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Int.J.Curr.Microbiol.App.Sci (2018) 7(12): 3066-3078 International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 12 (2018) Journal homepage: http://www.ijcmas.com Original Research Article https://doi.org/10.20546/ijcmas.2018.712.351 Influence of Seed Priming Treatments on Biochemical Parameters of Dry Direct Sown Rice (Oryza sativa L.) R. Pavani*, V. Umamahesh, A.R. Nirmal Kumar and Y. Reddi Ramu Department of Crop Physiology, S.V. Agricultural College, Tirupati- 517502, A.P., India *Corresponding author: ABSTRACT Keywords Seed priming, Gibberllic acid, KNO3, Alphaamylase Article Info Accepted: 24 November 2018 Available Online: 10 December 2018 The present investigation was carried out at S.V Agricultural College, Tirupati to know the effect of seed priming on biochemical parameters of dry direct sown rice (Oryza Sativa L.). A laboratory experiment was conducted in completely randomized design and replicated thrice with six popular aerobic rice genotypes i.e. MTU 1010, MTU 7029, JGL 20171, NLR33671, MTU 1075 and MTU 1112. Rice seeds were subjected to different concentrations of gibberillic acid with, 200, 500 and 1000 PPM and combination of both gibberillic acid and KNO3 treatments i.e. GA3 (200PPM, 500PPM, 1000PPM + KNO3 @3%), KNO3 @3% and control (Hydropriming/Water soaking), in order to know the effect of seed priming (Gibberllic acid and KNO 3) on various biochemical parameters like Reducing sugars (mg/g), Starch (mg/g) and Alpha amylase (%) activity were recorded at 2, 4 and 6 DAT. The results revealed that in all the biochemical parameters among Varieties MTU 1010, JGL 20171, NLR 33671 had recorded higher amount of reducing sugars, starch and Alpha amylase activity compared to MTU 7029, MTU 1075 and MTU 1112. Among treatments 1000 PPM GA3, GA3 (200 PPM, 500PPM, 1000PPM+KNO3@3%) are found to be best. Introduction Rice (Oryza sativa L.) is the most important cereal food crop of the developing world and the staple food of more than half of the world’s population. Globally rice is grown over an area of 161.83 million ha with an annual production of 717.8 million tonnes (IRRI, 2017). Irrigated rice is the major consumer of fresh water. It was estimated that by 2025, about 15-20 million hectares of irrigated rice will be affected due to water scarcity which threatens the productivity. Combining the growing demand for food with increasing water scarcity, rice producers in Asia need to produce more rice with less water. A major challenge in rice production is therefore to save water while maintaining or even increasing the grain yield (Yang and Zhang, 2010). Many water-saving technologies are currently used in rice production, including alternate wetting and drying irrigation, the rice intensification system, aerobic rice and the ground cover rice production systems (GCRPSs) (Qin et al., 2006). Among these aerobic rice is gaining 3066 Int.J.Curr.Microbiol.App.Sci (2018) 7(12): 3066-3078 popularity as a strategy for water saving agriculture. Aerobic rice can achieve yields of 4-6 tons per hectare with 50 - 70% less water compared to lowland rice it does not require flooded wetland (Qin et al., 2010). In aerobic rice production, the seeds are direct-seeded in aerobic soil without any standing water layer, which minimizes water use and boosts up water productivity by eliminating continuous seepage and percolation, reducing evaporation and eliminating wetland preparation (Nie et al., 2012; Singh et al., 2008). Season-long weed infestation in aerobic rice may cause yield reduction up to 80 % or complete failure of crop in extreme cases (Jayadeva et al., 2011; Sunil et al., 2010). Therefore, the aerobic rice cultivars should have the capacity of early seedling establishment, quick crop growth and yield stability. Identification of strong weed competitive rice cultivar is a feasible solution to inhibit the growth of weeds and it is a costeffective and safe tool for weed management (Zhao et al., 2006). Seedling vigour is a physiological trait and a sign of potential seed germination, seedling growth and tolerance to adverse climatic factors. On the other hand, it significantly improves the speed, uniformity and the final percentage of germination, and leads to ideal field appearance with good potential grain yield under direct-seeded conditions (Foolad et al., 2007). Thus, to suppress weed growth, early seedling vigour of an elite variety should be achieved. Seed priming is a viable option to attain this target. Seed priming, which is also called seed hardening, is a physiological seed enhancement method. It is a presowing treatment in which seeds are soaked in an osmotic solution that allows them to imbibe water and go through the first stages of germination, but does not permit radicle protrusion through the seed coat. Subsequently, the seeds can be dried to attain their original moisture content and stored or planted using conventional techniques. Thus in this paper the influence of seed priming with GA3 and KNO3 either alone or in combination was tested to know the amount of reducing sugars, starch and amylase content in rice seeds. Materials and Methods 0.1, 0.25 and 0.5 g each of GA3 (gibberellic acid, HIMEDIA) was dissolved separately 500 ml each in DDW along with 1.5 g KNO3 in each case to prepare a series of solutions that gives GA3 @ 200 ppm + KNO3 @ 3 %, GA3 @ 500 ppm + KNO3 @ 3 %, GA3 @ 1000 ppm + KNO3 @ 3 %. 3 % KNO3 was prepared by dissolving 1.5 g of KNO3 in 500 mL of DDW. Seeds were soaked in the respective treatmental solutions for 24 h and re dried overnight (about 12 h) and placed on petriplates. Seeds are moistened periodically with double distilled water. Reducing sugars, Starch, alpha amylase were estimated at 48h (2 days), 96h (4 days) and 144h (6 days) after soaking the seeds in different concentrations of GA3 and KNO3 treatments. By following standard protocols i.e; Nelson method for reducing sugars, Anthrone reagent method for estimation of starch and DNSA (Dinitro-salycilic acid) method for estimation of α- amylase content in rice seeds were recorded. Results and Discussion Reducing sugars (mg g-1) Maintenance of a higher amount of reducing sugar content is an important prerequisite for 3067 Int.J.Curr.Microbiol.App.Sci (2018) 7(12): 3066-3078 faster germination via enhanced metabolic activity of the embryo. Reducing sugar content was measured at 2, 4 and 6 DAT. A significant difference among varieties, treatments and their interaction was observed at all the stages and analyzed statistically and presented in table 1, 2 and 3 and Figure 1, 2 and 3. At 2 DAT it was observed that JGL 20171 (2.54) recorded significantly high reducing sugars followed by NLR 33671 (1.33). Among treatments T5 (GA3 @ 200 ppm + KNO3 @ 3%) (1.93) recorded significantly high reducing sugars followed by T6 (GA3 @ 500 ppm + KNO3 @ 3%) (1.79). T1 (control) (1.11) recorded lowest reducing sugars not only at this stage but also at 4 and 6 DAT (1.75 and 2.02). At 4 and 6 DAT the genotypes MTU 1010 (2.86 and 3.28) and JGL 20171 (2.77 and 3.04) recorded significantly highest reducing sugars whereas the lowest value was recorded in MTU 1112 (1.9 and 2.14). Among treatments T5 (GA3 @ 200 ppm + KNO3 @ 3%) (3.07 and 3.19) and T6 (GA3 @ 500 ppm + KNO3 @ 3%) (2.96 and 3.35) showed better results. The interaction effect was found to be significant only at 2 DAT where in V3T5 (3.20) recorded highest value. A progressive increase in reducing sugars content was observed from 2 DAT to 6 DAT. MTU 1010, for example recorded the reducing sugar content of 1.30, 2.86 and 3.28 at 2, 4 and 6 DAT respectively. The corresponding values for JGL 20171 were 2.54, 2.77 and 3.04. This increased availability of reducing sugars could be linked up with the activity of αamylase on breakdown of starch. Similar increase in reducing sugar content due to increased starch metabolism was also observed by Brain, 1959; Kuo and Yang, 1967; Basra et al., 2005 and Acharya et al., 2008. Starch (mg g-1) Starch represents the resource base of a seed. Higher starch content and its faster breakdown into sugars accelerate the metabolic processes of the embryo which leads to rapid cell division and cell expansion. Data on influence of different seed priming treatments on starch content at 2, 4 and 6 DAT were presented in tables 4, 5 and 6 and Figure 4, 5 and 6. From the data a gradual decrease in starch content was observed from 2 DAT to 6 DAT. Starch content in the genotype MTU 1010 for example at 2, 4 and 6 DAT was 41.2, 38.3, and 33.1 respectively. The corresponding values in MTU 1112 were 49.2, 46.2, and 42.1 respectively. Irrespective of the genotype starch content decreased with time. Among the varieties MTU 1075 and MTU 1112 (50.1 and 49.2) recorded significantly higher and at par values of starch followed by MTU 7029 (43.5), MTU 1010 (41.2), NLR 3367 (41.0) and JGL 2017 (40.9) which were at par. MTU 1075 and MTU 1112 recorded highest starch content even at 4 and 6 DAT. This might be due to slow breakdown of starch in these genotypes. Among treatments T8 (KNO3 @ 3%) (50.1), T1 (Control) (49.8), T2 (GA3 @ 200 ppm) (48.3) and T3 (GA3 @ 500 ppm) (46.9) recorded significantly higher and at par starch values where T5 (GA3 @ 200 ppm + KNO3 @ 3%) (38.8), T6 (GA3 @ 500 ppm+KNO3@3%) (39.4), T7(GA3@ 1000 ppm + KNO3 @ 3%) (40) and T4 (GA3 @ 1000 ppm) (41.4) recorded significantly low and at par starch content at 2 DAT. This could be due to the influence of these treatments on faster breakdown of starch. Almost a similar trend was observed at 4 and 6 DAT. The interaction effect was found to be non significant at all the stages. 3068 Int.J.Curr.Microbiol.App.Sci (2018) 7(12): 3066-3078 Table.1 Influence of different seed priming treatments and varieties on reducing sugars (mg g-1) at 2 days after treatment Variety MTU 1010 MTU 7029 JGL 20171 NLR 33671 MTU 1075 MTU 1112 Mean T1 0.98 1.00 1.89 0.89 0.87 1.00 1.11 T2 1.08 1.10 2.20 1.10 1.20 1.20 1.32 T3 1.12 1.20 2.60 1.30 1.17 1.20 1.43 T4 1.40 1.34 2.98 1.40 1.40 1.23 1.62 T5 1.84 1.83 3.20 1.67 1.56 1.45 1.93 T6 1.65 1.56 3.12 1.60 1.51 1.30 1.79 C.D. SE(d) SEm V 0.10 0.05 0.04 T 0.12 0.06 0.04 V×T 0.29 0.14 0.10 T7 1.30 1.48 2.30 1.50 1.34 1.32 1.54 T8 1.00 1.10 2.00 1.20 1.26 1.30 1.31 T1 : Control T5 : GA3 @ 200 ppm + KNO3 @ 3% T2 : GA3 @ 200 ppm T6 : GA3 @ 500 ppm+ KNO3 @ 3% T3 : GA3 @ 500 ppm T7 : GA3 @1000 ppm+ KNO3 @ 3 % T4 : GA3 @ 1000 ppm T8 : KNO3 @ 3% Mean 1.30 1.33 2.54 1.33 1.29 1.25 Table.2 Influence of different seed priming treatments and varieties on reducing sugars (mg g-1) at 4 days after treatment Variety T1 T2 T3 T4 T5 T6 T7 T8 Mean MTU 1010 MTU 7029 JGL 20171 NLR 33671 2.34 1.54 2.19 1.89 2.56 2.00 2.42 2.20 2.60 2.45 2.59 2.60 3.15 2.60 3.13 2.98 3.40 3.02 3.26 3.20 3.23 2.89 3.18 3.12 3.10 2.20 3.04 2.30 2.50 1.76 2.35 2.00 2.86 2.31 2.77 2.54 MTU 1075 MTU 1112 Mean 1.34 1.21 1.75 1.80 1.56 2.09 2.30 2.00 2.42 2.54 2.10 2.75 3.00 2.56 3.07 2.80 2.30 2.92 2.10 2.00 2.46 1.70 1.45 1.96 2.20 1.90 C.D. SE(d) V 0.16 0.08 0.06 T 0.19 0.09 0.07 V×T NS 0.23 0.16 SEm 3069 Int.J.Curr.Microbiol.App.Sci (2018) 7(12): 3066-3078 Table.3 Influence of different seed priming treatments and varieties on reducing sugars (mg g-1) at 6 days after treatment Variety MTU 1010 MTU 7029 JGL 20171 NLR 33671 MTU 1075 MTU 1112 Mean T1 T2 T3 T4 : : : : T1 2.67 2.00 2.40 2.00 1.56 1.43 2.01 T2 3.00 2.10 2.64 2.54 1.90 1.76 2.32 T3 3.30 2.56 2.98 2.98 2.40 2.10 2.72 T4 3.56 2.98 3.30 3.21 2.78 2.30 3.02 T5 3.56 3.10 3.40 3.30 3.00 2.76 3.19 T6 3.78 3.26 3.54 3.43 3.10 2.99 3.35 C.D. SE(d) SEm V 0.18 0.09 0.06 T 0.21 0.10 0.07 V×T NS 0.25 0.18 Control GA3 @ 200 ppm GA3 @ 500 ppm GA3 @ 1000 ppm T5 T6 T7 T8 : : : : T7 3.40 2.45 3.25 2.89 2.45 2.09 2.76 T8 2.98 1.98 2.80 2.80 1.90 1.65 2.35 Mean 3.28 2.55 3.04 2.89 2.39 2.14 GA3 @ 200 ppm + KNO3 @ 3% GA3 @ 500 ppm+ KNO3 @ 3% GA3 @1000 ppm+ KNO3 @ 3 % KNO3 @ 3% Table.4 Influence of different seed priming treatments and varieties on starch (mg g-1) at 2 days after treatment Variety MTU 1010 MTU 7029 JGL 20171 NLR 33671 MTU 1075 MTU 1112 Mean T1 46.2 51.0 43.9 47.1 56.5 53.8 49.8 T2 43.1 53.0 43.8 45.2 54.8 49.8 48.3 T3 41.2 46.0 42.5 42.5 56.1 52.9 46.9 T4 40.8 39.0 37.5 39.8 44.5 46.9 41.4 T5 33.6 38.5 38.5 33.6 43.9 44.5 38.8 T6 38.6 36.0 39.7 34.5 44.1 43.5 39.4 C.D. SE(d) SEm V 2.90 1.46 1.03 T 3.34 1.68 1.19 V×T NS 4.12 2.91 3070 T7 37.5 33.5 36.5 39.4 45.3 47.8 40.0 T8 48.5 51.0 44.8 46.2 55.5 54.6 50.1 Mean 41.2 43.5 40.9 41.0 50.1 49.2 Int.J.Curr.Microbiol.App.Sci (2018) 7(12): 3066-3078 Table.5 Influence of different seed priming treatments and varieties on starch (mg g-1) at 4 days after treatment Variety MTU 1010 MTU 7029 JGL 20171 NLR 33671 MTU 1075 MTU 1112 Mean T1 T2 T3 T4 : : : : T1 44.6 51.2 43.5 45.6 44.6 56.8 47.7 T2 45.7 42.5 41.7 45.8 48.5 55.6 46.6 T3 42.5 45.5 42.8 43.5 43.2 53.2 45.1 T4 31.8 33.8 30.6 34.8 36.5 38.2 34.3 T5 31.6 35.6 34.5 36.9 37.8 36.3 35.5 T6 34.5 36.8 36.2 32.8 36.5 37.1 35.7 C.D. SE(d) SEm V 2.70 1.36 0.96 T 3.12 1.57 1.11 V×T NS 3.84 2.72 Control GA3 @ 200 ppm GA3 @ 500 ppm GA3 @ 1000 ppm T5 T6 T7 T8 : : : : T7 32.5 40.1 33.5 37.4 38.6 36.5 36.4 T8 43.5 45.5 48.2 44.8 47.2 55.7 47.5 Mean 38.3 41.4 38.9 40.2 41.6 46.2 GA3 @ 200 ppm + KNO3 @ 3% GA3 @ 500 ppm+ KNO3 @ 3% GA3 @1000 ppm+ KNO3 @ 3 % KNO3 @ 3% Table.6 Influence of different seed priming treatments and varieties on Starch (mg g-1) at 6 days after treatment Variety MTU 1010 MTU 7029 JGL 20171 NLR 33671 MTU 1075 MTU 1112 Mean T1 38.3 40.5 38.7 44.6 51.3 52.4 44.3 T2 37.4 41.2 35.8 40.8 45.9 50.6 42.0 T3 35.5 38.9 36.3 43.9 47.8 42.3 40.8 T4 31.6 29.8 26.2 26.4 34.2 36.3 30.8 T5 29.4 30.5 24.8 27.3 30.5 38.4 30.2 T6 28.6 27.8 24.5 29.8 35.2 34.8 30.1 C.D. SE(d) SEm V 2.42 1.22 0.86 T 2.79 1.41 0.99 V×T NS 3.44 2.43 3071 T7 27.8 31.5 25.8 28.7 33.8 36.8 30.7 T8 36.5 35.7 39.5 42.7 46.7 45.1 41.0 Mean 33.1 34.5 31.5 35.5 40.7 42.1 Int.J.Curr.Microbiol.App.Sci (2018) 7(12): 3066-3078 Table.7 Influence of different seed priming treatments and varieties on alpha amylase (mg g-1) at 2 days after treatment Variety MTU 1010 MTU 7029 JGL 20171 NLR 33671 MTU 1075 MTU 1112 Mean T1 T2 T3 T4 : : : : T1 1.9 1.7 2.0 1.7 0.9 0.7 1.5 T2 1.9 2.0 2.1 1.5 0.9 0.8 1.5 T3 1.8 1.7 2.0 1.5 0.8 0.7 1.4 T4 2.4 2.2 2.4 2.2 1.3 1.3 1.9 T5 2.2 2.1 2.3 2.3 1.4 1.3 1.9 T6 2.3 2.2 2.4 2.3 1.3 1.2 2.0 C.D. SE(d) SEm V 0.11 0.06 0.04 T 0.13 0.07 0.05 V×T NS 0.16 0.11 Control GA3 @ 200 ppm GA3 @ 500 ppm GA3 @ 1000 ppm T5 T6 T7 T8 : : : : T7 2.3 2.2 2.4 2.1 1.3 1.1 1.9 T8 1.9 1.9 2.0 1.7 0.9 0.8 1.5 Mean 2.1 2.0 2.2 1.9 1.1 1.0 GA3 @ 200 ppm + KNO3 @ 3% GA3 @ 500 ppm+ KNO3 @ 3% GA3 @1000 ppm+ KNO3 @ 3 % KNO3 @ 3% Table.8 Influence of different seed priming treatments and varieties on alpha amylase (mg g-1) at 4 days after treatment Variety MTU 1010 MTU 7029 JGL 20171 NLR 33671 MTU 1075 MTU 1112 Mean T1 2.1 2.0 2.5 1.8 1.0 0.8 1.7 T2 2.2 2.0 2.4 1.6 0.9 0.8 1.6 T3 2.4 2.5 2.4 2.0 1.0 1.0 1.9 T4 2.7 2.3 2.6 2.8 1.4 1.4 2.2 T5 2.7 2.5 2.8 2.6 1.4 1.5 2.2 T6 2.8 2.6 2.8 2.3 1.9 1.6 2.3 C.D. SE(d) SEm V 0.13 0.07 0.05 T 0.16 0.08 0.06 V×T NS 0.19 0.14 3072 T7 2.8 2.6 2.9 2.5 1.8 1.3 2.3 T8 2.2 2.1 2.3 1.9 1.2 0.8 1.7 Mean 2.5 2.3 2.6 2.2 1.3 1.1 Int.J.Curr.Microbiol.App.Sci (2018) 7(12): 3066-3078 Table.9 Influence of different seed priming treatments and varieties on Alpha amylase (mg g-1) at 6 days after treatment Variety T1 T2 T3 T4 T5 T6 T7 T8 Mean MTU 1010 MTU 7029 JGL 20171 NLR 33671 MTU 1075 MTU 1112 Mean 1.6 1.4 1.6 1.2 0.9 0.7 1.2 1.5 1.7 1.8 1.6 0.8 0.9 1.3 1.6 1.4 1.9 0.9 0.7 1.2 1.3 2.1 2.0 2.0 1.8 1.2 1.2 1.7 2.2 1.8 2.0 2.1 1.6 1.4 1.9 2.5 2.0 2.1 2.3 1.6 1.3 2.0 2.7 2.1 1.9 1.8 1.7 1.4 1.9 1.2 1.3 1.2 0.8 1.0 0.7 1.0 1.9 1.7 1.8 1.6 1.2 1.1 C.D. SE(d) SEm V 0.10 0.05 0.04 T 0.12 0.06 0.04 V×T 0.29 0.15 0.10 T1 : Control T5 : GA3 @ 200 ppm + KNO3 @ 3% T2 : GA3 @ 200 ppm T3 : GA3 @ 500 ppm T4 : GA3 @ 1000 ppm T6 : GA3 @ 500 ppm+ KNO3 @ 3% T7 : GA3 @1000 ppm+ KNO3 @ 3 % T8 : KNO3 @ 3% Fig.1 Influence of different seed priming treatments and varieties on reducing sugars (mg g-1) at 2 days after treatment 3073 Int.J.Curr.Microbiol.App.Sci (2018) 7(12): 3066-3078 Fig.2 Influence of different seed priming treatments and varieties on reducing sugars (mg g-1) at 4 days after treatment Fig.3 Influence of different seed priming treatments and varieties on reducing sugars (mg g-1) at 6 days after treatment Fig.4 Influence of different seed priming treatments and varieties on starch (mg g-1) index at 2 days after treatment 3074 Int.J.Curr.Microbiol.App.Sci (2018) 7(12): 3066-3078 Fig.5 Influence of different seed priming treatments and varieties on starch (mg g-1) at 4 days after treatment Fig.6 Influence of different seed priming treatments and varieties on starch (mg g-1) at 6 days after treatment Fig.7 Influence of different seed priming treatments and varieties on alpha amylase (mg g-1) at 2 days after treatment 3075