Germination capacity of Thekopsora areolata aeciospores and the effect of cone rusts on seeds of Picea abies

Mature Norway spruce (Picea abies) cones of different ages and colonized by Thekopsora areolata were collected in northern Finland 2009–2010. The germination capacity of aeciospores collected from intact aecia was measured on water agar and compared across cone age. Seed formation was investigated in healthy cones and those infected by T. areolata, Chrysomyxa pirolata, Chrysomyxa ledi, and seed germination was also measured for healthy cones and those infected by T. areolata. Unsporulated aecia of T. areolata occurred in 0- to 4-year-old cones. Aeciospores from current-year cones did not germinate and the germination capacity was significantly higher in one- to three-year-old cones than in older or current-year cones. However, a small number of aeciospores remained viable in four-year-old cones. Seed number and apparent health were significantly lower in cones infected by T. areolata and C. pirolata than in healthy cones or cones infected by C. ledi. Seed germination was significantly lower in cones infected with T. areolata compared to seeds from healthy cones. Our results suggest that infected cones more than one-year old continue to spread T. areolata for several years after the initial infection and fruiting, and thus promote the likelihood of epidemics and virulence of local outbreaks. Although cones infected by T. areolata and C. pirolata form significantly fewer seeds and of diminished viability, C. ledi does not appear to affect seed formation and health in Norway spruce. We recommend all rust-infected cones to be removed from orchards to improve stand health, reduce the risk of local outbreaks, and thereby increase the production and quality of Norway spruce seed.     

Cone traits of jack pine and black spruce in young seedling seed orchards

The number of fertile and infertile scales, filled and empty seeds, cone volume, seed efficiency and the incidence of insect and disease damage to seed were evaluated for seven jack pine (Pinus banksiana Lamb) and six black spruce (Picea mariana [Mill.] B.S.P.) seedling seed orchards in northern Ontario, Canada. On average, the seed potential of jack pine and black spruce cones was 50 and 82 seeds, respectively. Cone volume and the number of fertile scales were under strong genetic control and well correlated with one another for both species. Seed efficiency values were high for jack pine (60%) but poor for black spruce (24%). The incidence of seed insect damage was less than 2.5% for both species and nil for seed diseases.     

Differences in growth and mineral nutrition of seedlings produced from ten white spruce seed orchards

To meet the needs for improved spruce seeds in the province of Quebec, Canada, 17 first-generation white spruce seed orchards (SO) were established. These SOs are located in different bioclimatic domains and contain seed trees originating from geographically and genetically distinct sources. To evaluate the influence of SO on seedling growth and morphology, seedlings produced with seeds originating from the ten most commonly used first-generation white spruce SO in Quebec were raised under similar nursery conditions. Tissue nutrient concentrations of seedlings evolved similarly among seed orchards during the second growing season. At the end of the growing season, only shoot phosphorus concentrations were significantly different. When modeled with a logistic function, there was a significant difference between height and diameter growth curve parameters of seedlings from distinct SO during the second growing season. These differences led to significant differences in the height and shoot dry mass of the seedlings at the end of their second growing season, but not in their diameter or root dry mass. The ten SOs were clustered in two groups according to the above-ground characteristics of their progeny. This limited amount of morphological diversity suggests that expanding the size of the present seed zones may be an appropriate course of action for white spruce seed production in Quebec.     

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.     

Pine somatic embryogenesis: analyses of seed tissue and medium to improve protocol development

The shift from vegetative to embryogenic growth requires tissue to enter a radically different program of development and can be studied in vitro through the development of somatic embryos. From an applied perspective somatic embryogenesis (SE) is expected to play an important role in increasing productivity, sustainability, and uniformity of future forests. For commercial use, SE technology must work with a variety of genetically diverse trees. Since the first reports of SE in Picea abies and Larix decidua in 1985, many different coniferous species have shown the ability to produce embryogenic tissue. However, initiation frequency is often low, many desired seed sources are recalcitrant, and culture survival is often poor, raising costs of somatic seedlings produced from successful genotypes. A number of tools are now available to improve embryogenic tissue initiation and somatic embryo development in vitro that have resulted from analytical studies of seed tissues, the seed environment and gene expression in megagametophyte, zygotic embryos and somatic embryos. Benefits have occurred from medium supplementation with hormones, plant growth regulators, hormone inhibitors and polyamines. Somatic embryo growth has been enhanced with medium supplementation of nutritional components including specific sugar types, vitamins, organic acids, and redox potential modifiers. Control of environmental factors including, water potential, pH, adsorption of medium components by activated carbon and liquid versus gelled medium have also led to SE protocol improvements. The use of analytical studies to duplicate the seed environment in vitro is improving protocol development resulting in increased initiation, improved yields and higher-quality somatic embryos.     

Effects of seed water content and storage temperature on the germination parameters of white spruce, black spruce and lodgepole pine seed

The effect of seed water content (WC) (2–3, 5–6 and 22–25%, on a fresh weight basis), storage temperature (+4, −20, −80 and −196°C) and storage duration (6, 12, 24, 48 and 60 months) on the germination of white spruce (Picea glauca (Moench) Voss), black spruce (Picea mariana (Mill.) B.S.P.) and lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) seed was investigated. Germination of white spruce control (untreated) seeds and seeds adjusted to 2–3% and 5–6% WC declined after 48 months of storage at −80 and −196°C, with a further decline at 60 months at −20, −80, −196°C. Germination remained high when control white spruce seeds and seeds with 2–3, 5–6% WC were stored at +4°C, over all storage durations. Generally, black spruce and lodgepole pine exhibited high germination at all storage temperatures at 2–3% and 5–6% WC as well as the control (untreated) seed, for up to 60 months in storage. Germination declined for all three species when seed was conditioned to 22–25% WC. This loss in germination was partially recovered in white spruce seed stored at +4, −20 and −80°C after storage durations of 24, 12 and 48 months, respectively, and in black spruce seeds stored at −20 and −196°C after storage durations of 24 months. Mean germination time (MGT) was relatively constant for all species, under all conditions, except for seed conditioned to 22–25% WC, where MGT increased for white spruce seed stored 48 months at −80 and −196°C, and for black spruce seed stored 24 months at +4 and −80°C and 60 months at −196°C. These results show that the optimal storage temperatures are 4°C for white spruce, and 4, −20, −80, and −196°C for black spruce and lodgepole pine, and 2–6% water content is optimal for all 3 species at these temperatures.     

Female fertility variation in mature Pinus sylvestris clonal seed orchards

Abstract

Female fertility is the basis for the output of seeds from clonal orchards and its variation is of major interest for the economics and biology of seed orchards, especially for the efficiency and diversity of seed orchard crops. Assessments of female fertility variation in 10 mature (>15 years old) seed orchards of Scots pine (Pinus sylvestris L.) were evaluated and compared. Depending on the individual orchard, fertility variation for each clone was assessed in slightly different ways, e.g. number of strobili, cones, seeds or litre of cones per ramet. Assessments in five of the orchards were made over consecutive years. The main result was that the clonal variation in mean female fertility per surviving ramet was lower than expected from the literature; the Kang–Lindgren sibling coefficient (Ψ) within individual years averaged 1.35. The variation between ramets within clones and years was of similar magnitude as that between clones. Clone by year interactions were noticeable, but were slightly lower than the variation between as well as that within clones in individual years. There was considerable variation in the variance components between years. The limited variation in female fertility indicated that it should not be a selection criterion when selecting clones for a seed orchard. Furthermore, it will not result in large differences between clones in seed set or large reductions in gene diversity in productive Scots pine seed orchards.     

Development of microsatellite markers for Thekopsora areolata,the causal agent of cherry spruce rust

Cherry spruce rust is a fungal disease of Norway spruce cones caused by Thekopsora areolata and responsible for significant losses in seed production in Sweden and Finland. Here, we report the first set of nine microsatellites, which will allow an effective genetic fingerprinting of T. areolata. The markers were isolated using the FIASCO method and were characterized using DNA from 49 single aecia sampled from spruce cones in three different seed orchards in Sweden. Eight of the nine markers were shown to be polymorphic among the aecia. The markers were unlinked and are therefore suitable for future population genetic studies.     

挪威云杉种源及家系种子播种品质的研究

通过对引进的芬兰挪威云杉5个种源和窄冠垂枝挪威云杉10个家系种子播种品质的方差分析和聚类分析研究表明,挪威云杉种源和窄冠垂枝挪威云杉家系种子净度达98％以上。种子的播种品质与地理分布和起源有关。由北向南种子的千粒重增加、发芽率提高、死亡率下降。另外,天然起源的种子播种品质低于种子园的种子。窄冠垂枝挪威云杉因天然分布区域极为狭窄、种群规模过小,导致由其它因素造成的未萌发百分率高。     

Genetic thinning of clonal seed orchards using linear deployment may improve both gain and diversity

The linear deployment algorithm defines a straight line relationship between the number of ramets and the breeding value of a given clone. However, when used to determine thinning in clonal seed orchards, there is an upper limit, determined by the number of ramets in the seed orchard prior to thinning. Linear deployment thinning maximises genetic gain and effective clone number whilst minimising thinning intensity, thus both production and genetic diversity are optimised. Here two applications of linear deployment to Swedish Norway spruce seed orchards are described.     

樟子松无性系种子园种子生产及其苗木培育

樟子松种子园无性系间的花粉量、种子产量均存在着差异,这种差异,是由樟子松无性系本身的遗传基因决定的。种子园中,往往少数无性系控制着园内50%以上的花粉量和种子产量。由于部分无性系种子产量低,育苗、造林时这些家系容易丢失。为减少家系的丢失数量,育苗时,应改善圃地的环境条件,增加土壤肥力,加强除草等抚育措施,提高育苗水平。     

The effect of seed pretreatment and sowing date on the nursery emergence of Sitka spruce (Picea sitchensis [Bong.] Carr.) seedlings

Sitka spruce seeds which had been: (1) untreated (U), (2) prechilled(P), or (3) prechilled and then redried and stored for 16 months(R), were sown into progressively warmer seed beds on four datesat monthly intervals from March to June. At each sowing date,samples of seed were germinated in the laboratory at optimum(20°C) and sub-optimum (10°C) temperatures. Prechillingand prechilling + redrying both increased the rate and totalamount of germination compared with untreated seed at each testtemperature. However in the nursery, the beneficial effectsof pretreating Sitka spruce seed were restricted to sowing inMarch and April when soil temperatures were sub-optimal forthe germination of untreated seeds. Pretreatment resulted inrapid seedling emergence at soil temperatures between 10°Cand 15°C, whereas untreated seed germinated slowly and seedlingemergence continued until high soil temperatures in June killedungerminated seeds. The pattern of seedling emergence from theredried seed was similar to that from the prechilled seed, exceptfor a lag in the start of seedling emergence probably due tothe extra time needed for redried seed to imbibe water in theseed beds. Thus redrying caused insignificant loss of seed performanceon the nursery. Seed sown in May and June experienced average temperatures closeto the optimum for germination of 20°C, however daily maximaregularly exceeded 35°C resulting in the cessation of seedlingemergence in all three seed treatments, and the loss of newlyemerged seedlings. Periods of warm weather from June onwardswere the main factors limiting the final number and size ofseedlings.     

用浓硫酸快速催芽黄刺玫种子的研究

黄刺玫(Rosa xanthina Lindl.)是北方广大地区的优良绿化树种之一。其种子的繁殖关键在于种子处理,种子不经处理,播种后发芽不整齐,给后期田间工作带来不便。本试验采用浓硫酸处理黄刺玫种子,获得了催芽处理时间短、种子发芽率高、幼苗出土快、苗木质量好、单位面积产量高、成本低等优点,为黄刺玫种子育苗提供了新的途径。     

Reduced fertilization capacity of SO2-fumigated Picea omorika-pollen

Dry pollen of Picea omorika was fumigated with 820 μg/m³ SO₂ for 3 , 4 , or 5 days. Few or no adverse effects occurred during subsequent in vitro germination: germination percentage was not affected at all, and reduction of the pollen tube length was only 10% in pollen exposed for 5 days. Nevertheless pollination with fumigated pollen resulted in reduced seed production. 41% fewer seeds per cone were produced, and only 33% were filled seeds, compared to 70% filled seeds of the control. Seed-weight was reduced from 3.6 g per thousand in the control to 3.0 g per thousand, when cones were pollinated with pollen fumigated for 5 days. Similar but less striking effects were found with pollen fumigated for 3 or 4 days.     

玛咖不同颜色种子表型性状及活力特性分析

比较分析棕黄色、棕红色和黑色3种颜色玛咖种子的大小、萌发特性、幼苗生长特性和酶活力,探讨3种颜色玛咖种子的表型性状及其与种子活力之间的相关性。结果表明,棕黄色和黑色种子的长、厚、厚宽比、千粒质量、发芽势、发芽率、发芽指数、活力指数、幼苗苗长、根长、单株鲜质量和干质量、POD活性、脱氢酶活性等性状之间无显著差异,但均显著高于棕红色种子(P<0.05);棕黄色和黑色种子的新鲜不发芽种子数、死种子数和不正常幼苗数均显著低于棕红色种子(P<0.05)。不同颜色玛咖种子的千粒质量与种子的长、厚存在显著正相关(P<0.05),种子发芽势、发芽率、发芽指数、活力指数均与千粒质量、POD和脱氢酶呈极显著正相关(P<0.01)。说明棕黄色和黑色种子活力高于棕红色种子,萌发能力更强。     

Inhibition of black spruce seedling growth by forest-floor substrates of central Newfoundland

The objective of this study was to determine if seedbed substrates consisting of F and H organic matter and Ae and Bf mineral material inhibited seed germination and subsequent seedling growth of black spruce. The study was conducted with seedbed substrates collected from eight pure blackspruce stands of four age classes (15, 30, 45 and 60 years) in central Newfoundland.No significant effect on percentage germination or primary shoot growth of seedlings was obtained when grown on F and H organic matter, Ae and Bf mineral material. However, growth and development of primary roots was significantly reduced in the F and H organic matter and Ae mineral material compared to the controls (washed sand). The inhibitory effect increased with stand age. The affected seedlings did not produce normal primary roots with root hairs. The primary root cells of the affected seedlings were significantly broader and shorter compared to the control seedlings. Mineral material from the Bf horizon did not have any significant effect on primary root growth of black spruce seedlings.     

世界松类无性系林业发展策略和现状

本文概述了当前世界集约工业人林发达国家在松类无性系林业发展中采取的策略和研究现状，突出介绍了他们把家系林业和无性系林业结合的经验。同时针对我国近２０年来松类种子园和无性繁殖技术的现状，提出了我国松类良种化工作的发展方向。     

影响杉木种子园良种产量的主要害虫及综合治理对策

在福建省洋口林场杉木种子园中常见的害虫有２６种，隶属７目２０科。其中杉木球果麦蛾、杉木扁长蝽和杉梢小卷蛾是影响良种产量的主要害虫。杉木球果麦蛾是中国新记录种，以幼虫危害球果的苞鳞、果轴及种子，使球果变色、干枯。杉木扁长蝽的危害及炭疽菌和散斑壳菌的侵染导致球果变色。１０月受害果率达３７．２％。测定结果表明，球果虫害及变色明显影响每百球果的鲜果重、种子重、千粒重及出籽率（平均下降２６．９％—７３．７％），但对种子的发芽率及涩籽率无显著影响，并提出以摘尽球果为主的综合治理措施。     

Seed cone abortion and full seed production in an indoor seed orchard with potted grafts of Picea abies

Abortion of seed cones and production of full seeds have been recorded in an indoor‐potted Norway spruce (Picea abies (L.) Karst.) seed orchard at Biri nursery in Norway. Seed cone buds aborted their normal development at much higher frequencies (22–45%) inside isolation bags than in an open‐air (4–12%) greenhouse environment. The grafts had been induced to flower the year prior to seed cone development. Treatment with gibberellin A_4/7 in conjunction with heat reduced the proportion of aborted, isolated flowers (13%) compared to treatment with heat alone (22%) in a clonally balanced material. The production of full seeds per cone increased from 3 in 1987 to 50 in 1991. The full seed production is discussed in relation to methods and timing of pollen forcing. It is anticipated that 1 kg of seeds could be produced annually in a 1250 m² greenhouse.     

Seed-cone receptivity and seed production potential in white spruce

Three to five ramets were selected from each of five white spruce clones for the study. Seed cones (megastrobili) were pollinated once and some were sampled at the different stages of development to study the pollination mechanism, seed-cone receptivity, and seed production potential.The proximal end of a seed cone emerged from the bud scales and was the area to be receptive first. As the seed cones continued to develop, the margins of the cone scales became reflexed to increase the surface area and to funnel pollen along the margins of two adjacent scales onto the micropylar arms. Pollen was transferred to a deep depression in the nucellus and it germinated in the depression a weel after pollination. Another week later the micropyle was sealed by the ingrowth and divisions of the cells in the micropylar canal. Receptivity of a seed cone lasted for about 10 days and the end of receptivity was signalled by the closure of cone scales.The optimal receptivity appeared to occur when seed cones approached the end of receptivity and this coincided with the peak of pollen shedding. It was evident that seed cones pollinated at this stage produced the most filled seeds, an average of 41.6 from a seed production potential of 88 seeds per cone. Total cone scales averaged 67.7 per cone of which 43.6 scales were fertile and located at the mid-portion of a cone.