Creation of genetic variability and development of varieties having higher yield potential depends on information about nature of gene action. The present investigation was undertaken to decipher the nature of gene action and allied genetic parameters involved in the inheritance of yield and yield-related component traits in opium poppy (Papaver somniferum L.). The biparental inbreeding progenies derived from four segregating base populations of crosses NB-1Kr40-3/3×NB-1Kr30+0.2-2/1, NB-5Kr40-7/2×58/1, NB-1Kr30+0.2-2/1×58/1 and NB-Kr40-3/3×NB-5Kr40-7/2 of opium poppy were analysed to study the gene actions involved in the inheritance of yield and component traits. Additive component of variance played a predominant role in North Carolina design (NCD)-I, while both additive and dominance genetic components were found important in NCD-III design. The presence of additive as well as nonadditive components of variance suggested that one or two generations of intermating in further generations followed by selection may lead to development of novel genotypes.

This study was undertaken to measure the genetic diversity and population structure of 48 barley accessions introduced from ICARDA using 51 polymorphic simple sequence repeat (SSR) markers to select unique parents for breeding. The mean polymorphic information content was 0.491, suggesting high polymorphism for the selected SSR markers among the barley accessions. The populationstructure indicated a fine genetic base only with two major clusters. All accessions had 100% membership probability in their respective clusters. Analysis of molecular variance revealed that most (78%) of the variation was attributed between populations, while 22% was due to variation among individuals within populations. Neighbour-joining (NJ) tree was constructed using this distance matrix and two major clusters were observed in it. Cluster 1 had all hulled barley accessions and cluster 2 had all hulless barley accessions. Cluster 2 could befurther divided into three subclusters. Principal coordinates analysis results were similar to the NJ tree, where the hulled and hulless barley accessions were grouped into separate clusters. This study established the existence of considerable genetic diversity among the 48 tested accessions. The selected genetic resources will be useful for barley breeding in India and other countries.