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Abstract Red algae are one of the sections of marine algae which include polysaccharides, proteins, polyunsaturated fatty acids, pigments, polyphenols, minerals, plant growth hormones. These components have well documented beneficial effect on human, animal and plant, mainly by protection of an organism from biotic and a biotic stresses and can be valuable components as fertilizer. Therefore, the aim of this study was concerned on two parts: Part I: Studying the effect of water extract or carrageenanes (1mg/ml) of C. crispus as antiviral agent to biocontrol potato virus Y in potato plants. Part II: Studying the effect of water extract of C. crispus as plant growth regulator. The present study was conducted in the Faculty of agriculture green house and farm; Ain shams University during the two successive seasons of 2012 and 2013. Potato tubers (Solanum tuberosum, Diamond) were grown in dark plastic bags. The potato seedlings inoculated with PVY, and treated with aqueous red algal extract (10, 20, 30%) and carrageenanes (1mg/ml), which were applied at three times. Wheat grains (Triticum aestivum L.) var., Sakha 93, was germinated in the field experience. The growing wheat plants were foliar sprayed twice (at flowering and grain development stages) by each of three concentrations (10, 20 and 30%) of Chondrus crispus extract under fertilizer recommendation of agriculture ministry. Part I: The results of potato experiment can be summarized as follows: (A) Potato leaves Photosynthetic pigments: The level of total chlorophylls (a, b) and carotenoids were significantly decreased in infected potato leaves by about 34% and 49% respectively. While, the foliar spraying with algal extract or carrageenan (1mg/ml) led to a significant increase in photosynthetic pigments concentration either pre or post virus inoculation. Proline concentration: Potato virus Y (PVY) inoculation caused a significant increase in proline concentration by about 17% than control plant. Also, foliar spraying with high concentrations of algal extract (20% and 30%) or carrageenanes (1mg/ml) led to a significant increase in proline concentration either pre or post virus inoculation. Total phenols concentration: Total Phenolic compounds concentration was significantly increased in infected potato leaves by about 21% than control plants. Foliar spraying with different concentrations of algal extract (10%, 20% and 30%) and carrageenan (1mg/ml) caused a significant increase in the level of phenols either in the presence or absence of PVY infection. Phenylalanine ammonia lyase activity: Potato virus Y inoculation led to a significant increase in phenylalanine ammonia lyase activity (PAL) by about 28% than control plant. Moreover, foliar spraying with different concentrations of algal extract (10%, 20% and 30%) or carrageenanes (1mg/ml) caused a significant increase in PAL activity either pre or post virus inoculation. Antioxidant enzymes: Infected potato leaves have significantly increased in peroxidase (POD) and polyphenol oxidase (PPO) activities by about 51% and 19% respectively. Foliar spraying with the highest concentrations of algal extract (20% and 30%) or carrageenanes (1mg/ml) either in the presence or absence of virus infection caused a significant increase in antioxidant enzymes activity than plant control. (B) Potato tubers: Starch concentration: Potato virus Y injury caused a significant decrease in starch concentration of the resultant tuber from infected potato plants by about 37% than control plants. While, the foliar spraying with different concentrations of algal extract and carrageenan (1mg/ml) led to a significant increase in starch concentration either pre or post virus inoculation. Except, the treatment of algal extract (at 10%), after infection, was significantly decreased in starch concentration of the resultant tuber. Total amylase activity: Amylase activity was significantly increased in the resultant tuber from infected potato plants. But, the foliar spraying with different concentrations of algal extract and carrageenan (1mg/ml) led to a significant decrease in amylase activity of the resultant tuber either in the presence or absence of injury. Except, the treatment of algal extract (at 10%), after infection, was significantly increased in amylase activity compared with plant control. The disease severity & Virus concentration: The disease severity and PVY concentration were reduced in the treated plants and tubers which sprayed with high concentrations of algal extract or carrageenanes (1 mg/ml) either pro or post virus inoculation.Part II: The results of wheat experiment can be summarized as follows: (A) Main flag leaf Photosynthetic pigments: The foliar spraying with algal extract (at 10% & 20%) were significantly increased in total chlorophylls (a, b) and carotenoids content of the main flag leaves compared to control. while, the highest concentration of algal extract (30%) caused a significant decrease in the level of pigments compared with control plants. Flag leaf area: Area of the main flag leaf was influenced by applications of Chondrus crispus extract. Compared to control, the main flag leaves area was increased irrespective of concentrations and maximum was 58.43 cm2 for the plants sprayed with 20 % C. crispus extract. (B) Yield and yield attributing characters: The yield of grain and quality were influenced by applications of Chondrus crispus extract. Compared to control, the yield of grain was increased irrespective of concentrations and maximum was 63.24% for the plants sprayed with 20 % C. crispus extract. The values of yield contributing characters like grain number, weight and length of spike were significantly improved for the plants received 20 % C. crispus extract. Also, the plant growth measurements (height and weight plant, weight and size of 1000 grain and specific test weigh) were significantly increased for the plants received 10% & 20 % C. crispus extract compared to control plants. In contrast, the highest concentration of algal extract (30%) led to a significant decrease in plant growth measurements (C) Wheat grain: Physo-chemical parameters of grains: The foliar spraying with different concentrations of algal extract did not cause significant differences in moisture content, Ash, Crude fat and Crude fiber percentages of wheat grain comparing with control. Carbohydrate fractions of wheat grains: Foliar spraying with highest concentration of algal extract (30%) caused a significant increase in reducing sugars (R.S) and total soluble sugars (T.S.S) of wheat grains by about 28% and 25% respectively, and caused a significant decrease in starch and total carbohydrates concentration by about 28% and 15% respectively. While, the foliar spraying with algal extract (at 10% and 20%) caused a significant decrease in R.S and a significant increase in non reducing sugars, T.S.S, starch and total carbohydrates concentration. Minerals content of grain: The grain content of macronutrients and micronutrients were influenced by applications of Chondrus crispus extract. Compared to control, the content of N and Se were increased irrespective of concentrations and maximums were 3.74% and 29 mg/kg respectively, for the plants sprayed with 30 % C. crispus extract. While, the lowest concentrations of algal extract (10% & 20%) caused a significant increase in macronutrients (N, P, K, Ca and Mg) and micronutrients (Fe, Cu, Zn, Mn, Na and Se) compared to control plants. Protein content of grain:The foliar spraying with different concentrations of algal extract was significantly increased in protein content comparing with control plants. Protein fractions: Foliar spraying with highest concentration of algal extract (30%) caused a significant increase in all protein fractions and caused a significant decrease in insoluble glutenin. While, the low concentrations of algal extract (10% & 20%) led to a significant increase in globulin concentration and soluble glutenin, and non significant increase in insoluble glutenin. Amino acids composition of wheat flour protein: The essential amino acids increased due to foliar algal extract (at 20%) which increase the nutritive quality of wheat flour. The 20% of algal extract gave the optimum concentration of essential amino acids in the wheat flour, while, the 30% does not achieve the same score of essential amino acids. Analytical characteristics of whole wheat flour: The foliar spraying with algal extract caused a significant increase in wet glutin (WG) and glutin deformation index (GDI). Falling number (FN) value was significantly increased in samples sprayed with highest concentration of algal extract (20%). While, the low concentration of algal extract (at 10% & 30%) led to a significant decrease in falling number values of whole wheat flour comparing with control. Alveograph rheological properties: By comparing the data to control, it can observe a decrease of L parameter and an increase of P parameter (linked to dough resistance) and of W parameter (the energy required for swelling up to breaking point of the dough) concomitant with foliar spraying with algal extract at 20% comparing with the treatment at 30% algal extract. It is worth mentioning that the foliar spraying with algal extract does not affect negatively on the alveograph rheological properties of dough, but improvement of rheological properties of wheat Egypt (weak glutin flour) by increasing the levels of protein, wet gluten, GDI, FN and also increase the values of P, W and P/L. (D) The main constituents of wheat straw: Foliar spraying with lowest concentrations of algal extract (10% &20%) were achieved a significant increased in ash percentage, macronutrients (N, P, K and Mg), micronutrients (Fe, Cu, Zn, Mn, Na and Se) and did not affect in crud protein and cellulose contents of straw compared to control plants. While, the highest concentration of algal extract (30%) led to a significant decrease in the ash percentage, nutrient elements (P, K, Fe, Mn, Zn and Cu) and increase in crud protein and cellulose contents compared to the control plants. According to the obtained results, growth, yield and quality enhancement in wheat under the investigation due to foliar application which attributed to the presence of nutrient elements and plant growth regulators presented in the extract of C. crispus. Hence the extract can be used as a supplemental fertilizer for various crops. Also worth mentioning, the foliar application with water extract and carrageenanes (1 mg/ml) of C. crispus enhanced potato plants tolerance to virus injury via activation of the antioxidant system and the accumulation of proline and phenols in leaves. However, the optimal concentration of algal extract was achieved at 20% withering pre or post inoculation with PVY. |