Black locust (Robinia pseudoacada L.) clonal seed orchards in Hungary

Black locust （Robinia pseudoacacia L.） is one of the most important stand-forming tree species in Hungary and its impor- tance is increasing in many countries. The main aim of the discussed new selection programme is to identify black locust clones with good performance and good form for setting up clonal seed orchards. As a result of selection programme 16 new black locust clones have been improved. In spring 2002 a black locust seed orchard was established with the newly selected clones. About 40% of the plants can be considered to belong to the height growth rate class 1 and 2. Hungary was the first country where micropropagated black locust planting material was used for seed orchard establishment.

Mutagenic Effects of Spaceflight Treatment on the Second-Generation Seeds of Alfalfa

[ Objective] To explore the effects of spaceflight on the second-generation seeds of alfalfa and provide a theoretical basis for mutation breeding. [Method] The seeds of Medicago stavia L. lines no. 1, no. 2 and no. 4 were carried into space by the Shijian-8 seed breeding satellite for a 15-d spaceflight treatment. After returning to the ground, seedlings were transplanted to field. Traits of the second-generation seeds of alfalfa were evaluated. [Result] The 1 000-grain weight of the second-generation seeds were 5% -9% significantly higher than that the control （P 〈 0.05）. The germination rate, seedling weight, shoot length and root length were significantly increased （P 〈 0.05）. The hard seed rate and the rate of moldy seeds were significantly decreased （ P 〈 0.05）. However, the rate of dead seeds was increased. [ Conclusion] Spaceflight treatment has positive mutagenic effects on the second-generation seeds of alfalfa.

Branching and growth of plantings in fifth year of a seedling seed orchard of Masson pine (Pinus massoniana Lamb.)

The features of branching and growth studied included height, diameter at breast height (DBH), total number of branches, annual height growth, annual branch elongation in the year of elongating, annual branch number for four consecutive years, diameter of branches of different ages, and diameter of stem where branch-whorl originates. For features of total growth and overall branching, no significant differences were found between families, except for DBH. For annual features, no significant differences were found in annual stem height growth, annual branch elongation in the year of elongation and diameter of branches. In the last four years, differences in number of branches were not significant in the first two years but were significant in the last two year; differences in stem diameter where branch-whorls grow were significant for the four consecutive years. Trend of annual growth and branching features of families can be divided into three types as increasing type, stable type and fluctuating type. Most of families have an increasing type with respect of annual height growth and annual branch elongation, while most families belong to a fluctuating type with annual branch number. The results indicated that in the fifth year after planted in seedling seed orchard, differences between families were mostly insignificant. This result may have two main explanations: one is the growth rhyme in early ages of Masson pine, the other one is the complex paternal components to form the open-pollinated families. Family selection seemed to be not useful based on the result. It is suggested to select some of families in the nursery instead of to use all the families when establishing seedling seed orchards with open-pollinated families from plus-trees.

Phenological observations on Larix principis-rupprechtii Mayr. in primary seed orchard

Through 5 years of phenological observations on Larix 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 phe-nological periodic table was drawn up. The correlation between various phenophases, the air temperature and active accumu-lated 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 pro-vide theoretical reference for working out the production plan of improved varieties and other management measures in seed orchard of Larix principis-rupprechtii.

Evaluation of seed production in a first-generation seed orchard of Chinese pine (Pinus tabuliformis)

We evaluated seed production in a first-gener- ation orchard of Chinese pine （Pinus tabuliformis） during the crucial transition period from first generation to advanced generations. Clones varied significantly in all traits related to seed production. Repeatability of these traits ranged from 0 to 0.96. Seed production per ramet （SPPR）, seed producing index （SPI）, the number of relative female strobili （RFS）, the number of scales, and the num- ber of ineffective scales had comparatively high repeata- bility at 0.86, 0.87, 0.89, 0.96, and 0.91, respectively. Correlation analysis showed that SPPR was greatly influenced by RFS and by the number of full seeds per cone. Finally, we showed that SPI was the best predictor of the seed-producing ability of clones. Our findings will assist seed orchard managers in effectively predicting and improving seed production of Chinese pine seed orchards.

Mode of pollen spread in clonal seed orchard of Pinus koraiensis

The patterns of effective pollen dispersal and the relationships between pollen dispersal and genetic composition in Pinus koraiensis are still unclear. Hence, we investigated the mode of pollen dispersal of P. koraiensis in a clonal seed orchard in Lushuihe Forestry Bureau, Jilin Province, using SSR molecular markers tech-nique and the method of maximum likelihood. A total of 13 pairs of nuclear microsatellites po-lymorphic primers were used in the paternity analysis. We analyzed 100 progenies and 150 paternities. A total of 56 alleles were detected in 13 loci with 3-6 alleles (4.3 alleles in average) in a single locus. The primers of SsrPt_ctg7170 and SsrPt_ctg5333 had the maximum (6) and the minimum (3) alleles, respectively. The averaged values of observed heterozygosity, expected heterozygosity and polymorphism information content of experimental groups were 0.648, 0.601 and 0.533, respectively. The mating dis-tance of P. koraiensis followed an approximately normal distribution. The most effective pollen for the female parent came from male parent trees 15-45 m away with an average mating dis-tance of 32.60 m and the longest of 67.88 m. The pollen source of offspring was not random but greatly affected by the wind direction during the pollination season of P. koraiensis. These re-sults have important implications for seed or-chard design to improve the genetic quality of seeds and seed production.

Improved genetic distance-based spatial deployment can effectively minimize inbreeding in seed orchard

Background:Inbreeding in seed orchards is expected to increase with the advancement of breeding cycles,which results in the delivery of crops with suboptimal genetic gain,reduced genetic diversity,and lower seed set.Here,a genetic distance-dependent method for clonal spatial deployment in seed orchards was developed and demonstrated,which reduced the inbreeding levels.The method’s main evaluation parameter of inbreeding is the genetic distance among individuals and the deployment method used an improved adaptive parallel genetic algorithm(IAPGA)based on Python language.Using inbreeding-prone Chinese Mongolian pine breeding population material originating from a single natural population,the proposed method was compared to a traditional orchard design and a distance-based design;namely,complete randomized block(RCB)and optimum neighborhood(ONA)designs,respectively.Results:With the advancement of selective breeding cycles,group separation among orchard related individuals is expected to increase.Based on the genetic distance among individuals,the IAPGA design was superior in significantly reducing the inbreeding level as compared to the two existing designs,confirming its suitability to advanced-generation orchards where relatedness among parents is common.In the 1st,2nd,and mixed generations clonal deployment schemes,the IAPGA design produced lower inbreeding with 87.22%,81.49%,and 87.23%of RCB,and 92.78%,91.30%,and 91.67%of ONA designs,respectively.Conclusions:The IAPGA clonal deployment proposed in this study has the obvious advantage of controlling inbreeding,and it is expected to be used in clonal deployment in seed orchards on a large-scale.Further studies are needed to focus on the actual states of pollen dispersal and mating in seed orchards,and more assumptions should be taken into account for the optimized deployment method.

Options for converting a clone trial of Eucalyptus camaldulensis into a clonal seed orchard considering gain,fertility and effective clone number

We evaluated a clone trial comprised of 20 ramets each of 40 Eucalyptus camaldulensis clones for growth and fertility at 4 years of age. The clones differed significantly in growth with 65-100 % survival in 38 clones while two clones had low survival （40 and 10 %）. Fecundity was high and fertility variation low, as indicated by the sibling coefficient value （ψ = 1.4） with 55 % of clones contributing 80 % of the fruits. Thinning strategies were considered to convert the clone trial to a clonal seed orchard and enhance both gain and diversity in seed crop. When clones were selected based on growth without con- sidering fertility, truncation selection （to retain clones with higher DBH than the trial mean value） would give 8 % gain, but 59 % reduction in effective population size （Ne）. Gain and predicted diversity （Ne） was highest when ramets were selected in linear proportion to the breeding value of each clone. Mass selection with the same intercept （for DBH） as truncation selection would give a moderate 3 % gain, but over two times higher predicted Ne than trunca- tion selection. When fertility of retained trees was con- sidered after thinning, mass selection would yield 52 % effective contribution from the orchard trees compared to only 30 % contribution from truncation selection and linear thinning. Higher representation of superior clones in linear thinning and mass selection would lead to greater fertilityvariation and over 30 % reduction in effective clone number （Nc） from that predicted （Ne, assuming equal fer- tility among ramets） before thinning.

施肥对日本落叶松母树种子球果和形质特征的影响

以日本落叶松1.5代和2代种子园为研究对象,施用N肥、P肥、K肥,采用正交试验设计,调查并分析了施肥处理对日本落叶松种子园母树球果和种子特性的影响,有效提高落叶松种子园种子产量,满足生产上对落叶松良种的需求。结果表明:从球果形质特征上看,施肥可显著促进日本落叶松1.5代和2代种子园单果质量、球果纵径和横径的增加,其中,1.5代种子园中,“N(0.4 kg/株)+P(0.6 kg/株)+K(0.6 kg/株)”处理的单果质量和球果纵径最大,分别达到4.01g和3.14cm,分别为CK的1.79倍和1.37倍,“N(0.2kg/株)+P(0.6kg/株)+K(0.4kg/株)”处理的球果横径最大,达到2.26cm,为CK的1.1倍;2代种子园中,“N(0.2 kg/株)+P(0.8 kg/株)+K(0.6 kg/株)”处理的单果质量、球果纵径和横径等指标均较高,分别达到8.23g、3.74 cm和2.58 cm。从种子形质特征上看,施肥对日本落叶松1.5代、2代种子园种子形质指标的影响有限,施肥仅对1.5代种子园种子纵径、横径和侧径及2代种子园千粒质量有显著影响。较高的K肥和适量的N肥施用量有利于球果和种子的增大,日本落叶松种子园施肥较优方案为N肥0.4 kg/株、P肥0.6 kg/株、K肥0.6 kg/株。

基于种实表型性状和SSR标记的杉木2代种子园遗传多样性分析

【目的】从表型和分子2个角度评估江西信丰县国家杉木良种基地杉木2代种子园的遗传多样性,明确种子园的遗传背景,为后期种子园的改良(去劣疏伐)、重建(亲本选择与配置)等提供依据,同时为开展杂交育种提供遗传信息。【方法】以江西信丰杉木2代种子园内51个建园无性系为研究对象,通过分析8个种实表型性状掌握种子园不同无性系间种实性状的差异,同时利用SSR标记从DNA水平进行遗传多样性评估。【结果】供试51个无性系在种实表型性状和DNA水平上均存在明显的变异和较丰富的遗传多样性。8个表型性状变异系数为10.53%~37.04%,其中球果和种子的平均变异系数分别为18.99%和14.01%,种子的变异系数较小,表明种子的稳定性要比球果的高;种实性状的Shannon-Weaver多样性信息指数平均为2.060,表明种实性状的多样性较丰富。在DNA水平,14个SSR标记在51个无性系中共扩增出68个等位位点,平均Shannon’s信息指数、平均Nei’s遗传多样性指数、平均观测杂合度和平均期望杂合度分别为0.925、0.506、0.486和0.511,表明信丰杉木2代种子园遗传多样性较丰富。基于种实表型性状和SSR标记均可将51个无性系分为两大类群,但两者的具体聚类结果存在较大差异,Mantel检验显示种实性状与SSR标记之间不存在相关性(r=0.064,P=0.870>0.05)。【结论】信丰杉木2代种子园遗传多样性较丰富,具有再选择空间和改良潜力。

基于种实性状的杉木第3代无性系种子园亲本评价

林木种子园是重要的林木良种基地,其主要任务是生产遗传品质和播种品质优良的种子并保证稳产高产。本研究以湖南省会同县第3代杉木无性系种子园中的29个无性系为研究对象,调查分析无性系球果纵径、横径、体积、产量及种子千粒重、发芽率、涩粒率、霉变率、发芽起始时间、发芽持续时间等10个指标,采用方差分析和主成分分析方法综合评价无性系的结实能力。研究结果表明,10个性状指标在29个无性系之间的差异极显著(P<0.01)。其中,球果产量变异最大,变异系数为103.53%;种子霉变率(75.40%)次之;再次为种子发芽率(38.21%)。不同无性系间,球果的纵径、横径、体积之间呈极显著正相关;种子发芽率与种子涩粒率呈极显著负相关、与种子霉变率之间存在显著负相关;球果的产量与球果的纵径、横径、体积等性状相关性不显著;种子的发芽起始时间与发芽持续时间呈显著负相关。基于球果、种子性状主成分分析的结果,筛选出综合性状排名前9位的6、27、22、23、28、26、5、14、9号无性系,可为第3代杉木无性系种子园去劣留优提供依据。

四川杉木2代种子园半同胞子代测定林生长性状的遗传变异分析

种子园子代测定林是开展推进种子园向升级换代的必要途径,对杉木第2代无性系种子园半同胞子代测定林13年生生长性状进行了遗传变异分析,以为杉木3代种子园的建设提供基础数据,结果表明:子代测定林的胸径、树高和材积在家系间、区组间以及二者的交互效应均存在显著差异,胸径和材积的家系遗传力为0.279和0.250,具有开展选优的价值和潜力;且胸径变异系数显示无论是在个体间还是在家系间生长都还在持续分化的过程中。51个家系胸径、树高和材积总的平均值分别为17.18 cm、12.61 m和0.1592 m3,相比对照均值现实增益分别为3.56%、2.66%和8.00%,材积现实增益超过10%的家系数量达21个,其中材积最大的家系现实增益达到了31.43%,现实增益明显。依据材积和胸径变异系数进行的综合优良度分析显示,T71,T78,T122,T152,T106,T114和T88等24个家系综合表现优异,可作为第3代无性系种子园建园材料的主要候选。

蒙古栎无性系种子园花量变异及空间分布

以吉林森工临江林业有限公司金山林场蒙古栎无性系种子园植株为对象,调查分析蒙古栎无性系雌、雄花空间分布规律。结果表明:无性系间单株标准枝数和标准枝小枝数差异达显著水平,无性系间小枝雄花序数、小枝雌花数、雄花序总数、雌花总数差异均达到极显著水平;依据雌、雄花数量将各无性系聚类成多花类群、中间类群和少花类群;蒙古栎种子园内,雌、雄花量上、下冠层间差异均达到显著水平,花量在树冠上、下层间的比为1∶0.27,说明雌、雄花绝大多数都分布在树冠上层;蒙古栎无性系雄花数量在树冠不同方向上(东、西、南、北)的比为1∶0.89∶0.92∶0.72,雌花量为1∶0.83∶0.87∶0.72。

不同代次杉木种子园子代中龄期生长测评

为测定评价杉木不同代次种子园子代生长情况,选择不同地区、不同代次杉木种子园子代材料营建生长测定林分,对林分中龄期的树高、胸径和单株材积进行统计分析,结果表明,不同代次子代间存在极显著的差异,达到统计学上的极显著水平,不同代次子代生长差异真实存在;树高、胸径和单株材积不同代次子代生长由大到小的顺序一致,均为小坑2.5代>小坑1.5代>信丰3代>信丰2.5代>韶关普通种>信丰15代,小坑2.5代生长最优。本研究结果证明粤北杉木栽培区以本地高世代杉木种子园生产的子代更适合,生长表现更好。

日本落叶松种子园和优树自由授粉家系选择与利用研究

在甘肃小陇山沙坝落叶松/云杉良种基地,采用完全随机区组试验设计,对25个种子园的自由授粉家系和30个优树自由授粉家系在日本落叶松采伐迹地进行了更新造林试验,应用SPSS16.0和ASReml v3.0对造林9年生数据进行了统计分析。结果表明:不论是种子园自由授粉家系还是优树自由授粉家系试验林,树高、胸径、材积等性状家系间具有丰富的遗传变异,家系不同性状间具有显著的相关性,表型变异系数和遗传变异系数最大的是材积。种子园自由授粉家系试验林树高、胸径、材积的家系遗传力和单株遗传力为0.492、0.680、0.694和0.093、0.162、0.171,优树自由授粉家系试验林树高、胸径、材积的家系遗传力和单株遗传力为0.560、0.544、0.496和0.128、0.109、0.096,家系性状遗传力大于单株遗传力,家系性状受到中等以上的遗传控制,家系选择潜力大。根据种子园自由授粉家系亲本育种值指导初级无性系种子园去劣疏伐、改建1.5代种子园。以材积为主要选择指标,兼顾胸径、树高,在家系择基础上配合单株选择,从种子园自由授粉家系和优树自由授粉家系各选择20个优良单株构建高阶生产群体,高阶生产群体的预期遗传增益和现实增益分别达到25.74%、22.85%和122.59%、154.22%。从种子园自由授粉家系选择的50个单株作为构建遗传改良群体的应用材料,将优树自由授粉家系选择的45个单株作为育种群体的补充材料,构建遗传品质不断提高和遗传基础不断拓展的改良群体应用材料。

油松高世代种子园亲本选择策略研究

【目的】通过油松高世代种子园建园亲本2种选择策略的对比与评价,为高世代高产稳产油松建园亲本选择策略的确定提供科学依据。【方法】以山西省隰县上庄油松初级种子园自由授粉子代测定林为基本群体,对42个油松半同胞家系的生长性状进行遗传变异分析,采用配合选择策略和最优单株直接选择策略筛选油松第二代种子园建园亲本,对比分析两种选择策略下,筛选出的优良单株的各性状平均生长量和平均预期遗传增益。【结果】油松半同胞家系间和家系内胸径、树高和材积生长均达到了极显著差异水平(P<0.01),配合选择策略与最优单株直接选择策略分别选出30个优良单株,其中有19个相同、11个不同。最优单株直接选择策略所筛选的11个特有优良单株的平均胸径、树高和材积生长量分别高出配合选择策略所筛选的11个特有优良单株7.72%、18.56%和31.01%,所筛选的30个优良单株的平均胸径、树高和材积的预期遗传增益比配合选择策略筛选的30个优良单株分别增加了15.52%、121.78%和29.38%。与每一优良家系入选1个优良单株的配合选择策略不同,最优单株直接选择策略筛选出的30个优良单株中,有29个优良单株分属于19个优良家系,另外1个优良单株(D12)属于非优良家系。【结论】配合选择策略会导致部分优良单株资源损失,最优单株直接选择策略更适合用于油松高世代种子园亲本材料的筛选。

日本落叶松无性系种子园和优树半同胞家系苗期比较

为缩短育种周期,降低田间试验规模,构建高阶遗传改良和繁育群体的应用材料。在沙坝国家落叶松(Larix gmelinii)、云杉(Larix asperata)良种基地,采用随机完全区组试验设计,对25个日本落叶松(Larix kaempferi(Lamb.)car.)无性系种子园和30个人工林优树自由授粉家系苗期的生长性状及遗传变异进行比较。同时以2年生苗高作为选择指标,对家系选择和家系内单株选择进行对比。结果表明:日本落叶松种子园自由授粉家系和人工林优树自由授粉家系的1年生及2年生苗的地径、苗高差异不显著,两者间2年生苗新梢生长量差异达显著水平(P<0.05)。人工林优树自由授粉家系比种子园自由授粉家系新梢生长量高3.27%。种子园自由授粉家系及人工林优树自由授粉家系1年生及2年生苗的生长性状均具有丰富的遗传变异,两者生长性状的表型变异系数均大于遗传变异系数。家系遗传力大于单株遗传力,家系选择潜力大。人工林优树自由授粉家系相比种子园自由授粉家系,其具有更加丰富的遗传变异。人工林优树自由授粉家系苗高的家系遗传力及单株遗传力分别为0.920及0.434,是种子园自由授粉家系的1.16及27.13倍。以2年生苗高为选择指标,苗高大于群体均值为家系入选标准,种子园及人工林优树自由授粉家系的入选率分别是52.00%及46.67%。家系选择时,种子园和人工林优树自由授粉家系苗高的遗传增益分别为6.46%及9.98%。在家系选择的基础上进行优良单株选择,单株入选率为8.00%及7.80%。单株选择时,苗高的遗传增益分别是1.42%及32.15%。在人工林优树自由授粉家系及家系内单株进行选择,其遗传增益分别是种子园自由授粉的1.54及22.64倍。日本落叶松种子园自由授粉家系和人工林优树自由授粉家系均具有丰富的遗传变异,人工林优树自由授粉家系生长性状的遗传变异比种子园自由授粉家系更为丰富,选择潜力更大。

Does ash dieback affect the reproductive ecology of Fraxinus excelsior L.?

Forest tree species reproduction is a key factor in maintaining the genetic diversity of future generations and the stability of forest ecosystems.The ongoing ash dieback disease could affect the reproductive ecology of Fraxinus excelsior L.and have a major impact on the quantity and quality of pollen and seeds.In this study,we investigated pollen production and viability of pollen and seeds of ash trees with different health status from 2018 to 2022.Inflorescences were collected from 105 trees(pollen production),pollen from 125 trees(pollen viability),and seeds from 53 trees(seed quality)in two seed orchards and in one floodplain forest in southern Germany.Not all parameters were examined at every site every year.The average pollen production per tree was estimated at 471.2±647.9 billion pollen grains.In addition,we found that a high number of inflorescences did not equate to high pollen production per inflorescence.Pollen production of healthy and diseased trees did not differ significantly,although only 47%of severely diseased male trees(vs.72%for healthy trees)produced flowers.With regards to pollen viability,the TTC test showed an average viability of 73%±17%.Overall,there was a slight tendency for diseased trees to have less viable pollen.However,a significant difference could only be calculated for trees in the floodplain forest.The percentage of germinable seeds in 2018 was 38%in the floodplain forest and 57%in one of the seed orchards.The percentage of viable seeds(TTC test)ranged from 17 to 22%in the orchards in 2020.Non-viable seeds were usually heavily infested by insects.In general,seed quality was not significantly different between healthy and diseased trees.Our results indicate that ash dieback affects flower formation and pollen viability but not pollen production or seed quality.Nevertheless,the fact that hardly any flowering was observed,especially for trees that were seriously affected,suggests a negative effect of ash dieback on reproductive performance.Thus,severely diseased trees will transfer their genes to a smaller extent to the next generation.

杉木嫁接繁殖技术研究进展

杉木是我国重要的速生用材树种,用途广泛,在我国人工造林中有重要作用。培育良种壮苗是实现杉木林速生丰产的重要措施。嫁接是营建杉木种子园的主要技术手段,用于快速繁殖杉木。本文综合大量国内外文献,从生理生化机制和分子调控机制层面概述了嫁接的基本原理,从嫁接方法、砧木选择、嫁接后管理3个方面重点综述了国内近60年关于杉木嫁接的研究概况,指出了目前杉木嫁接研究存在的不足以及今后发展的方向,以期为杉木种质资源保存、良种快速繁殖与推广提供参考。

不同杉木第3代种子园良种幼林生长差异

在福建省顺昌埔上国有林场,以7个杉木第3代种子园(南平洋口、南平卫闽、南平建阳、三明将乐、三明永安、漳州西陂、龙岩白砂)种子营建的3~6年生测定林为研究对象,经连续4 a的生长量调查和生物量测定,筛选适合于顺昌种植的杉木第3代种子园良种。结果表明:不同林龄、不同种子园良种测定林生长量、林分蓄积量及生物量具有一定的差异,综合林木生长量及林分生物量指标,筛选出三明将乐、南平建阳、南平卫闽的第3代杉木种子园良种为较适合顺昌种植,其6年生树高生长量依次为3.25、2.83、3.42 m,胸径生长量依次为4.57、4.30、4.85 cm,林分蓄积量依次为71.35、63.01、69.51 m^(3)·hm^(-2),地上部分总生物量依次为94.74、93.91、90.82 t·hm^(-2)。