The objectives of the present research were to determine the effects of water stress on seed-quality traits and to map QTLs controlling the studied traits under two different water treatments in a population of sunflower recombinant inbred lines (RILs). Two experiments were conducted in greenhouse and field conditions, each with well-watered and water-stressed treatments. The experiments consisted of a split-plot design (water treatment and RIL) with three blocks. Analyses of variance showed significant variation among genotypes, and a water treatment x genotype interaction was also observed for most of the traits. Two to 15 QTLs were found, depending on trait and growth conditions, and the percentage of phenotypic variance explained by the QTLs ranged from 5% to 31%. Several QTLs for oil content overlapped with QTLs for palmitic and stearic acid contents in all four conditions. An overlapping region on linkage group 3 (QTLs 2.OC.3.1 and 4.SA.3.1) was linked to an SSR marker (ORS657). A principal component analysis was performed on four fatty acid traits. Two principal components, P1 and P2, were used for QTL analysis. This method improved the ability to identify chromosomal regions affecting the fatty acids. We also detected the principal-component QTLs that did not overlap with the fatty acid QTLs. The results highlight genomic regions of interest in marker-based breeding programmes for increasing oil content in sunflower.

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Verticillium albo-atrum is responsible for considerable yield losses in many economically important crops, among them alfalfa (Medicago sativa). Using Medicago truncatula as a model for studying resistance and susceptibility to V. alboatrum, previous work has identified genetic variability and major resistance quantitative trait loci (QTLs) to Verticillium. In order to study the genetic control of resistance to a non-legume isolate of this pathogen, a population of recombinant inbred lines (RILs) from a cross between resistant line F83005.5 and susceptible line A17 was inoculated with a potato isolate of V. albo-atrum, LPP0323. High genetic variability and transgressive segregation for resistance to LPP0323 were observed among RILs. Heritabilites were found to be 0Á63 for area under the disease progress curve (AUDPC) and 0Á93 for maximum symptom score (MSS). A set of four QTLs associated with resistance towards LPP0323 was detected for the parameters MSS and AUDPC. The phenotypic variance explained by each QTL (R 2 ) was moderate, ranging from 4 to 21%. Additive gene effects showed that favourable alleles for resistance all came from the resistant parent. The four QTLs are distinct from those described for an alfalfa V. albo-atrum isolate, confirming the existence of several resistance mechanisms in this species. None of the QTLs co-localized with regions involved in resistance against other pathogens in M. truncatula.

To select the superior parents for the breeding program we oriented to produce new early-ripening cultivars, we evaluated more than 60 productive and vegetative characters in 108 native and imported cultivars grown in national collection for commercial apples located in Karaj, Iran, using an apple descriptor. The germination percentage of 100,000 hybrid seeds was 7% in the first year. In the second year, only 3000 from 7000 seedlings had to pass the final screening. Use of morphological markers as an early selection technique showed high efficiency in the apple breeding program. This study was conducted to determine heritability of certain morphological traits potentially used for selection of fruit early-ripening progenies in apple (Malus ×domestica Borkh.). Morphological traits in 3- and 4-year-old seedlings from 28 half-sib and 16 full-sib families were studied in 2007 and 2008, respectively. Parent–progeny correlations were analyzed using true-to-type progenies and their relative parents, all in the juvenile phase. Significant variations were observed between parental cultivars and half-sib and full-sib progenies for most of the studied traits. Positive correlations were found between seedling height and other morphological characters. A highly significant correlation (r = 0.98) was observed between branch distance along seedling stem and number of branches. The results showed that the heritability varied among the traits, ranging from moderate to high values. A high level of heritability was found in leaf chlorophyll concentration (LCC) and seedling heights in both half-sib and full-sib families. Heritability of half-sib progenies derived from the early-ripening parents was higher than the late-ripening parents. The relatively high heritability estimates for morphological traits, particularly in early-ripening cross combinations, suggested narrow-sense heritability as a criterion for early screening. The progenies of early cultivars exhibited the maximum and minimum heritability for seedling height (0.91) and leaf length (0.56), respectively. Oppositely, in the late-ripening progenies, the maximum and minimum heritability were found in LW and TD traits (0.79 and 0.42), respectively.

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Among nut crops, walnut exhibiting higher phytochemicals and bioactive molecules such as essential fatty acids, fiber, protein, amino acids, biogenic amines, phytosterols, vitamins E, B 1 , B 2 , B 6 , and phenolic compounds which are valuable for human health (Jahanban-Esfahlan et al., 2019;Jahanbani et al., 2018).Walnut kernels have the highest antioxidant activity in compare with the other nuts and dried fruits because they contain 120 phenolic compounds accompanying with other ROSs scavenging phytochemical molecules which show significant antioxidant po-

To investigate the effects of individual chromosomes on freezing resistance, as well as their interactions with the genetic background, reciprocal sets of chromosome substitution lines between two hard red winter wheat cultivars, ÔCheyenneÕ and ÔWichitaÕ, were used in this study. Duplicate lines for each chromosome were included to check background homogeneity. Two experiments were carried out in complete block designs with two replications for each duplicate. Crown and leaf water content and leaf wet weight were measured in the field experiments. Crown survival, electrolyte leakage and 50% lethality temperature (LT50) were measured in the laboratory. The results showed that ÔCheyenneÕ was more resistant than ÔWichitaÕ. Crown survival was significantly correlated with crown water content, crown wet weight and electrolyte leakage. Chromosomes 6A, 3B and 5D substituted from ÔWichitaÕ into ÔCheyenneÕ (ÔCNN-WIÕ), decreased the crown survival, and increased membrane stability, crown water content and crown wet weight of ÔCheyenneÕ. Thus, these chromosomes from ÔWichitaÕ decreased freezing resistance in ÔCheyenneÕ. Reciprocally, chromosomes 5A, 5D, 3B and 4D from ÔCheyenneÕ into ÔWichitaÕ increased crown survival and decreased crown water content and crown wet weight of ÔWichitaÕ. It was concluded that these chromosomes from ÔCheyenneÕ cause freezing resistance in ÔWichitaÕ and carry freezing-resistance genes.