scholarly journals Hybrid watermilfoil (Myriophyllum spicatum × Myriophyllum sibiricum) exhibits traits associated with greater invasiveness than its introduced and native parental taxa

2021 ◽  
Author(s):  
Wesley J. Glisson ◽  
Daniel J. Larkin
Keyword(s):  
Native Species ◽  
Myriophyllum Spicatum ◽  
Reproductive Potential ◽  
Growing Season ◽  
Surface Cover ◽  
Myriophyllum Sibiricum ◽  
Parental Taxon ◽  
Significant Difference ◽  
Number Of Stems ◽  
Native Invasive

AbstractHybridization has been associated with increased invasiveness in plants. In North America, the hybrid aquatic plant Myriophyllum spicatum × Myriophyllum sibiricum (hybrid watermilfoil, hereafter HWM) is a cross between non-native invasive Eurasian watermilfoil (M. spicatum, EWM) and native northern watermilfoil (M. sibiricum, NWM). Lab-based trials have demonstrated higher growth rates in HWM compared to EWM and NWM, but these patterns have not been systematically examined in the field. In this study, we compared the invasiveness of HWM to its parental taxa, EWM and NWM, by examining the amount and timing of: (1) flowering, (2) surface cover, and (3) biomass (using stem counts as a proxy). We conducted repeat surveys of Myriophyllum beds at eight lakes (2–3 lakes/taxon) in the Minneapolis–St. Paul Metropolitan area (Minnesota, USA) between June 2017 and November 2018. HWM produced more flower spikes earlier and overall, and maintained consistently more flower spikes throughout the growing season than EWM and NWM. In addition, surface cover reached greater annual peaks and was higher for longer throughout the growing season for HWM than for both parental taxa. We did not observe a significant difference in stem counts among the three taxa, but HWM did reach a higher maximum number of stems than either parental taxon. This study provides field-based evidence of increased invasiveness associated with hybridization between EWM and NWM; specifically, greater reproductive potential via flowering and greater surface cover may increase HWM spread, have greater impacts on native species, and pose more of a nuisance to lake users.

scholarly journals Initial development and gas exchange of Talisia subalbens (Mart.) Radlk. under different shading conditions

2011 ◽  
Vol 35 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Fernanda Carlota Nery ◽  
Hilton Morbeck de Oliveira ◽  
Amauri Alves de Alvarenga ◽  
Sara Dousseau ◽  
Evaristo Mauro de Castro ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Native Species ◽  
Cultivated Plants ◽  
Initial Growth ◽  
Initial Development ◽  
Basal Diameter ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Significant Difference ◽  
Different Levels

Ecophysiological studies under semi-controlled conditions in nurseries and greenhouses are essential to enable the use of native species to recover degraded areas and for commercial planting. Talisia subalbens (Mart) Radlk, 'cascudo', is a native fruiting species of the Cerrado on the verge of extinction. The ecophysiological performance of this species was evaluated in nursery conditions under different levels of shading (full sunshine, 30%, 50% and 70%). Initial growth, biomass allocation, gas exchange and chlorophyll content of the plants were analyzed. Full sunshine cultivated plants showed a higher accumulation of total, shoot, and root dry biomass. There was no significant difference in the root/shoot ratio among the treatments. Seedlings cultivated under full sunshine and 30% shading showed higher values for height, basal diameter, and leaf area. Differences in stomata conductance and photosynthesis rate were not observed among the different shading levels. Plants cultivated under 70% of shading had higher contents of chlorophyll a, b, and total. During the initial phase with higher levels of radiation were fundamental for the development of T. subalbens seedlings.

scholarly journals Assessment of the Potential of Eco-Friendly Nematicides in the Management of Root-Knot Nematodes on French Beans in Kenya

2019 ◽  
Vol 7 (1) ◽  
pp. 62-67
Author(s):  
E. O. Ogumo ◽  
W. M. Muiru ◽  
J. W. Kimenju ◽  
D. M. Mukunya
Keyword(s):  
Reproductive Potential ◽  
Negative Control ◽  
French Bean ◽  
Economic Losses ◽  
Root Knot Nematode ◽  
Population Densities ◽  
Root Knot Nematodes ◽  
French Beans ◽  
Wide Range ◽  
Significant Difference

Root-knot nematodes (RKN) (Meloidogyne spp) are a serious pest causing heavy economic losses in a wide range of agricultural crops. A trial was carried out to evaluate the effectiveness of various eco-friendly nematicides in the management of RKN affecting French bean. The field trial was carried out in two seasons with the following treatments; Rigel-G (salicylic acid), Phyto Protect (Sesame oil extract), Mytech (Paecilomyces lilacinus), Neemraj 0.3% (Azadirachtin), Vydate® (Oxamyl) as a positive control and an untreated control. Various rates; Rigel –G (2.5 ml/l), Phyto Protect (10 l/ha), Mytech (125 g/ha) Neemraj 0.3% (3L/ha) and Vydate® (6 l/ha) of treatments were administered and damage on plants was assessed based on galling indices, crop biomass and yield whereas nematode reproductive potential was assessed based on the J2 counts. There was no significant difference (P ≥ 0.05) in the nematode population densities and galling indices observed among the eco-friendly nematicides and the conventional nematicide (Vydate®). Eco-friendly nematicides had a significant (P ≤ 0.05) reduction of RKN J2 population densities compared to the negative control. The negative control had the highest mean of root-knot nematode densities (240 RKN/200 cc soil) and a galling index of 3.77 while Vydate and Neemraj had the lowest mean density (40 RKN/200 cc soil) in the first season. Similar results were observed in the second season with control having the highest RKN J2 population densities (285 RKN/200 cc soil) and a galling index of 3.89 and Vydate had the lowest (23 RKN/200 cc soil). The results of this study clearly indicate that eco-friendly nematicides can be fully adopted to suppress RKN in French beans as alternatives to conventional nematicides.

scholarly journals Prospects of practical use of new potatoes state varietal resources in the north-east Forest-Steppe of Ukraine

2019 ◽  
pp. 15-21 ◽  
Author(s):  
N.S. Kozhushko ◽  
M.M. Sakhoshko ◽  
M.G. Bashtovyi ◽  
D.V. Smilyk ◽  
V.I. Avramenko ◽  
...  
Keyword(s):  
Starch Content ◽  
Growing Season ◽  
Potato Production ◽  
Climatic Conditions ◽  
Forest Steppe ◽  
North East ◽  
The North ◽  
Significant Difference ◽  
New Varieties ◽  
Growing Conditions

According to statistic evaluation of the manifestation of signs of the economic suitability of state sort resources of 2019 registration potatoes when growing it in different agro-climatic conditions, a significant advantage of influence of the forest-steppe conditions was determined. Compared to Polesia the increase of yield rose for 4.1 t/ha or 18 % (НІР05 = 2.18, Ffact= 12.65 > F05 = 4.22) and the amount of trade potato for 22.72 ha or 20 % (Ffact = 58.87). There is also a tendency to increase the number of starch from unit of area for – 17 % and the total consumer properties for – 8 %.  However, there is a significant difference in the reduction of storability of products by 45 % and the lack of it’s resistance to macrosporiosis and late blight. It was proved that the yield of varieties for cultivation in the polesia zone by 25.7 % depended on the duration of the growing season (Ffact = 4.14 > F05  = 0.06). The relationship between yield and starch of potatoes in Polesia zone varieties  was determined – 23.6 % and in forest-steppe – 17.3 % and starch collection, respectively, 33.6 % and 28.0 %. The dependence of storability of potato which grew in the polesia zone and in forest-steppe from the amount of starch for 15 % was mathematically proved (Ffact = 2.11 > F05 = 0.17) і 11.3 % (Ffact = 1.52 > F05 = 0.24); the dependence of storability on the duration of the growing season in the Forest-Steppe conditions was confirmed(Ffact = 0.66 > F05  = 0.43). In addition, the 12 % of tasting grade of the Forest-Steppe varieties depended on the starch content amount (Ffact = 1.65 > F05 = 0.22). According to the results of the regression analysis, mathematical models have been developed to predict yields, culinary and consumer properties, and the storability of new potato varieties under different growing conditions. The project of a conveyor for the consumption of fresh product in summer  period with the involvement of varieties of early ripeness in the Forest-Steppe was presented: 80 days after planting – Sanibel, 90 days after planting – Medison, Paroli, 95 days after planting – Bazalia, Bernina, 100 days after planting – Donata, in the Polesia zone ‒ 80 days after planting – Sanibel, 90 days after planting – Paroli, 95 days after planting –Bazalia, 100 days after planting – Medison, Bernina, Donata. By distribution of varieties by predicted high content of phytonutrients there were bred varieties with red skin and creamy flesh – Bazalia and Sanibel, by high content with yellow flesh – Baltic Rosa and moderate content with white flesh – Oleksandrit, Fotynia, Ricarda. Introduction of new varieties with certain high adaptive potential of storability and content of bioactive compounds in potatoes will provide growth of potato production in the conditions of the northeast forest-steppe and increase its competitiveness in the domestic and foreign markets and will solve the problem of year-round consumption of fresh quality products.

Growth and Development of Organic Arsenical-Susceptible and -Resistant Common Cocklebur (Xanthium strumarium) Biotypes Under Noncompetitive Conditions

1994 ◽  
Vol 8 (1) ◽  
pp. 154-158 ◽  
Author(s):  
William E. Haigler ◽  
Billy J. Gossett ◽  
James R. Harris ◽  
Joe E. Toler
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Plant Height ◽  
Growth And Development ◽  
Reproductive Potential ◽  
Dry Weight ◽  
Growing Season ◽  
Xanthium Strumarium ◽  
Relative Growth ◽  
Growth Development

The growth, development, and reproductive potential of several populations of organic arsenical-susceptible (S) and -resistant (R) common cocklebur biotypes were compared under noncompetitive field conditions. Plant height, leaf area, aboveground dry weights, and relative growth rate (RGR) were measured periodically during the growing season. Days to flowering, bur dry weight, and number of burs per plant were also recorded. Arsenical S- and R-biotypes were similar in all measured parameters of growth, development, and reproductive potential. Populations within each biotype varied occasionally in plant height, leaf area, aboveground dry weights, and reproductive potential.

Genetic diversity and differentiation in populations of invasive Eurasian (Myriophyllum spicatum) and hybrid (Myriophyllum spicatum × Myriophyllum sibiricum) watermilfoil

2020 ◽  
Vol 13 (2) ◽  
pp. 59-67
Author(s):  
Ryan A. Thum ◽  
Gregory M. Chorak ◽  
Raymond M. Newman ◽  
Jasmine A. Eltawely ◽  
Jo Latimore ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Population Genetic ◽  
Myriophyllum Spicatum ◽  
Population Variation ◽  
Efficacy Evaluation ◽  
Submerged Aquatic Plant ◽  
Myriophyllum Sibiricum ◽  
Control Response ◽  
Herbicide Response

AbstractPopulation genetic studies of within- and among-population genetic variability are still lacking for managed submerged aquatic plant species, and such studies could provide important information for managers. For example, the extent of within-population genetic variation may influence the potential for managed populations to locally adapt to environmental conditions and control tactics. Similarly, among-population variation may influence whether specific control tactics work equally effectively in different locations. In the case of invasive Eurasian watermilfoil (Myriophyllum spicatum L.), including interspecific hybrids with native northern watermilfoil (Myriophyllum sibiricum Kom.), managers recognize that there is genetic variation for growth and herbicide response. However, it is unclear how much overall genetic variation there is, and how it is structured within and among populations. Here, we studied patterns of within- and among-lake genetic variation in 41 lakes in Michigan and 62 lakes in Minnesota using microsatellite markers. We found that within-lake genetic diversity was generally low, and among-lake genetic diversity was relatively high. However, some lakes were genetically diverse, and some genotypes were shared across multiple lakes. For genetically diverse lakes, managers should explicitly recognize the potential for genotypes to differ in control response and should account for this in monitoring and efficacy evaluation and using pretreatment herbicide screens to predict efficacy. Similarly, managers should consider differences in genetic composition among lakes as a source of variation in the growth and herbicide response of lakes with similar control tactics. Finally, laboratory or field information on control efficacy from one lake may be applied to other lakes where genotypes are shared among lakes.

scholarly journals Niche Models Differentiate Potential Impacts of Two Aquatic Invasive Plant Species on Native Macrophytes

Diversity ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 162
Author(s):  
Michael R. Verhoeven ◽  
Wesley J. Glisson ◽  
Daniel J. Larkin
Keyword(s):  
Native Species ◽  
Invasive Plant ◽  
Environmental Gradients ◽  
Myriophyllum Spicatum ◽  
Light Availability ◽  
Niche Overlap ◽  
Growth Cycle ◽  
Potamogeton Crispus ◽  
Starting Point ◽  
Niche Models

Potamogeton crispus (curlyleaf pondweed) and Myriophyllum spicatum (Eurasian watermilfoil) are widely thought to competitively displace native macrophytes in North America. However, their perceived competitive superiority has not been comprehensively evaluated. Coexistence theory suggests that invader displacement of native species through competitive exclusion is most likely where high niche overlap results in competition for limiting resources. Thus, evaluation of niche similarity can serve as a starting point for predicting the likelihood of invaders having direct competitive impacts on resident species. Across two environmental gradients structuring macrophyte communities—water depth and light availability—both P. crispus and M. spicatum are thought to occupy broad niches. For a third dimension, phenology, the annual growth cycle of M. spicatum is typical of other species, whereas the winter-ephemeral phenology of P. crispus may impart greater niche differentiation and thus lower risk of native species being competitively excluded. Using an unprecedented dataset comprising 3404 plant surveys from Minnesota collected using a common protocol, we modeled niches of 34 species using a probabilistic niche framework. Across each niche dimension, P. crispus had lower overlap with native species than did M. spicatum; this was driven in particular by its distinct phenology. These results suggest that patterns of dominance seen in P. crispus and M. spicatum have likely arisen through different mechanisms, and that direct competition with native species is less likely for P. crispus than M. spicatum. This research highlights the utility of fine-scale, abundance-based niche models for predicting invader impacts.

Study on Changes of Total Flavonoid Content in Suaeda salsa in Different Months of Growing Season

2014 ◽  
Vol 926-930 ◽  
pp. 1028-1031
Author(s):  
Wei Fang Zhong ◽  
Yue Hong Wang ◽  
Hong Ying Liu ◽  
Jin Hua Feng
Keyword(s):  
Theoretical Basis ◽  
Growing Season ◽  
Total Flavonoid ◽  
Suaeda Salsa ◽  
Uv Spectrophotometry ◽  
Total Flavonoid Content ◽  
Flavonoid Content ◽  
Significant Difference

Objective To investigate the changes of total flavonoid content of Suaeda salsa in different months of growing season, from May to November. Methods UV spectrophotometry was used for determination of the total flavonoid. Results The content of total flavonoid in Suaeda salsa was highest in September (67.75 mg·g-1) and was lowest in May (11.4 mg·g-1).The content was found to increase from May to September, and to decrease from September to November. Conclusion There is significant difference between total flavonoid content in Suaeda salsa from different months, which can be used to provide theoretical basis for harvesting and processing of Suaeda salsa.

scholarly journals Variasi Genetik pada Pertumbuhan Tanaman Konservasi Sumberdaya Genetik Cendana (Santalum album Linn.) Populasi Pulau Timor Bagian Timur

2016 ◽  
Vol 14 (1) ◽  
pp. 27 ◽  
Author(s):  
Sumardi Sumardi
Keyword(s):  
Native Species ◽  
Block Design ◽  
Genetic Material ◽  
Raw Material ◽  
Average Height ◽  
Santalum Album ◽  
Incomplete Block ◽  
Material Source ◽  
Incomplete Block Design ◽  
Significant Difference

ABSTRACT Sandalwood (Santalum album Linn.) Is a native species of East Nusa Tenggara that have high economic value because it contains oil in the hardwood that is used as a raw material for cosmetics and pharmaceuticals. However, sandalwood population in East Nusa Tenggara has declined severely caused of massive exploitation in the past without accompanied by the success of replanting. Excessive exploitation impact on the decreasing of genetic diversity. Conservation was initiatied by the Forestry Research Institute of Kupang in 2012 with Eastern Part of Timor Island as a genetic material source. This study was aimed to investigate the genetic variation of plant growth on sandalwood (Santalum album linn.) genetic conservation from Eastern Part of Timor Island until 8 months after planting. The research was designed using Incomplete Block Design (IBD), consists of 25 families, single treeplot and 10 blocks as replicates. The variance analysis showed there was no significant difference between the families tested and the average height and diameter growth of test plants respectively 51,02 cm and 4.70 mm. The families heritability (h2f)  estimation of height is 0.70 high category and the diameter is 0.53 medium category.   Key words : Population, conservation, variation, heritability ABSTRAK Cedana (Santalum album Linn.) merupakan jenis tanaman asli Nusa Tenggara Timur yang memiliki nilai ekonomi tinggi karena kandungan minyak atsiri pada kayu terasnya yang digunakan sebagai bahan baku industri kosmetik dan obat-obatan. Namun demikian populasi jenis ini di Nusa Tenggara Timur telah mengalami penurunan sangat tajam, akibat eksploitasi besar-besaran dimasa lalu yang tidak dibarengi keberhasilan penanaman kembali. Kondisi tersebut berdampak pada keragaman genetik cendana yang pernah ada di NTT. Tindakan konservasi mulai dilakukan oleh Balai Penelitian Kehutanan Kupang pada tahun 2012 yang berasal dari populasi Pulau Timor bagian Timur. Penelitian ini bertujuan untuk mengetahui variasi genetik pertumbuhan tanaman pada plot konservasi sumberdaya genetik cendana populasi Pulau Timor bagian Timur sampai dengan umur 8 bulan setelah penanaman. Penelitian disusun dengan rancangan Incomplete Block Design (IBD) yang terdiri dari 25 famili, single treeplot dan 10 blok sebagai ulangan. Hasil analisis varian tidak menunjukkan adanya perbedaan nyata antar famili yang diuji dengan nilai rerata pertumbuhan tinggi dan diameter masing-masing sebesar 51,02 cm dan 4,70 mm. Taksiran nilai heritabilitas famili (h2f) untuk tinggi sebesar 0,70 termasuk kategori tinggi dan diameter sebesar 0,53 termasuk kategori sedang. Kata kunci : populasi, konservasi, cendana, variasi, heritabilitas. Cara sitasi: Sumardi. (2016). Variasi Genetik pada Pertumbuhan Tanaman Konservasi Sumberdaya Genetik Cendana (Santalum album Linn.) Populasi Pulau Timor Bagian Timur, 14(1),27-31, doi:10.14710/jil.14.1.27-31

scholarly journals The effects of introducing the Amazonian squirrel monkey on the behavior of the northeast marmoset

2015 ◽  
Vol 45 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Fátima Luciana Miranda CAMAROTTI ◽  
Valdir Luna da SILVA ◽  
Maria Adélia Borstelmann de OLIVEIRA
Keyword(s):  
Squirrel Monkey ◽  
Native Species ◽  
Callithrix Jacchus ◽  
Observation Time ◽  
Saimiri Sciureus ◽  
Significant Difference ◽  
Negative Effect ◽  
Total Observation Time ◽  
Total Observation ◽  
The Impact

The squirrel monkey Saimiri sciureus, an endemic primate of the Amazonian Basin, has been introduced in many localities of the Atlantic Forest biome. Introduced exotic species gain a competitive advantage in their new environment because of a lack of natural predators, competitors or diseases. This advantage can result in a reduction in the resources for the endemic species. The aims of this work were to evaluate the level of adaptation, and monitor the forms of interaction and the impact caused by S. sciureus on the behavior of the native species Callithrix jacchus in the Saltinho Biological Reserve, Tamandaré, Pernambuco, Brazil. The behavior was assessed by use of scan sampling method, every 5 min. A total of 382 h (191 h or 2,292 scans per group) of time sampling was performed. Sixteen interactions were recorded. The interaction index was low and represented 2.4% of the total observation time. Interactions were significantly higher during the dry season (58.5%) relative to the rainy season (41.5%). Callithrix jacchus was intolerant to the presence of S. sciureus and the last one was more tolerant during the interactions. In the presence of S. sciureus, C. jacchus eating, foraging, resting, socializing, and self-grooming behaviors were reduced while alertness was increased. Territorial behavior showed no significant difference. In the presence of S. sciureus, on average, the group of marmosets assembled at a higher layer of the forest stratum. The results might indicate a negative effect of S. sciureus on the native species, C. jacchus.

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