Action of gibberellic acid (GA3) on dormancy and activity of alpha-amylase in rice seeds

O arroz é uma das espécies que apresenta dormência após a colheita, podendo esta ser prolongada durante o armazenamento das sementes. Este trabalho teve por objetivo determinar se o ácido giberélico (GA3) é um promotor eficiente da superação de dormência em sementes de arroz e avaliar mudanças nas estruturas biológicas via histoquímica. A cultivar utilizada foi a SCS122 Miura submetida a 0 mg L-1, 500 mg L-1 e 1000 mg L-1 de GA3. Foram realizadas análises de germinação, viabilidade, comprimento de raiz, parte aérea e plântula, microscopia óptica do amido e quantificação dos açúcares solúveis totais. A utilização de 500 mg L-1 e 1000 mg L-1 de GA3 foi eficiente para a superação da dormência de sementes de arroz, reduzindo o percentual de sementes dormentes para 4% e 1% respectivamente. Apesar de reduzir o percentual dormência, a presença de GA3 provoca aumento do percentual de plântulas anormais, e por isso, nas concentrações utilizadas, não pode ser recomendado como método de superação em sementes de arroz. A microscopia óptica é eficiente para verificar que com a superação de dormência, ocorre a degradação dos grânulos de amido, aumentando a disponibilidade de açúcares solúveis totais para o crescimento e desenvolvimento de plântulas.

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Effect of fusicoccin and gibberellic acid on germination and alpha-amylase expression in barley grains.

Seed biology: advances and applications. Proceedings of the Sixth International Workshop on Seeds, Merida, Mexico, 1999. ◽

10.1079/9780851994048.0341 ◽

2009 ◽

pp. 341-346

Author(s):

R. M. van der Meulen ◽

J. Vredenbregt-Heistek ◽

M. P. M. Caspers ◽

M. Wang

Keyword(s):

Gibberellic Acid ◽

Alpha Amylase ◽

Barley Grains

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Viability and Dormancy of Rice Seeds after Storage and Pre-Treatment with Dry Heat and Chemical Agents

Journal of Agricultural Science ◽

10.5539/jas.v9n7p175 ◽

2017 ◽

Vol 9 (7) ◽

pp. 175 ◽

Cited By ~ 2

Author(s):

Yvonne A. Mutinda ◽

James W. Muthomi ◽

John M. Kimani ◽

George N. Cheminigw’wa ◽

Florence M. Olubayo

Keyword(s):

Gibberellic Acid ◽

Seed Dormancy ◽

Seed Treatment ◽

Room Temperature ◽

Seed Quality ◽

Packaging Material ◽

Rice Seed ◽

Dry Heat ◽

Rice Seeds ◽

Pre Treatment

Inappropriate seed packaging and seed dormancy affects seed quality and consequently leads to reduced crop stand, low seedling vigour and reduced yields. The objective of the study was to determine the effect of seed packaging material and seed treatment on viability and dormancy in rice seeds. Effect of packaging material was evaluated by storing freshly harvested seeds of Basmati 370 and BW 196 varieties in polythene, khaki, cheese cloth, polypropylene (Pp) sack and gunny bag sat room temperature and at 6 oC for six months. Effect of seed treatment on dormancy was determined by pre-treatment of seeds with nitric acid at 0.1 M, 0.2 M, 0.5 M, 1 M and 2 M, gibberellic acid (GA3) at 1000 ppm, 2000 ppm and 5000 ppm, and hydrogen peroxide at 0.5 M, 1 M, 2 M, 3 M, 5 M and dry heat at 50 oC for 48 hours. The seeds were subjected to germination test on moist paper and data on percentage germination, seedling length and seedling dry weight were taken. Packaging material had a significant (P ≤ 0.05) effect on germination and vigour. At room temperature, seed stored in polythene bag had the highest germination 88.2% and 57.8% for BW 196 and Basmati 370, respectively. Basmati 370 in khaki bag stored in the cold room had the highest germination 48.3%, while BW 196 stored in polythene had the highest (86.0%). Pre-treatment of seeds reduced dormancy, with variety BW 196 showing the highest germination of up to 67%, while variety Basmati 370 had the lowest germination of up to 40%. Gibberellic acid (GA3) at 5000 ppm was the most effective in breaking seed dormancy resulting in up to 95.7% germination. The results of the study indicated that packaging rice seed in polythene bags for periods not exceeding six months and pre-treatment with GA3 maintains high seed viability and breaks dormancy, respectively, thus ensuring rapid and uniform germination of vigorous seedlings. This would reduce the period farmers have to wait after harvest before they can plant newly harvested rice seeds.

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Action of gibberellic acid (GA3) on dormancy and activity of alpha-amylase in rice seeds

Revista Brasileira de Sementes ◽

10.1590/s0101-31222002000100008 ◽

2002 ◽

Vol 24 (2) ◽

pp. 43-48 ◽

Cited By ~ 15

Author(s):

Antônio Rodrigues Vieira ◽

Maria das Graças Guimarães Carvalho Vieira ◽

Antônio C. Fraga ◽

João Almir Oliveira ◽

Custódio D. dos Santos

Keyword(s):

Enzyme Activity ◽

Gibberellic Acid ◽

Seed Dormancy ◽

Amylase Activity ◽

Alpha Amylase ◽

Rice Seed ◽

Efficient Treatment ◽

Soaking Time ◽

Forced Air ◽

Air Circulation

To evaluate the effectiveness of gibberellic acid (GA3) in breaking rice seed dormancy and the use of alpha-amylase enzyme activity as an indicator of the dormancy level, seed from the intensively dormant irrigated cultivar Urucuia were used. The seeds were submitted to a pre-drying process in a forced air circulation chamber under 40ºC during 7 days and submersed in 30 mL of GA3 solution under 0, 10, 30 and 60 mg/L H2O concentrations, during 2, 24 and 36 hours. After the treatments, the alpha-amylase activity was determined by using the polyacrilamide electrophoresis and spectrophotometry. At the same time, the germination test was made. The results indicated a gain in germination and in alpha-amylase activity in higher concentrations and soaking time of seeds in GA3. These observations support the conclusion that soaking seed in 60 mg GA3/L during 36 hours can be used as a quick and efficient treatment in breaking rice seed dormancy and is equivalent to the forced air circulation chamber at 40ºC during 7 days. The alpha-amylase enzyme activity proved to be as an efficient marker of the seeds dormancy level.

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Susceptibility of naked oat cultivars to seed sprouting

Open Life Sciences ◽

10.2478/s11535-014-0306-1 ◽

2014 ◽

Vol 9 (8) ◽

pp. 823-832

Author(s):

Andrzej Zieliński ◽

Magdalena Simlat ◽

Tomasz Wójtowicz ◽

Maria Moś

Keyword(s):

Abscisic Acid ◽

Gibberellic Acid ◽

Amylase Activity ◽

Alpha Amylase ◽

Falling Number ◽

Total Rainfall ◽

Naked Oat ◽

Germination Time ◽

Average Decrease ◽

Oat Cultivars

AbstractThe production of economically important cereals is accompanied by the phenomenon of sprouting which in naked cultivars may limit their reproduction and usability. The objective of the work is to evaluate the susceptibility to sprouting in naked oat cultivars, and to test the usefulness of sprouting indices. In the years 2008–2010 for seeds of 8 cultivars, differing in the degree of sprouting damage, the coefficient of sprouting (Cs) was determined. Germinability (GF), dynamics (GD) and average germination time (GAT) were determined for seeds germinating in the presence of abscisic acid (ABA), gibberellic acid (GA3) and under control conditions. Basing on the falling number (FN) in consecutive days of the sprouting induction, alpha-amylase activity was determined. The highest values of Cs were found in 2008, the year with the highest total rainfall and temperature. In the presence of ABA the GF decreased by 21%, the GAT was 4.7 days longer, and the GD decreased by 55% compared with other substrates. An increase in alpha-amylase activity contributed to a 50%, on average, decrease in FN at 10°C and 30°C after 48 and 24 h of incubation, respectively. In the analyzed years the greatest resistance to sprouting was found for Bullion seeds.

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