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Title:	The effect of elevated CO2 towards rice growth performance and gene expression of RBSC1 and rbcL
Authors:	Abzar (P81130)
Supervisor:	Che Radziah Che Mohd. Zain, Assoc. Prof. Dr.
Keywords:	Rice -- Varieties Rice -- Economic aspects Rice -- Disease and pest resistance Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	27-Mar-2019
Description:	The level of CO2 has been increased from 270 ppm to 394 in 2013 and it is predicated to reach at level 700 ppm by 2100. Rice is the most important staple food for more than half of world population while an increased in atmospheric CO2 concentration has had a profound impact on global rice production. Therefore, exploring the effects of the rapidly rising levels of atmospheric CO2 on rice growth and development in the future is very important. Hence, the present study was designed to elucidate the effect of elevated CO2 on rice growth and development. This study has three objectives as follows; to determine the effect of elevated CO2 on rice seedling germination, vigor and growth, to elucidate the effect of elevated CO2 on rice growth, physiological traits and yield and to study the expression of RuBisCO related genes (RBCS1 and rbcL) upon elevated CO2 treatment using RT-qPCR approach. The current study was carried out with two different CO2 concentrations namely; elevated CO2 (800 ppm) in glass house and ambient CO2 (400 ppm) in normal greenhouse. The data related to seed germination like emergence energy, germination percentage and seedling biomass were collected at day 9th. The growth-related data like plant height and leaves number were counted at maturity. Physiological traits were measured at 60th day after transplanting using a portable photosynthesis system while yield related data were collected at harvesting. A total RNA was extracted from rice leaves at four different stages for gene expression study of RBCS1 and rbcL using RT-qPCR. The variations in results were analyzed using one-way analysis of variance (ANOVA) with randomized complete block design (RCBD). The results of the study showed that CO2 elevation has positive effect on vigor index of rice seedling including germination percentage, emergence energy, seedling shoot and root length and seedling biomass. Similarly, the growth pattern and yield of rice plant have also been enhanced with increasing of CO2. High significant difference has been seen in tiller numbers, leave numbers, plant height, panicle numbers and 1,000 grains of rice plants between elevated CO2 and control. The physiological traits like stomatal conductance, transpiration rate, photosynthetic rate and chlorophyll content has been positively enhanced with CO2 elevation. A positive change has also seen in all the parameters in term of gene expression; rbcL gene was up regulated in stage one with two folds-change under elevated CO2. In stage two, there is a slight up regulation of rbcL gene in treatment with no statistically significant difference while in stage three and four the rbcL gene was down regulated in treatment while up regulated in control with one-fold-change for each stage. Similar pattern was followed by RBCS1 gene which was up regulated at stage one with three- fold change and one-fold-change at stage two under elevated CO2 while at stage three no significant difference was seen between treatment and control. At stage four RBCS1 was up regulated in treatment with less than one-fold-change by exposing high CO2 to rice plants. It was concluded that CO2 has the capacity of increasing rice growth performance and yield by enhancing photosynthesis and up-regulating RuBisCO related genes at early growth stages.,Master of Science
Pages:	101
Call Number:	SB191.R5A293 2019 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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