scholarly journals Effect of Water Salinity on Seeds Germination of Sterile Oat (Avena sterilis) and Rigid Rye Grass (Lolium rigidum) at Constant or Alternating Temperatures

Author(s):  
Khalid S. Alshallash Khalid S. Alshallash

Sterile oat (Avena sterilis) and rigid rye grass (Lolium rigidum) are well known grasses in many parts of the world. They grow in grasslands and arable lands. Both are recorded as serious weeds of arable lands in many countries worldwide. Seeds germination of both species were tested at four levels of water salinity concentrations (0, 100, 300, 500 mM/L of NaCl) and five different temperatures (Constant at 8 C ° or alternating temperatures of; 8/16, 10/18, 6/14, 10/20 C?). Photoperiods regime of 8 hours darkness and 16 hours of light at the constant temperature was implemented. The same was followed with the alternating temperatures with 8 hours darkness at the lower temperature and 16 hours light with the higher temperature. A. sterilis seeds showed better germination with high significance of (? 00.1) than L. rigidum seeds at all tested treatments. The mean number of germinated seeds of A. sterilis was (6) out of (20) seeds /petri dish whereas, it was nearly (3) geminated seeds with L. rigidum. Both species secured the highest germination percentage at level of alternating temperatures of (10/20 C °) with 40% (mean number of germinated seeds was 8 out of 20 seeds / petri dish) for A. sterilis and 25% (5 out of 20 seeds / petri dish) for L. rigidum. Although A. sterilis seeds showed some germination (25%) at constant temperatures of (8 C°), L. rigidum seeds were less in favorite of this climatic condition expressing its response to alternating temperatures. Generally, A. sterilis seeds showed better germination responses than L. rigidum seeds at all different level of tested temperatures. Moreover, A. sterilis seeds resist water salinity as high as 100 mM of NaCl/L and showed almost 50 % germination especially at its favorite alternating temperature of (10/20 C °). L. rigidum seeds also showed some resistance to 100 mM/L of NaCl giving about 35 % germination. However, both species gave poor germination at higher levels of water salinity of 300 and 500 mM of NaCl/L concentrations. Results confirmed that both species seeds germination are in favorite of moderate alternating temperatures condition expressing some resistance to water salinity. This explains both species invasion and persistence in arable lands being reported a serious weedy plant species especially in a Mediterranean climate and subtropical conditions. In addition those results showed some of the two species seed biological aspects, which could contribute to a better control practice of the two species in arable lands.

2021 ◽  
Vol 27 (2) ◽  
Author(s):  
Bouzid Nedjimi

In Mediterranean basin, Pinus halepensis Mill. is the dominant conifer used in afforestation and landscape projects. The ecological, aesthetic and commercial benefits make this conifer a precious tree for both woody production and land rehabilitation. Nevertheless, detailed studies on the adaptation of this tree to abiotic environmental constraints in the Mediterranean areas remain limited up until now. Therefore, laboratory experiments were conducted to assess the effects of the interactive impact of temperatures and salinity on the germinability potential of P. halepensis seeds. The cones of P. halepensis used in this experiment were harvested from the Gotaïa forest at Djelfa province, Algeria. The seeds were removed from their cones and surface-sterilized by soaking for five min in 10% NaClO. Seeds were germinated at three temperature regimes (10–20 °C, 15–25 °C and 20–30 °C) and four levels of salinity (0, 50, 100, and 150 mM NaCl) at photoperiodic lighting (16 h of light : 8 h of dark). For each treatment 04 replicates of 25 seeds were placed in Petri dish with 5 ml of test solutions. A completely randomized design (CRD) was used for the experiment. Results revealed that the uppermost germinability was recorded in distilled H2O and the progressive enhancement of NaCl significantly (P < 0.001) suppressed germination. At 15–25 °C (dark : light thermoperiod), P. halepensis seeds showed approximately 90% of germination at 0 mM NaCl. However less germination percentage (GP) was obtained at 10–20 °C and 20–30 °C. Values of Timson’s index were also suppressed significantly (P < 0.001) with an increase under salt stress at all thermoperiods but at least at 15–25 °C. These funding suggest that seeding of P. halepensis may be an effective path for rehabilitation of degraded lands where salinity and drought are major features of the arid ecosystems. Yet, this conclusion still needs verification by field experiments. Key words: Pinus halepensis; arid zones; sowing dates; afforestation; salt tolerance


2021 ◽  
Vol 27 (4) ◽  
pp. 446-452
Author(s):  
Kássia Barros Ferreira ◽  
Antonio Maricélio Borges de Souza ◽  
Ana Carolina Corrêa Muniz ◽  
Kathia Fernandes Lopes Pivetta

Abstract Palm seeds are indicative of being recalcitrant species. Seeds germination for many species, is slow and uneven, even in favorable conditions, often due to the resistance of the woody endocarp that makes them impermeable to water. Most species also have the characteristic of not tolerating the drying process at low moisture levels, thus losing their viability. In view of these considerations, the objective was to evaluate the effect of different periods of rehydration on the germinative process of seeds of royal palm, dwarf palm and jeriva. Seeds were homogenized and immersed in water containing 3 times their volume, with daily replacement. The experimental design used was completely randomized, with 5 treatments (0, 3, 6, 9, and 12 days of rehydration), with 4 replications of 25 seeds. The seeds were placed in transparent “gerbox” plastic boxes containing medium vermiculite as substrate and placed in BOD with a photoperiod of 16-hour of light and their respective optimum temperatures for each species. The number of germinated seeds was counted every 2 days until germination stabilized. The variables analyzed were germination percentage, germination speed index (GSI), average germination time (AGT) and distribution of germination over the days. Rehydration for 3 days increased the germination rate of royal palm seeds. For dwarf and jeriva species, rehydration did not influence the analyzed variables. The GSI and AGT were negatively influenced by the rehydration periods for royal palm. Rehydration prolonged the peak of germination of the studied species.


2016 ◽  
Vol 76 (2) ◽  
pp. 367-373 ◽  
Author(s):  
A. B. Lone ◽  
R. C. Colombo ◽  
B. L. G. Andrade ◽  
L. S. A. Takahashi ◽  
R. T. Faria

Abstract The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.


2019 ◽  
Vol 52 (1) ◽  
pp. 26-33
Author(s):  
M. Khoshkharam ◽  
W. Sun ◽  
Q. Cheng ◽  
M.H. Shahrajabian

Abstract Allelopathy is the detrimental effect of one crop on germination or development of a plant of another species. A factorial layout within completely randomized design with four replications was used to survey the influence of barley extract on corn seeds. Treatments included plant organs extract (leaf, stem, root and total), and different barley extract densities (Nosrat cultivar) includes four levels of 0%, 25%, 50% and 100%. The influence of barley extract was significant on coleoptile weight, radicle weight, radicle length and coleoptile length. Plant organs had meaningful effect on germination rate, germination percentage, coleoptile weight, radicle weight, radicle length and coleoptile length. Among all experimental characteristics, coleoptiles length was influenced by interaction between barley extract and plant organ. Although, the highest germination rate and germination percentage was related to 25% and 100% of barley extract density, the maximum coleoptile weight, radicle weight, radicle length and coleoptiles length was related to control treatment (0%). Leaf extract has obtained the higher values of germination rate, germination percentage, coleoptile weight, radicle weight, radicle length and coleoptile length. Interaction between control treatment (0% plant extract) and stem extract had obtained the highest coleoptiles weight, radicle weight, radicle length and coleoptile length. Hence, from the obtained results, it can be concluded that the extracts of barley may have allelopathic influence on germination and seedling growth of corn.


Author(s):  
Matthew Chidozie Ogwu ◽  
Aiwansoba Raymond Osas ◽  
Osawaru Moses Edwin

Watermelon, <em>Citrullus lanatus </em>(Thunberg) Matsumura and Nakai is a tropical fruit vegetable. Indole-3-acetic acid (IAA) is a popular phytohormone while lead (Pb) is a common environmental pollutant in urban and sub-urban centers. <em>C. lanatus</em> were obtained from Benin City with a view to study the effects of IAA on their germination in Pb polluted environment.  Germination percentage without IAA and Pb treatment in petri dish was significant after ten days. Hastened germination was observed when IAA and lead were used. About 100 % germination was recorded after seven days. This suggests that water melon seeds can initiate growth even in lead polluted environment. Optimum level of 5 ppm IAA with the different levels of lead treatments may be recommended. Most important was that higher concentrations of Pb in the control (without IAA) did not inhibit seedling shoot nor root growth. Longest seedling shoot length (cm) was 10.33 ± 1.24 and 12.13 ± 2.06 on the seventh and eighth day respectively with the combined treatment levels of 1 ppm IAA and 15 ppm Pb. On the ninth day, 15.27 ± 0.96 was obtained from 1 ppm IAA and 20 ppm Pb. Longest seedling root length (cm) values were recorded from the combined treatment levels of 0 ppm IAA and 10 ppm Pb for the seventh (9.10 ± 0.47) and ninth (10.37 ± 1.81) day respectively and 0 ppm and 15 ppm Pb on the eighth (9.37 ± 0.84) day. Significant means were also obtained with the treatment level of 0 and 20 ppm IAA. This present study suggest the germination of <em>C. lanatus</em> under Pb polluted environment may be rescued with optimum IAA.


Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 884-889 ◽  
Author(s):  
Francis E. Northam ◽  
Robert H. Callihan ◽  
Michelle M. Puchalski

This study documented an undescribed aspect of medusahead germination behavior. Fibrous hairs were consistently observed growing from the coleorhizal surface of germinating medusahead seeds. Three medusahead accessions were investigated to determine temperature effects on coleorhizal hair growth and germination. Coleorhizal hair emergence at 8 C was first noted at 72 h. By 24 h at 18 C, 15 to 74% of seeds had hairs, and at 28 C, hairs were visible on 75 to 94% of seeds. Germination at 18 and 28 C was 80% at 96 h; germination at 8 C did not exceed 80% until 168 h. Less than 4% of germinated seeds were without coleorhizal hairs. Appearance of coleorhizal hairs confirmed that germinating medusahead embryos were active at least 72 h before germination was complete. These data affirm coleorhizal hairs are a normal part of medusahead germination biology. Coleorhizal hairs probably aid early phases of medusahead seedling establishment.


2011 ◽  
Vol 25 (2) ◽  
pp. 252-261 ◽  
Author(s):  
Silvia Fogliatto ◽  
Francesco Vidotto ◽  
Aldo Ferrero

Weedy rice is a problematic weed that infests paddy fields worldwide. Differing populations, with varying physiological and morphological traits, characterize this weed. In particular, seed dormancy makes its control difficult. The objective of this study was to evaluate the germination behavior of five Italian weedy rice populations (two awnless, two awned, and one mucronate) after exposure of seeds to different field storage conditions (flooding, burial, and dry soil surface) during winter in two sites (Grugliasco and Vercelli, Italy). Seed samples were taken from each population, storage condition, and site, every 15 d for petri dish germinability testing. The two sites displayed slightly different germination patterns, which were probably due to the differing climatic conditions. One of the awned populations showed the highest (always exceeding 80%) and fastest germination percentage in all field conditions and sites, compared with the other four populations. Although flooding promoted germination in one awnless population, it delayed germination in two others (one awned and one awnless), attaining only 20% germination after more than 100 d. In all populations, burial delayed germination, whereas seed placement on the dry soil surface enhanced it. Our study indicated that autumn tillage that promotes weedy rice seed burial should be discouraged; spring tillage that exposes seeds to the soil surface and cause their depletion should be encouraged. The tested technique of winter flooding can also improve weedy rice control, despite its varying efficacy among populations. Cycles of flooding and drying followed by spring tillage might improve weedy rice seed control.


Author(s):  
Anne Caroline Dallabrida Avelino ◽  
Dayana Aparecida De Faria ◽  
Carlos Eduardo Avelino Cabral ◽  
Joadil Gonçalves De Abreu ◽  
Elisangela Clarete Camili ◽  
...  

The aim of this study was to evaluate the effects of Brachiaria seed contact time with 05-25-15 fertilizer (N-P2O5-K2O) on the seed’s physiological quality. The experimental design was a completely randomized design with four replicates. Treatments were arranged in a 5x4 factorial, being: five seeds contact times with fertilizer (0, 24, 48, 72 and 96 hours); four forages: Marandu palisadegrass, Piatã palisadegrass, Xaraés palisadegrass and Ruziziensis grass. The performed tests were: water content, germination (first count and germination percentage), tetrazolium (viability), electrical conductivity, accelerated aging, sand emergency and emergence speed index. Contact time of 05-25-15 fertilizer with Brachiaria seeds reduces linearly: Germination, emergence and emergence speed index of Brachiaria seeds; Piatã and Xaraés palisadegrass seeds viability; vigor (electrical conductivity), except in Ruziziensis grass seeds; and seeds germination of Piatã palisadegrass submitted to accelerated aging test (vigor). Piatã palisadegrass is the least recommended, among the analyzed grasses, for intercropping in simultaneous sowing.


2014 ◽  
Vol 924 ◽  
pp. 354-358
Author(s):  
Di Zhang ◽  
Qing Shan Li ◽  
Bai Feng Li ◽  
Wei Hong ◽  
Lian Liu

In o rder to research the influence of anion additives/ CeO2 on cabbage seeds, taking cabbage seeds as the test material. This paper detected the seeds' germination percentage and protein content by respectively adding unique concentration of anion additives and CeO2 in soil. The results show that different anion additives have distinct influences on seed's growth in the same situation. To be more specific, 1040 can noticeably improve seeds' germination percentage and protein content. Moreover, different contents of 1040 could have various impacts on seeds' germination percentage and protein content. Furthermore, precise content of CeO2 can also significantly improve seeds' germination rate and protein accumulation.


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