Previous studies with chromosome substitution lines between hard red winter wheat (Triticum aestivum L.) cultivars Cheyenne (CNN) and Wichita (WI) identified genes on chromosome 3A of WI which affect grain yield, yield components, grain volume weight, plant height, and anthesis date. This study was conducted to determine if the trait variation caused by chromosome 3A could be explained by major or minor gene segregation and if these genes are pleiotropic, linked, or independent on the chromosome. A population of recombinant inbred chromosome lines for chromosome 3A (RICLs-3A), developed between CNN and a chromosome substitution line CNN(WI3A), was evaluated in multi-location field trials in 3 yr. Our results indicate significant differences (P-< 0.05) between parental lines and among RICLs for grain yield, 1000-kernel weight, plant height, and anthesis date, but not for kernel number per spike, spike number per square meter, and grain volume weight. A 1:1 genetic ratio for anthesis date suggested the presence of a single segregating locus controlling the trait. None of the other agronomic traits could be separated into unequivocal groups and hence, major genes were not detected. This indicates that the traits were controlled either by several genes or few genes with enough environmental influence, or both, to obscure their effects. Significant correlations and possible crossover products between anthesis date, plant height, and 1000-kernel weight suggest that these traits were controlled either by linked gene(s) or by pleiotropic genes with additional genes affecting one of the traits.

Tomato is one of the most economically important vegetable crops in many parts of the world. Turkey and Iran are the main producers of tomatoes in the world. The objective of this study was to assess the genetic variation of 93 tomato landraces from East Anatolian region of Turkey and North-West of Iran, along with three commercial cultivars using 14 ISSR primers. The percentage of polymorphic loci (PPL) for all primers was 100%. The mean of expected heterozygosity (He) for the primers varied from 0.153 (UBC808) to 0.30 (UBC848). The dendrogram placed the landraces and commercial cultivars into nine groups. The genotypes originating from the same region, often located in the same group or two adjacent groups. The highest likelihood of the data was obtained when population were located into 2 sub-populations (K = 2). These sub-populations had Fst value of 0.16 and 0.21.

No abstract

Aluminum (Al) toxicity is a serious factor restricting crop productivity in acid soil, and Al is the major cause of phytotoxicity. However, the role of Al toxicity in interprimer binding site (iPBS) polymorphism, genomic instability, and DNA methylation has not been fully investigated. In the current study, the effects of different Al concentrations on iPBS polymorphism, genomic instability, and DNA methylation were investigated in seedlings of three wheat cultivars: Haymana 79, Kılçıksız, and Bezostaja 1. A higher aluminum concentration increased the polymorphism rate of the iPBS profile, but decreased genomic template stability in all cultivars. A higher Al concentration was found to cause DNA methylation. Furthermore, the coupled restriction enzyme digestion-iPBS technique was used to detect DNA cytosine methylation level, which could help in understanding the epigenetic mechanism. The occurrence of hypermethylation and hypomethylation was observed with respect to Al stress treatment, and Al was found to cause DNA methylation. Polymorphism in the CRED-iPBS profile and DNA methylation can be correlated to evaluate epigenetic changes under stress.

Efficient plant regeneration system from leaf base segments of wheat (Triticum aestivum L.) was developed. The factors affecting the callus formation and regeneration capacity of leaf segments of two genotypes; Bobwhite and Pavon 76, were investigated. The highest number of somatic embryos (SE) was obtained on Murashige and Skoog medium supplemented with 2 mg dm -3 2,4-dichlorophenoxyacetic acid + 1 mg dm -3 naphthalenacetic acid (14.7 SE per segment). Highest frequency of embryogenic callus (96 %) and somatic embryo formation (24.3 SE per segment) were achieved in the first segments. The highest plantlet regeneration was obtained after transfer of embryogenic calli to regeneration medium supplemented with 1 mg dm -3 kinetin (6.3 plantlets per segment).