Dane Virk

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Altering root morphology of rice (Oryza sativa L.) cultivars could improve yields in drought-prone upland ecosystems. Marker-assisted backcross breeding was used to introgress four QTLs for root traits into an upland rice cultivar. The QTLs had previously been identified under experimental conditions in a different genetic background. The introgressed lines(More)
The possibility of obtaining instant pure breeding lines by matromorph seed development in Pisum sativum L. has been investigated. Two types of maternal parents, namely, homozygous for the recessive marker genes and heterozygous for the dominant marker genes were pollinated with Lathyrus odoratus and the 'P174' variety of Pisum sativum L. carrying dominant(More)
Repeatability of mean downy mildew (Sclerospora graminicola (Sacc.) Schroet.) incidence, regression coefficients and deviation mean squares were investigated for 25 pearl millet (Pennisetum typhoides (Burm.) Stapf. & Hubb.) genotypes in 20 environments by correlating arrays of these stability parameters over subsets of the 20 environments arranged according(More)
Four near-isonuclear polycytoplasmic versions of 81A and two of Pb 402A male-sterile lines of pearl millet (Pennisetum typhoides) were used in factorial matings with five inbred male testers in different combinations in three sets. The cytoplasmic differences were studied for several agronomic traits using mean values and general combining effects (gca) of(More)
When the population under investigation consists of highly inbred lines the full triple test-cross of Kearsey and Jinks (1968) supplemented by the selfed progenies of the population allows unambiguous and independent tests for epistasis and the adequacy of the pure-breeding testers, L1 and L2. This can also be achieved by supplementing the simplified triple(More)
Regression analyses on grain yield of 20 hybrid and 13 composite varieties of pearl millet (Pennisetum typhoides (Burm. S. & H.)) evaluated at 19 sites in India were performed to assess their relative stability and to compare different measures of environmental values. A large portion of the significant genotype X environment interactions was attributed to(More)
Variability in breeding programmes for self-fertilised crops is created by crossing, and if the value of the crosses cannot be predicted in advance then this uncertainty means that a strategy of making many crosses is appropriate. However, since there is a limit to the capacity of a breeding programme, the more crosses that are made the smaller the size of(More)
The genetical consequences of common alleles in the L1 and L2 testers of a simplified version of the triple test-cross which is applicable to populations of inbred lines are examined. The test for epistasis under these circumstances becomes ambiguous and can spuriously detect non-allelic interactions when they may not exist although it still provides a test(More)
For studying the inheritance of metric traits, diallel cross and factorial mating designs are commonly used. Since factorial mating design is less restrictive in crossing plans, the genetic information drawn from it was compared with that from a diallel cross. The comparison was made using graphical, genetic components and combining ability analyses for(More)
The normally used joint linear regression analysis (OLS) is not appropriate for comparing estimates of stability parameters of varieties when the error variances of site means are heterogeneous. Weighted regression analysis (WLS), in these situations, yields more precise estimates of stability parameters. A comparison of the two analytical methods using the(More)