Amna Ali

Isolation, cultivation, purification and identification of bacterial species from microfauna of soil

Abstract : Soil is an excellent source of unknown microorganisms since bacteria, algae, protozoans, yeasts, moulds, and microscopic worms are routinely found in this environment. Therefore, soil is a medium in which life is sustained in a fragile biological balance. Bacteria play an important role in nutritional chains that are an important part of biological balance. In the present study, four different soil samples were collected from the rhizosphere of i) Sapota zapotilla, ii) Eucalyptus species, iii) Ficus religiosa from Lahore and iv) soil from Changa manga, Pakistan. A Total of 28 bacterial species were isolated and classified in the period between November 2008 and December 2009. All species were cultured on recommended media for verification of biochemical characteristics. The results showed that at least fifteen Gram-positive bacterial species were present in samples and these were considered as the major group constituting the bacterial population strains

Screening of diverse germplasms for genetic studies of drought tolerance in rice (Oryza sativa L.)

Twenty different rice lines were analyzed based on various genotypic and phenotypic seedling traits. Correlation and principal component analysis (PCA) were used to study these traits. The mean value of the root shoot traits of each genotype was analyzed at different levels of significance. The highest correlation was found in root length, shoot length (r = 0.856, r = 0.896) and shoot length and root number (r = 0.825, r = 0.818) in stress and normal condition respectively. The principal component exhibited more than one eigenvalue considered to be more important due to variation. The principal components (PC1 and PC2) having more than one eigenvalue for various traits were considered very important due to variation. The PC1 and PC2 for root length and shoot length same for both conditions showed variability of 76.2% and 78.5%, respectively. Different SSR markers were used to study the genetic diversity and screening of the rice genotypes for developing new breeding lines. The mean number of alleles per locus was 3.70, showing that the average polymorphism information content (PIC) was 0.500. A total of 63 alleles were also identified from the microsatellite marker loci. The overall objective of the study was to screen out the diverse parents, on the basis of different simple sequence repeats (SSR) primers and root morphological desirable traits, for a future cross breeding program for development of new rice varieties that are equally beneficial for farmers and the scientific community.