to believe that SSR loci isolated from two species within the big-bracted group might transfer to other Cornus species in all four of the major clades. The ability to transfer SSRs from C. florida and C. kousa to other Cornus species will play
Phillip A. Wadl, Xinwang Wang, John K. Moulton, Stan C. Hokanson, John A. Skinner, Timothy A. Rinehart, Sandra M. Reed, Vincent R. Pantalone and Robert N. Trigiano
Naomi R. Smith, Robert N. Trigiano, Mark T. Windham, Kurt H. Lamour, Ledare S. Finley, Xinwang Wang and Timothy A. Rinehart
laboratories ( Amador et al., 2001 ; Saunders et al., 2001 ; Savelkoul et al., 1999 ; Vos and Kuiper, 1997 ). In this study, AFLPs were generated to assess the genetic variability between selected cultivars and lines of Cornus florida and to construct a
K.R. Maluea, R.W Holton, S.E. Schlarbaum, E.T. Graham and R.N. Triaiano
Cornus florida L. floral development was monitored using standard paraffin histological techniques and light microscopy. Terminal buds (putative floral buds) were collected over 6 weeks from mature landscape trees located on The Univ. of Tennessee Agricultural Campus, Knoxville. Examination of samples taken at 3- to 7-day intervals revealed variations in development representing 1- to 2-week differences between florets in a single inflorescence, florets on the same tree and florets from different trees. Floral initiation occurred before July 19th in the 2 years of this study. Floral development followed typical angiosperm stages. Florets, although small, appeared morphologically mature by early September in both years.
K.R. Malueg, S.E. Schlarbaum, E.T. Graham and R.N. Trigiano
Development of Cornus florida L. pollen was monitored using standard paraffin histological techniques and light microscopy. Terminal buds (putative floral buds) were collected over a 6 weeks from mature landscape trees located on The Univ. of Tennessee Agricultural Campus, Knoxville. Examination of samples taken at 3- to 7-day intervals revealed variations in development representing 1- to 2-week differences between florets in a single inflorescence, florets on the same tree, and florets from different trees. Floral initiation occurred before 19 July in the 2 years of this study. Pollen development followed typical angiosperm stages: tapetal cells were multinucleate, pollen tetrads were tetrahedral, and meiosis occurred late in the developmental period. Pollen grains appeared morphologically mature by early September in both years.
Sandra M. Reed
Low seed set has been reported following self-pollinations of flowering dogwood (Cornus florida L.). The objective of this study was to verify the presence of self-incompatibility in C. florida. `Cherokee Princess' stigmas and styles were collected 1, 2, 4, 8, 12, 24, 48, and 72 hours after cross- and self-pollinations, stained with aniline blue and observed using a fluorescence microscope. Pollen germinated freely following self-pollinations, but self-pollen tubes grew slower than those resulting from cross-pollinations. By 48 hours after cross-pollination, pollen tubes had reached the bottom of the style while pollen tubes in self-pollinated flowers had only penetrated the upper third of the style. Evidence of reduced pollen tube growth rate in self-pollinations of `Cherokee Chief' and `Cherokee Brave' was also obtained. This study provides evidence of a gametophytic self-incompatibity system in C. florida. It was also determined that stigmas of C. florida `Cherokee Princess' are receptive to pollen from 1 day prior to anthesis to 1 day after anthesis.
Hailin Liu, Cunmeng Qian, Jian Zhou, Xiaoyan Zhang, Qiuyue Ma and Shuxian Li
Flowering dogwood ( C. florida L.), a member of the subgenus Benthamidia in Cornus , is a small- to medium-sized deciduous tree native to eastern North America ( Borer et al., 2013 ; McLemore, 1990 ; Rushforth, 1999 ). The species is prized
Phillip A. Wadl, Xinwang Wang, Andrew N. Trigiano, John A. Skinner, Mark T. Windham, Robert N. Trigiano, Timothy A. Rinehart, Sandra M. Reed and Vincent R. Pantalone
, Wilmington, DE); DNA quality was determined using 2% agarose gels stained with ethidium bromide and visualized in the 2000 Gel Documentation System (Bio-Rad Laboratories, Hercules, CA). Table 1. Cornus florida cultivars and breeding lines and C
Margaret T. Mmbaga, Lucas M. Mackasmiel and Frank A. Mrema
flowering dogwood ( Cornus florida ) ( Barnard and Gilly, 1986 ; Hodges, 1962 ; Mmbaga et al., 2018 ; Rowan, 1971 ; Seymour, 1969a , 1969b ; Smith and Bega, 1964 ). Macrophomina phaseolina effects on woody hosts are primarily on seedlings and young
R.B. Hardin, D J. Eakes, C.H. Gilliam and G.J. Keever
In a full-sun Auburn, Ala., field study, 23 cultivars and 1 forma of Cornus florida L. were evaluated for growth from 1994 to 1996 and bract characteristics in Spring 1996. The selections were divided into three groups for analyses: 1) white bracted with green foliage, 2) red or pink bracted with green foliage, and 3) variegated foliage. Among the white bracted cultivars with green foliage, `Weaver' and `Welch Bay Beauty' had the greatest height and stem diameter increases, `Autumn Gold' the least. `Cloud 9' had the largest bract size. `Welch's Junior Miss' had the greatest height increase, while `Stokes' Pink' had the greatest stem diameter increase for the red or pink bracted cultivars with green foliage, and f. rubra the least. `Red Beauty' had the largest bract size. There were no differences among the variegated cultivars in height increase or bract size; however, `First Lady' had the greatest stem diameter increase.
J.H. Craddock, S.M. Reed, S.E. Schlarbaum and R.J. Sauve
A series of experiments was conducted with flowering dogwood (Cornus florida L.) to evaluate in vitro pollen germination both prior to and following storage at various temperatures. For all experiments, pollen was germinated on an agar-solidified medium containing 20% sucrose. Collection method had a significant effect on germination of `Cherokee Chief', `Cherokee Princess', and `Cloud 9' pollen. Pollen obtained from anthers that had been collected prior to dehiscence and allowed to air-dry for 24 hours had a higher germination rate than did pollen that had undergone a desiccation treatment. None of the treated pollen tested, however, had a germination rate >25% of that of freshly collected pollen. The deleterious effect of dehydration could not be reversed by rehydration. Pollen germination was tested after 1, 4, 7, and 108 days at 5, –20, and –196 °C. Pollen stored at –196 and at –20 °C had a better germination rate than that stored at 5 °C. Germination was not significantly affected by length of storage, nor was there any significant temperature × length of storage interaction.