Rose rosette disease is incited by a negative-sense RNA virus (genus Emaravirus ), which is vectored by a wind-dispersed eriophyid mite ( P. fructiphilus ) ( Di Bello et al., 2015a ; Laney et al., 2011 ). Symptoms on roses include witches broom/rosette
H. Brent Pemberton, Kevin Ong, Mark Windham, Jennifer Olson, and David H. Byrne
David H. Byrne, Patricia Klein, Muqing Yan, Ellen Young, Jeekin Lau, Kevin Ong, Madalyn Shires, Jennifer Olson, Mark Windham, Tom Evans, and Danielle Novick
: the RRV, the eriophyid mite ( P. fructiphilus ) vector, and the rose ( Amrine, 2014 ; Byrne et al., 2015 ; Windham et al., 2014 , 2016 ). All these vary in their genetics and are influenced by the environment ( Fig. 1 ). Fig. 1. Rose rosette disease
Binoy Babu, Gary Knox, Mathews L. Paret, and Francisco M. Ochoa-Corona
ROSE ROSETTE DISEASE Roses are one of the most important ornamental flowering shrubs grown worldwide. In the United States, the total sales of shrub rose’s value was 204 million U.S. dollars in 2014 ( U.S. Department of Agriculture, 2015 ). Among
Kevin Ong, Madalyn Shires, Holly Jarvis Whitaker, Jennifer Olson, Joseph LaForest, and David H. Byrne
Rose rosette disease was described in the early 1940s ( Conners, 1941 ; Thomas and Scott, 1953 ). Since then, much of the work that was carried out to understand this disease was focused on multiflora roses until the 1990s. In recent years, RRD
Creighton L. Gupton and Barbara J. Smith
A study was conducted to determine if blackberry cultivars Humble, Rosborough, and Brazos transmit rosette (incited by Cercosporella rubi) resistance and to estimate heritability (h2). Plants of parents and offspring involving these cultivars were rated for rosette severity on a whole plant basis from 0 = no rosette to 7 = all buds infected or plant dead. An estimate of h2 was computed by regression of cross means on parental means. The mean rosette severity rating of plants from crosses was always intermediate between the cultivar and other parents. Only `Humble' transmitted enough rosette tolerance to be usable although `Rosborough' crosses were more tolerant than the other parents. The h2 estimate of 0.48 was fairly high but low variability among parents other than `Humble' would suggest little progress from mass selection.
Fan Li, Guoxian Wang, Rongpei Yu, Min Wu, Qinli Shan, Lifang Wu, Jiwei Ruan, and Chunmei Yang
Gypsophila paniculata , a flowering plant of the Caryophyllaceae family, is a small perennial herbaceous shrub ≈1 m tall and ≈1 m wide ( Toaima et al., 2016 ; Vettori et al., 2015 ). It is normally characterized by a rosette of grayish green basal
Katherine M. Solo, Sara B. Collins, Madalyn K. Shires, Ron Ochoa, Gary R. Bauchan, Liesel G. Schneider, Alan Henn, James C. Jacobi, Jean L. Williams-Woodward, M.R. Hajimorad, Frank A. Hale, John B. Wilkerson, Alan S. Windham, Kevin L. Ong, Mathews L. Paret, Xavier Martini, David H. Byrne, and Mark T. Windham
Rose rosette disease (RRD) has become established across much of the United States. The causal agent is Rose rosette virus (RRV) (genus Emaravirus) ( Di Bello et al., 2015 ; Laney et al., 2011 ), with the main mode of natural transmission being
Brent K. Harbaugh, Mark S. Roh, Roger H. Lawson, and Brent Pemberton
Three lisianthus [Eustoma grandiflorum (Raf.) Shinn.] cultivars 0, 10, 17, 24, or 31 days from sowing were grown in 28C soil for 0, 7, 14, 21, or 28 days to determine the effects of high temperature during seedling growth on the development of rosetted plants. Increasing the duration of high-temperature exposure increased the percentage of rosetted plants for all cultivars. Such exposure for 28 days resulted in 96%, 93%, and 18% rosetted plants for cultivars Yodel White, Yodel Pink, and GCREC-Blue, respectively. Seedling age did not affect percentage of flowering `Yodel Pink' plants, but as seedling age increased to 31 days, the percentage of flowering plants increased with `GCREC-Blue' and decreased for `Yodel White'. In a second experiment, four lisianthus cultivars were grown at 22C for 3 weeks and then exposed for 28 days to soil at 22, 25, 28, or 31C. Increasing soil temperature resulted in more rosetted plants for all cultivars. With soil at 31C, 83%, 58%, 19%, and 2% of the seedlings rosetted for the cultivars USDA-Pink, Yodel White, Little Belle Blue, and GCREC-Blue, respectively.
Blair Buckley III, James N. Moore, and John R. Clark
Rosette, incited by Cercosporella rubi (G. Wint.) Plakidas, is the most severe disease of blackberries in the southern United States. Sixteen blackberry cultivars and breeding selections were evaluated in a field test over a 3-year period for incidence and severity of rosette. Test plots were planted in a randomized complete block design with four replications. A plot consisted of a 3-m hedgerow of blackberry canes. Each test plot row was bordered on each side by a row of the rosette-susceptible cultivar Shawnee. Disease ratings were conducted on five random floricanes in each plot. Disease severity was rated with a 1 to 8 scale (1 = 0% floricane nodes with rosettes, 2 = 0% to 10%, 3 = 10% to 25%, 4 = 25% to 50%, 5 =50% to 75%, 6 = 75% to 90%, 7 = 90% to 100%, 8 = 100%). `Shawnee' and `Rosborough' had high incidence and severity. Cultivars and selections with moderate-high incidence and low-moderate severity were `Brazos', `Cheyenne', `Choctaw', A-1260, A-1442, A-1560, and A-1585. Cultivars and selections with zero-low incidence and severity were `Arapaho', `Humble', `Navaho', A-1374, A-1594, A-1616, and A-1617.
Creighton L. Gupton
Crosses between `Humble' and five other blackberry cultivars were made to determine the efficacy of `Humble' as a source of resistance to rosette (incited by Cercosporella rubi). Seven cultivars and three selections were planted at a disease free location and at a location where rosette is known to occur to determine the effect of double blossom on yield, berry weight, and ripening date. `Cheyenne' X `Humble,' `Humble' X `Brazos,' and `Navaho' X (`Humble' X `Brazos') produced progenies with various levels of resistance. Promising selections were made from the latter two crosses. Genotype X location interaction was significant for yield and not significant for either Julian date of 50% ripe fruit or weight per berry. These results suggest that rosette reduces yield but has little if any effect on weight per berry or ripening date. `Shawnee' and `Choctaw' were the highest yielding cultivars under disease free conditions; however, their yields were low in the test where they were infected with rosette. `Brazos,' `Choctaw,' and `Rosborough' were the earliest ripening and `Navaho' was the latest ripening cultivar.