Abstract
Fruit anthocyanins (ACY) of eight Prunus spp. representing two subgenera (subg.) and three sections (sect.) were analyzed using high-performance liquid chromatography (HPLC). Fruit of P. angustifolia Marsh., P. hortulana Bailey, and P. maritima Marsh. all North American members of subg. Prunus sect. Prunocerasus, were qualitatively identical in ACY composition, containing cyanidin-3-glucoside and cyanidin-3-rutinoside. Fruit of P. cerasifera Ehrh. and P. spinosa L., both Eurasian members of subg. Prunus sect. Prunus, contained small amounts of peonidin-3-gIuco-side and peonidin-3-rutinoside, in addition to the 3-glucoside and 3-rutinoside of cyanidin. Fruit of P. besseyi Bailey and P. pumila L. (subg. Lithocerasus sect. Microcerasus) contained cyanidin-3-glucoside and cyanidin-3-rutinoside. Fruit of P. pumila also contained trace amounts of peonidin-3-rutinoside. Fruit of P. japonica Thunb., a Chinese member of subg. Lithocerasus sect. Microcerasus, showed a complex ACY profile distinct from P. besseyi and P. pumila.
Abstract
Thermal and differential thermal analysis (DTA) are used to detect exotherms that result from the freezing of supercooled tissues (4). They provide a convenient and rapid means of assessing the hardiness of tissues that supercool, such as the floral primordia of Prunus spp. (3) and the compound buds of Vitis spp. (2). The inability to process a large number of tissue samples simultaneously, however, has been a major limitation of DTA. Ashworth et al. (3) described a computer-assisted data-logging system for recording thermal analysis data generated when Prunus flower buds were frozen. Multiple cooper-constantan thermocouples were used to increase the number of buds monitored on a given channel of a multichannel data-logger. Copper-constantan thermocouples, however, were not adequate with our instrumentation to discriminate exotherms generated by the freezing of individual shoot primordia of compound grapevine buds. Furthermore, anatomical barriers to ice propagation may be negated if thermocouples are inserted into buds to increase exotherm detection (5).
Abstract
‘Harcot’ is an attractive, early season, high quality apricot (Prunus armeniaca L.) with adequate cold hardiness and resistance to bacterial spot [Xantho-monas pruni (E.F.Sm.) Dows.], brown rot [Monilinia fructicola (Wint.) Honey], and perennial canker (Leucostoma spp.). It was introduced in 1977 to meet the need in Ontario for a better adapted, cold hardy and disease resistant cultivar for the fresh market.
Abstract
‘Harogem’ is an exceptionally attractive, very firm, high quality, mid- to late season apricot (Prunus armeniaca L.) suitable for the fresh market. It is cold hardy, resistant to brown rot [Monilia fructicola (Wint.) Honey], perennial canker (Leucostoma spp.), and skin cracking but moderately susceptible to bacterial spot [Xan-thomonas pruni (E. F. Sm.) Dows]. It was introduced in 1979 to meet the need for a better adapted, more consistently productive, cold hardy and disease tolerant cultivar for the Ontario fresh market.
Abstract
‘Veeglo’ is an attractive, high quality peach (Prunus persica (L.) Batsch) that matures during the last week in August, 9 days after ‘Redhaven’. Assessments indicate typical, moderate susceptibility to perennial canker (Leucostoma spp.) and moderate resistance to bacterial spot (Xanthomonas pruni (E.F. Smith) Dows.). ‘Veeglo’ was introduced to satisfy the requirement for a high quality fresh market or home preserving peach maturing between Redhaven and Loring, and adapted to climatic conditions in southern Ontario, Canada.
Abstract
A new root-knot nematode (Meloidogyne sp.) of peach which occurs in Florida overcomes the resistance of Okinawa and Nemaguard rootstocks (Prunus spp.). Resistance to this new nematode obtained from crosses and open-pollinated seedlings of Okinawa, Chico II, and P. davidiana has a heritability (narrow sense) of 0.31 ± .04. Two selections, Fla. 14-11 and Fla. 9-4, combine the nematode resistance of Okinawa and Nemaguard with resistance to the new nematode.
Genetics of tree architecture in peach ( Prunus persica (L.) Batsch). PhD Diss., Univ. Florida, Gainesville, FL Chavez, D.J. 2013 The North American plums ( Prunus spp.) and their use as germplasm resources: From populations to phylogenetic studies
Abstract
Seedlings or rooted cuttings of 35 lines of peach [Prunus persica (L.) Batsch] and other Prunus spp. were screened for resistance or tolerance to the ring nematode Criconemella xenoplax (Raski) Luc & Raski (Cx). Host reaction to Cx was evaluated by comparing root and shoot growth of infested plants with that of uninfested checks. Reaction of Cx to the host was reflected in nematode density per gram root dry weight (NPGR). Effects of Cx on root growth were not always correlated with increases in Cx per 100 cm3 of soil or in NPGR. Prunus japonica Thunb. and P. tomentosa Thunb. showed no Cx-related growth reduction and had lower Cx densities than most other lines. ‘Lovell’ peach had a smaller root system and fewer Cx per pot than ‘Nemaguard’ peach, but differences in NPGR were not significant. With high inoculum levels, significant differences in NPGR between lines, and in growth parameters within lines, could be detected after 6 months.
Abstract
Spray treatment a single dormant application of high concentrations of anionic (Triton CS7) and nonionic (Triton N57 and Triton X100) surfactants caused up to 5 days delay in bud break in apple (Malus domestica Borkh.), but had less effect on grape (Vitis spp.) and peach (Prunus persica (L.) Batsch) and none on pear (Pyrus spp.). Surfactants tended to extend the bud break period but were frequently lethal to buds, particularly at concentrations of 3% and 5% active ingredient. In field studies, surfactants delayed the early stages of flower bud development but not bloom of apple or peach and did not control apple scab caused by Venturia inaequalis (Cke.) wint. or powdery mildew caused by Podosphaera leucotricha (Ell & Ev.) Salm.
Abstract
‘Hargrand’ is an exceptionally large, firm-fleshed apricot (Prunus armeniaca L.) suitable for the fresh market, home canning and commercial processing, especially as puree for baby food. The tree is cold hardy and productive and tolerant to perennial canker (Leucostoma spp.). The fruits are moderately resistant to brown rot (Moniliniafructicola [Wint.] Honey), bacterial spot (Xanthomonaspruni [E. F. Sm.] Dows.) and skin cracking. ‘Hargrand’ ripens in the midseason with ‘Veecot’ and is being introduced for the Ontario fresh market to meet the need for better dual purpose cultivars in this season. It should be adapted to regions where ‘Goldcot’ and ‘Veecot’ are successfully grown.