Amelanchier laevis shoots were co-cultured with Agrobacterium tumefaciens carrying the binary vector pBI121, which encodes the B-glucuronidase (GUS) and neomycin phosphotransferase genes. Shoots were then rinsed briefly in liquid MS medium and plated onto culture medium containing carbenicillin. After approximately three months of culture, adventitious shoots were assayed for the presences of GUS by Southern blotting and histochemical assays. Southern analysis revealed a signal when genomic DNA from putatively transformed plants was hybridized with a probe from a segment of pBI121. Regenerated shoots also showed a deep blue color when incubated with X-gluc, although the expression was chimeric, that is, the activity appeared only in a percentage of the cells in each shoot. Callus tissue at the base of each shoot also showed high levels of GUS expression using a fluorogenic assay.
The U.S. Department of Agriculture, Agricultural Research Service, announces the release of onion inbred ‘B8667 A&B’ and synthetic population ‘Sapporo-Ki (SKI) -1 A&B’. Both of these releases represent a cytoplasmic male-sterile (A) line with its
101 POSTER SESSION 3B (Abstr. 159–164) Culture & Management–Woody Ornamentals/Landscape/Turf
ultraviolet-B radiation stress is one of the major factors causing quality decline of newly transplanted turfgrass ( Ervin et al., 2004a ). Exposure of the heat-stressed turfgrass sod to high levels of ultraviolet-B (280–320 nm) radiation at replanting causes
Abstract
Flavor is an important factor in establishing consumer preference of carrots. Although harsh, strong flavor frequently occurs in available cultivars, the dominance of mild flavor in hybrids from harsh and mild parents suggests that carrot flavor can be improved rapidly when mild-flavored inbreds are available (1). Carrot inbred B2566 has been selected as a source of improved flavor and was used as a male parent in experimental hybrids tested in California, Florida, and Wisconsin. B2566 has demonstrated good combining ability for important fresh market characteristics of color, shape, and seed productivity along with desirable mild, sweet flavor and succulent texture. Because of these qualities, B2566 is being released jointly by the USDA, the Univ. of Florida, and the Univ. of California.
J.B. Edmond Undergraduate Competition
(USDA Hardiness Zone 6b). Canopy width was calculated from an average of two perpendicular measurements made from dripline to dripline ( Table 1 ). Canopy width ranged from 135 to 401 cm among cultivars with distinct canopy shapes prominent with several
Abstract
A phenotypically sensitive gynoecious line of Cucurbita pepo L., NJ34, has been synthesized recently through crosses of monoecious inbreds and selection (3). NJ34 is 100% pistillate in some environments, but it differentiates a few staminate flowers in other environments. This line is BB, in which gene B conditions precocious yellow pigmentation of fruit. Since previous observations suggested that B can also increase female expression (1), a question arose: Is B essential for the synthesis of gynoecism in this species?
The objective of this study was to determine if selected strains of Agrobacterium could infect microshoots of Rhododendron catawbiense. Fifteen microshoot stems of R. catawbiense var. album `America', `Joe Paterno', and `Cunningham's White' were inoculated with two drops (about 25 μL) of wild type Agrobacterium tumefaciens strains C58 or B6 or with wild type A. rhizogenes strain E8/73. Five control shoots were inoculated with 1.2 mM KH2PO4 buffer. Microshoots were grown on woody plant medium (WPM) supplemented with 4.9 μM 2iP. Six weeks after inoculation galls that formed were excised from the microshoots and placed on WPM that lacked plant growth regulators but contained 300 mg·L-1 cefotaxime. In another study, these wild-type bacterial strains were genetically modified by inserting the pBINm-gfp5-ER plasmid, which contained genes coding for NPTII and green fluorescence protein (GFP), into the bacteria. These modified strains were inoculated on 15 stems of the three rhododendron cultivars and one variety. Calluses that formed were excised, placed on basal WPM with cefotaxime, and allowed to proliferate. Wild type C58 induced galls to form on `Joe Paterno', R.c. album, and `Cunningham's White' stems, whereas wild type B6 caused galls to form only on the latter two types of rhododendron. Wild-type E8/73 failed to induce gall formation on the rhododendrons. Only genetically modified B6 caused galls to form on only `Cunningham's White' microshoots (seven of 15 inoculated stems). Three of these galls fluoresced green under ultraviolet light. Physical presence of the NPTII and GFP genes in the plant genome was determined by polymerase chain reaction. This study demonstrated that R. catawbiense is susceptible to Agrobacterium infection, and this plant can be genetically transformed.
Abstract
The author of the article “A Gynoecious Line of B+B+Genotype in Cucurbita pepo” (HortScience 21:319, Apr. 1986), Oved Shifriss, wishes it noted that: “The genetic synthesis of gynoecism in Cucurbita is a subject of a pending application for a U.S. patent.”