This experiment was carried out to breed promising brown anther type male sterile lines of carrots having the desirable characteristics of higher seed yield and stable phenotypic expression of male sterility. Brown anther type male sterile lines used for this experiment had been derived from the male sterile sources selected from the seed multiplication plots of Shin Kurota cultivar in 1972. Brown anther type male sterile lines are, in general, good seed yielders but frequently show unstable phenotypic expression of male sterility as compared to petaloid type male sterile lines. Through several years of selection for male sterile lines and plants, brown anther type male sterile lines with good seed-yielding potentials and stable phenotypic expression similar to petaloid type were developed. Outline of the breeding scheme, potential benefits of these newly bred MS lines, etc. will be discussed.
Jiwan P. Palta* and Gerard Simon
Freezing stress resistance is composed of several components namely tolerance, avoidance and acclimation ability. These three components of freezing stress are heritable traits. We have demonstrated that progress in the improvement of freezing stress resistance can be made by individually selecting for various components of this resistance and then recombining them to get the desired plan. Freeze-thaw injury in carrots is manifested as damage to the foliage, cracks on the roots (especially on the crown), and crown root rot. We found that foliage damage following freeze-thaw stress was related to the tolerance of the foliage to ice formation. The formation of cracks in the crown and root tissue was related to formation of ice itself. The carrot breeding lines we tested varied considerably for the crown position in relation to soil surface. The carrot crowns and roots below the soil surface will be better in avoiding ice in the tissue, thus avoiding cracks. The freeze-thaw injury observed on the foliage in the field was highly correlated to the freeze-thaw tolerance of leaf tissue (measured as ion leakage from the leaf tissue) determined by controlled freeze-thaw test in the laboratory. Based on this work we developed a breeding strategy to improve frost hardiness in carrots by combining the characteristics that avoid ice in the crown and root tissues (e.g., crown position underground) with the characteristics that reduce foliage and root injury by ice (freezing tolerance of foliage). By using this strategy we were able to successfully obtain the desired plant. Two hardy carrot hybrids (Eskimo, Artico) were released by Vilmorin and their hardy characteristics have been confirmed under field conditions.
P.W. Simon, C.E. Peterson, and W.H. Gabelman
Warley M. Nascimento, Jairo V. Vieira, Giovani O. Silva, Kathleen R. Reitsma, and Daniel J. Cantliffe
), and germination at sub- or supraoptimal temperatures may be a desirable trait for incorporating into carrot breeding programs. High genetic variability observed among progenies from the ‘Brasilia’ carrot group suggested that simple breeding methods may
Bhimanagouda S. Patil, Kevin Crosby, David Byrne, and Kendal Hirschi
both processing and fresh market carrot cultivars ( Just and Simon, 2004 ). More recently other important antioxidant compounds have been identified and enhanced in carrot germplasm, including anthocyanins and lycopene. The carrot breeding program at
Mary Ruth McDonald, Kevin Vander Kooi, and Philipp Simon
Poster Session 53—Vegetable Breeding 2 21 July 2005, 1:15–2:00 p.m. Poster Hall–Ballroom E/F
Leonard M. Pike
`BetaSweet' is a new “designer” carrot that was conceived as a research project with the objective to create a new high-quality vegetable with unique characteristics. The gene responsible for purple or maroon color in carrots is a natural one and has been around for many years. Carrot breeders have discarded carrots which occasionally segregated to this color because orange has been the preferred traditional color. In 1989, three carrots grown from Brazilian seed were observed to have a blotchy maroon color mixed with the normal orange. Within two generations of breeding effort I had obtained a few carrot roots with near complete maroon exterior color and orange interior. The contrast of orange and maroon was very attractive in carrots cut as coins or sticks. The maroon and orange color would serve as the perfect way to identify and promote this new variety. Several additional generations were required using extensive laboratory testing for low terpenoids (strong carrot flavors), high sugars, high carotene, and crispy texture. Thousands of carrot roots were analyzed and selected for those qualities and for the dark maroon exterior and orange interior colors. The few best for those characteristics were intercrossed, and reselected for their adaptation when grown under Texas climatic conditions.
W.H. Gabelman, I.L. Goldman, and D.N. Breitbach
This research supported by the Wisconsin Carrot Grower's Association, the Wisconsin Muck Grower's Association, the Midwest Food Processor's Association, and Hatch projects 1025 and 3654, Wisconsin Agricultural Experiment Station, College of
Keita Sugiyama, Masami Morishita, and Eisho Nishino
1 Current address: Laboratory of Lettuce and Carrot Breeding, National Institute of Vegetable and Tea Science, 360, Kusawa, Ano, Mie 514-2392, Japan. E-mail address: email@example.com 2 Associate Professor. We thank Osamu Yoshida for his