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L. Bosch, F. Casañas, E. Sánchez, M. Pujolà, and F. Nuez

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Maria Jose Gonzalo, Elisabet Claveria, Antonio J. Monforte, and Ramon Dolcet-Sanjuan

morphological marker to discard hybrids produced by fertile M40 pollen. All the plant material, inbred lines, F 1 hybrids, and the monoecious pure line M40 were provided by Semillas Fitó (Barcelona, Spain), and because they are proprietary material, the

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Elisabet Claveria, Jordi Garcia-Mas, and Ramon Dolcet-Sanjuan

Homozygous doubled haploid lines (DHLs) from new cucumber (Cucumis sativus L.) accessions could be useful to accelerate breeding for resistant varieties. DHLs have been generated by in vitro rescue of in vivo induced parthenogenic embryos. The protocol developed involves the following: 1) induction of parthenogenic embryos by pollinating with pollen irradiated with a Co60 γ-ray source at 500 Gy; 2) in vitro rescue of putative parthenogenic embryos identified by their morphology and localized using a dissecting scope or X-ray radiography; 3) discrimination of undesirable zygotic individuals from the homozygous plants using cucumber and melon SSR markers; 4) determination of ploidy level from homozygous plants by flow cytometry; 5) in vitro chromosome doubling of haploids; and 6) acclimation and selfing of selected lines. Codominant markers and flow cytometry confirmed the gametophytic origin of plants regenerated by parthenogenesis, since all homozygous lines were haploids. No spontaneous doubled haploid plants were rescued. Chromosome doubling of haploid plants was accomplished by an in vitro treatment with 500 μm colchicine. Rescue of diploid or chimeric plants was shown by flow cytometry, prior to their acclimation and planting in the greenhouse. Selfing of colchicine-treated haploid plants allowed for the perpetuation by seed of homozygous lines. The high rate of seed set, 90% of the lines produced seed, facilitated the recovery of inbred lines. Despite some limiting factors, parthenogenesis is routinely used in a cucumber-breeding program to achieve complete homozygosity in one generation. Breeding for new commercial hybrid cultivars will be accelerated. DHLs are ideal resources for genomic analyses.

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Yan Yao, Yao Kong, Ping Zhang, Hua Zhang, Hong-di Huang, and Guang-guang Li

special vegetables in China. To satisfy the requirements for the breeding and genetic studies, a fast pure-line production procedure might prove important. Pure-line segregating populations are essential for plant breeding and genetic studies. Doubled

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Mark J. Bassett and Phillip N. Miklas

‘Painted Lady’ (Phaseolus coccineus L.) has bicolor flowers with vermilion banner petal and white wing petals. This flower color pattern is not known in common bean (P. vulgaris L.). The bicolor trait was backcrossed into common bean and its inheritance investigated, including allelism tests with other genes in common bean (T, P, and V) for flower color or pattern and brown seed coat. A pure line (line 33) with bicolor flower and dark olive brown seed coat was crossed to line 5-593 (no flower pattern and black seed coat). Data from the F2 and F3 progenies from that cross demonstrated that a single recessive gene controlled both the bicolor flower and dark olive brown seed coat by pleiotropic gene action. Allelism tests between the bicolor trait (line 179c) and standard genetic tester stocks involving the T, P, V, and Wb (white banner) genes for flower color or seed coat color demonstrated independence of bicolor from those genes and further supported the hypothesis of pleiotropic action on flower and seed coat. Also, the Wb gene was demonstrated to be independent of T and P. The gene symbol bic is proposed for the bicolor gene.

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Wei-Ling Chen and Hsueh-Shih Lin

-consuming when evaluating and recombining progeny selection ( Hallauer et al., 2010 ). Alternative selection systems, pure-line and mass selection, which have shown efficiency in autogamous crops, were suggested for high heritable traits ( Allard, 1960 ). The

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Nirmal K. Hedau, Shri Dhar, Vinay Mahajan, Pawan K. Agarwal, and Jagdish C. Bhatt

‘VL Tamatar 4’ ( Solanum lycopersicum or Lycopersicon esculentum Mill.) is a new tomato cultivar released for Agro-ecological Zone I (Uttarakhand, Northwest Himalaya, India). It was developed by a pure-line selection method from the exotic

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James L. Brewbaker

Brewbaker, 1994 ) as a multipurpose legume tree (forage, hardwood, fuelwood, shade, green manure). The pure-line bred from K636 also served as the parent of the widely grown forage cultivar Tarramba from Australia ( Dalzell et al., 2006 ). The male parent of

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Howard F. Harrison Jr., D. Michael Jackson, Judy A. Thies, Richard L. Fery, and J. Powell Smith

(Chitwood) Kofoid and White] resistance, and they do not produce seeds with impermeable seedcoats. Origin Lines US-1136, US-1137, and US-1138 were produced from landrace populations using a pure line selection procedure. In 1997, field screening trials were

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Wei-Ling Chen, Cheng-Hung Hsiao, and Hsueh-Shih Lin

subtropical and tropical climates ( Kuo, 1999 ). Because of its self-incompatibility, radish is cross-pollinated, which results in a high level of genetic variation ( Muminovic et al., 2005 ). During breeding, mass selection is generally inefficient, and pure-line