria,Eastern Victoria and all three seed orchards were better than others.The tamilies from Yunnan had the best frost tolerant and its survival was the highest.For growth,stem form and fungal tolerance,the families from Yunnan were similar to that from Southern Tasmania and Eastem Tasmania.Two-tree plots were strongly recommended over singletree plot designs for large-scale progeny trials.     

英德火炬松改良种子园无性系开花的时空变化

对英德火炬松改良种子园建园无性系的开花习性进行了观察，发现大部分无性系雌、雄花发育良好。无性系开花时间大约在3月4～26日，大多数无性系雌花在3月7—8日开始开放，少数在3月4～6日开始开放，雄花大多数在3月9～10日开始开放。总体上雌花比雄花早2～3d开放，早1～2d结束。全园雌花盛花期为3月8～17日，雄花盛花期为3月12～19日，雌、雄花盛花期有一个星期的时间相遇，自然条件下可保证充分授粉。种子园嫁接后第2年到第3年，90％以上的无性系开花，平均开花株率略高于70％；从第3年到第4年，100％的无性系开花，开花株率接近95％。说明嫁接后第3～4年，是种子园进入盛产的关键时期，也是实施人工控制授粉的有利时期。     

Screening wild cherry (Prunus avium) for resistance to bacterial canker by laboratory and field tests

Currently, bacterial canker caused by Pseudomonas syringae is a major cause of dieback and tree death in wild cherry (Prunus avium) plantations. The evaluation of breeding collections is needed to produce less susceptible clones or cultivars. Resistance tests were performed using excised shoots (1 and 2 years old) from 79 clones in the laboratory. A subset of 10 clones was also tested in the field. The clones were inoculated with four to seven isolates of a set of 15 isolates of P. s. pv. morsprunorum, P. s. pv. syringae, P. s. pv. persicae, P. syringae pv. avii and P. fluorescens. In the laboratory tests, older and larger shoots were more susceptible. In the field test, size and age of the shoots were not related to girdling by the bacterial canker. Two‐year‐old shoots were best for clonal discrimination. Correlations between 1 and 2‐year‐old shoots were significant but not high. The isolates varied a lot between experiments, but as the clone × isolate interactions were always low, breeding could thus be facilitated. The ranking of clones was conserved quite well between two laboratory tests, but not between two others. Good agreement was found for the best clones in the laboratory tests and in the field test. However, the two worst clones in the latter were among the best in one laboratory test. At least two independent tests in the laboratory are needed to evaluate resistance/susceptibility of clones. Broad sense heritability for resistance varied from 0.27 to 0.51. Although moderate, such heritability clearly encourages a breeding approach to reduce the problem of bacterial canker.     

华北落叶松初级种子园物候观测的研究(英文)

通过对华北落叶松初级种子园5年的物候观测,编制了年物候周期表。从种子园群体和无性系个体两方面,揭示出华北落叶松年物候周期规律。并分析阐明了物候期与气温和活动积温之间的相关性。还对无性系个体间物候的异同性及雌雄球花的相遇问题作了剖析。本项研究对种子园制订良种生产计划和经营管理具有重要价值。     

长白落叶松种子园雌、雄球花的分布特性

通过对2个产地长白落叶松种子园60个无性系雌、雄球花的分布、比例、颜色等进行定点观测,掌握了各无性系的花期及球果分布特性,结果表明：雌花为树冠下部较多,雄花以树冠中上部较多;♀∶♂近似为1∶10;球果颜色为黄绿色、紫红色,比例大致为2∶1。     

Flowering and Airborne Pollen Occurrence in a Pinus sylvestris Seed Orchard Consisting of Northern Clones

To explain the high background pollination rate detected in earlier studies, this study investigated the flowering phenology of a Scots pine seed orchard with respect to airborne pollen occurrence during 1992 and 1993. The receptive period of the female strobili and the shedding period of the male strobili were observed visually. Airborne pollen was monitored with Rotorod traps located inside and outside the seed orchard. There was no time gap in the onset of flowering between the earliest female and male strobili in 1992. Female flowering began 3 days earlier than male flowering in 1993, and the earliest strobili were probably pollinated by pollen transported long distance from more southerly areas. The almost simultaneous peak in pollen occurrence inside the seed orchard and in surrounding pine stands indicates that the seed orchard clones are not temporally isolated from sources of contamination. However, pollen concentrations inside the seed orchard were higher than those in the surrounding stands. Therefore, flowering phenology cannot sufficiently explain the observed pollen contamination rates in this seed orchard.     

Effects of gibberellin A(4 + 7) and bark-ringing on cone initiation in mature Picea sitchensis grafts

Large numbers of cones (strobili) were induced in a 10-year-old plot of mature grafts of Picea sitchensis (Bong.) Carr. All trees injected with 20 mg GA(4 + 7) in June initiated female and male cones in the same year. This treatment increased the number of female cones per plant 12-fold above the controls, more than doubling the percentage of cones that were female. Complete bark-ringing (done in May of the previous year) showed an additive effect with GA on the number of female cones formed, but a negative interaction on the number of male cones induced. Ringing promoted male cone production most when used alone. Treatments, singly or combined, also increased the proportion of cones that were lateral, compared with the preponderance of terminal male cones in the controls. The effects were apparently not directly associated with alterations in vegetative vigor, although these occurred causing a reduction in the proportion of buds containing vegetative shoots the following year. The clones differed in most characteristics, but both sparse and prolific clones were induced to reproductive activity. Viable seed yields per tree, and notional production from seed-orchards were enhanced almost 10-fold by GA injection, and about 4-fold by bark-ringing and GA + bark-ringing.     

Temporal and spatial variation of flowering among Pinus nigra Arn. clones under changing climatic conditions

Until recently, the most important factors affecting the economics and genetics of the seed crop from seed orchards were considered to be the timing and duration of flowering, variation in fertility and the total number of clones used to establish the seed orchards. Change in climatic conditions however is an emerging factor that could prove crucial regarding the timing of flowering and synchronization among clones and thus, the quality and quantity of seed production. The temporal and spatial variation in flowering phenology and the duration of flowering were studied in consecutive years in a Pinus nigra Arn. seed orchard. Sixty plus trees representing the distribution of the species in Northern Greece were used to establish the seed orchard, and nineteen ramets per clone were planted in a honeycomb experimental design in order to avoid kinship. Temporal variation among clones, as well as spatial variation among ramets within clones growing at different sites of the orchard were recorded, for initiation and duration of male and female flowering. The majority of clones were synchronized in dates of flowering during the year with weather conditions close to the long-term climatic conditions, except for a limited number of clones that were precocious or late flowering. The pronounced variability in climatic conditions over the 2 years strongly affected the flowering and synchronization among clones, resulting in almost complete asynchrony during the xerothermic year, which was characterized by a prolonged mean monthly temperature increase of 2.3 °C and a water deficit of 53% in a 7-month-period (November to May). These results suggest that one of the effects of a warmer and drier climate may be the lack of flowering synchronization, as pollen shedding might be completed before female conelets reach the phase of receptivity. The restriction of male parentage to a limited number of clones severely violates the panmixia assumption and could result in fertilization failure. The projected climate change for the Mediterranean region could potentially prove detrimental for fertility and flowering synchronization of forest trees, having consequences on the quantity and genetic diversity of the seed crop in seed orchards, and the natural regeneration of forest trees in forest ecosystems due to the reduced percentage of sound seed.     

Shoot growth patterns in saplings of Cleyera japonica in relation to light and architectural position

To gain further insight into crown development, the influences of shoot architectural position (branch order) and light environment on patterns of shoot growth of Cleyera japonica Thunberg (Theaceae) were investigated. Annual shoot length and light environment were positively correlated within same-order branches. Shoot length differed significantly among branch orders: shoot length was greater for the lower-order branches when light environments were comparable. Lower-order branches lengthened to a certain extent even if light availability was relatively low, whereas higher-order branches did not grow vigorously even when light availability was relatively high. Within same-order branches, branching was independent of the light environment of the shoot. Sylleptic shoot production differed significantly among branch orders, with most sylleptic shoots being produced on second-order branches. It is concluded that both light condition and architectural position of shoots must be considered when examining the mechanisms underlying crown development.