Pollination requirements for seed set in ulluco (Ullucus tuberosus)     

Leena Pietilä 《Euphytica》1995,84(2):127-131

Summary Pollination experiments were carried out on ulluco (Ullucus tuberosus), known as a very poor seed producer. All the clones used were diploids. The effect of self-vs. cross-pollination was studied in Experiment 1. Caged selfpollinated flowers produced no seeds. Different clones produced seeds in 0–8% of caged cross-pollinated flowers and in 5–19% of cross-pollinated non-caged flowers. Ulluco is thus basically an outbreeder.Experiment 2 studied whether seed set is limited by pollen availability. Total seed number per inflorescence number did not differ between plants treated with supplemental pollen and control plants; pollen availability thus did not limit seed set. The treated plants, however, produced more seeds in cross-pollinated than in other flowers on the plant, and the control flowers on treated plants produced fewer seeds than those on the control plants. In the treated plants, resources may have been allocated to artificially cross-pollinated flowers at the expense of other flowers. In some clones, seed set after artificial cross-pollination was at a level practicable for breeding work.  相似文献   

Hardening of Some Winter Wheat (Triticum aestivum L.), Rye (Secale cereals L.), Triticale (×Triticosecale Wittmack) and Winter Barley (Hordeum vulgare L.) Cultivars During Autumn and the Final Winter Survival in Finland     

Leena Maarit  Hömmö 《Plant Breeding》1994,112(4):285-293

Profound hardening is the prerequisite for survival of a cultivar over winter. In the present study, hardening abilities of 13 winter wheat, 10 rye, 3 triticale and 6 winter barley cultivars were determined in field samples collected during the autumns of 1990 and 1991 by measuring the amount of ion leakage from frost-treated leaf segments. The cultivars tested were selected from the Inter-Nordic Winterhardiness Project, in which Field Survival Indices were determined for a total of 23 winter wheat, 13 rye, 5 triticale and 11 winter barley cultivars in order to estimate winter survival potentials under Finnish conditions. The winter survival of the materials studied correlated well with their hardening ability assessed by using the electrolyte leakage method.  相似文献   

Seed of Ullucus tuberosus—An apomict or not     

Leena Pietilä  Paula Jokela  Jukka Salo 《Euphytica》1990,47(2):117-120

Summary The paper deals with variations in enzyme pattern in the seeds of ulluco, Ullucus tuberosus. Six seeds per clone, four clones and three enzyme systems (malate dehydrogenase, glutamate oxaloacetate transaminase and 6-fosfoglucose dehydrogenase) were examined. There was variation in enzyme pattern between the seeds of a single clone. It is concluded that ulluco is not an apomictic species but a truly sexual one. Consequences of these findings for breeding programmes of ulluco are pointed out.  相似文献   

A genome-wide association study of type 2 diabetes in Finns detects multiple susceptibility variants     

Scott LJ  Mohlke KL  Bonnycastle LL  Willer CJ  Li Y  Duren WL  Erdos MR  Stringham HM  Chines PS  Jackson AU  Prokunina-Olsson L  Ding CJ  Swift AJ  Narisu N  Hu T  Pruim R  Xiao R  Li XY  Conneely KN  Riebow NL  Sprau AG  Tong M  White PP  Hetrick KN  Barnhart MW  Bark CW  Goldstein JL  Watkins L  Xiang F  Saramies J  Buchanan TA  Watanabe RM  Valle TT  Kinnunen L  Abecasis GR  Pugh EW  Doheny KF  Bergman RN  Tuomilehto J  Collins FS  Boehnke M 《Science (New York, N.Y.)》2007,316(5829):1341-1345

Identifying the genetic variants that increase the risk of type 2 diabetes (T2D) in humans has been a formidable challenge. Adopting a genome-wide association strategy, we genotyped 1161 Finnish T2D cases and 1174 Finnish normal glucose-tolerant (NGT) controls with >315,000 single-nucleotide polymorphisms (SNPs) and imputed genotypes for an additional >2 million autosomal SNPs. We carried out association analysis with these SNPs to identify genetic variants that predispose to T2D, compared our T2D association results with the results of two similar studies, and genotyped 80 SNPs in an additional 1215 Finnish T2D cases and 1258 Finnish NGT controls. We identify T2D-associated variants in an intergenic region of chromosome 11p12, contribute to the identification of T2D-associated variants near the genes IGF2BP2 and CDKAL1 and the region of CDKN2A and CDKN2B, and confirm that variants near TCF7L2, SLC30A8, HHEX, FTO, PPARG, and KCNJ11 are associated with T2D risk. This brings the number of T2D loci now confidently identified to at least 10.  相似文献   

Using expert knowledge in combining green infrastructure and ecosystem services in land use planning: an insight into a new place-based methodology   总被引：1，自引：0，他引：1  

Leena Kopperoinen  Pekka Itkonen  Jari Niemelä 《Landscape Ecology》2014,29(8):1361-1375

Green infrastructure (GI) is a strategic planning instrument to achieve sustainable development. The main functions of GI are to protect biodiversity and safeguard and enhance the provision of ecosystem services (ES). In this paper we present the development of a semi-quantitative place-based method, aiming at assessing GI based on the provision potential of all main ES. Our method combines a wide spectrum of GIS data with expert assessments. Here we focus especially on how interaction with experts and local and regional actors impacted the method development. Our results showed that involving experts in dataset selection is very useful in compiling the most relevant data for the assessment of ES. Expert knowledge is also valuable in evaluating the actual coverage and quality of datasets. By involving both experts and local and regional actors in assessing ES provision potential we can add local knowledge to the general scientific understanding. Qualitative assessments can be complemented with quantitative data in our method. The resulting maps support land use planning, as they assist in identifying the multifunctional key areas of GI and in examining the provision potential of various ES. The group discussions involved in our method provided an additional benefit, as the experts and local and regional actors felt that this discussion platform enhanced their understanding of both GI and ES.  相似文献   

Sprouting of Populus tremula L. in spruce regeneration areas following alternative treatments     

Leena Hamberg  Minna Malmivaara-L?ms?  Irja L?fstr?m  Henna Vartiam?ki  Sauli Valkonen  Jarkko Hantula 《European Journal of Forest Research》2011,130(1):99-106

We investigated the efficiency of three different methods to restrict sprouting in European aspen (Populus tremula L.) in regeneration areas of spruce in Finland. The methods compared were (1) traditional method (cutting at 10?C15 cm height) (2) cutting at 1 m height, and (3) fungus treatment (cutting at 10?C15 cm height, and mycelium of a white-rot fungus, Chondrostereum purpureum [Pers. Ex Fr.] Pouzar was applied to freshly cut stumps). The results indicated that the fungus treatment can restrict the emergence and growth of stump sprouts better than other methods, whereas cutting at 1 m seemed to yield the lowest numbers of root suckers. However, differences between the treatments were not significantly different (P values were > 0.05). For future experimentation, we suggest that the cutting of higher stumps to control the number of root suckers should be combined with application of C. purpureum to restrict the emergence and growth of stump sprouts. We also suggest developing more efficient C. purpureum isolates to control European aspen stump sprouting.  相似文献   

Estimating forest data for analyses of forest production and utilization possibilities at local level by means of multi-source National Forest Inventory     

Helena Mäkelä  Hannu HirveläTuula Nuutinen  Leena Kärkkäinen 《Forest Ecology and Management》2011,262(8):1345-1359

The sample plot data of National Forest Inventories (NFI) are widely used in the analysis of forest production and utilization possibilities to support national and regional forest policy. However, there is an increasing interest for similar impact and scenario analyses for strategic planning at the local level. As the fairly sparse network of field plots only provides calculations for large areas, satellite image data have been applied to produce forest information for smaller areas. The aim of this study was to test the feasibility of generating forest data for a Finnish forest analysis tool, the MELA system, by means of the Landsat satellite imagery and the NFI sample plot data. The study was part of the preparation of a local forestry programme, where a strategic scenario analysis for the forest area of two villages (ca 8000 ha) was carried out. Management units that approximate forest stands were delineated by image segmentation. Stand volume and other parameters for each forest segment were estimated from weighted means of the NFI sample plots, where the individual sample plot weights were estimated by the k nearest neighbour (kNN) method. Two different spectral features were tested: single pixel values and average pixel values within a segment. The estimated forest data were compared with the forest data based on independent stand-level field assessments in two subareas, a national park and an area of forest managed for timber production.In the national park, the estimated mean volume of the growing stock from both spectral feature sets (about 160 m³ ha⁻¹) was clearly lower than that obtained from stand-level field assessment (186 m³ ha⁻¹). Using average pixel values within a segment resulted in a higher proportion of pine and a lower proportion of spruce volume than using single pixel values. It also resulted in an estimated felling potential nearly 10% higher over the first 10-year period in the scenario analysis of the area dedicated to timber production. However, the maximum long-term sustainable removal was at the same level (about 30,000 m³ year⁻¹) for both feature sets over the simulated 30-year period. The resulting annual felling area in the first 10-year period was 12% lower when the segment averages were applied, but the difference subsequently levelled off. The kNN approach in estimating initial forest data for scenario analyses at the local level was found promising.  相似文献   

Elevated temperature effects on germination and early growth of European aspen (Populus tremula), hybrid aspen (P. tremula × P. tremuloides) and their F2-hybrids     

Pertti Pulkkinen  Lu-Min Vaario  Leena Koivuranta  Niina Stenvall 《European Journal of Forest Research》2013,132(5-6):791-800

This study aimed to understand the interaction between temperature and genotype in terms of the effect on early seedling development of European aspen (Populus tremula) and various F₂-aspen hybrids. We evaluated the response of 16 different European aspen and F₂-hybrid families on seed germination, survival rate and seedling height in one- and two-family trials under three different temperature regimes. In one-family trials, higher germination and higher survival rates were observed in higher temperature (C1700), leading to taller seedlings. European aspen × hybrid aspen individuals (Asp × Hyb) had a higher survival rate and taller seedlings than Asp, Hyb × Asp or Hyb × Hyb individuals. The difference between Asp × Hyb and Hyb × Asp was pronounced. Both growth conditions and genotype (i.e., hybrid cross) had strong effects on germination, survival rate and height of European aspen and F₂-hybrid seedlings. However, the interaction of genotype and growth conditions also had a significant influence on survival rate and seedling height, but not on germination. Two-family trials involving European aspen and F₂-hybrids led to significant negative effects on germination and survival rate and also facilitation effects on seedling height. Similarly, genotype had strong effects on germination and survival rate. Different genotypes and traits affected survival rate and seedling height differently in different growth conditions. These differences were more pronounced in the warmest environment, i.e., 1,700 degree days. We conclude that introgression between F₂-hybrids and local European aspen is likely in the current climate, and any warming will likely favor certain F₂-hybrids, especially the most probable types (P. tremula × (P. tremula × P. tremuloides)).  相似文献   

Carbon and nitrogen release from decomposing Scots pine,Norway spruce and silver birch stumps   总被引：1，自引：0，他引：1  

Marjo Palviainen  Leena Finér  Raija Laiho  Ekaterina Shorohova  Ekaterina Kapitsa  Ilkka Vanha-Majamaa 《Forest Ecology and Management》2010

Stumps are the largest coarse woody debris component in managed forests, but their role in nutrient cycling is poorly understood. We studied carbon (C) and nitrogen (N) dynamics in Scots pine (Pinus sylvestris), Norway spruce (Picea abies), and silver birch (Betula pendula) stumps, which had decomposed for 0, 5, 10, 20, 30 and 40 years after clear-cutting in southern Finland. Carbon and N were released significantly faster from birch stumps than from conifer stumps. In 40 years, conifer stumps lost 78% and birch stumps 90% of their initial C. In contrast, the amount of N in stumps increased, indicating that external N accumulated in the stumps. After 40 years of decomposition, the amount of N was 1.7 and 2.7 times higher than the initial amount in pine and spruce stumps, respectively. Nitrogen was released from birch stumps, but only after they had decomposed for 20 or more years. On average, 59% of N stored in birch stumps was released during 40 years. The results indicate that the stumps of the major tree species in Fennoscandian forests are long-term C and, especially, N pools which serve as N sinks, thus potentially diminishing N leaching into ground water and watercourses after harvesting. This suggests that the removal of stumps for bioenergy production may markedly affect the nutrient status and nutrient cycling of boreal forests.  相似文献   

Towards interactive fish farming governance? a comparison of Finland and Sweden     

Timo Mäkinen  Pekka Salmi  Leena Forsman 《Aquaculture International》2014,22(2):711-721

The neighbouring countries, Finland and Sweden, compete in the same market with their aquaculture. Both countries have had, until recently, stringent environmental policies limiting production volumes. During recent years, however, Swedish fish farmers have been able to increase their production volume, and Finnish fish farmers have also redirected their investments to Sweden. Thus, the strict Finnish environmental permit policy has not benefited the Baltic Sea environment, but has moved the production volumes and employment opportunities to other locations in the Baltic Sea and its drainage basin. By comparing the Finnish and Swedish fish farming governance systems, we found that in Sweden, various types of formal and informal interaction and practice have enhanced the achievement of balanced decisions. This has only rarely been the case in Finland, which features a more authoritative decision-making culture. On the other hand, increased communication across the Finnish administrative sectors raises future prospects for more holistic fish farming governance, which balances economic, social and environmental goals.  相似文献