Simon: Release: B5280

UNITED STATES DEPARTNENT OF AGRICULTURE                       AGRICULTURAL RESEARCH SERVICE                          WASHINGTON, D.C. 20250                                   with                        THE FLORIDA and CALIFORNIA                     AGRICULTURAL EXPERIMENT STATIONS                      RELEASE OF CARROT INBRED B5280 The United States Department of Agriculture, Agricultural Research Service, and the California and Florida Agricultural Experiment Stations, announce the release of a carrot inbred B5280 to provide germplasm for developing improved genotypes and producing proprietary hybrids. Two hybrid combinations with B5280 were included among 100 entries in 1986 Florida and California carrot trials.  These two entries ranked 1 and 2 in Florida while one entry with B5280 as a parent, ranked among the top five in Califonia.  In the 1987 Florida and California carrot trials, four hybrid combinations with B5280 were included among 71 entries.  In Florida two of these entries ranked in the top five.  In California three ranked in the top five (see Attachment). B5280 was derived from a cross made in 1980 at the University of Wisconsin between B6345 (a medium orange Chantenay-shaped inbred derived from 'Imperator 58', 'Long Chantenay', and 'Danvers 126') and B10138 (a dark orange Danvers-shaped inbred from 'Danvers 126').  Beginning with the F2 generation, selection was made for dark orange color and long, blunt, smooth root shape.  Two generations beyond the F2, selection was also initiated for a mild, sweet flavor.  The best of four plants self-pollinated in the 1984 breeding plots produced seed for field row 5280 in Florida and California.  Now at F2MS2M2, B5280M is the result of six generations of selection for root shape and color and four generations of selection for culinary quality. A petaloid cytoplasmic male sterile counterpart, B5280S, is now at BC4. Roots of B5280 are 15-20 cm long, slightly tapered, blunt, very smooth, and dark orange.  In 1985 to 1987, the average total carotene content was 280 to 305 ppm compared with 70 to 100 ppm in 'Imperator 58'.  The flavor is sweet and mild with fairly succulent texture.  Desirable smoothness, blunt shape, high color, and flavor is conferred to a limited number of hybrid combinations with B5280.  B5280 tends to bloom late which limits its usefulness as a pollen parent but F1 hybrids with B5280 are abundant seed producers.  Although selection for Alternaria leaf blight tolerance was not made in the development of B5280, hybrid combinations with B5280 in 1986 and 1987 had vigorous tops and minimal disease damage.

Carrot Inbred B5280                                     page 2 Breeders seed of B5280M and B5280S will be pro-rated upon written requests before April 1, 1988, addressed to P.W. Simon, USDA, ARS, Department of Horticulture, University of Wisconsin, Madison, WI  53706. _________________________________       _________________________ Director, California Agricultural       Date  Experiment Station _________________________________       _________________________ Director, Florida Agricultural          Date  Experiment Station _________________________________       _________________________ Administrator, Agricultural             Date  Research Service

Table 1.  Average appearance scores of carrot hybrids evaluated by carrot breeders,          seed producers, and growers in Florida and California trials.                                                  Florida, 1986a     California, 1986b                                                   Mean                Mean Entry No.   Pedigree               Cage Source     Value  Rank         Value  Rank 6851        (4367x36402)x5280      513-4            4.1     1           2.8    40.5 6850        (8080x2302)x5280       513-3            4.0     2           3.4     4 6848        (8080x2302)x5276       512-3            3.4     3           2.2    89 6772        Apache                 ARCO             3.3     4.5         2.8    36 6826        Orlando Gold           522-3            3.3     4.5         2.9    23 6835        PSK 3282               Peto             3.2     7           3.7     1 6828        (4367x3640)2x2566      526-3            2.3    53.5         3.5     2 6823        Carolong               524-2            2.7    18.5         3.4     4 6834        Savory                 526-2            2.5    42           3.4     4 ________________________________________________________________________________________                                                 Florida, 1987c     California, 1987d                                                   Mean                Mean                                                   Value  Rank         Value  Rank 7399       (4367x3640)2x5280       631-6            3.9     1           4.4     1 7384       (4367x36402)xFN2-9      602-2            3.5    2.5          3.0    35 7378       (808Ox2302)x5280        513-3            3.5    2.5          3.7    4.5 7355       Discovery               Northrup King    3.4    4.0          3.2    23 7356       (8O8Ox2302)x6486        615-3            1.6    69           4.0    2.5 7405       Dagger 78               ARCO             2.6    25.5         4.0    2.5 7397       (6439x6274)2x5280       631-5            2.7    20           3.7    4.5 ________________________________________________________________________________________ a - 39 judges b - 43 judges c - 41 judges d - 48 judges Scores: 5=excellent, 4=good, 3=fine, 2=poor, 1=unacceptable

---