No abstract

Sesame mutants with closed capsules, determinate growth habit and wilt resistance, have been proposed to be suitable for intensive management conditions facilitating mechanized harvesting.

The identification of an amplified fragment length polymorphism (AFLP) marker linked to an agronomically useful trait in sesame is reported. A bulked segregant analysis (BSA) approach was adopted on segregating progenies of a cross between the closed capsule mutant line ‘cc3’, and the Turkish variety ‘Muganli‐57′. A total of 72 primer combinations were screened for linkage to the trait, but only one closely linked amplified fragment length polymorphism (AFLP) marker was identified. The linkage was confirmed by analysing the AFLP profile from single plants. The marker has the potential to accelerate breeding programmes aimed at modifying unwanted side‐effects of the closed capsule mutation by marker‐assisted selection.

To our knowledge, this is the first report on the use of factor analysis in determining characters for yield selection in chickpea (Cicer arietinum L.). The present investigation was undertaken to evaluate yield criteria in chickpea using phenotypic correlations and factor analysis. Factor 1 composed of biological yield, reaction to ascochyta blight (Ascochyta rabiei (Pass.) Labr.), plant height, grain yield and harvest index. Factor 2 consisted of branches and pods per plant. Factor 3 encompassed of only the grain weight. The total factors explained 92.9% of the total variance caused in the characters. The grain yield was positively and statistically significant correlated with biological yield, harvest index, plant height, branches and pods per plant, while it was negatively and statistically significant related with reaction to ascochyta blight and grain weight. Biological yield, harvest index, plant height and reaction to ascochyta blight instead of many selection criteria should previously be evaluated in selection to increase the grain yield in chickpea breeding programs. Pods per plant should be handed together with and branches per plant. Apart from the other selection criteria, the grain weight should solely be evaluated to select large grained genotypes.

This is the first report on molecular studies and tagging of the dt gene regulating determinate growth habit in sesame. The development of determinate cultivars has become an objective of high priority in sesame breeding programmes. Random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) techniques were investigated for the development of molecular markers for this induced mutant character. In order to identify molecular markers linked to determinate growth habit, a segregating F 2 population was developed from a cross between determinate mutant line, dt-1 and an indeterminate Turkish cultivar, Muganlı-57. Using the F 2 segregating population and bulked segregant approach, two ISSR marker loci originated from a (CT) 8 AGC primer were detected. The association was confirmed by analysing the ISSR profile from single plants originating from a F 2 segregating population for the trait. This marker is potentially useful for assisting sesame breeding programmes by marker assisted selection and can facilitate the integration of determinate growth habit into new genetic backgrounds.