**3.1. Experiment # 1**

Lab experiment was conducted at PMAS-Arid Agriculture University Rawalpindi. Nine wheat varieties were selected namely, Sehar-06, Wafaq-2001, Freed-06, Dhurabi, NARC-09, NARC-11, Lasani-08, Bars-09 and Punjab-11. Thirty seeds were randomly selected from each variety and were sterilized with ethanol solution. PEG6000 solution was prepared at three different concentrations viz; 12.5 g/250 ml (−0.50 bars) (PEG−0.50), 25 g/250 ml (−1.48 bars) (PEG−1.48) and 37.5 g/250 ml (−2.95 bars) (PEG−2.95). The sterilized seeds of the above mentioned nine varieties were placed in the Petri dishes on the filter papers soaked with the above mentioned solutions of PEG. The sowing was done on 23rd October 2013. The effect of PEG on germination and seedling vigor traits of wheat varieties were studied to check which variety performed well under higher concentrations of PEG producing higher degree of drought.

*3.2.1. Crop parameters and statistical analysis*

cance was determined to compare means.

**4.1. Experiment # 1 (screening analysis)**

**4. Result and discussion**

Root length was taken at three leaf, anthesis and maturity with the help of a foot ruler. Roots of the plant were separated from the shoot and also any soil, if present, was removed. Afterwards the samples were weighed on a weighing balance. Root-shoot ratio was calculated by first measuring the root length and then the shoot length and then the ratio was calculated. Root fresh weight was measured by weighing the root samples on a weighing balance. Fresh root samples were oven dried for 24 h and weighed afterwards on a weighing balance. Root fresh weight and root dry weight are separately measured and then the ratio was calculated. Number of spikelets per spike was calculated of three spikes and then average was taken. Numbers of seeds of three spikes were counted and then its average was taken to get number of seeds per spike. Spikes were collected from the plants and were weighed on a weighing balance to get spike weight. 100 grains were separated on the seed counting tray and weight of those 100 grains were calculated on a weighing balance. The data obtained was statistically analyzed. Analysis of variance (ANOVA) were used to determine means and LSD at 5% level of signifi-

Effect of Phosphorus on Root Signaling of Wheat under Different Water Regimes

http://dx.doi.org/10.5772/intechopen.75806

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Experiment 1 was conducted for screening analysis to select best wheat genotypes. Highest germination percentage was recorded for T2 (87.78%) followed by T1 (87.03) while lowest was at T4 (80.1%) (**Table 1**). There was 20% difference among T2 and T4. In the meanwhile, all the genotypes behaved differently for germination percentage. Maximum germination (96.67%) was recorded for genotype NARC-2009 while minimum germination percentage (76.50%) was recorded for genotype Dhurabi. There was 8% difference among genotype NARC-2009 and Dhurabi for germination percentage. The interactive effects were statistically significant at 1% P level. Maximum germination percentage was recorded for NARC-2009 (100%) at T1 and T2 while minimum germination percentage was recorded for genotype BARS-09 (66.67%) under T1. The treatments depicted significant effect on root fresh weight of different genotypes. All the genotypes varied considerably for root fresh weight (RFW) (**Table 2**). Maximum root fresh weight was recorded for genotype NARC-2009 (0.12 g) while minimum root fresh weight was recorded for genotype Lasani-08 (0.09 g). There was 24% difference among NARC-2009 and Lasani-08 for root fresh weight. Similarly, all the treatments differed potentially for root fresh weight. Maximum root fresh weight was recorded for T1 (0.11 g) while minimum root fresh weight was observed under T3 (0.08 g). In the same way the interactive effects for root fresh weight was potentially significant at 1% P level. Maximum root fresh weight was recoded for genotype NARC-2009 under T1 (0.14 g) followed by genotype Sehar-06 under T2 while minimum root fresh weight (0.06 g) was recorded for genotype Lasani-08 under T4. Results depicted significant variation for root length for different treatments on wheat
