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Abstract
Three-week old plants of 10 cantaloupe varieties grown in 3-inch peat pots were transplanted to the field from April 15 to 24 for a S-year period. Field seeded plots were direct seeded the same day and 7-10 days earlier.
The yield and fruit weight from transplants were significantly higher than those from field seeded plants. The total soluble solids content of fruit from transplants averaged more than 2 per cent higher than that of field seeded plants started the same date. When field seeded 7-10 days earlier, the difference was not as great; however, total soluble solids were consisently higher in fruit from transplants. Two factors were possibly responsible for the higher yields, fruit weights, and soluble solids. Because field seeded plants matured later, foliar diseases were more severe and plants were also exposed to additional cloudiness and rainfall.
Fruit of transplants matured approximately 14 days earlier than that of field seeded plants started the same date. When field seeding was accomplished 7-10 days before transplanting, fruit from field seeded plants matured only 7-10 days after the transplants.
The Chinese chestnut (Castanea mollissima) has been cultivated in China for more than 1000 years. During this period, indigenous cultivars and traditional cultivation practices have been used. China is the leading producer of Chinese chestnut (Castanea mollissima) with 37% of the world' s production. In the last 4 years, improved cultivars and improved cultural practices have resulted in marked increases in production.
The leading provinces in Chestnut production are Hopei, Hubei, and Shandong. Severe injury, crop losses and tree mortality have resulted from the chestnut gall wasp in China Yields have increased greatly in Hubei province through cooperative breeding and developmental research between the Department of Horticulture Auburn University and the Hubei Academy of Agricultural Sciences. Two resistant seedlings from Auburn University are being utilized to save the chestnut industry in China and possibly worldwide.
The Chinese chestnut (Castanea mollissima) has been cultivated in China for more than 1000 years. During this period, indigenous cultivars and traditional cultivation practices have been used. China is the leading producer of Chinese chestnut (Castanea mollissima) with 37% of the world' s production. In the last 4 years, improved cultivars and improved cultural practices have resulted in marked increases in production.
The leading provinces in Chestnut production are Hopei, Hubei, and Shandong. Severe injury, crop losses and tree mortality have resulted from the chestnut gall wasp in China Yields have increased greatly in Hubei province through cooperative breeding and developmental research between the Department of Horticulture Auburn University and the Hubei Academy of Agricultural Sciences. Two resistant seedlings from Auburn University are being utilized to save the chestnut industry in China and possibly worldwide.
Observations made during 3 six week periods of cooperative breeding and development research between the Department of Horticulture, Auburn University and the Hubei Academy of Agricultural Sciences indicates that different valuable germplasm of many fruits are present in China. Such cooperation provides the opportunity for the exchange of enhanced germplasm and cultivars to improve many of the horticulture crops of America and China. Resistance to diseases and insects and tolerance to drought, heat and nutrition stresses are found in the material.
The crops that appear to have the most immediate potential are the citrus with cold hardiness, kiwi of many improved types, pears of many types with fire blight resistance to chestnut blight and chestnut gall wasp, plums and plumcots with resistance to borers and many other crops such as raspberry, hawthorn, thorn pear and wolfberry.
The watermelon has been cultivated in China for more than 1000 years. During most of this period, indigenous cultivars and traditional cultivation practices were used. In the last decade, many improved cultivars have been developed and the use of plastic mulch and other improved cultural practices have been utilized. China has become the largest producer of watermelons with the production area increasing to 1 million hectares and 15 million tons in 1988.
Watermelons are grown in almost all production areas of China. The production areas are: the Northwest inland dry region, the North China plain region, and the Changjiang (Yantzi river) valley rainy region. Severe injury and crop losses occur from Fusarium wilt, (Fusarium oxysporium v. niveum) anthracnose (Colletotrichum laginarium), and gummy stem blight (Didymella bryonaea). Cooperative breeding and developmental work was initiated between the Dept. of Horticulture, Auburn University and the Hubei Academy of Aggricultural Science and the Hubei Agricultural College, Jing Zhou to evaluate cultivar and germplasm and to develop multiple disease resistant melons that produce high yields of excellent quality fruit.
The American or Allegeny chinquapin (Castanea pumila) is native to the same area of the United States as the American chestnut (C. dentata) from Florida to Canada and westward to Arkansas. The high-quality nuts are an excellent source of food for wildlife and humans. Resistance to chestnut blight (Cryphnuectria parasitica) was discovered in seedlings in virgin forest at Elgin Air Force Base, Fla., with observations of plants for 35 years. A recurrent selection breeding program was established at Auburn Univ. to improve the blight resistance, precocity, dwarfism, pest resistance, cold hardiness, yield, and quality. A number of seedlings appear to be very promising selections for improvement of the American chinquapin. Since there is little information available regarding hereditability of certain traits in perennial tree species, results of breeding at Auburn Univ. should provide us with guidance for further improvement of the American chinquapin.
Abstract
Inheritance of resistance to Colletotrichum lagenarium (Pass.) Ell. & Halst. race 2 in watermelon (Citrullus lanatus (Thunb.) Matsum & Nakai) was determined in progeny from crosses between resistant plant introductions (PIs) 189225, 271778, and 326515 and susceptible cultivars ‘Charleston Gray’, ‘Jubilee’, ‘Crimson Sweet’ and AWB-10 advanced line. Parents and progenies were screened for resistance in field and greenhouse plantings. Resistance of F1 plants indicated resistance was dominant. The F2 plants segregated 3 resistant: 1 susceptible. The backcross of the F1 to the susceptible parent segregated 1:1. Resistance in all Pis tested was controlled by a single dominate gene pair.
Abstract
Diseases, particularly gummy stem blight [Didymella bryoniae (Auersw.) Rehm], downy mildew [Pseudoperonospora cubensis (Berk, and Curt.) Rostow], and powdery mildew [Sphaerotheca fuliginea (Schlecht) Poll], are major factors limiting production of muskmelon in the southern United States (Anonymous, 1962; Chiu, 1948; Ellis, 1951; Norton and Prasad, 1965; Prasad and Norton, 1967; Winstead et al., 1960). Severe economic losses have been reported in the field, in transit, and in storage. Although satisfactory control of gummy stem blight (GSB), downy mildew (DM), and powdery mildew (PM) may be accomplished with the proper application of organic fungicides during normal weather conditions, chemical control is not effective during periods of high humidity and rainfall. Furthermore, only three cultivars—Chilton, Gulfcoast, and AU-rora-are reported to be resistant to GSB (Norton, 1971; Norton, 1972; Norton et al., 1985). The discovery that plant introduction 140471 had a high level of resistance to GSB (Sowell et al., 1966) led to the initiation of an Alabama Agricultural Experiment Station muskmelon breeding program to develop multiple disease-resistant breeding lines with high yields of excellent-quality fruit (Norton and Prasad, 1965; Prasad and Norton, 1967).
Abstract
Progeny from a hybridization of C. melo L. (PI 140471), a feral Cucumis melo, with the nematode-resistant African horned cucumber (C. metuliferus E. Mey.) (PI 292190) were screened for resistance to Meloidogyne incognita acrita Chitwood. Although C. metuliferus exhibited resistance, no resistance was observed in PI 140471 nor in the F2 generation after inoculation with a larval suspension having 600 larvae/ml. However, when grown in contact with chopped galled roots, certain progeny appeared to be resistant. Evaluation of egg mass production revealed that the resistant plants produced significantly fewer eggs than susceptible plants.
The Chinese chestnut (Castanea mollissima Blume) is a valuable germplasm resource for horticultural traits such as resistance to chestnut blight (Cryphonectria parasitica), excellent quality, wide adaptation, and consistent high yield. The Chinese chestnut breeding program was established at Auburn Univ. in 1933 from nuts directly introduced from China by the USDA. A recurrent selection breeding program with progeny from the 1933, 1953, and 1991 plantings with selection for blight resistance, precocity, nut size, and storage quality, yield, and pest resistance. Cultivars released from the 1933 planting were `Alaling,' `Alamore', and `Black Beauty'. `AU-Cropper', `AU-Leader', and `AU-Homestead' were named from the 1953 planting. Two blight-resistant, precocious seedlings, AU-91-P1-26 and AU-P4-26, appear to be very promising selections for improvement of all Chinese chestnut cultivars for nut size and other selection traits. Since there is little information available regarding heritability of certain traits in perennial tree species, results of 65 years of breeding at Auburn Univ. should provide us with guidance for further improvement of selection traits in chestnut breeding.