Since the 1980s, there has been consistent progress in breeding and selection of cold-hardy, disease-resistant grape cultivars that are adapted to the cool, humid climates of the eastern and central United States. Many of these cultivars are based
factors could be minimized and the results would be more broadly applicable. Our first screening project involved primarily common rootstocks and other citrus selections ( Castle and Manthey, 1998 ). The selections ranked in terms of Fe 3+ reduction rates
breeding. Recent reports revealed not all grapefruit and pummelo cultivars contain high level of FCs ( Widmer, 2005 ; Widmer and Haun, 2005 ); some selections and low acid mutants have undetectable (read zero) or little amount of the components. Currently
Realized heritability estimates of bolting percentage, pink root and fusarium basal rot severities and incidences, and percentage of single-centered bulbs were estimated for half-sib families of an intermediate-day, open-pollinated onion (Allium cepa L.) population using selection response analysis. Half-sib families were selected based upon an index that equally weighted bolting percentage, pink root and fusarium basal rot severities and incidences, percentage of single-centered bulbs, and bulb quality. Families were subjected to one cycle of half-sib family recurrent selection. Pink root and fusarium basal rot severity was reduced by 17% and 7%, respectively, with realized heritability estimates of 1.28 and 0.65, respectively. More progress for pink root severity was made than was selected. Disease incidence was reduced by 18% and 12%, respectively, with heritability estimates of 0.65 and 0.60, respectively. Very little progress was made for the percentage of single-centered bulbs and this was reflected in a heritability estimate of 0.17. Selection based upon multiple characters at the same time may reduce the effectiveness of making improvements in a single trait. However even with low to moderate heritability, improvements were made, and suggest that further improvements can be made through selection.
A heterogeneous cucumber (Cucumis sativus L.) population (mostly gynoecious) was evaluated at five locations for single-plant fruit yield at the mature-fruit stage in 1981. Seeds from the highest-yielding plants were then harvested, combined, and partitioned into five lots. Seeds were combined such that each location received only the superior genotypes from the other four locations. This procedure was continued for an additional four cycles using two types of selection: single-plant selection for fruit number at the mature-fruit stage (1981–82) and half-sib family selection at the once-over harvest stage (1983–84). In 1985, yield improvement from selection was measured by compositing the seeds of the selected plants or families from each of the four cycles and five locations and planting them at the five locations. No progress was made for total, marketable, or early yield. Percentage of culls was reduced an average of 0.7% per cycle. Genotype by environment interaction among the diverse locations may have prevented progress for yield.
Bruce 12-4 is a plum selection released for breeding purposes that possesses an unusual combination of disease resistance, tree longevity, cold hardiness and other characteristics. The seedling requires chilling of 700 hr of temperature below 7.2°C (45°F). This seedling has consistently produced high yields of fruit in central Alabama (Fig. 1).
A study was conducted to investigate the extent of genetic variations and the interrelationships of several quality traits of cultivars of navy and pinto bean (Phaseolus vulgaris L.) grown at 3 locations in Michigan. The measured traits were seed weight, initial weight of solids, surface color of dry and processed beans (L, aL, bL), weight of soaked beans, hydration ratio, clumps, splits, texture, washed and drained weight, and processed bean moisture. Significant cultivar differences were observed for most of the traits in both classes of beans. Location effects were highly significant for all traits. Certain traits showed significant cultivar × location interactions. Phenotypic correlation coefficients among pairs of characters indicated that, with few exceptions, there were low assocations among quality characters. Principal component analysis confirmed the independence of traits. A selection strategy based on a tandem selection procedure followed by construction of selection indices was suggested.
(NTEP), including the 2007 and 2013 National Bermudagrass Tests ( NTEP, 2007 , 2013 ). In addition, three OSU experimental lines were included in this test: OKS 2009-3, OKS 2011-1, and OKS 2011-4. These latter three selections were included because of
and five- to 25-fold, respectively. Based on their results, and comparing their data with the contrasting observations from other rose salinity studies, Cabrera and Perdomo (2003) contended that rootstock selection was a key factor involved in
-used cultivars were ‘Strawberry Festival’ and ‘Florida Radiance’, which occupied ≈60% and 10% of planted acreage, respectively. The UF strawberry breeding program has sought to improve fruit quality attributes over time through phenotypic recurrent selection