Abstract
‘Cullinan’ and ‘Havis’ peaches were released by the Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland on June 3, 1977. ‘Cullinan’ (Fig. 1) is an attractive, high-quality cultivar ripening after ‘Red-haven’ season, with the highest resistance to bacterial spot (Xanthomonas pruni (E. F. Smith) Dows) recorded by the screening method used at Beltsville. ‘Havis’ (Fig. 2) is a highly-blushed, high quality cultivar ripening just before ‘Rio Oso Gem’.
Thirty-two tomato (Lycopersicon esculentum Mill.) or L. pimpinellifolium (L.) Mill. accessions were inoculated with race T2 of Xanthomonas campestris pv. vesicatoria (Xcv) in a field experiment at Wooster, Ohio, in 1995. Plants from accessions which segregated for race T2 resistance in greenhouse tests were selected and these are designated by hyphenated extensions below. The eight most resistant accessions from 1995 and PI 262173 were retested in 1996. Lycopersicon esculentum accession PI 114490-1-1 had virtually no Xcv symptoms either year. Lycopersicon pimpinellifolium accessions LA 442-1-Bk and PI 128216-T2 expressed a high level of resistance in 1995, but only partial resistance in 1996. Accessions with partial resistance for both seasons were PI 79532-S1, PI 155372-S1, PI 126428, PI 271385, PI 195002, PI 262173, Hawaii 7998, and Hawaii 7983. PI 79532-S1 is a L. pimpinellifolium accession and the remaining seven are L. esculentum. Twenty accessions tested in 1995 for T2 plus 10 other accessions were also tested for race T1 resistance in Presidente Prudente, Sao Paulo, Brazil, in 1993. Hawaii 7983, PI 155372-S1, PI 114490, PI 114490-S1, and PI 262173 had greater resistance to T1 than the susceptible control, `Solar Set'. Comparisons with earlier experiments, in which accessions were inoculated with race T1 or T3, indicated that the most consistent source of resistance to all three races was PI 114490 or selections derived from it.
Thirty-three tomato (Lycopersicon esculentum Mill.) or L. pimpinellifolium (L.) Mill. accessions were inoculated with race T2 of Xanthomonas campestris pv. vesicatoria (Xcv) in a field experiment at Wooster, Ohio, in Summer 1995. These included accessions selected for race T2 resistance in greenhouse tests in Florida, and accessions from Hawaii, Brazil, and Bulgaria. One L. esculentum (PI 114490-1-1) and three L. pimpinellifolium (PI 340905-S1, PI 128216-T2, and LA 442-1-BK) accessions had no Xcv symptoms. This is the first report of resistance to Xcv race T2. Partial resistance was found in PI 271385, PI 79532-S1, PI 155372-S1, PI 195002, and PI 126428. Most of the 33 genotypes were tested for race T1 resistance in Presidente Prudente, Sao Paulo, Brazil in summer 1993. Hawaii 7983, PI 155372-S1, PI 114490, PI 114490-S1, and PI 262173 had greater resistance to T1 than the susceptible control `Solar Set'. Comparisons with earlier experiments in which accessions were inoculated with race T1 or T3 indicated that the most consistent source of resistance to all three races was PI 114490 or selections from it.
Abstract
A study was made of the importance of the source of apricot (Prunus armeniaca L.) and plum (P. salicina Lindl.) buds on subsequent development of bacterial spot caused by Xanthomonas campestris pv. pruni (Smith) Dye on scion shoots and their rootstocks. Visibly infected buds budded onto ‘Marianna’ rootstock took poorly, and all developing shoots became infected. Symptomless, suspect buds from diseased trees had an increased rate of take, and fewer shoots were infected. Visually healthy buds collected from healthy trees gave the highest rate of take and lowest percentage of shoot infection.
spot [incited by Xanthomonas arboricola pv. pruni ( Smith, 1903 ) Vauterin et al., 1995 ] and should provide a high-quality option for growers in areas where bacterial spot disease is a concern. Overall, ‘Effie’ is an excellent midseason white
to 2 weeks before ‘Souvenirs’ and ‘White Cloud’, 3 to 4 weeks before ‘White County’ and ‘White River’, and 4 to 5 weeks before ‘White Diamond’. It has very good resistance to bacterial spot ( Xanthomonas arboricola pv. pruni ) and should provide a
freestone and has low acid flavor with very firm slow-melting flesh. It has also shown excellent postharvest storage potential. This new development also has very good resistance to bacterial spot [caused by Xanthomonas arboricola pv. pruni (Smith, 1903
’ is an early, midseason clingstone with non-melting flesh like that found in processing cling peaches. It has a standard acid flavor. These cultivars have good to very good resistance to bacterial spot [caused by Xanthomonas campestris pv. pruni
Tomato (Lycopersicon esculentum Mill.) accessions were tested for hypersensitivity and rated for resistance following field inoculation with tomato race 3 (T3) of the bacterial spot pathogen Xanthomonas campestris pv. vesicatoria (Doidge) Dye (Xcv) in 1992 and 1993. Hawaii 7981, PI 126932, PI 128216, and selections of the latter two expressed hypersensitivity. Hawaii 7981, only tested in the field in 1993, was nearly symptomless and developed significantly less disease than any other accession. PI 128216 had a level of disease similar to susceptible `Solar Set' when tested in 1993. However, a selection from it (PI 126218-S) was significantly more resistant than `Solar Set' in both years. Although PI 126932 had a level of disease similar to `Solar Set' in both years, a selection from it (PI 126932-1-2) was significantly more resistant than `Solar Set' in 1993. Other accessions without hypersensitive responses but more resistant than `Solar Set' for two seasons were PI 114490, PI 126428, PI 340905-S, and PI 155372. Hawaii 7975 was significantly more resistant than `Solar Set' in the one season it was tested.