Comparative study of grain yield and BIOCHEMIcal traits of different rice varieties grown under saline and normal conditions.

S. K. Khan, J. Iqbal and M. Saeed*

School of Biological Sciences, University of the Punjab, Lahore, Pakistan.
*Department of Botany, Government College University, Faisalabad, Pakistan.
Corresponding Author e-mail: saeed242@hotmail.com

ABSTRACT

Salinity is a major abiotic stress limiting rice production worldwide. Grain yield and different biochemical traits are important in crop adaptation and tolerance to salinity stress. In the present study, 24 rice varieties were evaluated by conducting field trials under natural saline condition (salinity block) and normal field condition during 2010 and 2011. Twenty four rice varieties were categorized into four groups- salt tolerant, moderately salt tolerant, moderately salt susceptible and salt susceptible based on salinity tolerance and grain yield data of two years. Pokkali, Basmati-198 and Sathra-278 were categorized as salt tolerant varieties. All categories of rice varieties showed distinct differences in studied biochemical traits under saline conditions compared to control. Higher amount of total cations were ruinous for rice plant, whereas, higher amount of K+ and Ca++ were beneficial under saline condition signifying that uptake of selective cations were imperative for rice plant. Under saline condition, K+ uptake ratio and total cations uptake ratio showed significant positive and very highly significant negative correlation with grain yield, respectively in 2010, whereas those traits showed non-significant correlation in 2011. Again, Na+ uptake ratio showed non-significant negative and significant negative correlation with grain yield in 2010 and 2011, respectively. Both years data revealed that among salt tolerant varieties minimum amount of Na+ and total cations uptake, maximum amount of K+ and Ca++ and lower ratio of Na+/K+ uptake were observed under salinity stress. Na+ uptake, Na+/K+ uptake, Na+ uptake ratio  and uptake ratio of Na+/K+ had negative correlation, whereas, K+ uptake, Ca++ uptake, K+ uptake ratio, Ca++ uptake ratio showed positive correlation with grain yield under saline condition indicating that lower uptake of Na+, higher uptake of K+ and Ca++ were responsible for higher grain yield under saline condition and salt tolerant category varieties had the same uptake trend of Na+, K+ and Ca++.
Key words: rice, salinity, yield, biochemical.