A HISTOLOGICAL STUDY OF SEED SHATTERING IN REED CANARY GRASS

1963 ◽  
Vol 43 (2) ◽  
pp. 200-205 ◽  
Author(s):  
S. G. Bonin ◽  
B. P. Goplen

Individual spikelets of reed canary grass (Phalaris arundinacea L.) were examined histologically to determine the mechanism of seed shattering. It was observed that shattering is a two-stage process, involving disarticulation of the rachilla approximately 12 days after anthesis, followed by subsequent release of the seed from the glumes. In both high- and low-shattering greenhouse-grown material no spikelets were observed histologically in which the seed was still attached later than 14 days after anthesis. In low-shattering clones the glumes retained the seed within the spikelet. No clear-cut histological differences in glume structure were observed between high- and low-shattering clones. The presence of a constriction at the base of the glumes of some spikelets of high-shattering clones requires further investigation since this indicates the possibility of selection based on glume morphology. Differences in glume length and seed weight among clones were not significantly correlated with shattering percentage. However, within clones, shattered seeds were heavier than non-shattered seeds.

1963 ◽  
Vol 43 (1) ◽  
pp. 59-63 ◽  
Author(s):  
S. G. Bonin ◽  
B. P. Goplen

A method of evaluating individual grass plants for seed shattering is described. The procedure involves harvesting a sample of culms from each plant, just prior to the start of shattering in the field, and maturing these detached culms indoors, sustained in tap water. A machine is described which is used to provide a uniform amount of shattering stress to each culm sample by means of a series of agitations of controlled severity. A mean coefficient of variation of 12.04 per cent was obtained using this technique on 32 clones of reed canary grass. The application of the technique to other species is discussed.


2000 ◽  
Vol 9 (3) ◽  
pp. 239-251 ◽  
Author(s):  
M. SAHRAMAA ◽  
L. HÖMMÖ

Production of reed canary grass (Phalaris arundinacea L.) seed in Finland may be of interest in the near future. Seed production characters of cultivars Palaton and Venture were studied between 1995 and 1998 at Jokioinen. Effects of harvest time on seed yield, thousand seed weight and seed germination were evaluated for 'Palaton'. Seed yield varied from 2 to 432 kg ha-1, being only 100 kg ha-1 on average. In the years of highest seed yields the optimum harvest time was 15 days after complete anthesis. At that time high seed yield was associated with a low proportion of shattered seeds and high thousand seed weight and good seed germination. In an additional experiment, the effect of storage temperature and storage time on seed germination were investigated for 'Venture'. Storage temperature had no significant influence on final germination, but warmer storage significantly speeded up germination rate as recorded after 7 days of germination. After 7 days the percentage of germinated seeds was also significantly higher for seeds stored for >10 months than with seeds stored for


Tellus B ◽  
2008 ◽  
Vol 60 (2) ◽  
Author(s):  
N. J. Shurpali ◽  
N. P. Hyvönen ◽  
J. T. Huttunen ◽  
C. Biasi ◽  
H. Nykänen ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3703
Author(s):  
Ming-Chien Hsiao ◽  
Wei-Ting Lin ◽  
Wei-Cheng Chiu ◽  
Shuhn-Shyurng Hou

In this study, ultrasound was used to accelerate two-stage (esterification–transesterification) catalytic synthesis of biodiesel from used cooking oil, which originally had a high acid value (4.35 mg KOH/g). In the first stage, acid-catalyzed esterification reaction conditions were developed with a 9:1 methanol/oil molar ratio, sulfuric acid dosage at 2 wt %, and a reaction temperature of 60 °C. Under ultrasound irradiation for 40 min, the acid value was effectively decreased from 4.35 to 1.67 mg KOH/g, which was decreased to a sufficient level (<2 mg KOH/g) to avoid the saponification problem for the subsequent transesterification reaction. In the following stage, base-catalyzed transesterification reactions were carried out with a 12:1 methanol/oil molar ratio, a sodium hydroxide dosage of 1 wt %, and a reaction temperature of 65 °C. Under ultrasound-assisted transesterification for 40 min, the conversion rate of biodiesel reached 97.05%, which met the requirement of EN 14214 standard, i.e., 96.5% minimum. In order to evaluate and explore the improvement of the ultrasound-assisted two-stage (esterification–transesterification) process in shortening the reaction time, additional two-stage biodiesel synthesis experiments using the traditional mechanical stirring method under the optimal conditions were further carried out in this study. It was found that, under the same optimal conditions, using the ultrasound-assisted two-stage process, the total reaction time was significantly reduced to only 80 min, which was much shorter than the total time required by the conventional method of 140 min. It is worth noting that compared with the traditional method without ultrasound, the intensification of the ultrasound-assisted two-stage process significantly shortened the total time from 140 min to 80 min, which is a reduction of 42.9%. It was concluded that the ultrasound-assisted two-stage (esterification–transesterification) catalytic process is an effective and time-saving method for synthesizing biodiesel from used cooking oil with a high acid value.


Appetite ◽  
2015 ◽  
Vol 95 ◽  
pp. 399-407 ◽  
Author(s):  
Elisabeth Vesnaver ◽  
Heather H. Keller ◽  
Olga Sutherland ◽  
Scott B. Maitland ◽  
J.L. Locher

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