Morpho-physiological and Molecular Analysis for Drought Tolerance in Three Cereal Species

Abstract

The present study was under taken to screen Sorghum, Finger millet and Oats genotypes for drought tolerance and assessment of genetic diversity with the help of ten Cytochrome P450 based molecular markers and five different DERB Gene specific primers. Three different treatments of PEG-6000 i.e 5%, 10% and 15% were used to create the drought stress. Eleven seedling traits viz germination percentage, root length, shoot length, total length, shoot fresh weight, root fresh weight, total fresh weight, shoot dry weight, root dry weight, total dry weight and seedling vigour index were scored for all the genotypes belonging to three cereal species. Drought stress tolerance indices were calculated for all theses eleven different seedling traits for all the genotypes studied. Based on these drought tolerance indices all the genotypes were compared and categorized into four different drought stress tolerant categories. In oats among all genotypes four genotypes (‘EC-576061’,‘AOS-1-1’, ‘JHO- 2002-6’ and ‘EC-246176’) were grouped as highly tolerant and two genotypes (‘JHO-2002-6’ and ‘AOS-1-9’) were considered as highly susceptible. Similarly in Sorghum, genotype ‘CSV-21F’ was grouped as highly tolerant. Whereas in finger millet genotype ‘GPV-45’ was found highly tolerant and ‘VL-140 Almora’ was highly susceptible. Among the three cereal species studied, Finger millet was found more tolerant to drought stress compared to oats and sorghum. At molecular level genetic diversity of all genotypes was analyzed using ten universal primer pairs for Cytochrome P450 markers and five different species specific DERB Gene primers. In Gene specific analysis PIC values varied from 0.07 to 0.73 with an average of 0.33 and resolving power varied from 0 to 2.72 with an average of 1.21.In Cytochrome P450 analysis PIC values varied from 0.02 to 1.00 with an average of 0.97 and resolving power varied from 0.48 to 4.64 with an average of 2.24. Cytochrome P450 is found more suitable to identify highly diverse genotypes of oats which can be utilized in future for breeding. Combined study of Cyt p450 marker and Gene specific primer system together provide wider genome coverage and were found to be better indicator of the genetic relationships. No association was found between clustering of genotypes on the basis of the molecular marker analysis and on the basis of morphological parameters related to drought stress.