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Mirko Siragusa, Fabio De Pasquale, Loredana Abbate and Nicasio Tusa

A collection of 18 accessions of sour orange (Citrus aurantium L.) coming from Sicily and other countries was investigated by two polymerase chain reaction (PCR)-based DNA marker technologies. Ten inter-simple sequence repeat (ISSR) primers and fifteen randomly amplified polymorphic DNA (RAPD) primers were used to identify and to evaluate the genetic variability and relationship of accessions. A total of 111 ISSR and 145 RAPD amplified fragments were used to estimate the Dice's coefficient of similarity for cluster analysis using a unweighted pair-group method using an arithmetic averaging (UPGMA) algorithm. The genetic relationships identified using ISSR and RAPD markers were highly concordant, such that the correlation between ISSR and RAPD genetic distance (GD) estimates was r = 0.93. The ISSR and RAPD analysis of 18 sour orange accessions found a high grade of genetic diversity in foreign accessions, while a low variability was detected in local accessions. Sicilian accessions could be grouped in two distinct clusters, including indistinctly plants from three origin regions. Some markers could be linked to the different growing areas. The ISSR and RAPD molecular reference system seems to be suitable for a fine identification of tightly related plants and the obtained results can form the basis for future setting up of Citrus rootstock genetic improvement projects.

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Enrique I. Sánchez-González, Adriana Gutiérrez-Díez and Netzahualcóyotl Mayek-Pérez

genotypes. Therefore, the objective of this study was to assess the outcrossing rate and genetic variability in progenies of Mexican race avocado genotypes by SSR and ISSR markers, which will enable the establishment of new strategies for the conservation

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Amanda J. Hershberger, Tracie M. Jenkins and Carol Robacker

indigenous to the southeastern United States: S. marilandica and the federally endangered Spigelia gentianoides ( Gould, 1997 ). To aid recovery of S. gentianoides , research on the genetic variability of the natural populations of this species has been

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Yeun-Kyung Chang, Richard E. Veilleux and Muhammad Javed Iqbal

hybrids for market demands. Despite the economic importance of Phalaenopsis , the genetic potential of Phalaenopsis has not been fully exploited. An assessment of genetic variability is important for the use of genetic resources and for determining

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Rolland Agaba, Phinehas Tukamuhabwa, Patrick Rubaihayo, Silver Tumwegamire, Andrew Ssenyonjo, Robert O.M. Mwanga, Jean Ndirigwe and Wolfgang J. Grüneberg

bioavailability of products processed from yam beans merit further research. More information on Fe in yam bean is required to determine if this trait merits breeding effort. Literature Cited Abinasa, M. Ayana, A. Bultosa, G. 2011 Genetic variability, heritability

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Abe Shegro Gerrano, Patrick Olusanmi Adebola, Willem Sternberg Jansen van Rensburg and Sonja Louise Venter

, however, requires information on the genetic variability that exists among available germplasm. Information on the genetic heritability and genetic advance of the targeted traits is also important for efficient selection. This study was therefore carried

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Long Ma, Kevin E. Kenworthy, Huangjun Lu and Ronald Cherry

heritability estimates of common carpetgrass Crop Sci. 48 2017 2025 Greene, N. Kenworthy, K. Quesenberry, K. Unruh, J. Sartain, J. 2008b Diversity and relatedness of common carpetgrass germplasm Crop Sci. 48 2298 2304 Hallauer, A.R. 1970 Genetic variability for

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Eric J. Votava and Paul W. Bosland

Random amplified polymorphic DNA (RAPD) analysis can provide a means of evaluating and comparing genetic variability within cultivars. The purpose of this study was to evaluate the relative genetic variability between accessions of two open-pollinated bell pepper cultivars: 'California Wonder', an heirloom cultivar, and 'Jupiter', a modern cultivar. RAPD molecular markers were used to assess the genetic variability between accessions of these two cultivars. The high levels of genetic variability found among accessions of 'California Wonder' may preclude its use as a standard cultivar in research.

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S. Wolf, Y. Lensky and N. Paldi

Fruit and seed set in insect-pollinated agricultural crops rely primarily on honeybees because of their ease of management and transportation. In many fruit and vegetable crops, the number of bee visitations can be the limiting step in obtaining optimal yield. Increasing the attractiveness of flowers to honeybees could, therefore, provide a useful means of improving fruit yield and seed production. Genetic variability in attractiveness to honeybees was found within the genus Citrullus. The number of daily visits per flower ranged from six to 12 among cultivars. Moreover, most of the visits to the more attractive cultivars occurred in the first hour of bee activity, whereas visits to the less attractive cultivars started later in the morning. A positive relationship was found between the frequency of bee visitations and seed number per fruit. Analyses of floral attributes indicated no genetic variability in flower size, amount of pollen grains, or nectar volume; however, differences were observed in the concentration of sucrose and total sugars in the nectar. A positive relationship was found between attractiveness to bees and nectar sugar concentration, suggesting that this characteristic is one of the parameters responsible for variability in attractiveness to honeybees.

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Zhanao Deng, Jinguo Hu, Fahrettin Goktepe, Brady A. Vick and Brent K. Harbaugh

Cultivated caladiums are valued for their bright colorful leaves and are widely used in containers and landscapes. More than 1500 named cultivars have been introduced during the past 150 years, yet currently only about 100 cultivars are in commercial propagation in Florida. Caladium tubers produced in Florida account for 95% of the world supplies. Loss of caladium germplasm or genetic diversity has been a concern to future improvement of this plant. In addition, the relationship among the available cultivars, particularly those of close resemblance, has been lacking. This study was conducted to assess the genetic variability and relationship in commercial cultivars and species accessions. Fifty-seven major cultivars and 15 caladium species accessions were analyzed using the target region amplification polymorphism marker technique. This marker system does not involve DNA restriction or adaptor linking, but shares the same high throughput and reliability with the amplified fragment length polymorphism system (AFLP). Eight primer combinations amplified 379 scorable DNA fragments among the caladium samples. A high level of polymorphism was detected among the species accessions as well as among cultivars. These markers allowed differentiation of all the cultivars tested, including those hardly distinguishable morphologically. Clustering analysis based on these DNA fingerprints separated the cultivars into five clusters and Caladium lindenii far from other caladium species. The availability of this information will be very valuable for identifying and maintaining the core germplasm resources and will aid in selecting breeding parents for further improvement.