|JOHNSON-CICALESE, JENNIFER - Rutgers University|
|VORSA, NICHOLI - Rutgers University|
|HONIG, JOSH - Rutgers University|
|WARD, DANIEL - Rutgers University|
Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/3/2015
Publication Date: 5/1/2015
Publication URL: https://handle.nal.usda.gov/10113/61543
Citation: Johnson-Cicalese, J., Vorsa, N., Polashock, J.J., Honig, J., Ward, D. 2015. Heritability of fruit rot resistance in American cranberry. Journal of the American Society for Horticultural Science. 140(3):233-242.
Interpretive Summary: Fruit rot disease of cranberry dramatically decreases yield and fruit quality. Without chemical control, the entire crop would be lost in the northeastern growing areas (New Jersey and Massachusetts). Chemical application, although currently necessary, can negatively impact human health and the environment. Rot-resistant selections are available in the breeding program but yield poorly or have other undesirable traits. To address this problem, rot-resistant selections were crossed with high-yielding varieties that also had other desirable traits, such as good fruit color. Over 1600 offspring from these crosses were evaluated in field plots. We found that we were able to combine desirable traits and several selections that are rot resistant and have good fruit quality and yield are being further evaluated for release as new cultivars. These results are useful to fruit breeders, especially those working on cranberries. Release of new rot-resistant cultivars will directly benefit farmers.
Technical Abstract: Fruit rot is the primary threat to cranberry production in the northeastern U.S., and increasingly in other growing regions. Efficacy of chemical control is variable since the disease is caused by a complex of pathogenic fungi. In addition, cranberries are often grown in environmentally sensitive areas. Thus, a major focus of the cranberry breeding program is to develop cultivars with improved fruit rot resistance. Several genetic sources of broad-based field fruit rot resistance (FFRR) have been identified in our germplasm collection. However, many of the most resistant accessions lacked one or more attributes required to be commercially acceptable. These resistant accessions were used in crosses with elite high-yielding selections and in 2009, 1624 progeny from 50 crosses were planted in 2.3 m2 field plots. In 2011-2013, under field conditions with very limited fungicide applications early in the season, disease pressure was severe, allowing evaluation for FFRR. Plots were rated on a 1-5 scale (where 1 = no rot and 5 = 80-100% rotted fruit) for incidence of fruit rot and rotted fruit counts were collected from selected plots to corroborate the ratings. There was a good correlation between years (2011 vs. 2012: r = 0.59; 2012 vs. 2013: r = 0.62), and between ratings and counts (r = 0.75). Significant differences were found between and within families in both fruit rot ratings and rotted fruit counts. Moderately high heritability estimates were obtained with offspring-midparent regression (R2 = 0.66), indicating additive genetic variance. Introgression of FFRR into higher-yielding genetic backgrounds was also accomplished as several progenies exhibiting high FFRR also had commercially viable yield (> 67000 kg/ha) as well as good berry size and color. Selections are being further evaluated for potential cultivar release.