‘Felinem’, ‘Garnem’, and ‘Monegro’ are three almond × peach hybrid rootstocks released to address the problems of Prunus growing in Mediterranean conditions not solved by the presently available rootstocks. These new rootstocks are characterized by red leaves, good vigor, easy clonal propagation, resistance to root-knot nematodes, adaptation to calcareous soils and other Mediterranean agroecological conditions, and graft compatibility with the whole range of peach and almond cultivars as well as some plum and apricot cultivars.
Antonio J. Felipe
Jordi Canals, Jorge Pinochet and Antonio Felipe
The influence of temperature and age of the plant was determined on nematode reproduction on a susceptible almond (Prunus amygdalus Batsch.) and on a resistant peach-almond hybrid (P. persica Stok. × P. amygdalus Batsch.) rootstock inoculated with Meloidogyne javanica (Treub) Chitwood. Experiments were conducted under greenhouse conditions in heated and unheated sand beds. `Garrigues' almond inoculated with 3000 nematodes per plant showed extensive galling, high final nematode population levels, and high counts of nematodes per gram of root at 27 and 32C. The hybrid G × N No. 1 showed minimal galling and reproduction at 27C but higher levels of galling and final population and nematode counts per gram of root at 32C, suggesting a partial loss of resistance with temperature increase. One-month-old and 1-year-old plants of `Garrigues' were susceptible following inoculation with 2000 nematodes per plant, although plantlets (l-month) were significantly more affected. Plantlets of hybrid G × N No. 1 were also susceptible, but 1-year-old plants were resistant. Resistant genotypes (G × N selections) seem to require root tissue maturation before expressing full resistance.
Carolina Fernández, Jorge Pinochet, Daniel Esmenjaud, George Salesses and Antonio Felipe
New Prunus rootstocks and selections were evaluated for their reaction to Meloidogyne arenaria (Neal) Chitwood, M. incognita (Kofoid & White Chitwood), or M. javanica (Treub) Chitwood. Most of the clones were peach-almond hybrids (P-AHs) [P. persica (L.) Batsch × P. dulcis (Mill.) D.A. Webb] or plums of Spanish and French origin. In a first experiment, the P-AH Hansen 2-168 and plums GF-31 (P. cerasifera Ehr.) and GF 8-1 (P. cerasifera × P. munsoniana Weigth et Hedr.) were highly resistant to the mixture of five isolates of M. javanica. The P-AHs Barrier and Titan × Nemared were resistant and moderately resistant, respectively; GF-677, MB 3-13, MB 2-2, and MB 2-6 were susceptible. In the second and third experiment, the plums P 1079, P 2175, the hybrids Afgano (P. dasycarpa Ehrh.), G × N No 22, and G × N No 15, both P-AHs, and Nemared peach were highly resistant to mixtures of five isolates of M. incognita or M. arenaria. The plums P 2980 (P. cerasifera) and GF 8-1 tested against either root-knot species were also highly resistant. Cachirulo × (G × N No 9), a P-AH, showed less resistance to M. arenaria than to M. incognita. Montclar (P. persica) and the P-AHs Torrents AC and GF-677 were susceptible to both species.
Eduard Alcañiz, Jorge Pinochet, Carolina Fernández, Daniel Esmenjaud and Antonio Felipe
Fourteen Prunus rootstocks were evaluated against mixtures of several isolates of the root-lesion nematode Pratylenchus vulnus Allen and Jensen in three greenhouse experiments. Most of the tested rootstocks are new releases or materials in advanced stages of selection that also have incorporated root-knot nematode resistance. The plums Torinel (Prunusdomestica L.) and Redglow (P. salicina Lindl. P. munsoniana Wight and Hedrick cv. Jewel) showed a moderately resistant response; their final nematode population levels were lower or slightly higher than inoculation levels. Low nematode reproduction also was found in the peach–almond hybrid G N No 22 [P. persica (L.) Batsch P. dulcis (Mill.) D.A. Webb] and the plum Bruce (P. salicina P. angustifolia Marsh.), and although these rootstocks did not perform as well as Torinel and Redglow, they also appear to be poor hosts for P. vulnus.
Rafel Socias i Company, Ossama Kodad, José M. Alonso and Antonio J. Felipe
‘Mardía’ is a new almond cultivar released because of its good agronomical traits and very late blooming time, 2 weeks later than ‘Felisia’, the latest blooming cultivar released so far. It is characterized by its slightly upright growth habit, early ripening, high and regular bloom density, autogamy (S6Sf genotype), high fruit set, tolerance to diseases, hard shell, large kernel, very high content of oleic acid, and low content of linoleic acid.
Jorge Pinochet, Cinta Calvet, Adriana Hernández-Dorrego, Ariadna Bonet, Antonio Felipe and Marian Moreno
Two trials involving 20 Prunus rootstocks were conducted under greenhouse conditions to screen for resistance to root-knot nematode [Meloidogyne javanica (Treub.) Chitwood]. Many of the tested materials are interspecific hybrid rootstocks and represent new commercial peach (P. persica Batsch) and plum (Prunus sp.) releases or experimental genotypes of Spanish, French, and Italian origin. In the first trial, the rootstocks Adesoto 101 (P. insititia L.), Bruce (P. salicina Lindl. × P. angustifolia Marsh.), Ishtara, AC-952 (P. insititia), Garnem [P. dulcis (Mill.) D.A. Webb × P. persica], Cadaman [P. persica × P. davidiana (Carr.) Franch], and Orotava (P. salicina) were immune or resistant to a mixture of 10 isolates of M. javanica. The remaining rootstocks, Myrocal (P. cerasifera Ehr.), Montclar (P. persica), and Adafuel (P. dulcis × P. persica), were susceptible. In the second screening trial, the plum rootstocks Adesoto 101, Adara (P. cerasifera), Myro-10 (P. cerasifera), Constantí (P. domestica L.), and AD 105 (P. insititia) were immune to the root-knot nematode. Cadaman, G × N No. 17 (P. dulcis × P. persica), and Tetra (P. domestica) were resistant. Laroda F1OP (P. salicina), Myro-almond (P. cerasifera × P. dulcis), and the peach–almond hybrids Mayor, Adafuel, and Sirio were susceptible.
Carolina Fernández, Jorge Pinochet, Daniel Esmenjaud, Maria Joao Gravato-Nobre and Antonio Felipe
The influence of salinity and plant age on nematode reproduction was determined on two susceptible and six root-knot-nematode-resistant Prunus rootstocks inoculated with Meloidogyne incognita (Kofoid and White). Experiments were conducted under greenhouse conditions over 120 (plant age study) and 75 (salinity study) days. Following inoculation with 4000 nematodes per plant, susceptible 2-month-old GF-677 (Prunus persica L. Batsch. × P. dulcis Mill. Webb) and Montclar (P. persica) were affected significantly more than 1-year-old plants. Barrier (P. persica × P. davidiana Carr. Franch.) plantlets showed a partial loss of resistance in relation to older plants, suggesting that a root tissue maturation period is required for expression of full resistance. Nemared (P. persica); G × N No 22 (P. persica × P. dulcis); and the plums GF 8-1 (P. cerasifera Ehrh. × P. munsoniana Wight and Hedrick), PSM 101 (P. insititia L.), and P 2980 (P. cerasifera) maintained their high level of resistance or immunity, regardless of plant age. Nematode reproduction was higher in GF-677 rootstock in saline soil. Nemared and Barrier showed similar low galling and nematode reproduction in nonsaline and saline soil. PSM 101 immunity to M. incognita was not affected by soil condition.
Jorge Pinochet, Carolina Fernández, Cinta Calvet, Adriana Hernández-Dorrego and Antonio Felipe
Twenty-nine commercial and experimental Prunus rootstocks, most with incorporated root-knot nematode [Meloidogyne javanica (Traub.) Chitwood] resistance, were evaluated against mixtures comprising nine populations of the root-lesion nematode Pratylenchus vulnus Allen and Jensen. Nearly all tested materials were susceptible. Five cultivars with high resistant levels were further challenged with seven P. vulnus populations individually. `Redglow' (Prunus salicina Lindl. × P. munsoniana Wight and Hedrick) was the only rootstock that showed broad resistance to all populations. The rootstocks `Torinel' (P. domestica L.), AC-595 (P. domestica × P. insititia L.), `Marianna 4001' (P. cerasifera Ehr. × P. munsoniana), and `Felinem' [P. dulcis (Mill.) D. A. Webb × P. persica (L.) Batsch] showed resistance to one or a few P. vulnus populations. Several supposedly resistant sources proved to be susceptible. Tests of crosses made between parents of diverse genetic background with partial resistance to P. vulnus indicate that a descendant with potential P. vulnus resistance is difficult to obtain. Pathogenic diversity among P. vulnus populations appears to be high.
Carlos Alberto Lecona-Guzmán, Sheila Reyes-Zambrano, Felipe Alonso Barredo-Pool, Miguel Abud-Archila, Joaquín Adolfo Montes-Molina, Reiner Rincón-Rosales and Federico Antonio Gutierrez-Miceli
Factors such as slow growth, low rates of sexual and asexual reproduction, and viability of seeds among others limit the massive propagation of Agave americana L. by conventional methods. In this study, callus induction and shoot proliferation was determined in A. americana using Murashige and Skoog (MS) medium supplemented with dicholorophenoxyacetic acid (2,4-D) and 6-benzyl adenine (BA). Meristematic tissue was used as the explants, and were placed on MS medium supplemented with 30.0 g·L−1 sucrose with 0.11, 0.18, or 0.45 μm 2,4-D and 11.0, 22.0, 38.2, 44.0, 58.7, or 73.3 μm BA. Treatments were implemented according to factorial experimental design 3 × 6. After 1 month, the number of explants with callus was determined, whereas the numbers of shoots per explant were monitored after 4, 16, 20, and 36 weeks. The maximum percent of explants with callus was obtained with 0.11 μm 2,4-D and 58.7 and 73.3 μm BA, whereas the maximum numbers of shoots per explant (71) were obtained with 0.11 μm 2,4-D and 73.3 μm BA. The effect of different concentrations of indolebutyric acid (IBA) in the rooting of shoots was evaluated. There were no significant effects of IBA on the number of roots, root length, and axillary roots. Plantlets were acclimatized in the glasshouse and they did not show any phenotypic alteration. This is a highly efficient protocol for the in vitro propagation of A. americana via indirect organogenesis.