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Showing 3 results for Alpha-Amylase

Mahsa Nazer, Seyed Mohammadreza Ehteshami, Masoumeh Salehi, Ali Kafighasemi,
Volume 6, Issue 1 (9-2019)
Abstract


Extended Abstract
Introduction: Guar (Cyamopsis tetragonolob) which belongs to fabaceae and leguminosae families is self-pollinating and is indigenous to India and Pakistan. This plant is suitable for growth in dry, damp and sandy soils, and can tolerate saline and relatively alkaline soils. Determining the best time for harvesting seeds and its timing with maximum quality is one of the important issues in the field of seed production management. The changes in the physiological quality of seeds occur during development until seed treatment. The use of high-quality seeds plays an important role in the final yield of crops. The purpose of this study was to determine the most suitable time for harvesting seeds because seed moisture content at harvest time is one of the most important factors affecting seed quality.
Materials and Methods: This research was carried out in July 2013 at Iraqi Research Station in Gorgan, Golestan, Iran in a split-plot design with four replications. The treatments consisted of the time of harvesting the seeds from the mother's base in six stages (with different moisture content) and harvesting places (upper, middle, and bottom pods) so that, starting from the podding, every 7 days, the seeds were removed from the base. The mother was harvested and such traits as germination rate, germination percentage, seedling vigor, seed moisture content, and alpha-amylase activity were calculated. In this research, a logistic model was used to study the changes in germination percentage, germination rate, seedling vigor index and straw index during seed dressing on Guar.
Results: The results of this study showed that the hypothesis that seed reaches its maximum quality at the end of the period of seed filling is confirmed, suggesting that with a moisture content of 30 and 14% in late seed filling period, Guar seeds have the highest quality. In general, the results of the present study confirm that the stages of development and management of Guar seeds on maternal basis have an impact on its quality. In the early stages of growth (humidity 85, 80 and 62 percent), due to prematurity and lack of essential seed structures, the qualitative traits of germination percentage, germination rate, seedling vigor, and strawberry index were low, and with the evolution of essential structures and reduced seed moisture content (58, 30 and 14%), the quality traits increased.
Conclusions: In general, it can be concluded that the best timing for harvesting Guar seeds with the highest quality in Golestan province is when seed moisture reaches 14% or 100 days after planting, and the pods formed at the bottom are the ones with the highest quality.
 
 
Highlights:
  1. To investigate the qualitative indices of Guar seed on the mother plant during seed filling period
  2. To determine the best harvest time and its adaptation with the highest quality of Guar seed

Rahim Tarbali, Ali Asghar Aliloo, Manouchehr Farjami Nejad,
Volume 7, Issue 2 (3-2021)
Abstract

Extended Abstract
Introduction: The weed invasion is one of the main yield-reducing factors in crops. They are potent competitors on vital resources which limits the availability of the resources for crops. Allelopathy is one of the weeds' abilities that commonly with inhibitory influences, affects plant communities' behavior. Therefore, the evaluation of these compounds' effects is important on crop plants. Also, the identification of allelopathic plants and their bioactive compounds can be a suitable approach to weed management. Thus, the aim of this study was the evaluation of the allelopathic potential of C. falcate on germination indices of wheat seeds and the mode of action of the extract on some enzyme activities. Furthermore, secondary metabolites in methanolic root extract were identified and reported.
Materials and methods: Germination and seedling experiments of Triticum aestivum var. Sardary seeds were tested by 0, 5%, 10%, 15%, and 20% concentrations of C. falcata root extracts based on CRD with four replications at the research laboratory of Maragheh University during 2018-19. Also, the influence of the extract was studied on enzyme activities of alpha-amylase, catalase, peroxidase, superoxide dismutase, and polyphenol oxidase. Furthermore, chemical compounds of the root methanolic extract identified by GC/MS instruments.
Results: Germination percentage and germination rate decreased significantly with the increase in the concentration of the extract, and germination stopped at concentrations above 15%. The results of seedling growth showed severe inhibitory effects of the extract on radicle and shoot organs of wheat seedlings that associated with reducing of the lengths and weights of the organs, and consequently, the vigor of seedling declined. The extract significantly reduced the activity of alpha-amylase, however, the activities of antioxidant enzymes first increased at low and medium concentrations but at high concentrations, the activities declined. The phytochemical analysis identified 62 compounds in the root of this plant that Octadecatrienal, Dihydro-4H-pyrazolo [3, 4-d] pyrimidin-4-one, Hexadecanoic acid, Hexadecanoic acid, 2-hydroxy-1 (hydroxymethyl) ethyl ester, Isopropyl isothiocyanate, and Cyclohexanone could be effective compounds on seed germination.
Conclusion: C. falcata had a very strong inhibitory effect on the seed viability and seed vigor of the wheat seeds. According to the results, the mode of action of the allelopathic compounds is induced by induction of oxidative stress and inhibition of seed reserves remobilization during germination. The high sensitivity of alpha-amylase activity to allelochemicals was detected in this experiment. The decrease in the activity of all studied enzymes at high concentrations of C. falcata root extract was also significant. Stearic acid and palmitic acid derivatives accounted for about 30% of the compounds, which are very likely to interfere with the activity of the enzymes.

 Highlights:
  1. Allelopathy effects of C. falcata root extract on germination indices of wheat were studied.
  2. Chemical compounds identified were in methanol extract of the plant roots of C. falcate.
  3. Oxidative stress is induced by the allelochemicals of C. falcata.

Mohaddese Heydarzade, Seyed Mohammadreza Ehteshami, Mohammad Rabiee,
Volume 9, Issue 1 (9-2022)
Abstract

Extended Abstract
Introduction: Guar (Cyamopsis tetragonoloba L.) is an annual, dicotyledonous plant of the legume family, also known as cluster beans. This plant can tolerate salinity and drought stress well. Optimal planting date and plant density are factors affecting the quality and quantity of crops. The distribution of plants in the field influences the absorption and productivity of environmental factors affecting the growth and intra- and inter- competition and eventually is one of the factors determining the quantity and quality of yield. Different planting dates set off different conditions in terms of temperature day length, relative humidity, solar radiation, ripening and harvest time and thus, affect the quantitative and qualitative characteristics of seeds. The purpose of this experiment is to evaluate the quality and also to evaluate some of the germination characteristics of Guar seeds at different dates and planting densities under the climatic conditions of Guilan.
Materials and Methods: This experiment was conducted in the spring and summer of 2017 in the research farm of Rasht Rice Research Institute located in Gil Pardehsar village at Sangar as a factorial based on a randomized complete block design with three replications. Experimental treatments included four planting dates (12 May, 26 May, 9 June and 23 June) and three plant densities (20, 40 and 60 plants. m-2). Seed harvesting was done as the pods in 75% of the plants in each plot turned brown and traits such as germination percentage, germination rate, root and shoot length and fresh and dry weight of roots and shoots, longitudinal index of seedling vigor, 1000- grain weight, electrical conductivity and alpha-amylase activity were investigated.
Results: The results of the present study showed that guar seeds had the highest quality on 26 May and a density of 40 plants.m-2. Due to favorable climatic conditions during the period of seed filling, germination rate, germination percentage, seedling vigor index, root length and 1000- grain weight was high on 26 May. The amount of these traits decreased with delay in planting. The amount of electrical conductivity in 23 June date of planting treatment showed the highest value. The highest level of alpha-amylase activity was observed on 9 June.
Conclusions: In general, it can be concluded that the best planting date and plant density of guar seeds in Guilan province with the highest quality of seeds and germination is on 26 May and 40 plants.m-2.

Highlights:
1- Guar seed germination traits were evaluated at physiological maturity.
2- In terms of germination traits of guar seeds, the best planting date was 26 May and the best plant density was obtained at 40 per square meter

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