Investigating physiological and biochemical

CHAPTER 3 
 
RESULTS AND DISCUSSION 
Study 1 
3.1: Screening of linseed genotypes (Linum usitatissimum L.) for 
salt tolerance 
3.1.1. Introduction 
Selection and screening of a large pool of species, varieties and/or genotypes is 
essential to explore and identify genes and germplasm for conventional breeding 
programs to produce and evolve new salt stress tolerant species, varieties and/or 
genotypes. This strategy involves the useful knowledge of plant responses to salt 
stress at various growth stages as it was studied in different crops like rice (Shannon, 
1998), sorghum (Azhar and Khan, 1997), wheat (Ali et al., 2002; Khan et al., 2003b), 
soybean (Kamal et al., 2003), cotton (Azhar and Ahmad, 2000) and maize (Khatoon 
et al., 2010). These also provide clues to plant breeders looking for plants of 
economic importance with improved salt tolerance.
Linseed is important due to its medicinal and industrial by-products and it possess 
a wide range of salt tolerance and can be successfully grown on marginal salt-affected 
soils. Thus to assess the magnitude of variation for salt stress tolerance in linseed in 
quick, precise and simple way, this research was being carried out. This research 
focused on classification of genotypes on the basis of root and shoot dry biomass, root 
length, and ionic parameters, i.e., Na
+
, K
+
and Na
+
/K
+
ratio. 
 
 

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54 
3.1.2. Materials and method 
3.1.2.1. Plant culture and experimental design
 
A solution culture study was conducted between October and December 2010 in 
the rain protected wire house of Institute of Soil and Environmental Sciences, 
University of Agriculture Faisalabad. Seeds of 60 linseed genotypes were collected 
from Ayub Agriculture Research Institute (AARI), Faisalabad. The healthy and 
sterilized seeds of genotypes were sown in trays containing two inches layers of sand.
After 15 days, seedlings were wrapped with the foam at root shoot junction and 
transplanted in polystyrene sheets with holes in them floating over 200 L capacity 
iron tubs, lined with polythene sheet containing ½ strength Hoagland’s nutrients 
solution (Hoagland and Arnon, 1950) and aerated by the air pump continuously. The 
culture solution was changed on weekly basis. The design of the experiment was CRD 
with factorial arrangement having three replications. The pH of solution was 
maintained between 6.0 and 6.5 with commercial HCl or NaOH.