We have developed improved procedures for recovery of haploid and doubled haploid (DH) melon plants, using hybrids derived from crosses of lines with multiple virus resistance. Seeds formed after pollination with irradiated pollen were cultured in liquid medium for 10 days before excision of the embryos for further culture. This made it easier to identify the seeds containing parthenogenetic embryos, thereby reducing the effort required and increasing the percentage of plants recovered. The plants obtained (approximately 175) were transferred to a greenhouse for evaluation. Three fertile lines were identified, and selfed seeds were obtained for evaluating virus resistance. Flow cytometry of leaf tissues showed that two of these lines were spontaneous DH and the third was a mixoploid containing haploid and diploid cells. The other plants remained sterile through the flowering stage. Flow cytometry of 20 sterile plants showed that all were haploid. Attempts to induce chromosome doubling by applying colchicine to greenhouse-grown plants were unsuccessful. Shoot tips from the haploid plants were used to establish new in vitro cultures. In vitro treatment of 167 micropropagated haploid shoots with colchicine produced 10 diploid plants as well as 100 mixoploid plants. Pollen from male flowers that formed in vitro on the colchicine-treated plants was examined. High percentages of viable pollen that stained with acetocarmine were found not only in the diploids but also in >60% of the plants scored as mixoploid or haploid by flow cytometry. Efficient recovery of DH from hybrid melon lines carrying combinations of important horticultural traits will be a valuable tool for melon breeders.

‘Marketmore 97’ is the most recent addition to a series of disease-resistant slicing cucumbers developed in the Cornell University Department of Plant Breeding. The fruit have green skin with white spines and an average length and diameter of 18.8 cm and 4.8 cm, respectively. Broad resistance to a number of destructive diseases and insects makes this cultivar well-suited to low-input agricultural systems at the scale of the home gardener or the commercial grower. In addition to the cucumber mosaic virus (CMV), cucumber scab (Cladosporium cucumerinum Ell. & Arth.), downy mildew (Pseudoperonospora cubensis Berk & Curtis), and powdery mildew (Sphaerotheca fuliginea Schl. ex Fr.) resistances of ‘Marketmore 76’, ‘Marketmore 97’ contains resistance to alternaria leaf spot [Alternaria alternata (Fr.) Keis.], Ulocladium leaf spot (Ulocladium cucurbitae Let. & Roum.), target leaf spot (Corynespora cassiicola Berk. & Curt.), watermelon mosaic virus, papaya ringspot virus, and zucchini yellow mosaic virus. Furthermore, the bitterfree character of this cultivar is responsible for nonpreference of the striped cucumber beetle (Acalymma vittatum Fab.) and spotted cucumber beetle (Diabrotica undecimpunctata howardi Barber). Finally, a near isogenic line of ‘Marketmore 97’ is available that is gynoecious. A replicated trial of ‘Marketmore 97’ conducted in New York in 2006 confirmed comparable yield and quality to other Marketmore cultivars.

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`PMR Delicious 51' is a new and improved version of the `Delicious 51' eastern type melon (Cucumis melo L.). It was developed in the Department of Plant Breeding at the Cornell University Agricultural Experiment Station in Ithaca, N.Y. It is well adapted for northeastern U.S. conditions and shows potential for good adaptation in the northwest. It is well suited for home gardeners, market gardeners, and commercial growers who want to grow an open-pollinated (OP) melon. `PMR Delicious 51' has excellent resistance to powdery mildew races 1 and 2 (Podosphaera xanthi) and resistance to fusarium wilt (Fusarium oxysporum f. sp. melonis) race 2.

`Hannah's Choice F1' is a new, high quality eastern type muskmelon (Cucumis melo L.) with multiple disease resistance. It was developed in the Department of Plant Breeding at the Cornell University Agricultural Experiment Station in Ithaca, N.Y. It is well adapted for northeastern U.S. conditions and shows potential for good adaptation in the northwest. With multiple disease resistance it is well suited for home gardeners, market gardeners, and commercial growers. `Hannah's Choice F1' has excellent resistance to powdery mildew races 1 and 2 (Podosphaera xanthi) and some tolerance to Fusarium root rot (Fusarium oxysporum f. sp. melonis) race 2. In addition, it has resistance to watermelon mosaic virus (WMV), papaya ringspot virus (PRSV), and zucchini yellow mosaic virus (ZYMV). This is the first commercial melon to have combined resistance to these three potyviruses. Also, it has shown some field tolerance to spider mites (Tetranychus urticae). Lastly, it has shown some field tolerance to downy mildew (Pseudoperonospora cubensis), angular leaf spot (Pseudomonas syringae pv. lachrymans), and gummy stem blight (Didymella bryoniae). In 2001, 2002, and 2003 it was grown in replicated trials in New York and in 2002 and 2003 in Oregon.