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- Author or Editor: Robert J. Griesbach x
Somatic cell genetics is a relatively new discipline which relies upon various plant tissue culture techniques. This discipline may be defined broadly as any genetic or physiological investigation involving cultured cells, and includes such areas as gene transfer, gene regulation, cell selection for genetic variants, control of development, and regulation of metabolism.
Flower color results from the interaction of a pigment (anthocyanin) with a co-pigment (usually a flavonone or flavonol) at a specific pH. At more alkaline pHs (pH 5 to 6), an anthocyanin/co-pigment complex is blue; while at more acidic pHs (pH 3-4), the same anthocyanin/copigment complex is red. In Phalaenopsis pulcherrima, a mutation in pH resulted in a bluer flower color. The difference in pH between the normal-colored magenta flowers (pH 5.8) and mutant violet flowers (pH 5.5) was due to a single co-dominantly inherited gene.
Considerable diversity exists in Capsicum L. germplasm for fruit and leaf shape, size and color, as well as plant habit. This morphological diversity, together with diverse ripe fruit color and varying hues of green to purple and variegated foliar pigmentation, affords myriad opportunities to develop unique cultivars for ornamental applications. The Agricultural Research Service of the United States Department of Agriculture announces the release of a new pepper [Capsicumannuum (L.)] cultivar named `Black Pearl'. `Black Pearl' is intended for ornamental applications and affords growers a new crop to add to their bedding and landscape plant assortment. `Black Pearl' combines black foliage with erect clusters of small round red-pigmented fruit. The vibrant fruit and foliage colors of this new cultivar add interest to the summer and fall garden. Black Pearl' has been trialed extensively for use as a bedding plant where its compact growth habit, black foliage, and brightly colored fruit provide an attractive ornamental display. Limited evaluations suggest that this cultivar is equally well suited for pot culture under high light conditions. `Black Pearl' was designated a 2006 All America Selection award winner after completion of national trials in 2004. `Black Pearl' is a release made available from a cooperative research and development agreement with Pan American Seed Company. Seed of `Black Pearl' is available from Pan American Seed Company, 622 Town Road, West Chicago, IL 60185. Plant Variety Protection for `Black Pearl' is pending.
The U.S. Department of Agriculture’s Agricultural Research Service (ARS) and universities have a long and successful history of developing enhanced germplasm and cultivars that are transferred through public release. Today, nonprotected public release may not be the most appropriate mechanism. Intellectual property (IP) protection as it pertains to the plant germplasm and cultivars is involved and complex. Unlike other scientific areas, in the United States there are three distinct mechanisms to protect plants—namely, utility patents, plant patents, and plant variety protection certificates. Each of these mechanisms offers different criteria for protection and covers different types of plants. This article is a practical tool to help research institutions and scientists decide when to consider releasing a germplasm or cultivar, which factors to consider, who should be involved, and whether IP protection is appropriate.
Considerable diversity exists in Capsicum L. germplasm for fruit and leaf shape, size, and color as well as plant habit. Using F1, F2, and backcross generations developed from diverse parental stocks, this report describes the inheritance patterns and relationships between unique foliar characters and diverse fruit and plant habit attributes. Our results demonstrate that pepper fruit color, shape, and fruit per cluster were simply inherited with modifying gene action. Broad-sense heritability for fruit color and shape and fruit per cluster was high, whereas narrow-sense heritability for these characters was moderate to low. Although fruit clustering was simply inherited, the number of fruit per cluster exhibited a quantitative mode of inheritance. High fruit counts per cluster were linked with red fruit color and anthocyanin pigmented foliage. Fruit shape was linked with immature fruit color and inherited independently of mature fruit color. Leaf color, length, and plant height were quantitatively inherited. Leaf shape did not vary, but leaf length varied and was positively correlated with leaf width. Broad-sense heritability for leaf characters, including leaf length, leaf width, and leaf color, was high. With the exception of leaf width, which exhibited low narrow-sense heritability, high narrow-sense heritability for leaf characters denoted additive gene action. Plant height displayed high broad-sense heritability. Moderate narrow-sense heritability suggested that additive effects also influence plant height. Analysis of segregating populations demonstrated that red and orange fruit color can be combined with all possible leaf colors from green to black. These results provide new data to clarify and extend available information on the inheritance of Capsicum fruit attributes and provide new information on the genetic control of leaf characters and plant habit.
Ornamental peppers are a novel and growing segment of the ornamentals industry. Currently available varieties are utilized as pot plants and in bedding plant applications. Utilizing unimproved populations developed from initial crosses with Indian Capsicum land races, germplasm lines with unique gene combinations for multiple fruiting, fruit orientation, leaf pigmentation and leaf variegation were developed and released by USDA-ARS. Via introgression of diverse Capsicum species accessions and heirloom varieties into these populations, more recent efforts seek to exploit abundant genetic variation for fruit shape, size, color and pungency, foliar attributes, and plant growth habit to develop new pepper germplasm for ornamental and dual ornamental/culinary applications. Fruit pungency of selected material may range from mild to extremely pungent. Fruit shape may be round, conical, or lobed. Whereas small fruit size is generally well suited for ornamental applications, ornamental/culinary types exploit larger upright conical or small bell-shaped fruit. Plant foliage may be uniformly green in color, exhibit varying degrees of anthocyanin accumulation, or display variegation. Inheritance of selected attributes, potential barriers to development of select recombinants, and examples of representative advanced selections in the breeding program will be presented.