Search

Background & Aims: Drought stress negatively affects wheat crop production worldwide. Selection of drought tolerant varieties and application of silicon (Si) can help to uplift the crop production. The present investigation was aimed to screen drought tolerant wheat varieties by evaluating the potential of Si fertilization.Study was conducted in two sets of experiments, in first (hydroponic) investigation two wheat varieties out of eleven were screened out based upon agronomic parameters, membrane stability, potassium (K+) distribution and tolerance index. The screened varieties were then subjected to different silicon fertilizers under water deficit pot conditions in second experiment and impact of Si sources was monitored via agronomic, physiological and biochemical attributes.Faisalabad-08 and Anaj-17 were best performing varieties in tested parameters. The silica fertilizer application improved the growth, physiological, biochemical and ionic attributes under water deficit and increased the grain yield of crop. Among tested sources, silicic acid proved best as compared to other silicates in terms of ameliorating the osmotic stress. The silicic acid application improved the root and shoot growth parameters i.e. increased plant height by 13% and grain yield by 43%, relative water contents (30%), membrane stability (46%), antioxidant activity (up to 64%), organic solutes production and silicification of cell wall by increasing Si uptake by 9 folds.It was observed that combined use of tolerant varieties and silica fertilizer as silicic acid can uplift plant growth and production under water deficit conditions. Further field investigations are recommended to check crop economics of applied treatments.Methods: Drought stress negatively affects wheat crop production worldwide. Selection of drought tolerant varieties and application of silicon (Si) can help to uplift the crop production. The present investigation was aimed to screen drought tolerant wheat varieties by evaluating the potential of Si fertilization.Study was conducted in two sets of experiments, in first (hydroponic) investigation two wheat varieties out of eleven were screened out based upon agronomic parameters, membrane stability, potassium (K+) distribution and tolerance index. The screened varieties were then subjected to different silicon fertilizers under water deficit pot conditions in second experiment and impact of Si sources was monitored via agronomic, physiological and biochemical attributes.Faisalabad-08 and Anaj-17 were best performing varieties in tested parameters. The silica fertilizer application improved the growth, physiological, biochemical and ionic attributes under water deficit and increased the grain yield of crop. Among tested sources, silicic acid proved best as compared to other silicates in terms of ameliorating the osmotic stress. The silicic acid application improved the root and shoot growth parameters i.e. increased plant height by 13% and grain yield by 43%, relative water contents (30%), membrane stability (46%), antioxidant activity (up to 64%), organic solutes production and silicification of cell wall by increasing Si uptake by 9 folds.It was observed that combined use of tolerant varieties and silica fertilizer as silicic acid can uplift plant growth and production under water deficit conditions. Further field investigations are recommended to check crop economics of applied treatments.Results: Drought stress negatively affects wheat crop production worldwide. Selection of drought tolerant varieties and application of silicon (Si) can help to uplift the crop production. The present investigation was aimed to screen drought tolerant wheat varieties by evaluating the potential of Si fertilization.Study was conducted in two sets of experiments, in first (hydroponic) investigation two wheat varieties out of eleven were screened out based upon agronomic parameters, membrane stability, potassium (K+) distribution and tolerance index. The screened varieties were then subjected to different silicon fertilizers under water deficit pot conditions in second experiment and impact of Si sources was monitored via agronomic, physiological and biochemical attributes.Faisalabad-08 and Anaj-17 were best performing varieties in tested parameters. The silica fertilizer application improved the growth, physiological, biochemical and ionic attributes under water deficit and increased the grain yield of crop. Among tested sources, silicic acid proved best as compared to other silicates in terms of ameliorating the osmotic stress. The silicic acid application improved the root and shoot growth parameters i.e. increased plant height by 13% and grain yield by 43%, relative water contents (30%), membrane stability (46%), antioxidant activity (up to 64%), organic solutes production and silicification of cell wall by increasing Si uptake by 9 folds.It was observed that combined use of tolerant varieties and silica fertilizer as silicic acid can uplift plant growth and production under water deficit conditions. Further field investigations are recommended to check crop economics of applied treatments.Conclusion: Drought stress negatively affects wheat crop production worldwide. Selection of drought tolerant varieties and application of silicon (Si) can help to uplift the crop production. The present investigation was aimed to screen drought tolerant wheat varieties by evaluating the potential of Si fertilization.Study was conducted in two sets of experiments, in first (hydroponic) investigation two wheat varieties out of eleven were screened out based upon agronomic parameters, membrane stability, potassium (K+) distribution and tolerance index. The screened varieties were then subjected to different silicon fertilizers under water deficit pot conditions in second experiment and impact of Si sources was monitored via agronomic, physiological and biochemical attributes.Faisalabad-08 and Anaj-17 were best performing varieties in tested parameters. The silica fertilizer application improved the growth, physiological, biochemical and ionic attributes under water deficit and increased the grain yield of crop. Among tested sources, silicic acid proved best as compared to other silicates in terms of ameliorating the osmotic stress. The silicic acid application improved the root and shoot growth parameters i.e. increased plant height by 13% and grain yield by 43%, relative water contents (30%), membrane stability (46%), antioxidant activity (up to 64%), organic solutes production and silicification of cell wall by increasing Si uptake by 9 folds.It was observed that combined use of tolerant varieties and silica fertilizer as silicic acid can uplift plant growth and production under water deficit conditions. Further field investigations are recommended to check crop economics of applied treatments. [ABSTRACT FROM AUTHOR]

Background and aims: The growth of green plants depends not only on photosynthesis, but also on the successful remobilization and translocation of seed phosphorus (P) reserves to the vegetative parts of the developing seedling during early growth. Remobilization and photosynthesis are therefore two parallel and co-coinciding processes involved in better seedling establishment and early growth. Methods: A study was conducted to evaluate the priority of developing maize seedlings to translocate the remobilized seed P reserves and external P uptake to seedling root and shoot sinks during 4 weeks of early growth. Two fluxes of P in growing seedlings, one from seed remobilized P reserves and one from external P uptake, were distinguished by labelling external nutrient solution P with P. Results: The seedling phytomass was equally distributed between seedling roots and shoots for 530 cumulated degree days after sowing. Seedlings partitioned up to 71 % of P from seed reserves and up to 68 % of P acquired from the nutrient solution, to the shoots, depending on the seed P content and P concentration in the nutrient solution. It appears that accumulation of P slows down in seedling roots corresponds to the translocative functions of root P towards shoots for start of photosynthesis. Conclusions: Our results suggest that the major part of seed P reserves and external P uptake were used in early development of the seedling and the preferred sink was seedling shoots. [ABSTRACT FROM AUTHOR]

Background and aims: Phosphorus (P) nutrition is very important during early maize seedling growth. Remobilization of endogenous seed P and uptake of exogenous P are therefore of prime importance during this period. Our objectives were to study the effect of the availability of endogenous and exogenous P on i) remobilization of endogenous seed P, ii) the beginning of exogenous P uptake and its intensity, iii) their interaction and effect on seedling development. Methods: Seeds with high and low reserves of endogenous seed P were cultivated at three rates of availability of exogenous P (0, 100, 1,000 μM) over a growth period of 530 cumulated degree days after sowing. Exogenous P was labeled with radioactive P (P) to distinguish the two fluxes of P in seedlings, one due to remobilization of seed P and the other to uptake of exogenous P. Results: Initially, 86% of endogenous seed P was localized in the scutellum, mainly in the form of phytate, regardless of initial endogenous seed P. At 89 cumulated degree days after sowing (base temperature: 10°C), 98% of seed phytate was hydrolyzed in all treatments. In treatments with available exogenous P, significant uptake of exogenous P started at 71 cumulated degree days after sowing. Efficient uptake of exogenous P depended on its availability, but was independent of phytate hydrolysis and seedling P status. Significant loss of P from germinating seeds due to efflux was observed and was also independent of the availability of exogenous P. Conclusions: Our results show that hydrolysis of seed P was not influenced by the availability of exogenous P, and conversely, that uptake of exogenous P was not influenced by endogenous P in the seed. This suggests that remobilization of endogenous seed P and uptake of exogenous P by seedling roots are controlled independently. [ABSTRACT FROM AUTHOR]

Adequate phosphorus (P) nutrition during early stages is critical for maize growth. Our objective was to evaluate the relative contribution of seed P reserves and exogenous P to maize nutrition during early growth stages. Seedlings were grown with labeled nutrient solution (P). Seedlings were harvested periodically over the course of the three-week study. Initially, 87% and 77% of the total C and N in seeds were located in the endosperm, whereas 86% of seed P was located in the scutellum as phytate. Up to the 7th day after sowing, 96% of phytate was hydrolyzed. Hydrolyzed forms of P were temporarily stored in the seed before being translocated to growing organs, suggesting that the hydrolysis of phytate was not a limiting step for P supply to seedlings. Significant P uptake by roots was observed from the 5th day after sowing on. Both sources of P supplied roots and leaves, with a slightly higher proportion of P from seed reserves going to leaves rather than to roots. Of total seed P, 60% and 92% was exported towards newly growing seedlings till 7th and 17th days after sowing and ceased to be a significant source of P for growth thereafter. We conclude that although both P supply processes overlap in time, seed P was the main P source during early growth stages. [ABSTRACT FROM AUTHOR]