(RGAs) in Prunus : A resistance map for Prunus Theor. Appl. Genet. 111 1504 1513 Lambert, P. Hagen, L.S. Arus, P. Audergon, J.M. 2004 Genetic linkage maps of two apricot cultivars ( Prunus armeniaca L.) compared with the almond Texas × peach Earlygold
Ke Cao, Lirong Wang, Gengrui Zhu, Weichao Fang, Chenwen Chen, and Pei Zhao
Martina Göttingerová, Michal Kumšta, and Tomáš Nečas
. Pantelidis, G. Petri, E. Tzoutzoukou, C. Karayiannis, I. 2008 Physical characters and antioxidant, sugar, and mineral nutrient contents in fruit from 29 apricot ( Prunus armeniaca L.) cultivars and hybrids J. Agr. Food Chem. 56 10754 10760 Fermenia, A
Lamia Krichen, Joao M.S. Martins, Patrick Lambert, Abderrazzak Daaloul, Neila Trifi-Farah, Mohamed Marrakchi, and Jean-Marc Audergon
. 105 298 305 Hormaza, J.I. 2001 Molecular characterization and similarity relationships among apricot ( Prunus armeniaca L.) genotypes using simple sequence repeats Theor. Appl. Genet. 104 321 328
Fatih Ali Canli, Murat Sahin, Nurettin Temurtas, and Mustafa Pektas
rise to the routine use of these treatments in apricot production. Units Literature cited Agusti, M. Juan, M. Almela, V. Speroni, C. 1994 The effect of 2,4-DP on fruit development in apricots ( Prunus armeniaca L.) Sci. Hort. 57 51 57 Andrews, P
L. Burgos, T. Berenguer, and J. Egea
Eight apricot (Prunus armeniaca L.) cultivars were self- and cross-pollinated to determine pollen compatibility. Pollen tube growth in the laboratory and the percentage of fruit set in the orchard were evaluated. The results confirmed that `Moniqui Fino' and `Velázquez Tardío' are self-incompatible and established that `Gitano', `Pepito del Cura', and `Velázquez Fino' are also self-incompatible. No cross-incompatibility was found in the 25 cross-combinations.
Gregory L. Reighard, David W. Cain, and William C. Newall Jr.
More than 400 genotypes of Prunus were evaluated for “in field” rooting and survival from fall-planted hardwood cuttings treated with 2000 ppm IBA. Cultivars of European and Japanese plums originating from species and interspecific hybrids of the section (sect.) Prunus had the highest survival. Cuttings from cultivars of sand cherry (sect. Microcerasus) and peach (sect. Euamygdalus) averaged 28% to 54% lower survival than European and Japanese plums. Few cultivars of almonds (sect. Euamygdalus), apricots (sect. Armeniaca), and American plums (sect. Prunocerasus) rooted from hardwood cuttings. Chemical name used: 1H-indole-3-butyric acid (IBA).
Sorkel A. Kadir and Edward L. Proebsting
Flower buds of 20 Prunus species showed quite different strategies to cope with low temperatures. Buds of most species deep supercooled. The two hardiest species, both from the subgenus Padus (P. padus L. and P. virginiana L.), did not supercool and survived -33C with no bud kill. Prunus serotina J.F. Ehrh., also in Padus, did supercool. Prunus nigra Ait., P. americana Marsh, P. fruticosa Pall., and P. besseyi L.H. Bailey had a low minimum hardiness level (MHL), small buds, and a low water content. Exotherms were no longer detectable from the buds of these species after 2 days at -7C and some buds survived -33C. Prunus triloba Lindl. and P. japonica Thunb. were similar to that group, but no buds survived -33C. Prunus davidiana (Carriere) Franch., P. avium L., and P. domestica L. had a relatively high MHL but hardened rapidly when the buds were frozen. Prunus persica (L.) Batsch., P. subhirtella Miq., P. dulcis (Mill) D. A. Webb, and P. emarginata (Dougl. ex Hook) Walp. deep supercooled, had large flower buds and a high MHL, and were killed in the Dec. 1990 freeze. Prunus salicina Lindl., P. hortulana L.H. Bailey, P. armeniaca L., and P. tomentosa Thunb. were in an intermediate group with a moderately low MHL and a moderate rate of hardiness increase while frozen. Prunus dulcis and P. davidiana had a low chilling requirement and bloomed early, whereas P. virginiana, P. fruticosa, P. nigra, and P. domestica had high chilling requirements and bloomed late.
Stephen M. Southwick
Commercially grown apricots (Prunus armeniaca), peaches (Prunus persica), nectarines (Prunus persica), plums (Prunus salicina and Prunus domestica), and pluots (Prunus salicina × Prunus armeniaca) have a tendency to produce high numbers of flowers. These flowers often set and produce more fruit than trees can adequately size to meet market standards. When excessive fruit set occurs, removal of fruit by hand-thinning is common to ensure that fruit size meets market standards. Over the years there have been numerous attempts to find chemical or physical techniques that would help to reduce costs associated with and improve efficiencies of hand-thinning; however, using alternate strategies to hand-thinning have not been widely adopted in stone fruit production. In the past 10 years, through the continuing efforts of scientists throughout the world in public and private institutions and business, it appears that there are chemical sprays capable of reducing the need for hand-thinning in stone fruit. Management of flowering by reducing the number of flowers on apricot, peach, nectarine, plum, and prune has shown promise under climatic conditions such as those found in the San Joaquin Valley of California. By applying gibberellins during May through July, flowers in many stone fruit cultivars can be reduced in the following season. The reduction in flower number does not generally lead to an increase in fruit set. As a result, fruit numbers are reduced, the need for hand thinning can be reduced, and in some cases eliminated. There are risks associated with reducing flower number before climatic conditions during bloom or final fruit set are known. However, given the changes in labor costs and market demands, especially in the developed world, the benefits may outweigh the risks. The application and implications of these summer gibberellin applications toward reducing flower numbers will be discussed as it relates to commercial stone fruit growing.
P. Martínez-Gómez, M. Rubio, F. Dicenta, and T.M. Gradziel
Sharka [(plum pox virus (PPV)] mainly affects Prunus species, including apricot (Prunus armeniaca L.), peach (Prunus persica L.), plum (Prunus salicina Lindl., Prunus domestica L.), and, to a lesser degree, sweet (Prunus avium L.) and sour cherry (Prunus cerasus L.). Level of resistance to a Dideron isolate of PPV in seven California almond [P. dulcis (Miller) D.A. Webb], five processing peach cultivars, and two peach rootstocks was evaluated. In addition, almond and peach selections resulting from interspecific almond × peach hybridization and subsequent gene introgression were tested. Evaluations were conducted in controlled facilities after grafting the test genotypes onto inoculated GF305 peach rootstocks. Leaves were evaluated for PPV symptoms during three consecutive cycles of growth. ELISA-DASI and RT-PCR analysis were also employed to verify the presence or absence of PPV. Peach cultivars and rootstocks showed sharka symptoms and were ELISA-DASI or RT-PCR positive for some growth cycles, indicating their susceptibility to PPV. Almond cultivars and almond × peach hybrids did not show symptoms and were ELISA-DASI and RT-PCR negative, demonstrating resistance to PPV. Two (almond × peach) F2 selections as well as two of three backcrossed peach selections also showed a resistant behavior against the PPV-D isolate. Results demonstrate a high level of resistance in almond and indicate potential for PPV resistance transfer to commercial peach cultivars.
P. Martínez-Gómez, M. Rubio, and F. Dicenta
The resistance to a Dideron isolate of Plum pox virus, which causes sharka disease, of four apricot (Prunus armeniaca L.) cultivars from North America (`Harlayne', `Henderson', `Sunglo', and `Veecot') and a Greek cultivar Lito (a cross of American cultivar Stark Early Orange × Greek cultivar Precoce Tirynthos) was evaluated. `Stark Early Orange' and `Canino', previously rated as resistant and susceptible respectively, were included as controls. Resistance, herein, was defined as inability to infect plants by graft-inoculation and negative assays by enzyme-linked immunosorbent assay. Cultivars found to be resistant were: `Harlayne', `Henderson', `Sunglo', `Lito', and `Stark Early Orange'. Cultivars Veecot and Canino were susceptible.