**4. Materials and methods**

During the current study, 100 wheat lines (**Table 1**) including well-adapted wheat cultivars were evaluated for important root traits. A total of 102 PCR-based markers were applied aiming to understand their genetic structure and to identify molecular markers that are closely associated to quantitative trait loci (QTLs) of important root traits (**Table 2**). Plant germination, DNA extraction and PCR profiling followed previously published standard procedures [32]. Further, population structure of these lines was analyzed with general linear model (GLM) and mixed linear model (MLM) approaches using TASSEL software with their default setting for identification of QTLs associated with important root traits.


Association Mapping of Root Traits for Drought Tolerance in Bread Wheat http://dx.doi.org/10.5772/67242 


**Table 1.** List of wheat lines and cultivars used in the current study.

But with no confusion, it is the result of myriad environmental, political, economic and social issues. The current global climatic conditions are to hit Pakistan, and therefore, the search for diverse and drought-tolerant sources of crop plants is of paramount significance to feed its ever-growing population. Marker-assisted selection is a cry of the day for yield improvement in drought stress areas of Pakistan. Thus, the use of molecular markers for tagging of drought

During the current study, 100 wheat lines (**Table 1**) including well-adapted wheat cultivars were evaluated for important root traits. A total of 102 PCR-based markers were applied aiming to understand their genetic structure and to identify molecular markers that are closely associated to quantitative trait loci (QTLs) of important root traits (**Table 2**). Plant germination, DNA extraction and PCR profiling followed previously published standard procedures [32]. Further, population structure of these lines was analyzed with general linear model (GLM) and mixed linear model (MLM) approaches using TASSEL software with their default

setting for identification of QTLs associated with important root traits.

**S. no Genotypes S. no Genotypes** Sonalika 2 Shalimar 88 Merco 2007 4 Khyber 83 Manther 6 Chenab 70 Lr-230 8 Soghat 90 Ksk 10 Pari -73 Maxi pak 12 Chakwal 86 Indus 79 14 Wadanak 98 Bakhtawar 94 16 Nori -70 Wadanak 85 18 ZA-77 Abdaghar 97 20 Kaghan 93 Margalla 99 22 Dawar 96 Uqab 2000 24 Suliman 96 Raskoh 26 AS-2002 Haider 2002 28 LYP-73 Local white 30 Noshera 96 MH-97 32 Sindh 81 Zarlashta 90 34 Fakhri sarhad

Punjab-76 36 10737

resistance genes is needed [14, 15, 31].

Wheat Improvement, Management and Utilization

**4. Materials and methods**


**Table 2.** List of PCR primers/molecular markers used in the current study.
