scholarly journals Effects of brassinosteroids and gibberellin on water uptake and performance of soya bean seeds under different temperatures

2021 ◽  
Vol 49 (2) ◽  
pp. 141-157
Author(s):  
Kantima Thongsri ◽  
Kanokwan Teingtham ◽  
Juangjun Duangpatra ◽  
Jutamas Romkaew

Low temperature has negative effects on seed performance and seedling growth in soya bean, reducing stand establishment. It was hypothesised, that seed treatment with plant hormones could improve seed imbibition and performance at low temperature. Therefore, the effects of 24-epibrassinolide (EBL) and gibberellic acid (GA3) on soya bean seed germination were studied. Seeds of 'CM60' and 'CM0701-24' were imbibed with 0.25 or 0.50 ppm EBL, 50 or 100 ppm GA3, or distilled water at 10, 15, 20 and 25°C. The seed imbibition patterns of the two soya bean varieties followed a similar trend. Low temperature delayed seed imbibition resulting in longer time to reach the end of phases 1 and 2 of seed germination as compared with high temperature. Soya bean seeds treated with 50 or 100 ppm GA3 showed increased germination index, shoot and root length and reduced mean germination time. Thus, 50-100 ppm GA3 could be used as a pre-soaking seed treatment to improve soya bean seed and seedling performance under low temperature.

2020 ◽  
Vol 13 (2) ◽  
pp. 20
Author(s):  
P. R. Diesel ◽  
V. N. Silva

Millet is an important summer grass used as forage grass due to good bromatological characteristics and easy adaptation to Brazilian environmental conditions. However, when sowing the crop early in the southern region, situations may occur where low temperatures affect germination and seedling development. Thus, the present work had the objective of evaluating the germination and initial development of millet using Biozyme TF® biostimulant as a way to attenuate the effects of different temperatures. The experimental design was completely randomized, in a factorial scheme 3 x 5 (temperatures x doses) with four replicates each. The temperatures used were 15 °C, 20 °C and 25 °C and the doses used were: 0 (control); 0.25; 0.5; 0.75 and 1 ml kg-1. After the treatment, the seeds were evaluated by: germination test, germination speed index, shoot and root length and seedling dry mass. The data obtained were submitted to analysis of variance with Sisvar® software and, when found significant, the regression analysis was performed. The germination of millet seeds is favored, under low temperature stress conditions, with seed treatment at the dose of 0.50 ml kg-1 of biostimulant. The biostimulant does not influence millet germination speed index. Under low temperature thermal stress the biostimulant minimally increases the length and dry mass accumulation of millet seedlings and attenuates the negative effects on root growth. The accumulation of dry mass of the roots decreased with increasing dose of the biostimulant under thermal stress condition.


2011 ◽  
Vol 194-196 ◽  
pp. 895-898 ◽  
Author(s):  
Dong Wei Li ◽  
Hai Yan Liu ◽  
Ju Hong Fan ◽  
Ren He Wang ◽  
Bi Juan Luo

We carried out experiments of the mechanical properties of frozen pipes under different temperatures (-5°C, -10°C, -15°C), obtained axial tensile stress - strain curves of the steel and performance of the overall bending under low temperature conditions. The results showed that: the freezing pipes bending capacity increased with the decrease of temperature, but the stiffness was decreased with the decreasing temperature; the steel yield strength and ultimate strength were both increased with the decrease of temperature, the elongation and sectional shrinkage were decreased with the decrease of temperature. The test results provided the basis for the further research of frozen pipes’ ductile-brittle transition, fracture and other acts in low temperature, and provided reference for the selection of frozen pipe and engineering design.


FLORESTA ◽  
2019 ◽  
Vol 50 (1) ◽  
pp. 923
Author(s):  
Ademir Kleber Morbeck Oliveira ◽  
Jose Carlos Pina

Germination is considered a critical step in the seedling production process aiming the recovery of environments. Thus, understanding the germination behavior of native species with potential for economic use contributes to the development of the forest seed and seedling chain. Considering the limited information on the tree species Pouteria torta subesp. torta, this study aimed to evaluate its seed germination and formation of normal seedlings using different temperatures and substrates. The experiment was conducted in germination chamber in a research laboratory using two substrates (paper and vermiculite) and six temperatures (20, 25, 30, 35, 20-30 and 25-35 °C) in a completely randomized design in a 2x6 factorial arrangement. Daily evaluation was conducted to verify primary root emission, seed vigor, and seedling formation. The results indicated that the primary root protrusion process began after 20 days of testing under the best conditions, with germination time lasting longer than two months. The results obtained also showed that there was interaction between factors, with use of the vermiculite substrate and the temperatures of 35 and 25-35 °C producing the best germination rates and germination speed index, and use of the paper substrate and the temperatures of 30 and 35 °C showing the best mean germination time. Considering the analyzed variables (germination, germination speed index, and formation of normal seedlings), the temperatures of 35 and 25-35 °C and the vermiculite substrate are the most suitable for the production of Pouteria torta subesp. torta seedlings.


2015 ◽  
Vol 21 (2) ◽  
pp. 173
Author(s):  
Priscilla Brites Xavier ◽  
Janie Mendes Jasmim

Cacti are widely used as ornamental plants and seed germination is a major method for preserving genetic diversity. Thus, an experiment was carried out to evaluate the effects of different temperatures and substrates on seed germination of Hamatocactus setispinus. Seeds were sown in gerbox boxes containing either germination paper (S1), sand (S2) or vermiculite (S3). After placing the seeds on the substrates, the boxes were kept in germination chambers at 20, 25, 30 and 35° C for 30 days, under a photoperiod of 16 hours. The experiment was in a completely randomized design with four replicates. The speed germination index (SGI), mean germination time (MT) and germination rates (%) were evaluated. The best results were observed at 25º C. The highest SGI (3.94) was observed on seed germination paper, but MT values and germination rates on this substrate did not differ from those obtained on sand. Therefore, both substrates could be used for germination of this cactus species.


2020 ◽  
Vol 53 (2) ◽  
pp. 185-194
Author(s):  
A. KHELOUFI ◽  
L. M. MANSOURI ◽  
H. KHETTACHE

Cherimoya (Annona cherimola Mill.) has an exceptional flavor and aroma, which makes it a fruit with great potential. However, little is known about its propagation by seeds. According to the scientific literature, the germination of cherimoya seeds is affected much more by external conditions than by internal conditions. Germination of cherimoya variety ‘Concha Lisa’ were tested for germination at constant temperatures of 25, 30, 40°C, and at room temperature, varying from 20-25°C, coupled with total darkness. Seeds were sown in Petri dishes (0.8% agar water), for 25 days of incubation. The kinetics of germination was determined according to five closely related parameters, viz. final germination percentage (FGP), mean germination time (MGT), coefficient of velocity of germination (CVG), time to 50% germination (T50) and seedling length (SL). The temperature of 30°C was found optimally suitable with 70.8% FGP, 17.5 days MGT and 3.91 cm SL, while the room temperature of 20-25°C slightly improved germination with only 25% FGP. Furthermore, significant decrease in FGP and SL was observed at 25°C and 40°C of temperature in comparison to 30°C. The analysis also revealed that cherimoya seed germination, day 10-15 after seed sowing is suitable for final counts. An overview on the emergence of cherimoya seedlings, during a 12-week period in pots is presented.


2014 ◽  
Vol 21 (2) ◽  
pp. 309-326 ◽  
Author(s):  
Dorota Szopińska

Abstract The decrease of seed quality during storage is strongly associated with damage caused by free radicals. Some compounds of natural origin, known due to their antioxidative and antifungal properties, may be potentially used in organic production for seed treatment as an alternative to pesticides. The aim of the experiment was to study an ability of hydrogen peroxide and organic acid to improve germination, vigour and health of non-deteriorated and deteriorated zinnia seeds. Two seed samples, cv. Illumination and Orys, varying in initial infestation with fungi were tested. For deterioration seeds were kept at 30°C and 80% RH for 30 days. Seed quality tests were performed before and after deterioration for controls and seeds soaked in 3.0% hydrogen peroxide solution and in 1.0 and 5.0% solutions of ascorbic and lactic acids for 10, 30 and 60 min. The controls were untreated seeds, seeds soaked in 0.2% solution of Kaptan zawiesinowy 50 WP for 30 min and seeds soaked in distilled water for 10, 30 and 60 min. Treating zinnia seeds with organic acids more significantly affected seed germination and health after deterioration than before, and improvement of germination capacity was usually correlated with decrease of the percentage of abnormal diseased seedlings. Deterioration had no influence on mean germination time, whereas in particular cases treating seeds with hydrogen peroxide and organic acids negatively affected this parameter. After deterioration regardless of treatment increased number of seeds free from fungi. Lactic acid followed by hydrogen peroxide and ascorbic acid effectively limited growth of A. alternata, A. zinnia and Fusarium spp. on zinnia seeds, however at higher concentration negatively affected seed germination and vigour. Moreover, treating seeds with hydrogen peroxide and organic acids many a time increased seeds infestation with B. cinerea.


Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 700 ◽  
Author(s):  
Jing Feng ◽  
Yongbao Shen ◽  
Fenghou Shi ◽  
Chengzhong Li

The embryos of Ginkgo biloba L. are generally reported to undergo after-ripening and be underdeveloped at the time of dispersal, which suggests that the seeds have morphological dormancy (MD) or morphological physiological dormancy (MPD). The aim of this work is to determine whether embryos of a G. biloba population are well-developed at the time of seed dispersal, and whether the seeds are dormant or not. From 8 September, which was the 140th day after flowering (140 DAF), seeds were collected separately from trees (T) and the ground (G) every 10 days until 7 December (230 DAF), resulting in a total of 10 samples. The changes in vertical diameter, transverse diameter, fresh weight, water content, and embryo length during seed development were measured. Simultaneously, the effects of different temperatures (15, 25, 30, and 35 °C) on seed germination, dormancy, and germination characteristics of G. biloba seeds were studied. Results showed that the embryos of G. biloba seeds were well developed and had no morphological dormancy. On 18 September (150 DAF), embryos were visible with a length of 2.5 mm. On 7 December (230 DAF), at the time of seed dispersal, their length was 17.1 mm. The germination percentage of the isolated embryos and seeds increased as the delay in seed collection increased, but there was no significant difference between T and G (p > 0.05). On 7 December (230 DAF), the germination of the isolated embryos reached 98%, indicating that the embryos were nondormant. Without pretreatment, seed germination was 82.57% within four weeks at 25 °C. Furthermore, the germination test at different temperatures showed the highest germination percentage at 30 °C (84.82%). Obviously, the G. biloba seeds were nondormant. The mean germination time (MGT) of the seeds at 30 and 35 °C was significantly lower than that of the seeds at 15 and 25 °C, and the speed of germination (SG) was significantly higher than that of the seeds at 15 and 25 °C. Although there was no significant difference in the seed-germination percentage between 30 and 35 °C, a portion of the seeds (9.5%) rotted at 35 °C. Therefore, 30 °C was the most favorable germination temperature for G. biloba seeds. This is the first study that reports G. biloba seeds with no dormancy.


2020 ◽  
Vol 21 (1&2) ◽  
pp. 187-192
Author(s):  
Hariom Saxena ◽  
Naseer Mohammad ◽  
Samiksha Parihar ◽  
Sant Kumar

An experiment was conducted to investigate the effect of different seed treatment and potting media on germination percentage and associate parameters in Stereospermum suaveolens, a threatened dashmool species during May, 2019 at Silviculture Nursery of Tropical Forest Research Institute, Jabalpur (Madhya Pradesh). Experimental treatments comprised of twenty treatment combinations consisting of four different seed treatment and five growth mediums. Data on daily seed germination was recorded and used for estimation of final germination percentage (FGP), mean germination time (MGT), coefficient of velocity of germination (CVG), germination rate index (GRI), time spread of germination (TSG), energy period (EP) and peak value of mean germination (PVMG). Critical perusal of analysis revealed that treatment combination ‘Sand + Hot Water’ was resulted in positive effect on all the characters studied and could be used for mass raising of seedlings of S. suaveolens.


2018 ◽  
Vol 62 (2) ◽  
pp. 97-107 ◽  
Author(s):  
Nina Keith

Abstract. The positive effects of goal setting on motivation and performance are among the most established findings of industrial–organizational psychology. Accordingly, goal setting is a common management technique. Lately, however, potential negative effects of goal-setting, for example, on unethical behavior, are increasingly being discussed. This research replicates and extends a laboratory experiment conducted in the United States. In one of three goal conditions (do-your-best goals, consistently high goals, increasingly high goals), 101 participants worked on a search task in five rounds. Half of them (transparency yes/no) were informed at the outset about goal development. We did not find the expected effects on unethical behavior but medium-to-large effects on subjective variables: Perceived fairness of goals and goal commitment were least favorable in the increasing-goal condition, particularly in later goal rounds. Results indicate that when designing goal-setting interventions, organizations may consider potential undesirable long-term effects.


2003 ◽  
Vol 769 ◽  
Author(s):  
C. K. Liu ◽  
P. L. Cheng ◽  
S. Y. Y. Leung ◽  
T. W. Law ◽  
D. C. C. Lam

AbstractCapacitors, resistors and inductors are surface mounted components on circuit boards, which occupy up to 70% of the circuit board area. For selected applications, these passives are packaged inside green ceramic tape substrates and sintered at temperatures over 700°C in a co-fired process. These high temperature processes are incompatible with organic substrates, and low temperature processes are needed if passives are to be embedded into organic substrates. A new high permeability dual-phase Nickel Zinc Ferrite (DP NZF) core fabricated using a low temperature sol-gel route was developed for use in embedded inductors in organic substrates. Crystalline NZF powder was added to the sol-gel precursor of NZF. The solution was deposited onto the substrates as thin films and heat-treated at different temperatures. The changes in the microstructures were characterized using XRD and SEM. Results showed that addition of NZF powder induced low temperature transformation of the sol-gel NZF phase to high permeability phase at 250°C, which is approximately 350°C lower than transformation temperature for pure NZF sol gel films. Electrical measurements of DP NZF cored two-layered spiral inductors indicated that the inductance increased by three times compared to inductors without the DP NZF cores. From microstructural observations, the increase is correlated with the changes in microstructural connectivity of the powder phase.


Sign in / Sign up

Export Citation Format

Share Document