Search Results
Abstract
Adaptation to upland soils was investigated in a diallel study involving progeny of 4 blueberry (Vactinium) clones consisting of 1 highbush blueberry (V. corymbosum L.) clone and 3 interspecific hybrids. Both general and specific combining ability were significant. Seedling progenies of NJUS 11 (V. ashei × V. atrococcum) and US75 (V. darrowi × V. corymbosum) grew well on an upland soil. Although not included in the diallel crosses, NJUS 64 (V. myrsinites × V. angustifolium) progenies also grew well on upland soil.
Abstract
‘Lester’ strawberry (Fragaria × ananassa Duchesne) was bred and selected to overcome a serious fault (red stele root rot susceptibility) of its productive, high-quality ‘Raritan’ parent, a major cultivar in the northeastern United States. ‘Lester’ offers strawberry growers of this region a cultivar that is resistant to red stele root rot, has attractive, good quality fruit, and ripens 2 to 3 days before ‘Raritan’. The cultivar was named for Lester W. Greeley of Farmington, N.H., who recently retired from the USDA, where he was associated with small grain, vegetable, and small fruit improvement programs for a period spanning more than 30 years. Greeley first noted the consistent plant and fruit production and high fruit recovery (often >90% marketable) of the selection later named in his honor.
Abstract
Fifty seedlings each of 8 tetraploid interspecific populations involving 6 Vaccinium species were examined for date of flowering, date of fruit ripening, fruit yield, color, firmness, and size. The 8 progenies contained from 25 to 75% highbush blueberry (V. corvmbosum L.) germplasm. There were significant differences among the 8 populations for all fruit characters and for the number of days from bloom to ripe fruit. Only 2 backcross progeny populations (75% high-bush blueberry) produced significant numbers of seedlings that met the selection criteria for 4 fruit characters.
Abstract
Hexaploid Vaccinium hybrid progenies, including F1, F1 intercross, F1 × F2, BC1, BC1 intercross, and BC1 × F2 crosses between V. ashei Reade and V. constablaei Gray, and an intercross between late-blooming V. ashei genotypes, established in the commercial blueberry production area in eastern North Carolina, were compared among themselves and with 2 highbush blueberry (V. corymbosum L.) cultivars for flowering, ripening, primary mummy berry infection, crop, and fruit characteristics. There were significant differences among progenies for all traits, with sufficient variability for selection within most progenies. Differences reflected specific parent combinations rather than type of cross with the V. ashei–V. constablaei derivative progenies. The experiment included both V. ashei and V. ashei–V. constablaei derivative progenies that produced a high percentage of seedlings flowering with or later than highbush blueberries. Two percent of the V. ashei–V. constablaei derivative seedlings bloomed and ripened with the early ripening highbush cultivar ‘Croatan’. Crop ratings were variable in all progenies, and high sds for the cultivars indicated that a high percentage of the variation was environmental. Primary mummy berry infection significantly reduced the crop in several progenies but was not responsible for the poor overall crop performance of most. Mean fruit size of the V. ashei intercross was large enough for hand harvest, while all but the 2 smallest-fruited V. ashei- V. constablaei derivative progenies were large enough for mechanical harvesting. Fruit of most progenies were commercially acceptable for color, picking scar, firmness, and flavor.
Abstract
Young highbush blueberry seedlings (Vaccinium corymbosum L.) from 26 crosses of a partial diallel were inoculated with Phytophthora cinnamomi Rands by dipping the roots into a mycelial slurry. The seedlings were grown 90 days in sand in the greenhouse and rated for resistance to root rot damage. Of the 2412 inoculated seedlings, 214 (8.9%) were resistant. The 2 parental clones that produced the largest percentage of resistant seedlings were US 141 and G-164; within their progenies, each produced an average of 18% resistant seedlings. Mean squares for general (GCA) and specific combining ability (SCA) were significant at the 1% and 5% levels, respectively. The mean square estimate for GCA was about 5 times higher than that for SCA, While both additive and nonadditive effects are important, rapid improvement can be made by phenotypic selection. Resistance to P. cinnamomi in blueberry progenies studied appears to be partially recessive and quantitatively inherited. Inoculation of young seedlings by root dipping in a mycelial slurry of P. cinnamomi and growing the seedlings in sand provided rapid identification of resistant plants.
Abstract
‘Allstar’ is a vigorous and productive Junebearing strawberry (Fragaria × ananassa Duch.) that produces very large, firm fruit of good quality in late midseason. It is the most recent introduction in a series of red stele root rot-resistant cultivars developed in the cooperative strawberry improvement program of the U.S. Department of Agriculture and the University of Maryland. ‘Allstar’ combines multiple-race resistance to red stele incited by Phytopthora fragariae Hickman with resistance to other root and leaf diseases, has unusually broad adaptation within the eastern United States, and performs well under a number of cultural regimes. Its name implies superior performance under diverse soil, climatic and cultural conditions.
Abstract
‘Hull Thornless’ (Rubus sp., is a vigorous and productive thornless blackberry cultivar with firm, sweet, fruit. It is named for the late John W. (Jack) Hull, formerly of the University of Maryland, the University of Arkansas, and the U.S. Department of Agriculture, who spent most of his life breeding blackberries and raspberries. ‘Hull Thornless’ is the fifth in a series of tetraploid, genetically thornless blackberry hybrids developed by the USDA and cooperating agencies (4). It is adapted principally to USDA Plant Hardiness Zones 6-8.
Abstract
‘Bluechip’ is a cane canker-resistant midseason cultivar of highbush blueberry (Vaccinium corymbosum L.). It has very large fruit, excellent color, stem scar, firmness, and a pleasant acid flavor. The name is intended to suggest that this cultivar possesses exceptionally desirable fruit flavor and texture. Released cooperatively by the North Carolina Agricultural Research Service and the U.S. Department of Agriculture, ‘Blue-chip’ is intended principally for fresh fruit production in areas subject to cane canker caused by Botryosphaeria corticis (Demaree & Wilcox) Arx & Muller.