scholarly journals Sowing Green Seed Without Stratification Does Not Shorten Juvenility or Increase Plant Size in Common Lilac (Syringa vulgaris)

HortScience ◽  
2020 ◽  
Vol 55 (11) ◽  
pp. 1781-1787
Author(s):  
Tyler C. Hoskins ◽  
Jason D. Lattier ◽  
Ryan N. Contreras

Common lilac is an important flowering shrub that accounts for ≈$20 million of sales in the U.S. nursery industry. Cultivar improvement in common lilac has been ongoing for centuries, yet little research has focused on shortening the multiple-year juvenility period for lilacs and the subsequent time required between breeding cycles. The practice of direct-sowing of immature “green” seed has been shown to reduce juvenility in some woody plants, but it has not been reported for common lilac. This study investigated the effects of seed maturity [weeks after pollination (WAP)], pregermination seed treatment (direct-sown vs. cold-stratified), and postgermination seedling chilling on the germination percentage, subsequent plant growth, and time to flower on lilac seedlings. All seedlings were derived from the female parent ‘Ludwig Spaeth’ and the male parent ‘Angel White’. Seeds harvested at 15 and 20 WAP resulted in 58% (sd ± 9.9%) and 80% (sd ± 9.0%) germination, respectively, which were similar to that of dry seed collected at 20 WAP with stratification (62% ± 4.2%). Seedlings from the green seed collected at 15 and 20 WAP were also approximately three-times taller than those of dry seed groups DS1, DS2, and DS3 after the first growing season. Over the next two growing seasons, there were no differences in seedling height across all treatments. Flowering occurred at the beginning of the fourth season and without differences among treatments. These results indicate that the collection and direct sowing of immature, green seed can be used to successfully grow lilac seedlings, but that they do not reduce the juvenility period. However, this method can provide more vegetative growth in year one to observe early vegetative traits such as leaf color, and it can provide more material for DNA extraction to support molecular research.

Author(s):  
Marcelo Laranjeira Pimentel ◽  
Henara Valéria Miranda Castro ◽  
Mike Kirixi Munduruku ◽  
Larissa Conceição Cunha Ponte ◽  
Deyvielen Maria Ramos Alves ◽  
...  

The use of fungi in seed treatment can improve the plant's physiological characteristics. The aim of this study was to evaluate the influence of the use of Trichoderma harzianum on the physiological quality of bean seeds. The experiment was set up and conducted in the forest seed laboratory of the Federal University of Western Para, in a randomized design, using 4 procedures on the basis of a colony forming unit (CFU): T1 (0 CFU), T2 (4 x 109 CFU), T3 (8 x 109 CFU) and T4 (12 x 109 CFU), with 5 repetitions. Germination percentage (G%), germination speed index (GSI), hypocotyl length (HL) and radicle length (RL) were evaluated as variables. The data were analyzed by variance analysis and the averages were compared using the Tukey test (p≤0.05), in addition to the regression analysis, using the Minitab© version 18 statistical software. There were differences between the germination percentage tests, in which T2 obtained 100% of germinated seeds, for GSI it was observed that T2 and T3 were equal and superior to the other treatments, while for RL T1 and T2 obtained the best results, however, for HL there were no statistical differences between treatments. T2 was more efficient in the physiological quality of seeds to germination percentage and germination speed index


Weed Science ◽  
1976 ◽  
Vol 24 (2) ◽  
pp. 233-234 ◽  
Author(s):  
Abdollah Bassiri ◽  
Iraj Rouhani

Seeds of wild safflower (Carthamus oxyacanthaBieb.) collected from the Bajgah area, Iran, in 2 successive years were subjected to stratification and scarification treatments and their germination percentage and subsequent seedling growth (length) were measured at room temperature (23 ± 2 C). Maximum germination and seedling length occurred in the seeds stratified in moist sand at 4 C for 2 weeks. The response of the freshly-harvested seed to scarification was linear while that for 1-yr-old seed was quadratic. Both scarification and stratification independently increased germination but germination never reached the viability level of the seed.


2020 ◽  
Vol 68 (6) ◽  
pp. 439
Author(s):  
Julie Christine Scaloppi ◽  
Andréa Lúcia Teixeira de Souza

Seedling planting is the most common strategy used to reintroduce tropical native tree species; however, direct sowing has simplicity and operational ease advantages. Functional traits such as seed size and growth rates have been shown to be relevant for better plant performance. We evaluated the effects of intraspecific variation in seed size and the reintroduction strategy simultaneously on the development of Hymenaea courbaril (L.) and Enterolobium timbouva (Mart.) introduced in an abandoned eucalyptus plantation over 462 days. Plants from small, medium and large seeds were reintroduced by planting seedlings and direct seeding. Both species achieved high rates of emergence and survival was high in the two reintroduction strategies. Seed size was not related to emergence and mean time to emergence for either species. The survival of both species was higher than 74% in the field, and seed size had little effect on survival rates. In general, H. courbaril plants introduced by direct sowing had higher growth, and seed size correlated positively with stem size. In contrast, the growth of E. timbouva plants introduced by seedling planting was higher than in plants introduced by direct sowing regardless of seed size. The light requirements of this species seem higher than for H. courbaril. Our results suggest the feasibility of reintroducing species by direct sowing in eucalyptus understory, but since plant growth varies between species, there may be a balance between the advantage of the initial plant size provided by planting seedlings and the advantage of a better root development provided by direct sowing.


Agriculture ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 484
Author(s):  
Helena Viric Gasparic ◽  
Mirela Grubelic ◽  
Verica Dragovic Uzelac ◽  
Renata Bazok ◽  
Maja Cacija ◽  
...  

European sugar beet was mostly grown from seeds treated by neonicotinoids which provided efficient control of some important sugar beet pests (aphids and flea beetles). The EU commission regulation from 2018 to ultimately restrict the outdoor application of imidacloprid, thiamethoxam, and clothianidin could significantly affect European sugar beet production. Although alternative insecticides (spinosad, chlorantraniliprole, neem) are shown to have certain effects on particular pests when applied as seed treatment, it is not likely that in near future any insecticide will be identified as a good candidate for neonicotinoids’ substitution. The aim of this research is to evaluate residue levels (LC-MS/MS method) of imidacloprid and thiamethoxam applied as seed dressing in sugar beet plants during two growing seasons in fields located in different agro-climatic regions and in greenhouse trials. In 2015, 25 to 27 days post planting (PP) maximum of 0.028% of imidacloprid and 0.077% of thiamethoxam were recovered from the emerged plants, respectively. In 2016, the recovery rate from the emerged plants 40 days PP was 0.003% for imidacloprid and 50 days PP was up to 0.022% for thiamethoxam. There were no neonicotinoid residues above the maximum residue level in roots at the time of harvesting, except in case of samples from thiamethoxam variant collected from greenhouse trials in 2016 (0.053 mg/kg). The results of this research lead to the conclusion that the seed treatment of sugar beet leaves minimal trace in plants because of the complete degradation while different behavior has been observed in the two fields and a glasshouse trial regarding the residues in soil. Dry conditions, leaching incapacity, or irregular flushing can result in higher concentrations in soil which can present potential risk for the succeeding crops. The results of our study could provide additional arguments about possible risk assessment for seed treatment in sugar beet.


2010 ◽  
Vol 37 (5) ◽  
pp. 448 ◽  
Author(s):  
Alex Whan ◽  
Nicole Robinson ◽  
Prakash Lakshmanan ◽  
Susanne Schmidt ◽  
Karen Aitken

The economic and environmental consequences of inefficient use of nitrogen (N) fertiliser in agricultural crops is of concern worldwide, so new crop varieties with improved nitrogen use efficiency (NUE) are sought. Here, we report the first study of mapping quantitative trait loci (QTL) for nitrogen physiology traits in sugarcane. QTL analysis was undertaken for each parent of a segregating bi-parental sugarcane mapping population. We grew 168 progeny under limiting (0.2 mM NH4NO3) and non-limiting (5.0 mM NH4NO3) N supplies in two glasshouse experiments. Significant marker-trait associations (MTA) were detected in each treatment for shoot dry weight, root dry weight, total shoot N, shoot internal NUE (iNUE; measured as units shoot dry weight per unit N), leaf protein content and glutamine synthetase (GS) activity. MTA for GS activity did not co-locate with other traits except leaf protein content, indicating that variation in GS activity is not linked to plant size or iNUE during early growth. Under high N, there were no significant MTA for iNUE among markers from the male parent, Q165, an Australian commercial cultivar, but six MTA were found for markers inherited from the female parent, IJ76–514, a Saccharum officinarum ancestral variety. The results indicate that variation for iNUE under high N may be lower in commercial varieties than unimproved genotypes. Further, four MTA were consistent with previous field-based research on sugar and biomass production. Our study provides initial evidence that QTL may be incorporated in sugarcane breeding programs targeting improved NUE.


2007 ◽  
Vol 85 (2) ◽  
pp. 160-166 ◽  
Author(s):  
Kari Lehtilä ◽  
Kristina Holmén Bränn

The evolution of flower size may be constrained by trade-offs between flower size and other plant traits. The aim of this study was to determine how selection on flower size affects both reproductive and vegetative traits. Raphanus raphanistrum L. was used as the study species. Artificial selection for small and large petal size was carried out for two generations. We measured the realized heritability of flower size and recorded flower production, time to flowering, plant size, and seed production in the two selection lines. The realized heritability was h2 = 0.49. Our study, therefore, showed that R. raphanistrum has potential for rapid evolutionary change of floral size. The lines with large flowers produced smaller seeds and started to flower later than the lines with small flowers. There was no trade-off between flower size and flower number, but the lines selected for large flower size had more flowers and a larger plant size than lines selected for small flowers. Estimates of restricted maximum likelihood (REML) analysis of pedigrees also showed that flower size had a positive genetic correlation with start of flowering and plant height.


2010 ◽  
Vol 34 (4) ◽  
pp. 1103-1112 ◽  
Author(s):  
Rubens José Campo ◽  
Ricardo Silva Araujo ◽  
Fábio Luís Mostasso ◽  
Mariangela Hungria

Soybean is a major grain crop in Brazil, and yields can be considerably improved by inoculation with selected Bradyrhizobium strains. However, the incompatibility between inoculation and seed treatments with fungicides and micronutrients represents a major barrier to the achievement of high rates of biological N2 fixation. Inoculation practices that can alleviate the negative effects of agrochemicals must therefore be found and in-furrow inoculation seems to be an attractive alternative. This study reports the results of seven field experiments conducted in three growing seasons in Brazil; three in soils previously cropped with inoculated soybean (> 10(4) cells g-1 of soil of Bradyrhizobium), and four in areas where the crop was sown for the first time (< 10² cells g-1 of soil of Bradyrhizobium). The compatibility with fungicides and micronutrients was compared in seeds inoculated with peat or liquid inoculants, or treated with different doses of liquid inoculant in-furrow. In areas with established Bradyrhizobium populations, seed-applied agrochemicals did generally not affect nodulation, but also did not increase yields, while inoculation always increased N grain accumulation or yield, and N fertilizer decreased both nodulation and yield. Where soybean was sown for the first time, the seed treatment with agrochemicals affected nodulation when applied together with peat or liquid inoculant. In-furrow inoculation alleviated the effects of seed treatment with agrochemicals; the best performance was achieved with high Bradyrhizobium cell concentrations, with up to 2.5 million cells seed-1.


2021 ◽  
Vol 42 (2) ◽  
pp. 455-470
Author(s):  
Vanderléia Mathias ◽  
◽  
Cileide Maria Medeiros Coelho ◽  

Although the accelerated aging test is widely used to determine seed vigor, there are methodological variations in seed exposure time at 41 °C. Therefore, the objective was to indicate the most appropriate seed exposure time to segregate lots that also exhibits a correlation with seedling emergence in the field, and establish vigor levels using the aforementioned test. Soybean seed samples were collected at pre-sowing, representing 100 lots in the 2016/2017 growing season and 125 lots in the 2017/2018 season from different warehouses in 4 regions of Santa Catarina state (SC). Physiological quality was evaluated by germination, accelerated aging (24 and 48 h at 41 °C) and field emergence tests. The results were submitted to descriptive statistical analysis and Pearson’s correlation analysis (p < 0.05). The rank sum index, associated with the Scott-Knott clustering method, was used to classify physiological quality. The average germination percentage was 90 and 91% in the 2016/2017 and 2017/2018 growing seasons, respectively. Vigor obtained an average of 86 (2016/2017) and 85% (2017/2018), when seeds were submitted to accelerated aging for 48 h, and 89% (both seasons) for 24 h. In regard to field emergence, the average was 85 and 80% in the 2016/2017 and 2017/2018 growing seasons, respectively. Considering the 225 lots, the greatest correlation with field emergence was observed in vigor - 48 h (r = 0.71 p < 0.05). Rank sum classification made it possible to establish vigor-based categories, whereby batches with over 85% vigor by 48-h accelerated aging were classified as high vigor, 70 to 84% medium vigor, and under 70% low vigor.


HortScience ◽  
2019 ◽  
Vol 54 (11) ◽  
pp. 1902-1906 ◽  
Author(s):  
Tyler Hoskins ◽  
Ryan N. Contreras

Sweetbox (Sarcococca confusa) is an evergreen shrub valued for attractive foliage, winter fragrance, black fruit, as well as shade and drought tolerance. The high degree of apomixis in Sarcococca limits the effectiveness of conventional breeding practices. However, mutation breeding may be a valuable tool to induce variation in seedling crops. As such, a study was conducted to expose seeds of S. confusa to ethyl methanesulfonate (EMS) at varying concentrations and exposure durations, and to evaluate the effects on seed germination, growth, and relative frequency of polyembryony. In 2010, seeds of S. confusa were treated with 0%, 0.2%, 0.4%, 0.8%, and 1.2% EMS for 24 and 48 hours. Seeds were sown and the relative germination and occurrence of polyembryony were recorded. Seedlings were later evaluated for size and phenotypic variation in the subsequent growing seasons. Percent germination was found to decrease with increasing EMS rates in the 24- and 48-hour treatments. The occurrence of polyembryony also decreased with increasing EMS rates in the 24-hour treatment but was observed to be greatest at 0.2% EMS. No significant differences in plant size index (SI) were found after four growing seasons. When mature, seeds were collected from any plants that bore fruit in each treatment and were then sown. The percentage of plants that bore fruit in each treatment decreased with increasing EMS rates, although the germination rate of these seeds did not differ. A chlorophyll mutant and several dwarf forms were identified in this population as well. They have been propagated asexually for future evaluation as new cultivars. This study demonstrates the utility of chemical mutagenesis to induce phenotypic variation in S. confusa while reducing the rate of polyembryony.


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