13 research outputs found
Assessment of genetic diversity among Pakistani wheat (Triticum aestivum L.) advanced breeding lines using RAPD and SDS-PAGE
Genetic diversity was assessed among 32 advanced wheat breeding lines
included in the National Uniform Wheat Yield Trials (2006-07) of
Pakistan using molecular (DNA) and biochemical (SDS-PAGE) markers. Of
the 72 RAPD primers used for initial screening, 15 were found
polymorphic. A total of 140 bands (61.4% polymorphic) were generated by
the 15 random decamer primers. Genetic similarity coefficients ranged
from 0.81 to 0.94 for rainfed and from 0.70 to 0.93 for the normal
seeding date group. Cluster analysis using the unweighted pair group
method of arithmetic averages (UPGMA) clustered the 32 advanced wheat
breeding lines into one major and three small groups. Maximum level of
polymorphism (90%) was observed for the primer OPA-05. Lines N9 and N11
showed the least genetic similarities (0.70-0.82 and 0.71-0.83,
respectively) with rest of the lines studied. Line RF1 had the maximum
similarity (0.81-0.94) with other lines. Wheat lines included in the
normal seeding date were relatively distantly related than those in the
rainfed group. Seed storage protein analysis produced 19 subunits
ranging from 29-120KDa. Similarity coefficients ranged from 0.53 to 1.0
for the normal seeding date and from 0.47 to 1.0 for the rainfed group.
High molecular weight subunits (particularly 120KDa) showed greater
polymorphism than the lower molecular weight subunits. Narrow genetic
base was observed in wheat lines included in the rainfed group. DNA
fingerprinting of advanced breeding lines may help to avoid release of
varieties with narrow genetic base in the future
Assessment of genetic diversity among Pakistani wheat (Triticum aestivum L.) advanced breeding lines using RAPD and SDS-PAGE
Genetic diversity was assessed among 32 advanced wheat breeding lines
included in the National Uniform Wheat Yield Trials (2006-07) of
Pakistan using molecular (DNA) and biochemical (SDS-PAGE) markers. Of
the 72 RAPD primers used for initial screening, 15 were found
polymorphic. A total of 140 bands (61.4% polymorphic) were generated by
the 15 random decamer primers. Genetic similarity coefficients ranged
from 0.81 to 0.94 for rainfed and from 0.70 to 0.93 for the normal
seeding date group. Cluster analysis using the unweighted pair group
method of arithmetic averages (UPGMA) clustered the 32 advanced wheat
breeding lines into one major and three small groups. Maximum level of
polymorphism (90%) was observed for the primer OPA-05. Lines N9 and N11
showed the least genetic similarities (0.70-0.82 and 0.71-0.83,
respectively) with rest of the lines studied. Line RF1 had the maximum
similarity (0.81-0.94) with other lines. Wheat lines included in the
normal seeding date were relatively distantly related than those in the
rainfed group. Seed storage protein analysis produced 19 subunits
ranging from 29-120KDa. Similarity coefficients ranged from 0.53 to 1.0
for the normal seeding date and from 0.47 to 1.0 for the rainfed group.
High molecular weight subunits (particularly 120KDa) showed greater
polymorphism than the lower molecular weight subunits. Narrow genetic
base was observed in wheat lines included in the rainfed group. DNA
fingerprinting of advanced breeding lines may help to avoid release of
varieties with narrow genetic base in the future
Genetic diversity associated with agronomic traits using microsatellite markers in Pakistani rice landraces
Genetic diversity underlies the improvement of crops by plant breeding.
Land races of rice ( Oryza sativa L.) can contain some valuable
alleles not common in modern germplasm. The aim here was to measure
genetic diversity and its effect on agronomic traits among rice
land-race genotypes grown in Pakistan. Diversity was measured using
thirty-five microsatellite markers and seventy-five genotypes. Among
the markers used a total of 142 alleles were detected at 32 polymorphic
SSR loci, while three loci were monomorphic in Pakistani rice
landraces. The number of alleles identified by each marker ranged from
2 to 13 with a mean of 4.4. Size differences between the smallest and
largest alleles varied from 11bp to 71bp. Polymorphism information
content ranged from 0.124 to 0.836, with an average of 0.569. At nine
microsatellite loci, basmati-type landraces amplified more different
alleles than those in the coarse-type. DNA markers RM70 and RM72
divided the rice landraces on the basis of days to flowering. A
dendrogram based on total microsatellite polymorphism grouped 75
genotypes into four major clusters at 0.40 similarity coefficient,
differentiating tall, late maturing and slender aromatic types from the
short, early and bold non-aromatic ones. It inferred that Pakistani
landraces have diverse genetic bases and can be utilized in future
breeding programs. The DNA markers developed will assist in genotype
identification, purity testing and plant variety protection