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Sweet corn is one of the most important vegetable crops in the United States, however the morphology and phylogeny of open-pollinated sweet corn cultivars has not been studied. Fifty eight open-pollinated sweet corn cultivars were characterized with thirty-four descriptors to provide information for breeders interested in broadening the genetic base of sweet corn. Principal component analysis and cluster analysis were performed to classify sweet corn cultivars based on morphology. Also, relationships among morphological variables in this set of cultivars were determined. The general ordination of cultivars followed an axis representing earliness, and plant, leaf, and tassel size, while ear and kernel attributes were less variable. The morphological variability among all of the widely used sweet corn cultivars, except `Country Gentleman', was not greater than the variability found among the `Golden Bantam' strains. Based on morphology, 52 of the cultivars could be considered as one race, which we propose be called `Northeastern Sweets'. These may be a subset of the race `Northern Flint'. Five of the remaining cultivars are from the north-central or southwestern United States and may represent races from those areas. The sixth cultivar is `Country Gentleman', a commercially important sweet corn cultivar. Due to the importance of `Country Gentleman' and the introgression of nonsweet germplasm into modern sweet corn, we believe that sweet corn should be defined based on its use as a vegetable and on the presence of one or more genes that increase sugar levels in the endosperm.

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hepatoprotective activities ( Alsayari and Wahab 2021 ; Ivanisova et al. 2017 ; Khadivi and Beigi 2022 ; Liu et al. 2022 ; Sapkota et al. 2023b ; Yao et al. 2023 ). Jujube cultivars have a wide variety of traits such as tree size, tree shape, fruit size

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Genetic improvement of peach, a diploid plant species (2n = 16), has resulted in the development of a large number of cultivars ( Fideghelli et al., 1998 ; Okie, 1998 ). Cultivars are classified into non-melting, clingstone types in which the flesh

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More than 170 pecan [Carya illinoensis (Wangenh.) K. Koch] cultivars were evaluated formalate dehydrogenase, phosphoglucose isomerase, phosphoglucomutase, leucine aminopeptidase (LAP), and diaphorase (DIA). Isozymes of LAP were observed in two regions after starch gel electrophoresis. The faster region of activity (Lap-1) was polymorphic and consistently expressed in leaves, wood, and roots. Controlled crosses suggest that Lap-1 is simply inherited and controlled by at least two alleles. DIA was well resolved and storable only from leaf material and produced a complex banding pattern. The ability to differentiate among cultivars by isozymes was good. The 177 cultivars sorted into 72 classes. Forty of the cultivars (23%) possessed a unique series of isozyme patterns. Most cultivars (124 of 177) shared common banding patterns with less than four other cultivars. From the inheritance models of four isozymes, some historical pedigrees can be questioned. Most notably,' Western Schley' could not have been parented by `San Saba' based on the inheritance of Mdh-1 and Lap-1.

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Male and female fertility, seed germination, and progeny fertility were used to determine cultivar fertility in species of Lythrum. One short-, 11 mid-, and six long-styled cultivars were included in this study. Duplicates of several cultivars from different nurseries and three unknown cultivars from Minnesota gardens were also collected. Plants from 17 Minnesota and one Wisconsin population of L. salicaria served as fertile male and/or female testers. Pollen stainability (usually 100%) showed low levels of male gamete abortion. Pollen size within and among anther type varied widely; possible 2n gametes were present in primarily the short- and mid-anther morphs. Seed production per capsule from legitimate cross-pollinations, using cultivars as male parents with Minnesota or Wisconsin female testers, averaged 48 ± 36 across style morphs. Cultivars differed as males, as did anther morphs. With female fertility tests, seed set per capsule ranged from zero to 152 and averaged 54 ± 40 in legitimate pollinations (i.e., pollinations between stamen and styles of the same length). Seed set for other crosses showed similar trends. Only `Morden Gleam' produced no seed with all legitimate pollinations, although illegitimate selfs or interspecific crosses produced seed. Seed from legitimate crosses of L. salicaria × cultivars had 30% to 100% germination. Common male and female parents within each legitimate crossing group were not significantly different. This study showed that the cultivars are highly fertile when used as male or female parents with wild purple loosestrife, native species (L. alatum Pursh.), or other cultivars. Thus, cultivars grown in gardens could serve as pollen or seed sources for the continued spread of purple loosestrife. The implications of cultivar fertility, especially interspecific F1 hybrids, is discussed in relation to the spread of noxious weeds in wetlands.

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of environmental protection between field and greenhouse production systems ( Kadir et al., 2006 ; Heidenreich et al., 2008 ). Most high tunnels in the United States and Canada are used for fall-fruiting primocane cultivars to extend the harvest

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Abstract

Pedigrees of 134 North American strawberry (Fragaria × ananassa Duch.) cultivars introduced since 1960 were used to calculate 1) the genetic contribution of founding clones to these cultivars; 2) genetic relatedness among these cultivars; and 3) inbreeding coefficients of these cultivars. Fifty-three founding clones accounted for the pedigrees of these cultivars, with a mean genetic contribution ranging from <0.1% to 11%. Cultivars were clustered according to the genetic contribution into groups strongly related to geographic region of origin. Cultivars developed in California plus those derived in large part from California germplasm were a distinct cluster. The remaining cultivars divided strongly into two geographical divisions, with cultivars of a western or northern origin primarily in the first division, and cultivars of a southern or eastern origin primarily in the 2nd division. Cluster groups within each division also were related to the region of origin of cultivars. Cultivars also were clustered on the basis of Wright’s coefficient of relationship, a measure of genetic relatedness. Cluster groups from this analysis were strongly related to region of origin of cultivars, and were similar in content to groups based on genetic contributions. Inbreeding coefficients ranged from 0.0 to 0.875, but were <0.5 for all cultivars developed from cross-fertilization. Inbreeding coefficients were related partly to region of origin of the cultivars, but this relationship was probably an indirect result of unequal numbers of generations of controlled hybridization from common ancestors. For example, cultivars developed in California, which resulted from more generations of hybridization, generally had higher inbreeding coefficients. Strategies are suggested for maintaining and increasing genetic diversity of North American breeding populations.

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Dieffenbachia Schott is an important ornamental foliage plant genus. A total of 30 species has been recognized, but most cultivars come from or are related to a single species, D. maculata (Lodd.) G. Don. At least 11 of the cultivars are sports or somaclonal variants. As a result, the potential lack of genetic diversity in cultivated Dieffenbachia has become a concern. However, no research has been conducted to determine the genetic relatedness of the cultivars. This study analyzed the genetic similarity of 42 Dieffenbachia cultivars using amplified fragment length polymorphism (AFLP) markers. Six primer sets, selected from an initial screening of 48, generated a total of 453 scorable AFLP fragments of which 323 (71%) are polymorphic. All cultivars were clearly differentiated by their AFLP fingerprints. A dendrogram was constructed using the unweighted pair-group method of arithmetic averages, and principal coordinated analysis was carried out to show multiple dimensions of the distribution of the cultivars. The 42 cultivars were divided into three clusters; clusters I and II comprise 18 and 23 cultivars, respectively. Jaccard's similarity coefficients for cultivars in the clusters I and II varied from 0.44 to 0.95 and 0.41 to 0.87, respectively. These results indicate that broadening the genetic variability in the Dieffenbachia gene pool is needed, but the genetic similarity of many cultivars is not as close as previously thought. Additionally, Jaccard's similarity coefficients between most sports or somaclonal variants and their parents were 0.73 or lower, suggesting that accumulation of somatic mutations through tissue culture may play a role in the increased variation between some sports or variants and their parents.

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Abstract

Starch gel electrophoresis of leaf tissue samples was used to distinguish pineapple [Ananas comosus (L.) Merr.] cultivars. Isozyme genotypes at two peroxidase and three phosphoglucomutase loci allowed the unique identification of 15 of the 27 cultivars examined. The hypotheses that some cultivars originated as either sports or hybrids were confirmed by the allozyme data.

Open Access

As genetic factors affect strawberry (Fragaria ×ananassa Duch.) fruit development and quality, changes in metabolite concentrations were studied during fruit development of four strawberry cultivars grown in the field: three commercial cultivars (Capitola, Elsanta and Dover) and a genotype from Centre Interrégional de Recherche et d'Expérimentation de la Fraise, France (`CF1116'). Major and minor metabolites changed with development. The two strawberry cultivars with the highest starch content at early stages, `Capitola' and `Elsanta', also had the highest fruit weight at harvest. There was no correlation between strawberry weight and osmolarity. At maturity, significant differences were observed among cultivars for most of the metabolites studied. `Capitola' and `Elsanta' responded similarly for most measured variables. `CF1116' was characterized by high juice osmolarity and high sucrose, inositol, glutamine, arginine and alanine concentrations, and low citrate and malate concentrations. `Dover' was characterized by a high galactose concentration and low asparagine and alanine concentrations. Organic acid differences among cultivars appeared early during development, while differences in soluble sugars appeared during maturation. The developmental pattern of each amino acid varied among cultivars. Timing of the biochemical differences observed among cultivars provides some information on their metabolic origin.

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