cultivars disseminating to Central Asia, the Mediterranean coast, Europe, America, and Japan ( Layne and Bassi, 2008 ; Wang and Zhuang, 2001 ). The main relatives of cultivated peach, namely P. mira , P. davidiana , P. kansuensis , and P. ferganensis
between peach and the related species P. davidiana C-26712 that was subsequently backcrossed to peach ( Sherman et al., 1991 ). P. kansuensis ‘A1’ trees grown in Byron, GA, are short-stature and highly branched trees. Peach × P. kansuensis hybrids are
development of additional molecular markers within these regions. Materials and Methods Plant material. Seven P. persica rootstock cultivars and two P. kansuensis cultivars were used in this study. Resistance to RKN was evaluated in 1998 at Zhengzhou Fruit
, including NC_014697 from peach ( Jansen et al., 2011 ), NC_023956 from P. kansuensis , and NC_023798 from P. mume . They are valuable resources to develop in silico polymorphic microsatellites as discrepant repeat motifs among the genomes that can be
Abstract
Semihardwood cuttings of 82 genotypes of peach [Prunus persica (L.) Batsch] and complex hybrids of peach with almond (P. amygdalus Batsch), P. davidiana, P. kansuensis, and P. persica vulgaris siberica were rooted under mist. Average rooting percentages ranged from 7% to 100%. Peach selections generally rooted well with the exception of hardy rootstock selections. P. davidiana rooted poorly, but most of its hybrid progeny rooted well. P. kansuensis and its hybrid progeny rooted well. Peach x almond F1 hybrids generally rooted poorly; the rooting percentage was higher in backcrosses to peach.
Abstract
The genus Pyrus has been classified into at least 22 primary species. These can be grouped by geographical distribution and/or taxonomic relationships. The European group includes P. communis L., P. nivalis Jacq., and P. cordata, (Desv.) Schneid. The North African group contains P. longipes Coss. and Dur., P. gharbiana Trab., and P. mamorensis Trab. The west Asian group consists of P. syriaca Boiss., P. elaeagrifolia Pall., and P. amygdaliformis Vill., P. salicifolia Pall., P. glabra Boiss., P. regellii Rehd., (syn. P. bucharica and P. heterophylla Reg. & Schmalh). The medium to large fruited east Asian species are P. pyrifolia (Burm.) Nak., P. kansuensis, P. ussuriensis Max., P. hondoensis Kik. and Nak., while the Asian “pea” pear species are P. calleryana Dcne., P. betulaefolia Bung., P.fauriei Schneid., P. dimorphophylla Makino, and P. koehnei Schneid. (3, 27). A number of nonprimary species also appear in the literature, which may be either botanical varieties, subspecies, or interspecific hybrids. Among the east Asian group, P. bretschneideri Rehd. is a probable hybrid of P. betulaefolia and the cultivated forms of P. pyrifolia; P. phaeocarpa Rehd. may be a P. betulaefolia × P. ussurensis hybrid, whereas P. serrulata Rehd. is a probable interspecific hybrid involving P. pyrifolia and P. calleryana.
Total cellular DNA has been extracted from leaves and\or seed of Prunus dulcis, P. persica, P. mira, P. davidiana, P. persica subsp. ferganensis, and P. triloba. Chloroplast restriction fragments have been visualized by Southern blot analysis using heterologous probes from a petunia chloroplast library. Analysis of preliminary data separates the species into three groups. The first contains P. dulcis, P. mira, and P. davidiana; the second P. kansuensis, P. persica, and P. persica subsp. ferganensis; and the third P. triloba.
PCR amplification using oligos for cytosolic glyceraldehyde-3-phosphate dehydrogenase yields genomic fragments approximately 1kb in size from P. dulcis and P. triloba. Sequence analysis will be performed to determine species relationships at the gene level.
and by U.S. Dept. of Agriculture-Agricultural Research Service special grants 85-CRSR-2-2573 and 87-CRSR-2-2999. We thank Judith White and Lynn Luszcz for technical assistance and P.M. Burrows for advice. The cost of publishing this paper was defrayed
Abstract
Open-pollinated progeny from 15 peach (Prunus persica) cultivars, two peach × P. kansuensis hybrids, and one peach almond (P. amygdalus) hybrid were evaluated for their cold hardiness and for tolerance to Cytospora canker following artificial inoculation with Leucostoma persoonii. Winter hardiness was negatively correlated with canker necrotic length (r = −0.26**) and positively correlated with canker rating (r = 0.26**), as indicated by qualitative ratings. The half-sib families differed for canker necrotic length following fall inoculation, indicating that individuals with increased tolerance to L. persoonii canker could be selected from the population. Progeny from the cultivar Yennoh exhibited the shortest canker necrotic length following fall inoculation, and all the inoculated branches were visually healthy. ‘Yennoh’, a plant introduction from Russia, may have a higher tolerance to Leucostoma than has previously been found in U.S. germplasm.
differing growth habits: Kansu peach ( P. kansuensis Rehder), almond [ P. dulcis (Mill.) D.A. Webb], and peach [ P. persica (L.) Batsch]. Kansu peach, a wild peach relative, has a dense canopy with profuse branching under the growing conditions of the