Latest Research News on growth of rice : Nov 2021

Effect of silicon on the growth of rice plant at different growth stages

Rice plants (Oryza sativa L. cv. Akebono) were cultured in Kimura B solution. The effect of silicon on plant growth and the characteristics of the uptake and distribution of silicon at different growth stages were studied from both aspects: the addition and removal of silicon during the vegetative, reproductive and ripening stages.

When silicon was removed during the reproductive stage, the dry weights of straw (stem+leaf blade) and grain decreased by 20 and 50% respectively, compared with those of the plants cultured in the solution with silicon throughout the growth period. Conversely, when silicon was added during the reproductive stage, the dry weights of straw and grain increased by 243 and 30%, respectively, over those of the plants cultured in a solution devoid of silicon throughout the growth period. The effect of silicon on the dry weights of straw and grain was small when silicon was either added or removed during the vegetative and ripening stages.[1]



Effect of brassinosteroids on salinity stress induced inhibition of seed germination and seedling growth of rice (Oryza sativa L.)

The effect of 24-epibrassinolide and 28-homobrassinolide on the inhibitionof germination and seedling growth of rice (Oryza sativa) induced bysalinity stress was studied. Brassinosteroids were found to reverse theinhibitory effect on germination and seedling growth. The activation ofseedling growth by brassinosteroids under salinity stress was associatedwith enhanced levels of nucleic acids and soluble proteins.[2]


Cell wall peroxidase activity, hydrogen peroxide level and NaCl-inhibited root growth of rice seedlings

The changes in cell-wall peroxidase (POD) activity and H2O2 level in roots of NaCl-stressed rice seedlings and their correlation with root growth were investigated. Increasing concentrations of NaCl from 50 to 150 mM progressively reduced root growth and increased ionically bound cell-wall POD activity. NaCl had no effect on covalently bound cell-wall POD activities. The reduction of root growth by NaCl is closely correlated with the increase in H2O2 level. Exogenous H2O2 was found to inhibit root growth of rice seedlings. Since ammonium and proline accumulation are associated with root growth inhibition caused by NaCl, we determined the effects of NH4Cl or proline on root growth, cell-wall POD activity and H2O2level in roots. External application of NH4Cl or proline markedly inhibited root growth, increased cell-wall POD activity and increased H2O2 level in roots of rice seedlings in the absence of NaCl. An increase in cell-wall POD activity and H2O2 level preceded inhibition of root growth caused by NaCl, NH4Cl or proline. NaCl or proline treatment also increased NADH-POD and diamine oxidase (DAO) activities in roots of rice seedlings, suggesting that NADH-POD and DAO contribute to the H2O2 generation in the cell wall of NaCl- or proline-treated roots. NH4Cl treatment increased NADH-POD activity but had no effect on DAO activity, suggesting that NADH-POD but not DAO is responsible for H2O2 generation in cell wall of NH4Cl-treated roots.[3]


Effect of Different Methods of Zn Application on Rice Growth, Yield and Nutrients Dynamics in Plant and Soil

Zinc (Zn) deficiency is widely spread in Egyptian paddy soils and has negative impact on national rice (Oryza sativa L.) production. Field experiments were conducted at the research farm of the Rice Research and Training Center, Sakha, Egypt, to evaluate the effects of different methods of Zn application on rice growth, yield of Sakha 104 and nutrients dynamics in soil and plant. The experiment included four treatments: no Zn, root soaking, foliar and soil application. The results indicated that Zn application by different methods, significantly increased number of tillers, panicles, plant height, 1000-grain weight; filled grains% and grains yield of Sakha 104. Among the different of Zn application, soil application of 15 kg ha-1 as ZnSO4.H2O caused highest increase in total N percentage, total K percentage and available Zn content in both grain and straw, however, the percentage of total P decreased significantly. Zinc content in soil after harvesting was significantly affected by Zn application. Different methods of Zn tend to increase the total N and total K contents of soil but decreased P concentration significantly. [4]


On Improving Seed Germination and Seedling Growth in Rice under Minimal Soil Salinity

Aims: It was assumed that two- way approach i.e. nutrient-priming with potassium salt of the seeds and later on ammonium sulphate application may be binary beneficial for growth of rice besides evidencing genetic variability under salt stress

Study Design: The experiment was laid out in Complete Randomized Design with three replications.

Place and Duration of Study: The study was conducted in laboratory and glass house of Soil Salinity Research Programme of Land Resources Research Institute at National Agricultural research Centre, Islamabad, Pakistan during the period from May to August, 2016.

Methodology: Seeds of Oryza sativa (cv. KS-282 and BAS 385) were primed with potassium nitrate. In the second phase of the study, the primed seeds were raised in a minimal saline soil with ammonium sulphate nutrition gradually up to 150 mg Kg -1.

Results: Bas-385 was more responsive for mean germination time than KS-282. In Bas-385 and KS-282 germination was 100 and 90 percent. Germination rate index of Bas-385 was 16 percent higher than that of KS-282. Biomass of Bas-385 seedlings was higher than that of KS-282 with the treatments. In both the cultivars of rice, Na+/K+ ratio was in antagonistic relation R = (- 0.99) with the gradual increase in ammonium sulphate application. Potassium ion was accordant with sulphate ion and N concentration.  Bas-385 was more tolerant to KS-282 based on Na+/K+ ratio and bio mass.

Conclusion: BAS 385 (salt sensitive) superseded to KS-282 (salt tolerant) under minimal salt stress due to nutrient priming and then enhanced nutrition.  [5]


Reference

[1] Ma, J., Nishimura, K. and Takahashi, E., 1989. Effect of silicon on the growth of rice plant at different growth stages. Soil Science and Plant Nutrition, 35(3), pp.347-356.

[2] Anuradha, S. and Rao, S.S.R., 2001. Effect of brassinosteroids on salinity stress induced inhibition of seed germination and seedling growth of rice (Oryza sativa L.). Plant Growth Regulation, 33(2), pp.151-153.

[3] Lin, C.C. and Kao, C.H., 2001. Cell wall peroxidase activity, hydrogen peroxide level and NaCl-inhibited root growth of rice seedlings. Plant and Soil, 230(1), pp.135-143.

[4] Ghoneim, A.M., 2016. Effect of different methods of Zn application on rice growth, yield and nutrients dynamics in plant and soil. Journal of Agriculture and Ecology Research International, pp.1-9.

[5] Ali, A., Mahmood, I.A., Suhaib, M., Ullah, M.A. and Ishaq, M., 2017. On Improving Seed Germination and Seedling Growth in Rice under Minimal Soil Salinity. Asian Research Journal of Agriculture, pp.1-7.

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