Fourteen genotypes including two checks varieties were evaluated for agronomic traits and their adaptability study on two different sowing dates at the experimental farm of Nuclear Institute for Food and Agriculture, Tarnab, Peshawar, Pakistan. The combined analysis of variance showed that there were significant variations among genotypes, dates of sowing and their interaction. Based on regression coefficient (bi) and mean square deviation from linear regression ( 2 ) for the individual genotypes regarding the parameters Viz. plant height, spike length, spikelets spike -1 , number of tillers plant -1 and grain yield (kg) plot -1 under consideration, most of the genotypes responded negatively with respect to all the traits under late planting condition. However, some of the genotypes such as CT-09117, CT-09137, CT-09141 and SRN-09111 revealed stable performance with respect to the yield assorted traits. They have been recommended for the late planting conditions where sowing is delayed due to some unavoidable circumstances than the other elite wheat genotypes. KEYWORDSNormal and late sowing, yield components, environmental effects, Triticum aestivum L.

Mixed inheritance analysis using joint segregation analysis was investigated in 6 basic populations (P 1 , F 1 , P 2 , BC 1 , BC 2 , and F 2 ) of 4 wheat crosses, i.e. Hashim-08 × LU-26, Farid-06 × Shafaq, Parula × Blue Silver, and TD-1 × D-97603, for grain filling duration during the crop season of 2011/2012. In cross Hashim-08 × LU-26, the duration of grain filling was controlled by 1 major gene and the additive-dominance-epistasis of polygenes (model D). In cross Farid-06 × Shafaq, the duration was controlled by additive-dominanceepistasis of 2 major genes (model B-1). However, in crosses Parula × Blue Silver and TD-1 × D-97603, the period of grain filling was under the control of 2 mixed groups of genes including additive-dominant-epistatic major genes plus the additive-dominant-epistasis of polygenes (model E and model E-1, respectively). In cross Hashim-08 × LU-26, the variation and heritability of the polygenes were greater than those of the major gene, whereas these components were low in cross Parula × Blue Silver. In crosses Farid-06 × Shafaq and TD-1 × D-97603, no polygenes were involved and the duration of grain filling was mainly under the influence of major genes. For the duration of grain filling, the maximum environmental variation revealed the influence of environment. Results suggested that due to its maximum heritability, early selection would be feasible in cross Hashim-08 × LU-26, while due to low heritability and variation in cross Parula × Blue Silver, delayed selection will be effective. Yield improvement based on duration of grain filling could be done through selection in later generations until the accumulation of the maximum favorable additive genes is achieved.

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Bread wheat (Triticum aestivum L.) germplasm consisting of 45 genotypes were clustered phenotypically using ten morphological traits and Area Under Disease Progress Curve (AUDPC) as measure of stripe rust resistance. The clustering was ratified by using twenty three molecular markers (SSR, EST and STS) linked to stripe rust (Puccinia striiformis f. sp. tritici) resistant QTLs. The aim was to asses the extent of genetic variability among the genotypes in order to select the parents for crossing between the resistant and susceptible genotypes with respect to stripe rust. The Euclidian dissimilarity values resulted from phenotypic data regarding morphological traits and AUDPC were used to construct a dendrogram for clustering the accessions. Using un-weighted pair group method with arithmetic means, another dendrogram resulted from the similarity coefficient values was used to distinguish the genotypes with respect to stripe rust. Clustering based on phenotypic data produced two major groups and five clusters (with Euclidian dissimilarity ranging from 2.44 to 16.16) whereas genotypic data yielded two major groups and four clusters (with percent similarity coefficient values ranging from 0.1 to 46.0) to separate the gene pool into highly resistant, resistant, moderately resistant, moderately susceptible and susceptible genotypes. With few exceptions, the outcome of both type of clustering was almost similar and resistant as well as susceptible genotypes came in the same clusters of molecular genotyping as yielded by phenotypic clustering. As a result seven genotypes (Bakhtawar-92, Frontana, Saleem 2000, Tatara, Inqilab-91, Fakhre Sarhad and Karwan) of diverse genetic background were selected for pyramiding stripe rust resistant genes as well as some other agronomic traits after hybridization.